AU677774B2

AU677774B2 - Heat treatment of metal castings and integrated sand reclamation

Info

Publication number: AU677774B2
Application number: AU35946/93A
Authority: AU
Inventors: Scott P Crafton
Original assignee: Consolidated Engineering Co Inc
Current assignee: Consolidated Engineering Co Inc
Priority date: 1992-08-13
Filing date: 1993-01-27
Publication date: 1997-05-08
Anticipated expiration: 2013-01-27
Also published as: ATE165030T1; CN1097662A; JP2849213B2; DE69318000T3; BR9305607A; JPH11129055A; DE69318000T2; JPH07506299A; ES2114039T5; ES2114039T3; EP0612276B1; WO1994004297A1; DE69318000D1; CA2121047C; EP0612276B2; KR100263975B1; CN1090066C; AU3594693A; TW213490B; EP0612276A1

Abstract

The method and apparatus for reclaiming substantially pure sand from a heat treating furnace (19); wherein a casting with sand core and/or sand mold, comprising sand bound by a combustible binder, attached thereto is introduced into the heat treating furnace (19); or, wherein portions of sand core and/or sand mold that are not attached to a casting are introduced into the heat treating furnace (19). Wherein, the reclaiming within the furnace (19) is carried out, in part, by a fluidizer (40) that promotes binder combustion by one or more processes of agitating, heating, and oxygenating. Wherein the characteristics of the reclaimed sand (25) are selectively controlled by controlling the dwell time of the sand (25) within the heat treating furnace (19).

Description

OPI DATE 15/03/94 AOJP DATE 09/06/94 APPLN. ID 35946/93 PCT NUMBER PCT/US93/00722 fIng II IIII~ III ii l iii II (51) International Patent Classification 5 B22D 17/22, 29/00 Al (11) International Publication Number: (43) International Publication Date: WO 94/04297 3 March 1994 (03.03.94) (21) International Application Number: (22) International Filing Date: 2 Priority data: 07/930,193 13 Augus PCT/US93/00722 7 January 1993 (27.01.93) t 1992 (13.08.92) (71)Applicant: CONSOLIDATED ENGINEERING COM- PANY OF-&fERGIA, INC. [US/US]; 2871 MCCollum Parkway, Kennesaw, GA 30144-3651 (US), (72) Inventor: CRAFTON, Scott, P. 743 Edgeware Lane, Kennesaw, GA 30144 (US).

(74) Agents: ISAF, Louis, T. et al.; P.O. Box 720601, Atlanta, GA 30358-2601 (US).

(81) Designated States: AU, BR, CA, JP, KR, European patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE).

Published With international search report.

677774

SEC

104 TV O (54)Title: HEAT TREATMENT OF METAL CASTINGS AND #NNASAND RECLAMATION (57) Abstract The method and apparatus for reclaiming substantially pure sand from a heat treating furnace wherein a casting with sand core and/or sand mold, comprising sand bound by a combustible binder, attached thereto is introduced into the heat treating furnace or, wherein portions of sand core and/or sand mold that are not attached to a casting are introduced into the heat treating furnace Wherein, the reclaiming within the furnace (19) is carried out, in part, by a fluidizer (40) that promotes binder combustion by one or more processes of agitating, heating, and oxygenating. Wherein the characteristics of the reclaimed sand (25) are selectively controlled by controlling the dwell time of the sand (25) within the heat treating furnace (19).

I

HEAT TREATMENT OF METAL CASTINGS AND INTEGRATED SAND

RECLAMATION

BACKGROUND OF THE INVENTION The present invention relates generally to the field of heat treating metal castings and the field of reclaiming sand from sand cores and sand molds used to make metal castings.

Generally, prior art methods and apparatus require that two or three distinctly separate steps be taken in order to heat treat a metal casting formed by a permanent mold or sand mold with a sand core, and reclaim sufficiently pure sand from the sand mold or sand core. The present invention allows for heat treating and reclamation of sufficiently pure sand ini a single step.

Methods and apparatus for manufacturing metal castings are well known. Molds and cores are used to displace molten material so that when the molten material is solidified, a casting is formed that reflects the features of the mold and core. Molds have the exterior features of the casting formed on the interior walls of the mold and cores have the interior features of the casting formed on the exterior surface of the core. The cores are typically made from sand whereas the m-olds are sometimes made from sand. Sand .*.molds and cores are typically pre-miolded from a mixture of sand and a combustible hinder, For simplicity, sand molds and sand cores are referred 25 to hereafter as simply sand cores.

In accordance with some of the prior art, once the casting is formed, three distinctly different steps are carried out in order to heat treat the metal casting and reclaim sufficiently pure sand from the sand core. The first step separates portions of sand core from the casting. The sand core is typically separated from the casting by one or a combination of means. For example, sand may be chiseled away from the casting or the casting may be physically shaken to break-up the sand core and remove the sand. Once the sand is removed from the casting, the second and third steps are carried out. In this typical, three-step prior art, the order in which the second and third steps are taken is not important, since the sand has already been separated from the casting. The second step consists of heat treating the casting. The casting is typically heat treated if it is desirable to strengthen or harden the casting. The third step consists of purifying the sand that was separated from the casting. The purification processes is typically carried out by one or a combination of means. These may include burning the binder that coats the sand, abrading the sand, and passing portions of the sand through screens. It is important that the reclaimed sand be sufficiently pure in order for it to be properly reused in the construction of new sand cores. It is also helpful if the reclaimed sand is rounded, at least to some degree, so as to assist in the casting of smooth surfaces and to assist in good bonding of the sand grains which causes strong cores. Therefore, portions of sand may be rv-subjected to reclaiming processes until sufficiently pure sand is reclaimed.

The purity of the rer;laimied sand can be measured in terms of the quantity of unburned binder. The less unburned binder, the more pure the sand. While seeking increased purity, some sand is reduced to "fines". Fines is the term used for sand particles smaller than a specified size. Fines are so small that they require excessive amounts of binder. These two measures (purity and fines) generally oppose each other in that the higher the measure of one, the lower the measure of the other. It is important to balance these measures; therefore. it is imi-portant that the sand reclaiming processes be capable of controlling these measures.

In accordance with the present inventor's previous invention disclosure of Australian patent application No. 19062/92, only one step need be t~iken in order to heat treat metal castings formed by sand cores and reclaim sand from the sand cores. This is carried out by introducing the castings, with the sand cores attached thereto, into a furnace with anl oxygenated atmosphere that is heated to at least the combustion temperature of thle sand core binder material. This causes combustion of some of the binder of the sand core which, in combination with other means, causes the sand core to separate from the casting. The system disclosed in AU 19062/92 promotes more binder com-bustion than is required to separate the sand core from the casting. The system disclosed in application AU 19062/92 ejects sand from the furnace in a sufficiently pure state for some applications; but, that system is not capable of conibusting a sufficient amount of binder (or otherwise processing the sand core) so as to render sand that is sufficiently pure for certain other applications. Also, that system does not make provisions for varying the characteristics of the reclaimed sand; no selective control over sand roundness, arnount of fines, or amount of unburned binder in the reclaimed sand is possible. Therefore, the sand reclaimed using the method and apparatus disclosed in application AU 19062/92 may require further processing in order to obtain sand that is sufficiently pure for certain applications or sand that has certain charac teris tics. Therefore, previous sand reclaiming systems are inherently inefficient in that they require at least a two step process, carried out in two separate venues by separate, specialized equipment, in order to heat treat a metal casting formed by a sand core and reclaim sufficiently pure sand from the sand core, There is a need, therefore, for a more efficient method, and associated apparatus, that allows for more efficient heat treatment, sand core removal, and reclamation of sufficiently pure sand from the sand core.

SUMMARY OF THE INVENTION In a first aspect of the present invention there is provided an appariL tus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: a furnace for receiving the casting therewithin; furnace heating means for heating said furnace to a temperature 0 sufficient to loosen portions of sand core from the casting, while the casting is in said furnace; and means for reclaiming, within said furnace, sand of loosened portions of sand core, wherein said means for reclaiming includes, at least, a collection means for collecting loosened portions of sand core within said furnace, and a fluicdizer so positioned and so constructed to fluidize, within said furnace, the collected portions of sand core, to remove binder from the sand of the cores A second preferred aspect of the present invention provides an apparatus for heat treating a casting and reclaiming sand from portions of sand core, comprising sand bound by a combustible binder, said appa -atus conipris ing: a furnace for receiving a casting therewithin; furnace heating means for heating said furnace: 4 furnace reclaiming means for at least partially reclaiming sand from portions of sand core within said furnace, said furnace reclaiming means including a means for contemporaneously exposing the portions of sand core to anr oxygenated atmosphere and agitating the portions of sand core; and a supplemental sand reclamation assembly operatively upstream of said furnace reclaiming means and including, at least, a reclaimer hopper, located outside of said furnace, defining a reclaimer interior and including, at least, a reclaimier inlet, through which portions of sand core are deposited into the reclaimer interior, and a reclaimer outlet, from which partially reclaimied portions of sand core pass out of the reclaimer interior, means for partially reclaiming portions of sand core within the reclaimer interior, and discharge means, connected to said reclaimner outlet, for ejecting partially reclaimed portions of sand core into said furnace such that the partially reclaimed portions of sand core are subjected to said furnace reclaiming means within said furnace; and means for removing binder from the sand of the cores within the furnace.

The iu~vention in a third aspect, also provides a method for heat treating a casting with sand core, comprising sand bound by a combustible binder, a tached thereto and for reclaiming sand from the sand core, said method comprising the following steps: introducing the casting into a furnace; heating the furnace such that portions of sand core are loosened from the casting while the casting is in the furnace; and reclaiming, within the furnace, sand of loosened portions of sand core, wherein said step of reclaiming includes, at least, collecting loosened portions of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core to remove binder from the sand of the cores.

The present invention provides an improved method and apparatus for collecting sand within a heat treating furnace, purifying the sand, and ejecting the sand from the furnace. The present invention can reclaim sand that is more pure than that typically extracted from heat treating furnaces.

The method and apparatus of the present invention also allows for selective control over the amount of binder and fines in the sand ejected from the furnace.

The present invention uses a process of "fluidization", referred to herein as a fluidizer. This fluidization process passes air, from a pressurized source? through sand collected in the furnace causing portions of thle sand to be suspended and act like a turbulent fluid. The fluidizer, in conjunction with other components in the furnace, causes the binder portion of sand cores to sufficiently combust within the furnace so that sufficiently pure sand is reclaimed. In one embodiment, the sand cores, from which binder is conbusted, are attached to the castings that are transported into thle furnace.

A preferred furnace embodiment, and some of the elements within the furnace are disclosed in AU 19062/9 2. The fluidizer and some of the elements associated with it are disclosed for the first time in this application.

The fluidizer of the preferred embodiment of the present invention causes the fluidization of sand that has collected within the furnace hopper.

The fluidizing causes portions of sand to abrade against one another, and in at least one embodiment, to also abrade against a metal target, in a manner that exposes the binder. The exposed binder then comibusts. The process is repeated until a sufficient amount of binder has been combustedl to satisfy the user as to the purity of the sand.

In the preferred embodiment of thle present invention, thle fluidizer adds oxygen to the furnace hopper so as to promote binder combustion, in one preferred en-bodimlent of thle present invention, the fluidizer is supplied with preheated air from a secondary heat source so as to further promote binder combustion. In an alternate, preferred embodiment, the air of the fluidizer is not pre-heated. In accordance with one aspect of thle present invention, multiple fluidizers are employed, and, in such embodiment, appropriate fluidizer embodiments are chosen and selectively placed along a multiple zoned furnace.

The present invention further includes methods and apparatus for dischmarging reclaimed sand from the furnace. In the preferred embodiment of the present invention, this discharging is controlled so as to control the volume of sand contained in the furnace. This affects the amount of time that sand is subjected to the fluidlizing, thus effecting a control over the charac tenis tics of thle reclaimed sand.

Ani alternate embodiment of the present invention includes a supplemental sand reclamation unit (the "SSRU"). The supplemental sand reclamation unit, which functions in conjunction with the furnace heat source and in conjunction with the fluidizer and other components in the furnace, provides supplemental reclamation of sand previously reclaimed fromn casting cores. For example, sand collected from prior art shakers and sand discharged from the troughs of the furnace of AU 19062/92 is reprocessed by the supplemental sand reclamation unit. The supplemental sand reclamation unit includes a bdi that is outside of the furnace. A tube is connected to a bin outlet and passes into the furnace. The tube passes, within the furnace, in close proximity to furnace heaters and terminates toward the furnace hopper. Collected sand is deposited into the bin where it is heated to above the binder combustion temperature and exposed to an oxygen-rich atmosphere; this causes an initial hinder combustion. The sand then enters the tube. While passing through the tube, the sand is heated by the furnace heaters and further binder combustion occurs. When the sand exits the tube it falls into the furnace where it is, preferably, further purified by the in-furnace sand reclamation unit of the present inivention.

It is, therefore, a feature of the present invention to provide an improved method and apparatus for heat treating castings, with sand core material attached thereto, and reclaiming sand from- the sand core material.

Another feature of the present invention is to provide an imiproved *~:method and apparatus for removing sand core material from a casting and reclaiming sand from the sand core mnaterial.

Another feature of the present invention is to provide a method and apparatus for reclaiming, within a furnace, sand from portions of sand core that are separated from castings within the furnace.

Another feature of the present invention is to provide a method and apparatus for agitating, within a furnace, sand that is collected within the furnace.

Another feature of the present invention is to provide a method and apparatus for fluidizing, within a furnace, sand that is collected within the furnace.

Another feature of the present invention is to provide a method and apparatus for enhancing combustion, within a heat treating furnace, of binder that coats sand that is collected in the furnace.

A fourth aspect of the present invention is provides a method for heat treating a casting with sand core attached thereto and for reclaiming sand from portions of sand core, comprising sand bound by a combustible binder, said method comprising the following steps: introducing the casting into a furnace; heating the furnace including, at least, the step of loosening portions of sand core from the casting while the casting is in the furnace; introducing unattached portions of sand core into the furnace, wherein the unattached portions of sand core are not attached to the casting; and reclaiming, within the furnace, sand of loosened portions of sand core and sand of unattached portions of sand core, wherein said step of reclaiming includes, at least, collecting the portions of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core.

A fifth aspect of the present invention provides an apparatus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: a furnace for receiving the casting therewithin: a furnace heating means for heating said furnace such that portions of sand core are loosened and fall from the casting while the casting is in H said furnace; a reclaimning means for reclaiming, within said furnace, sand of loosened portions of sand core, wherein said means for reclaiming includes, at least, a means for contemporaneously exposing loosened portions of sand core to an oxygenated atmosphere and agitating the loosened portions of sand core; collection means disposed within said furnace for collecting the loosened portions of sand core such that collected portions of sand core have a high probability of being recurrently acted on by said reclaiming means; discharge means for discharging reclaimed sand from said furnace; and regulating means for controlling the discharging operation of said discharge means such that the length of time that collected portions of sand core are subjected to said reclaiming means is automatically controlled to sufficiently reclaimi sand within said furnace to a state reusable for cores.

A sixth aspect of the present invention provides a method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the furnace to a temperature in excess of the combustion temperature of the binder material; containing the casting, with the at least a portion of the sand core the rein, within the heated furnace; comibusting binder material of at least a portion of the sand core disposed within the casting, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting; fluiclizing the collected portions of the sand core within a flow of air whereby sand is at least partially reclaimed from the collected portions of the sand core, 20 wherein the flow of air is directed into the furnace, and wherein the flow of air is oxygenated and contributes to the creation of an oxygenated atmosphere within the furnace, which oxygenated atmosphere facilitates, at least in part, the comnbusting step; and the at least partially reclaimed sand away from the seventh aspect of the present invention provides a mi-ethod for heat a treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace system, wherein the furnace system defines a heat treating region, and a reclaiming region disposed below the heat treating region and in heat and gaseous communication with the heat treating region, 8/1 wherein the furnace system includes a support assembly for supporting the casting within the heat treating region, and wherein the introducing step includes a step of placing the casting upon the support assembly; heat treating the casting while the casting is disposed within the heat treating region; dislodging portions of the sand core from the casting while the casting is disposed within the heat treating region, wherein the dislodging step incl,c.es a step of combusting binder material of the portion of the sand core: causing the dislodged portions of the sand core to fall from the casting and the support assembly into the reclaiming region; r reclaiming, at least partially and within the reclaiming region, sand S: from the fallen portions of the sand core, wherein the reclaiming step includes a step of further combusting binder material of the fallen portions of the sand core, wherein the further combusting step includes a step of agitating the fallen portions of sand core within an oxygenated atmosphere; and conveying the recl.-med sand away from the furnace system, 20 whereby heat treatment, core removal, and at least partial sand reclamation are accomplished in an integrated process associated with a single furnace system.

An eighth aspect of the present invention provides a method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: providing an oxygenated atmosphere which is heated to a temperature in excess of the combustion temperature of the binder material; introducing the casting, with at least a portion of the sand core therein, into the heated oxygenated atmosphere; wherein the introducing step includes a step of placing the casting upon a support assembly within the heated oxygenated atmosphere; wherein the casting is exposed to the heated oxygenated atmosphere to permit binder material to comnbust; and 8/2 wherein portions of the sand core are loosened from and fall from the cavity of the casting and the support assembly while the casting is within the furnace; collect.ng, distant from the casting and the support assembly, the portions of the sand core which fall from the support assembly prior to all of the binder material being combusted therefrom; maintaining the collected portions of the sand core within the oxygenated atmosphere to combust binder material from the collected portions of the sand core, wherein the maintaining step includes a step of agitating the collected portion:: of the sand core within the heated oxygenated atmosphere, whereby sand is at least partially reclaimed from the collected portions of the sand core; and conveying the at least partially reclaimed sand away from the heated oxygenated atmosphere.

A ninth aspect of the present invention provides a method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: 20 introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the furnace to a temperature in excess of the combustion temperature of the binder material; containing the casting, with the at least a portion of the sand core therein, within the heated furnace; combusting binder material of at least a portion of the sand core disposed within the casting, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting; fluidizing the collected portions of the sand core within a flow of heated gas such that sand is at least partially reclaimed from the collected portions of the sand core, S wherein the flow of heated gas is directed into the furnace, and wherein the flow of heated gas contributes to the heating of the furnace; and conveying the at least partially reclaimed sand away from the furnace.

A tenth aspect of the present invention provides a method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing a casting with at least some sand core therein into a furnace, wherein the furnace includes a support assembly for supporting the casting within a heat treating region of the furnace, and wherein the introducing step includes a step of placing the castig Lupon the support assembly; heating the heat treating region to a tei-mperature sufficient to heat treat ~.the casting and sufficient to comnbust the binder material of the sand core; burning binder material of the sand core within the heat treating region to release sand core portions from the casting, wherein the released sand core portions fall from the cavity of the casting and the support assembly while the casting is within the furnace; reclaiming, at a reclaiming region distant from the casting and the support assembly, at least some sand from portions of the fallen sand core .:..portions, wherein the reclaiming step includes a step of burning binder material of p~ortionms of the fallen sand core portions, the burning step including contemporaneous steps of agitating and exposing the fallen sand core portions to ani oxygenated atmosphere, and wherein the reclaiming region and the furnace are proximately located such that heat passes between the reclaiming region and the heat treating region; and thereafter conveying sand and any attached binder material away from the heat treating region.

8/4 An eleventh aspect of the present invention provides a methoid for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the furnace to a temperature in excess of the combustion temperature of the binder material; providing an oxygenated atmosphere within the furnace; containing the casting, with the at least a portion of the sand core therein, within the oxygenated atmosphere in the heated furnace to permit binder material to comibust, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting prior to the binder material being comibus ted therefrom to form a bed of *loosened portions of sand core within the oxygeniated atmosphere; fluidizing the bed of loosened portions of sand core such that sand is at least partially reclaimed from the bed of loosened portions of sand core, the fluidizing step including a step of burning binder material from the bed of loosened portions of sand core, whereby fumes are generated; capturing and at least partially incinerating the fumnes within the furnace; aimd conveying the at least partially reclaimed sand away from the furnace.

S A twelfth aspect of the present invention provides a furnace system for heat treating a casting having a sand core and reclaimi-ing sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the furnace system comprising: a heat treating region for receiving the casting therewithlin; a support assembly for supporting the casting within the heat treating region;: and a heating means for heating said heat treating region to a temperature sufficienit to loosen portions of the sand core from the casting while the casting is in said heat treating region; a reclaiming region disposed below said heat treating region and in he-at and gaseous communication with said heat treating region, wherein the loosened portions of the sand core fall under the force of gravity from the casting and said support assembly into said reclaiming region; and a fluidizer for fluidizing and reclaiming sand from the fallen portions of the sand core disposed within said reclaiming region.

A thirteenth aspect of the present invention provides a method for reclaiming sand from a sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within 10 the casting, and the m-ethod comprising the steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the casting and the sand core therein to a temperature in **.excess of the combustion temperature of the binder material, whereby binder material of the sand core comnbusts and portions of the sand core are loosened from the cavity of the casting while the casting is within the furnace; and timt isfluidizing the loosened portions of the sand core within a flow of gas thti dir-ected into the furnace, a A fourteenth aspect of the invention provides a method of processing acasting, comprising the steps of: introducing the casting into a furnace, which casting, when introduced into the furnace, has a sand core associated therewith comprising sand bonded together by a binder; removing portions of the sand core from the casting while the casting is in the furnace; fluidizing within the furnace removed portions of sand core; and while performing the removing and fluidizing steps, at least partially heat treating the casting within the furnace.

A fifteenth aspect of the invention provides a method for heat treating a casting with sand core, comprising sand bound by a binder, attached thereto and for reclaiming sand from the sand core, said muethod comprising the following steps: introducing the casting into a furnace; heating the furnace such that portions of sand core are loosened from the casting while the casting is in the furnace; and reclaiming, wiliin the furnace, sand of loosened portions of sand core, wherein said step of reclaiming includes, at least, collecting loosened portions of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core.

A sixteenth aspect of the invention provides a method for reclaiming sand from a sand core, the sand core comprising sand particles bound together by binder material, the sand core defining a cavity within the casting, and the method comprising the steps of; introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the casting and the sand core therein to a temperature in excess of the combustion temperature of the binder material, whereby binder material of the sand core comnbusts and portions of the sand core are loosened from the cavity of the casting while the casting is within the f urnace; and fluidizing the loosened portions of the sand core within a flow of gas that is directed into the furnace.

Other objects, features and advantages of the present invention will become apparent upon reading and understanding this specification, taken in conjunction with the accompanying drawings.

25 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cut-away view of a combination heat treating furnace and in-furnace sand reclamation unit, in accordance with the preferred embodiment of the present invention.

WO 94/04297 PCT/US93/00722 9 Fig. 2 is a cut-away view of selected elements of the sand reclamation unit of Fig. 1.

Fig. 3 is a cut-away top view of selected elements of the sand reclamation unit of Fig. 1, showing some of the elements that are cut-away in Fig. 1.

Fig. 4 is a cut-away top view of selected elements of the sand reclamation unit of Fig. 1, showing some of the elements that are cut-away in Fig. 1.

Fig. 5 is a cut-away side view of the discharge valve assembly of Fig. 1.

Fig. 6 is a cut-away top view of a portion of an in-furnace sand reclamation unit, in accordance with an alternate, preferred embodiment of the present invention.

Fig. 7 is a cut-away side view of a portion of the apparatus of Fig. 6.

Fig. 8 is a cross-sectional view of the fluidizer conduit of Fig. 6, taken along line 8-8 of Fig. 7.

Fig. 9 is a side view of an in-furnace sand reclamation unit, in accordance with an alternate, preferred embodiment of the present invention.

Fig. 10 is a detailed perspective view of the fluidizing ring of Fig. 9.

Fig. 11 is a cross-sectional view of the fluidizing ring of Fig 9, taken along line 11-11 of Fig. Fig. 12 is a cross-sectional view of the fluidizing ring of Fig 9, taken along line 12-12 of Fig. 11.

Fig. 13 is a cut-away view of a portion of an infurnace sand reclamation unit, in accordance with an alternate embodiment of the present invention.

Fig. 14 is a cut-away view of a multi-zone embodiment of the heat treating furnace and in-furnace sand reclamation system, in accordance with the present invention.

WO 94/04297 PCr/US93/00722 Fig. 15 is an isolated side view of a supplemental sand reclamation unit which is part of an alternate embodiment of the present invention.

Fig. 16 is a cut-away, side view of the supplemental sand reclamation unit of Fig. 15 mounted on top of the combination heat treating furnace and infurnace sand reclamation unit.

Fig. 17 is a cut-away view of the reclaimer hopper of Fig. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT This section of the specification consists of two parts. The first part introduces components and describes their orientation and interconnections. The second part describes the operation of the components and provides some examples of acceptable components.

Referring now in greater detail to the drawings, in which like numerals represent like components throughout the several views, Fig. I shows a partially cut-away view of a combination heat treating furnace 19 and in-furnace sand reclamation unit 20, in accordance with the preferred embodiment of the present invention.

The in-furnace sand reclamation unit 20 includes a hopper 30 which has a hopper wall 31 and defines a hopper inlet 33 and a hopper outlet 35. A portion of the hopper wall 31 and other elements are cut-away in Fig. 1 so that elements shown can be clearly seen. The in-furnace sand reclamation unit 20 further includes a fluidizer 40, guidance tube 80, abrasion disk 90 and a discharge valve assembly 100. The fluidizer 40 is shown passing through the hopper wall 31. The guidance tube 80 is shown oriented above the fluidizer within the hopper 30. The abrasion disk 90 is shown oriented above the guidance tube 80 within the hopper 30. The discharge valve assembly 100 is shown connected to the WO 94/04297 PCT/US93/00722 11 hopper outlet 35. In the preferred embodiment of the present invention, the hopper 30 of the in-furnace sand reclamation unit 20 doubles as the hopper 30 of the heat treating furnace 19. An appropriate heat treating urnace 19 is disclosed in l1-a 1 n1c .J.

The specification of U.

A is hereby incorporated herein by reference. The discharge valve assembly 100 provides a path to the outside of the furnace.

Fig. 2, which is a cut-away side view of selected elements of Fig. 1, shows the fluidizer 40 of the preferred embodiment of the present invention, in greater detail. Sand 25 is also shown, in representative form, collected at the hopper outlet The fluidizer 40 is seen as including a fluidizer conduit 41; the fluidizer conduit 41 has a fluidizing end 42 that is within the hopper 30 and a source end 43 that is outside of the hopper 30. A portion of the fluidizer conduit 41 has been cut-away to expose a conduit interior 44 which is defined by the fluidizing conduit 41. The source end 43 of the fluidizer conduit 41 is sealed by an end plate 47. The end plate 47 is attached to the source end 43 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding. A portion of the end plate 47 is cut away in Fig. 2, to fully expose a heater The heater 60 is secured through the end plate 47 in a manner that facilitates removal for repair or replacement with a different type of heater. The heater 60 has an exhaust end 61 located within the conduit interior 44 and an intake end 62 outside of the fluidizer conduit 41. Pressurized air is supplied into the intake end 62 of the heater 60 through an air intake 65. In the preferred embodiment of the present WO 94/04297 PCT/US93/00722 12 invention, the heater 60 is a high pressure gas burner.

In an alternate embodiment of the present invention, the heater 60 consists of an electric heating element.

Other heater types are acceptable.

A signal generating pressure gauge 70 is connected to the fluidizer conduit 41 by a gauge conduit 71.

This connection is such that the signal generating pressure gauge 70 is in communication with the conduit interior 44 and can sense the pressure within the fluidizer conduit 41. A signal adjuster 74 is associated with the signal generating pressure gauge The signal generating pressure gauge 70 is connected to an electric power supply by a gauge power cable 72. The signal generating pressure gauge 70 is connected by a signal cable 73 to the discharge valve assembly 100, which is not shown in Fig. 2.

The fluidizer end 42 of the fluidizer conduit 41 is turned upward in Fig. 2 toward a the guidance tube and the abrasion disk 90. The guidance tube part of which is cut away in Fig. 2, has a tube wall 81 and defines a tube passage 82. The abrasion disk part of which is cut away in Fig. 2, has disk back 92 and a concave disk face 91.

Fig. 3 is a top view of the apparatus of Fig. 2 in greater detail and with the abrasion disk 90 removed.

As shown in Fig. 3, the guidance tube 80 is connected to tube support rods 85a,b which are connected to the hopper wall 31. These connections are made in a manner as would be understood by those reasonably skilled in the industry; for example, by welding or bolting. The guidance tube 80 is positioned such that the guidance tube 80 is oriented above the fluidizer end 42 of the fluidizer conduit 41 and the tube passage 82 is in-line with the conduit interior 44 at the fluidizer end 42.

WO 94/04297 PCT/US93/00722 13 Fig. 4 is a top view of the apparatus of Fig. 2 in greater detail. In Fig. 4 the disk face 91 of the abrasion disk 90 is oriented toward the fluidizer end 42 and is therefore not seen. As seen in Figs. 2 and 4, the abrasion disk 90 is connected to disk support cables 95 which are attached to the hopper wall 31.

The cables 95 have a disk end 96, a hook end 97, and a turnbuckle 98 disposed between the disk end 96 and the hook end 97. The disk ends 96 of the cables 95 are attached to the abrasion disk 90 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting. The hook end 97 of each cable 95 is attached to the inner hopper wall 31 by an eyehook 99; the hook ends 97 are hooked to eyehooks 99. The eyehooks 99 are connected to the hopper wall 31 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting. There are a plurality of eyehooks 99, each of which is oriented so that the height of the abrasion disk 90 above the fluidizer end 42 is capable of being adjusted, as will be explained below. The fluidizer end 42, conduit interior 44, and guidance tube 80 are not seen in Fig. 4 because they are concealed by the abrasion disk Fig. 5 is a cut-away side view of the discharge valve assembly shown in Fig. I. The discharge valve assembly 100 includes a double dump valve 110 and a pneumatic valve operator 130. The double dump valve 110 has a valve inlet 111 and a valve outlet 112. The valve inlet 111 is connected to the hopper outlet (see Fig. 1) in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting. The valve outlet 112 is located outside of the heat treating furnace 19 such that the double dump valve 110 provides a path from within the WO 94/04297 PCT/US93/00722 14 hopper 30 to the outside of the furnace 19. A portion of the double dump valve 110 is cut away in Fig. 5 to expose a first disk 116, a second disk 117, a first seat 118, and a second seat 119. The pneumatic valve operator 130 is connected to the double dump valve 110, in a manner that is understood by those reasonably skilled in the art, such that the pneumatic valve operator 130 controls the operation of the double dump valve 110. The pneumatic valve operator 130 is connected to a pneumatic supply line 131 and the signal cable 73. In an alternate embodiment of the present invention, the pneumatic valve operator 130 is replaced with an electric, motorized valve operator; hydraulic valve operator; or some other type of valve operator.

Fig. 6 and Fig. 7 show an alternate, preferred embodiment of the present invention. Fig. 6 is a cutaway top view of portions of the present invention in accordance with the alternate embodiment. This alternate embodiment does not include the guidance tube 80 or abrasion disk 90. This alternate embodiment does include a fluidizer 40' which is somewhat similar to the fluidizer 40 of the preferred embodiment. However, the fluidizer 40' has a fluidizer conduit 41' that splits into three fluidizer conduits 41'a,b,c, each of which pass through the hopper wall 31. The fluidizer conduits 41'a,b,c originate from a conduit header The conduit header 55 originates from the source end 43 of the fluidizer conduit 41'. Also, the fluidizer ends 43'a,b,c are sealed in a manner that would be understood by those reasonably skilled in the industry; for example, with a plug 50. Also, as is indicated by Fig. 7, which is a side view of the fluidizer showing a portion of the hopper 30, each fluidizer conduit 41'a,b,c defines a plurality of fluidizing holes 51 that are oriented toward the hopper outlet WO 94/04297 PCT/US93/00722 (In Fig. 7, two of the fluidizer conduits 41'b,c are concealed by one of the fluidizer conduits 41'a.) Fig.

8 is a cross-sectional view taken along line 8 8 in Fig. 7; only one fluidizer conduit 41'a is shown for simplicity; the other conduits 41'b,c being similarly constructed. As seen in Fig. 8, the fluidizing holes are in communication with the conduit interior 44'.

Also, in the embodiment shown in Figs. 7 and 8, the fluidizing holes 51 are spaced linearly and radially along the portion of the fluidizer conduit 41'a that faces the hopper outlet 35. Preferably, the angle between the center-lines 52 defined by two fluidizing holes 51 that are radially positioned with respect to one another is ninety degrees. In alternate embodiments of the present invention, the fluidizing holes 51 are spaced in a different manner.

Another alternate embodiment of the present invention, which is not shown, is similar to the previously disclosed alternate embodiment of Figs. 6-8, except that the fluidizer conduit 40 splits into six fluidizer conduits. Three of the six fluidizer conduits penetrate one furnace hopper 30 and the other three of the six fluidizer conduits penetrate a different furnace hopper 30. Actually, there are a variety of alternate embodiments of the present invention that are variations upon those just disclosed. Although not shown in Figs. 6 and 7, the signal generating pressure gauge 70, with all of its associated elements, is included in these alternate embodiments of the present invention.

Fig. 9 shows an alternate, preferred embodiment of the present invention which does not include the guidance tube 80 or the abrasion disk 90. In this alternate embodiment, a fluidizing ring 140 is disposed between the hopper outlet 35 and the valve inlet ill.

WO 94/04297 PCT/US93/00722 1'6 The fluidizing ring 140 is connected to the hopper outlet 35 and the valve inlet 111 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting. Also shown in Fig. 9 is a fluidizer conduit The fluidizer conduit 41'' defines a conduit interior 44'' (not shown). The fluidizer conduit 41'' has a fluidizing end which is connected to the fluidizing ring 140, and a source end into which pressurized air is supplied.

Fig. 10 is a detailed perspective view of the fluidizing ring 140 of Fig 9. The fluidizing ring 140 includes a hollow ring frame 141 which defines a ring interior 142 (see Fig. 11). The fluidizing ring 140 bounds an open area 145 that is in communication with the ring interior 142 by way of a plurality of fluidizing holes 146 that are defined by the ring frame 141. Only two of the fluidizing holes are labeled in Fig. 10 for simplicity. The ring frame 141 further defines a conduit connection hole 147. The ring frame 141 is connected at the conduit connector hole 147 to the fluidizing end 42'' of the fluidizer conduit 41'' such that the conduit interior 44'' is in communication with the ring interior 142. This connection is made in a manner that would be understood by those reasonably skilled in the industry; for example, by welding.

Fig. 11 is a cross-sectional view taken along line 11 11 in Fig. 10. Fig. 11 shows the ring interior 142. Fig. 12 is a cross sectional view taken along line 12 12 in Fig. 11. Fig 12 shows one of the plurality of fluidizing holes 146 defined by the ring frame 141. The fluidizing holes 146 are angled steeply enough so that portions of sand core which pass through the open area 145 defined by the ring frame 141 cannot WO 94/04297 PCr/US93/00722 17 easily migrate up, through the fluidizing holes 146, into the ring interior 142.

In an alternate embodiment of the present invention, no signal generating pressure gauge 70 is included. As shown in Fig. 13, which is a cut-away view, this alternate embodiment of the present invention includes signal generating sensors 170a,b,c that are mounted within the hopper 30, to the hopper wall 31. The sensors 170a,b,c are mounted such that they detect a predetermined level of sand core in the hopper 30. Each signal generating sensor 170a,b,c is connected by signal cable 73' to the discharge valve assembly 100 (not shown in Fig. 13). A selector 171 is associated with the signal generating sensors 170a,b,c.

In the preferred embodiment of this alternate embodiment, the signal generating sensors 170a,b,c are electric probes.

Fig. 14 shows a multi-zone embodiment of the present invention, which includes a multi-zone furnace 211 employing several embodiments of the in-furnace ind reclamation unit 20. An example of furnace 211 is uisclosed in application Serial No. 07/705.626. As disclosed, in Fig. 14 hereof, the furnace 211 includes: a work chamber 215; zones 216A-H; furnace heaters 218; a pre-heat chamber 224; a furnace input door 225; a furnace upper end 226; a furnace discharge door 227; a furnace lower end 228; a roller hearth 234; rollers 236; baskets 240, for transporting castings; axial fans 244; a furnace top 245; screens 252; baffles 253; a sand conveyor 259; and a central collection bin 260.

For a clear understanding of the furnace 211, please refer to application Serial No. 07/705,626, which has been incorporated into this specification. The furnace 211 further includes hoppers 30 and discharge valve assemblies 100. Zones 216A,B are equipped with the WO 94/04297 PCT/US93/00722 18 fluidizer 40 (see Figs. 1, 2, 3, and 4) guidance tube and abrasion disk 60. The pre-heat chamber and Zone 216E are equipped with the fluidizer 40' (see Figs. 6, 7, and and Zones 216F,G,H are equipped with the fluidizer 40'' (see Figs. 9, 10, 11, and 12).

Sand 25 is shown, in representative form, collected at the hopper outlet Fig. 15 shows a supplemental sand reclamation unit 180 which is part of an alternate embodiment of the present invention. The supplemental sand reclaiming unit 180 includes a reclaimer hopper 181 which has a reclaimer inlet 182, a reclaimer outlet 183, and a reclaimer wall 184. The supplemental sand reclamation unit 180 further includes a discharger 190 that has a discharger inlet 191 and a discharger outlet 192. In the preferred, alternate embodiment, the discharger 190 is a screw auger. The discharger inlet 191 is connected to the hopper outlet 183 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting. The supplemental sand reclamation unit 180 further includes a delivery tube 195 that defines a tube interior 199.

The delivery tube 195 also has a tube inlet 196, a tube outlet 197, and an oxygen supply line 198 that is in communication with the tube interior 199. The tube inlet 196 is connected to the discharger outlet 192 in a manner that would be understood by those reasonably skilled in the industry; for example, by welding or bolting.

Fig. 16 is a cut-away view of the supplemental sand reclamation unit 180 of Fig. 15 mounted on top of the combination heat treating furnace 19 and in-furnace sand reclamation unit 20 in accordance with an alternate embodiment of the present invention. The reclaimer hopper 181 and discharger 190 are located WO 94/04297 PCT/US93/00722 19 outside of the heat treating furnace 19. The delivery tube 195 penetrates the heat treating furnace 19 and is in close proximity to u-tube furnace heaters 218'. The tube outlet 197 is oriented toward the hopper inlet 33.

Fig. 17 is a cut-away view of the reclaimer hopper 181 of Fig. 15. A portion of the reclaimer wall 184 is cut-away to show a reclaimer interior 185 that is defined by the reclaimer wall 184. Included within the reclaimer interior 185 are heaters 186, oxygen suppliers 187 and a level indicator 188. The reclaimer hopper 181 also includes a recycle exhaust duct 189 that exhausts into the heat treating furnace 19 and a baghouse exhaust duct 198.

OPERATION

Referring back to Figs. 1 and 14, as the casting, with sand core attached thereto, is acted upon in accordance with the method and apparatus disclosed in application Serial No. 07/705,626, portions of sand and sand core fall through the hopper inlet 33 and sand collects w;thin the hopper 30 toward the hopper outlet.

Before a defined level of sand accumulates in the hopper 30, the first disk 116 and second disk 117 within the double dump valve 110 are maintained in contact with the first seat 118 and second seat 119, respectively. Therefore, as portions of sand and sand core continue to fall through the hopper inlet 33, the level of sand core within the hopper 30 increases.

Figs. 1, 2, 3, and 4 disclose the first, preferred embodiment of the present invention. The equipment and process that are at the heart of the first, preferred embodiment are referred to as "high temperature fluidization with a target". In this embodiment, pressurized air is supplied through the air intake Oxygenated and heated exhaust from the heater WO 94/04297 PCT/US93/00722 discharges from the fluidizer end 42 of the fluidizer conduit 41. As the level of sand rises above the level of the fluidizer end 42, fluidization begins; the oxygenated and heated exhaust fluidizes portions of sand core that are above the fluidizer end 42. That is, the exhaust passes up through the sand, causing the sand to be suspended and act like a turbulent fluid.

The fluidization further propels portions of sand through the guidance tube passage 82 where the trajectory of the entrained portions of sand is oriented toward the disk face 91 of the abrasion disk Portions of sand contact the abrasion disk 90 and fall back toward the fluidizer end 42 where they are further fluidized. The portions of sand that are fluidized abrade against each other and the disk face 91. The abrasion caused by this process knocks away ash that is adhered to the sand. This exposes unburned binder and thus promotes binder combustion. In addition to promoting binder combustion by exposing unburned binder, the fluidizer 40 promotes combustion by providing a hot and oxygenated environment. Thus, the exposed binder combusts to promote purification of the sand reclaimed from the sand core. Since the "high temperature fluidization with a target" incorporates a variety of techniques to reclaim sand (which include, at least, fluidization, fluidization in combination with an abrasion disk, heating to promote combustion, and oxygenating to promote combustion) it has a relatively high capacity as compared the processes referred to below.

Some alternate embodiments of the present invention, one of which is shown in Figs. 6, 7, and 8, are referred to as "hot fluidization". "Hot fluidization" does not propel portions of sand core toward a target. However, "hot fluidization" is WO 94/04297 PCT/US93/00722 21 otherwise similar to "hot fluidization with a target".

Pressurized air is supplied through the air intake Oxygenated and heated exhaust from the heater discharges from the fluidizer holes 51. As the level of sand approaches the level of the fluidizing holes 51, fluidization begins. Fluidization is promoted and enhanced by the placement and orientation of the fluidizing holes 51. The portions of sand that are fluidized abrade against each other. The abrasion caused by this process knocks away ash that is adhered to the sand. This exposes unburned binder and thus promotes binder combustion. In addition to promoting binder combustion by exposing unburned binder, the fluidizer 40' promotes combustion by providing a hot and oxygenated environment. Thus, the exposed binder combusts to promote purification of the sand reclaimed from the sand core. Since "hot fluidization" does not utilize a target, it does not typically cause as much abrasion as "hot fluidization with a target". Thus, "hot fluidization" typically exposes less binder than and therefore causes less combustion than "hot fluidization with a target". Therefore, "hot fluidization" typically has less capacity than "hot fluidization with a target". Thus, "hot fluidization with a target" is used where relatively large portions of sand and sand core fall through the hopper inlet 33 and "hot fluidization" is used where relatively moderate portions of sand and sand core fall through the hopper inlet 33.

Other alternate embodiments of the present invention, one of which is shown in Figs. 9, 10, 11, and 12, are referred to as "cool fluidization". "Cool fluidization" is somewhat similar to "hot fluidization" except that it does not incorporate heating.

Pressurized air is supplied to the source end 43'' of WO 94/04297 PCT/US93/00722 22 the fluidizer conduit The pressurized air passes into the ring interior 142 by way of the fluidizer end 42'' of the fluidizer conduit 41'' and the conduit connection hole 147. The pressurized air then escapes from the fluidizing ring 140 through the fluidizing holes 146. As the level of sand rises above the fluidizing holes 146, fluidization begins. The portions of sand that are fluidized abrade against each other. The abrasion caused by this process knocks away ash that is adhered to the sand. This exposes unburned binder and thus promotes binder combustion. In addition to promoting binder combustion by exposing unburned binder, the fluidizer 40'' promotes combustion by providing added oxygen to the environment (the heat necessary for combustion is provided by the heat treating furnace 19). Thus, the exposed binder combusts to promote purification of the sand reclaimed from the sand core. Since "cool fluidization" does not add heat to promote combustion, it does not typically cause as much combustion as "hot fluidization".

Therefore, "cool fluidization" typically has less capacity than "hot fluidization". Thus, "cool fluidization" is used where relatively small portions of relatively clean sand fall through the hopper inlet 33. "Cool fluidization", in addition to reclaiming sand, cools portions of sand before they pass through the double dump valve 110. This protects the double dump valve 110 from heat related stress and strain and allows for the use of a less expensive double dump valve 110.

As specified above, the different embodiments of the present invention have different capacities. As specified in application Serial No. 07/705,626, different zones 216 (see Fig. 14) within a continuousprocess furnace 211 have different capacities for WO 94/04297 PCT/US93/00722 23 loosening sand core from castings. Therefore, it is necessary to reclaim more sand in some zones 216 and less from others. In accordance with one multi-zone embodiment of the present invention, as shown in Fig.

14, higher capacity embodiments of the in-furnace sand reclamation unit 20 (for example Figs. 1 4) are employed in high capacity zones 216A,B; moderate capacity embodiments of the in-furnace sand reclamation unit 20 (for example Figs. 6 8) are employed in the pre-heat chamber 224 and moderate capacity zones 216E; and lower capacity embodiments of the in-furnace sand reclamation unit 20 (for example Figs. 9 12) are employed in lower capacity zones 216F,G,H of the furnace 211. Likewise, it is preferred to employ higher capacity embodiments of the present invention in higher capacity batch-type furnaces and lower capacity embodiments of the present invention in lower capacity batch-type furnaces.

In several embodiments of the present invention, the signal generating pressure gauge 70 and the equipment associated with it, serves to provide positive control over the level, and therefore the volume, of sand that accumulates within the hopper (refer to Figs. 2 and As portions of sand continue to fall through the hopper inlet 33, the level of sand within the hopper 30 increases. As the level increases there is more resistance to the flow of air from the fluidizer end of the conduit 42 and the back-pressure in the fluidizer conduit 41 increases. The signal adjuster 74 associated with the signal generating pressure gauge 70 is set such that when a certain backpressure is detected within the conduit interior 44 by the signal generating pressure gauge 70, a "high level" signal is generated. The pneumatic valve operator 140 receives the "high level" signal by way of the signal WO 94/04297 PCT/US93/00722 24 cable 73. While the pneumatic valve operator 140 r-ceives the signal it operates the double dump valve 120. The double dump valve 120 is operated such that the first disk 126 and second disk 127 alternately move away from and then return to the first seat 118 and second seat 119, respectively. This operation is such that while the first disk 116 is not in contact with the first seat 118, the second disk 117 is in contact with the second seat 119, and visa-versa. Thus, while the double dump valve 110 is operating and sand is flowing from within the hopper 30 to outside of the heat treating furnace 19 by way of the double dump valve 110, back-pressure is maintained at the hopper outlet 35 such that fluidization is not disrupted. It is important that back-pressure is maintained at the hopper outlet 35 because the pressurized air that is being supplied through the fluidizer conduit 41 will take the path of least resistance. If both the first disk 116 and the second disk 117 where off of their seats, and there was a level of sand within the hopper, the path of least resistance would be through the doubled dump valve 110 to the atmosphere outside of the furnace. Therefore, the pressurized air would flow through the double dump valve 110 rather than forcing its way up through the sand accumulated in the hopper.

In an alternate embodiment of the present invention, the double dump valve 110 is replaced with a star valve or screw auger, or another type of device that performs a discharging and a sealing function.

In alternate embodiments of the present invention, signal generating sensors 170, mounted to the hopper wall 31 (see Fig. 13), serve to provide positive control over the level, and therefore the volume, of sand that accumulates within the hopper 30. In one embodiment the signal generating sensors 170 consist of WO 94/04297 PCf/US93/00722 electric capacitance probes. An electric capacitance probe is mounted to the hopper wall at each position that corresponds to a level at which it is desired to operate the double dump valve 110. The particular level at which the double dump valve will operate is established by operating the selector 171 which establishes which electric probe is controlling. As the level of sand increases and comes into contact with the controlling electric probe, a "high level" signal is generated. The pneumatic valve operator 140 receives the "high level" signal by way of the signal cable 73'. When the pneumatic valve operator 140 receives the signal it operates the double dump valve 110 as is disclosed above.

The characteristics of reclaimed sand are controlled by controlling the dwell time of portions of sand within the hopper 30. The longer the dwell time, the longer the amount of time that the portions of sand are fluidized. When portions of binder coated sand are fluidized for a relatively longer period of time, less binder is contained in the reclaimed sand but more fines are contained in the reclaimed sand. When portions of binder coated sand are fluidized for a relatively shorter period of time, more binder is contained in the reclaimed sand but less fines are contained in the reclaimed sand. The dwell time is controlled by controlling the volume of sand that is allowed to accumulate in the hopper 30. The greater the volume of sand allowed to accumulate in the hopper 30, the greater the dwell time (assuming a constant input of sand). The volume of sand that is allowed to accumulate in the hopper 30 is selected by adjusting the signal adjuster 74 in the one disclosed preferred embodiment of the present invention or by adjusting the selector 171 in the second disclosed embodiment of the WO 94/04297 PCT/US93/00722 26 present invention. In the embodiment which includes the signal generating pressure gauge 70, a larger volume of sand accumulates in the hopper 30 when the signal adjuster 74 is adjusted so that the signal generating pressure gauge 70 emits a "high level" signal at a higher pressure. A smaller volume of sand accumulates in the hopiper 30 when the signal adjuster 74 is adjusted so that the signal generating pressure gauge 70 emits a "high level" signal at a lower pressure. In the embodiment which includes signal generating sensors 170 a larger or smaller volume of sand is allowed to accumulate in the hopper 30 by adjusting the selector 171 to select the signal generating sensor 170 that is mounted at the level that corresponds to the desired volume.

Referring back to Figs. 2 and 4, the characteristics of the reclaimed sand are also controlled, in the preferred embodiment of the present invention, by adjusting the height of the abrasion disk 90 above the fluidizer end 42 of the fluidizer conduit 41. The height is adjusted by loosening the turnbuckles 98, unhooking the hook ends 97 from the eyehooks 99, hooking the hook ends 97 to the appropriate eyehooks 99, and tightening the turnbuckles 98. These components can be accessed by entering the hopper 30 through the furnace 19 or through trap doors in the hopper wall 31. Generally, when the height of the abrasion disk 90 is decreased more abrasion occurs because propelled portions of sand impact the abrasion disk 90 with more force; therefore, less binder is contained in the reclaimed sand and more fines are contained in the reclaimed sand. Generally, when the height is increased less abrasion occurs because propelled portions of sand impact the abrasion disk with less force; therefore, more binder is contained in WO 94/04297 PCT/US93/00722 27 the reclaimed sand and less fines are contained in the reclaimed sand.

Referring back to Figs. 15-17, the supplemental sand reclamation unit 180 is used, in conjunction with the fluidizer 40 and other components in the heat treating furnace 19, to further purify sand that has already been reclaimed by some other process, and to reclaim sand from portions of sand core initially reclaimed by another process. The portions of sand core and coated sand that are introduced into the supplemental sand reclamation unit 180 are not adhered to castings. For example only, if a core was accidently molded into the wrong shape such that it could not be used for casting, it could be crushed and the portions thereof could be introduced into the supplemental sand reclamation unit 180. Portions of sand core and coated sand are introduced into the supplemental sand reclamation unit 180 through the reclaimer inlet 182. The heaters 186 and oxygen suppliers 187 maintain an atmosphere within the reclaimer interior 185 that causes some of the binder associated with the introduced sand and portions sand core to combust such that sand is reclaimed within the reclaimer hopper 181. The reclaimed sand is transferred from the reclaimer hopper 181 to the delivery tube 195 by the discharger 190. The sand within the delivery tube 195 is drawn by gravity from the tube inlet 196 toward the tube outlet 197. The sand in the delivery tube 195 is heated due to the fact that the delivery tube 195 is in close proximity to utube furnace heaters 218'. The sand in the delivery tube 195 is also exposed to oxygen that is supplied through the oxygen supply line 198. Therefore, at ieast some exposed binder that passes through the delivery tube 195 is combusted. As sand passes from WO 94/04297 PCT/US93/00722 28 the tube outlet 197 it falls into the hopper 30 where it is further purified by fluidization, as is discussed above.

The embodiments of the present invention can be constructed from a variety of materials and include a variety of components. The following is offered for example only. The hopper 30, guidance tube 80, and abrasion disk could be made out of various abrasion resistant alloys. More specifically, the hopper 30 and guidance tube 80 could be made out of 4130, 4140 or 1020 steel, and the abrasion disk 90 could be made out of a cast high manganese alloy. The fluidizing ring 140 could be constructed of A36 structural steel square tubing. The high pressure burner, which serves as the heater 60 in one embodiment of the present invention, could be an Eclipse brand. The signal generating pressure gauge 70 could be a Dwyer brand photoelectric gauge. The electric capacitance probes, that serve as the signal generating sensors 170 in one embodiment of the present invention, and the level indicator 188 could be an Endress Hauser brand, LSC 1110 Series capacitance probe. A low voltage is applied to these probes, and when the probe comes into contact with some material (for example sand) current flows into the material and the probe senses the current flow. The double dump valve 110 could be a Ni-Hard and nickel chrome alloy high temperature double dump valve made by Plattco Corporation. The Fluidizer conduit 41 can be constructed from stainless steel. The heater 186 could be a National brand silicon carbide heating element.

Whereas this invention has been described in detail with particular reference to preferred embodiments and alternate embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention, WO 94/04297 PCT/US93/00722 29 as described herein before and as defined in the appended claims.

We Claim:

Claims

1. An apparatus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: a furnace for receiving the casting therewithin; furnace heating means for heating said furnace to a temperature sufficient to loosen portions of sand core from the casting, while the casting is in said furnace; and mneans for reclaiming, within said furnace, sand of loosened portions of sand core, wherein said means for reclaiming includes, at least, a collection means for collecting loosened portions of sand core within said furnace, and a fluidizer so positioned and so constructed to fluidize, within said furnmace, the collected portions of sand core, to remove binder from the sand of the cores.

2. The apparatus of Claim 1, further comprising a supplemental sand reclamation assembly operatively upstream of said furnace and including, at least, a reclaimer hopper, located outside of said furnace and defining a hollow reclaimer interior, wherein said reclaimer hopper includes, at least, a reclaimer inlet, through which portions of sand core are deposited into the reclaim-er interior, and a reclaimer outlet, fromn which partially reclaimed portions of sand core pass out of said reclaimer interior, means for partially reclaiming portions of sand core within the reclaimer interior, and discharge means, connected to said reclaimier outlet, for ejecting partially reclaimed portions of sand core into said furnace such that the partially reclaimed portions of sand core are subjected to said means for reclaimng within said furnace.

3. The apparatus of Claim 1, wherein said fluidizer includes, at least, a Source of pressurized gas, and a fluidizer conduit which defines a hollow conduit interior, wherein said fluidizer conduit extends from a first end that is in comnmunication with said source of pressurized gas and terminates at a second end in a manner that causes the collected portions of sand core to be fluidized within said furnace. 30/1

4. The apparatus of Claim 3, further comprising a fluidizing ring connected to said second end of said fluidizer conduit, wherein said fluidizing ring includes, at least, a ring frame at least partially bounding a central open area and defining, a hollow ring interior in communication with the conduit interior of said fluidizer conduit, and a plurality of fluidizing portals communicating between the central open area and the ring interior. S. 5. The apparatus of Claim 3, wherein said fluidizer further includes, at S 10 least, a heater for heating loosened portions of sand core to a temperature above e the combustion temperature of the binder of the loosened portions of sand core, and said source of pressurized air includes, at least, a source of oxygen, "whereby binder of loosened portions of sand core is combusted. e a

6. The apparatus of Claim 3, wherein, said furnace heating means includes, at least, means for heating loosened portions of sand core that are within said furnace to above the combustion temperature of the binder of the loosened portions of sand core, and said source of pressurized air includes, at least, a source of oxygen, whereby binder oflositinai pertions of sand core is combusted.

7. The apparatus of Claim 6, whieoria said means for reclaiming further includes, at least, an abrasion disc within said furnace, wherein said fluidizer and said abrasion disk are constructed and oriented such that loosened portions of sand core are propelled by said fluidizcr toward said abrasion disk such that loosened portions of sand core contact said abrasion disk in a manner that contributes to the reclaiming of sand.

8. The apparatus of Claim 3, further comprising: discharge means for discharging reclaimed sand from said furnace, and regulating means for controlling the discharging operation of said discharge means such that the length of time that collected portions of sand core are subjected to said fluidizer is automatically controlled to control the amount of.fines and the amount of binder that are included with the reclaimed sand dischar2ed from said furnace.

9. The apparatus of Claim 8, wherein said discharge means includes, at least, a double-'limp valve. S: 10. The apparatus of Claim 8, wherein, said furnace includes, at least, a furnace upper portion, and a furnace lower portion, and said collection means includes, at least, a hopper including, at least, a hopper inlet defining an opening in the furnace lower portion that is oriented such that loosened portions of sand core fall into said hopper inlet, a hopper outlet defining an opening *"elow said hopper inlet, and a hopper wall connecting said hopper inlet to said hopper outlet such that a hopper interior is defined and a passage exists through the hopper interior from said hopper inlet to said hopper outlet, wherein said hopper wall is angled such that, under the force of gravity, the portions of sand core that fall into said hopper S.e. *inlet are collected within the hopper interior and tend to accumulate toward said hopper outlet, and said discharge means is connected to said hopper outlet.

11. The apparatus of Claim 10, wherein said discharge means includes, at least, a discharge duct having a duct first end, a duct second end, and a duct side-wall that defines a duct passage therethrough, wherein the duct passage first end is connected to said hopper outlet and said duct second end is located outside of said furnace such that reclaimed sand passes from the hopper interior, through said duct, and is discharged from said furnace, an operator means for selectively controlling the passage of portions of sand core through the duct passage, and 32 means for maintaining a seal at said hopper outlet such that fluidization is not disrupted while reclaimed sand is discharged from said furnace.

12. The apparatus of Claim 10, wherein said fluidizer conduit penetrates said hopper wall and said second end of said fluidizer conduit is located within the hopper interior near said hopper outlet such that collected portions of sand core are fluidized within the hopper interior.

13. The apparatus of Claim 10, further comprising a fluidizing ring connected to said second end of said fluidizer conduit, wherein, said fluidizing ring includes, at least, a ring frame at least partially bounding a central opei. area and defining, a hollow ring interior in communication with the conduit interior of said fluidizer conduit, and a plurality of fluidizing portals communicating between the central open area and the ring interior, and said fluidizing ring fluidizes the portions of sand core that fall into said hopper inlet and tend to accumulate toward said hopper outlet.

14. The apparatus of Claim 13, wherein, said fluidizing ring is disposed between said hopper outlet and said discharge means such that portions of sand core pass from said hopper outlet, through the central open area defined by said ring frame of said fluidizing ring, and into said discharge means, and said fluidizing portals are angled steeply enough so that portions of sand core which pass .0 through the central open area cannot easily migrate up, through the fluidizing portals into the ring interior. :o 15. The apparatus of Claim 10, wherein, said regulating means includes, at least, measurement means for determining the amount of portions of sand core collected within the hopper interior, and signal means for generating a signal when said measurement means determines that a d predetermined amount of portions of sand core is within the hopper interior, and *said discharge means is responsive to said signal of said signal means to effect discharge of portions of sand core, wherein portions of sand core pass from the hopper interior and are discharged from said furnace.

16. The apparatus of Claim 15, wherein, said fluidizer interacts with the collected portions of sand core within the hopper interior to define a back-pressure in the conduit interior of said fluidizer conduit, wherein the back- pressure increases as the depth of the collected portions of sand core within the hopper interior increases, said measurement means includes, at least, a gauge in communication with the conduit interior for determining the back-pressure, and said signal means generates a signal when the back-pressure reaches a predetermined level, whereby a specified amount of portions of sand core is maintained within the hopper interior.

17. The apparatus of Claim 16, wherein said signal means includes, at least, a signal adjustment means for selectively specifying the back-pressure at which said signal means generates said signal, whereby the amount of portions of sand core that collect within the hopper interior is selectively controlled, whereby the length of time that portions of sand core remain in the hopper interior and are subjected to said fluidizer is selectively controlled, whereby the amount of binder and fines contained with the reclaimed sand discharged from said furnace is selectively controlled.

18. The apparatus of Claim 15, wherein said measurement means includes, at least, a sensor mounted to said hopper wall at a predetermined height above said hopper outlet, wherein said signal means generates a signal when the collected portions of sand core in the hopper interior define a level of portions of sand core that is at or above said height of said sensor.

19. The apparatus of Claim 15, wherein said measurement means includes, at leastL, a plurality of sensors mounted to said hopper wall, each sensor of said plurality of sensors being at a different one of a plurality of predetermined heights above said hopper outlet, wherein each of said plurality of predetermined heights corresponds 20 to a desired amount of portions of sand core in the hopper interior, and said signal means further includes, at least, selector means for selectively specifying one sensor of said plurality of sensors as controlling, wherein, as the level of portions of sand core in the hopper interior increases and portions of sand core contact said sensor of said plurality of sensors that is controlling, said signal means generates said signal, whereby the amount of portions of sand core that collect within the hopper interior is selectively controlled, whereby the length of time that portions of sand core remnain in the hopper interior and are subjected to said fluidizer is selectively controlled, whereby the amiount of binder and fines contained with the reclaimned sand discharged from said furnace is selectively controlled.

20. An apparatus for heat treating a casting and reclaiming sand from portions of sand core, comprising sand bound by a combustible binder, said apparatus comprising: a furnace for receiving a casting therewithin; furnace heating means for heating said furnace; furnace reclaiming means for at least partially reclaiming sand from portions of sand core within said furnace, said furnace reclaiming means including a means for contemporaneously exposing the portions of sand core to an oxygenated atmosphere and agitating the portions of sand core; and a supplemental sand reclamation assembly operatively upstream of said furnace reclaiming means and including, at least; a reclaimer hopper, located outside of said furnace, defining a reclaimer interior and including, at least; a reclaimer inlet, through which portions of sand core are deposited into the reclaimer interior; and a reclaimer outlet, from which partially reclaimed portions of sand core pass out of the reclaimer interior; means for partially reclaiming portions of sand core within the reclaimer interior; and discharge means, connected to said reclaimer outlet, for ejecting partially reclaimed portions of sand core into said furnace such that the partially reclaimed portions of sand core are subjected to said furnace reclaiming means within said furnace; and means for removing binder from the sand of the cores within the furnace.

21. The apparatus of Claim 20, wherein said means for partially 2 o: reclaiming portions of sand core within the reclaimer interior of said :'.".supplemental sand reclamation assembly includes, at least, means for heating portions of sand core within the reclaimer interior to above the combustion temperature of the binder of the portions of sand core, and means for oxygenating the reclaimer interior, whereby binder of portions of sand core is combusted.

22. The apparatus of Claim 20, wherein said means for contemporaneously exposing includes, at least, a fluidizer.

23. The apparatus of Claim 20, further comprising, at least, a screw auger disposed between said discharge means and said reclaimer outlet, a baghouse exhaust duct in conmmunication with the reclaimer interior for eliminating airborne particles from the reclaimer interior, and a recycle exhaust duct in communication with the reclaimer interior for exhausting heat from said supplemental sand reclamation assembly to said furnace. 34/1

24. A method for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said method comprising the following steps: introducing the casting into a furnace; heating the furnace such that portions of sand core are loosened from the casting while the casting is in the furnace; and reclaiming, within the furnace, sand of loosened portions of sand core, wherein said step of reclaiming includes, at least, collecting loosened portions of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core to remove binder from the sand of the cores. The method of Claim 24, wherein, said step of reclaiming further includes, at least, heating loosened portions of sand core to above the combustion temperature of the binder, and said step of fluidizing includes, at least, the steps of exposing loosened portions of sand core to an oxygenated atmosphere and abrading combustion by-products off of loosened portions of sand core, whereby binder of loosened portions of sand core is exposed to the oxygenated 20 atmosphere, whereby binder of loosened portions of sand core is combusted.

26. The method of Claim 25, wherein said step of abrading includes, at least, the step of causing loosened portions of sand core to abrade against loosened portions of sand core.

27. The method of Claim 25, wherein said step of abrading includes, at least, the step of causing loosened portions of sand core to abrade against an abrasion disk.

28. The method of Claim 24, wherein said step of fluidizing includes, at least, causing loosened portions of sand core to be suspended and act like a turbulent fluid.

29. The method of Claim 24, wherein said step of fluidizing includes, at least, exposing loosened portions of sand core to an oxygenated atmosphere. The method of Claim 29, wherein said step of reclaiming further includes, at least, heating the loosened portions of sand core that are exposed to an oxygenated atmosphere to above the combustion temperature of the binder, whereby binder of portions of sand core is combusted.

31. The method of Claim 24, further comprising the following steps: discharging reclaimed sand from the furnace; and selectively controlling the intensity of said reclaiming; whereby the amount of fines and the amount of binder that are included with the reclaimed sand discharged from the furnace are selectively controlled.

32. The method of Claim 31, wherein, said step of reclaiming further includes, at least, abrading portions of sand core, and said step of selectively controlling the intensity of said reclaiming includes, at least, selectively controlling the intensity of abrading.

33. The method of Claim 31, wherein, :said step of reclaiming further includes, at least, propelling portions of sand core from a first location along a path, and •.providing an abrasion disk within the path at a distance from the first location, whereby the propelled portions of sand core abrade against the abrasion disk, and said step of selectively controlling the intensity of said reclaiming includes, at least, the step of varying the distance between the abrasion disk and the first location from which portions of sand core are propelled.

34. The method of Claim 24, further comprising the following steps: discharging reclaimed sand from the furnace; and regulating the duration of said reclaiming, whereby the amount of fines and the amount of binder that are included with the reclaimed sand discharged from the furnace are selectively controlled. The method of Claim 34, wherein, said step of reclaiming further includes, at least, heating loosened portions of sand core to above the combustion temperature of the binder, said step offluidizing includes, at least exposing heated portions of sand core to an oxygenated atmosphere, whereby binder of portions of sand core is combusted, and said step of regulating the duration of said reclaiming includes, at least, regulating said discharging to automatically control the amount of time that portions of sand core are contained in the furnace and therefor the amount of tinme that portions of sand core are subjected to said step of reclaiming, whereby the amount of fines and the amount of binder that are included with the reclaimed sand discharged from the furnace are selectively controlled.

36. Tfhe method of Claim 35, wherein said step Of regulating said discharging includes, at least, the step of automatically controlling the quantity of portions of sand core contained in the furnace.

37. The method of Claim 35, wherein said step of regulating the discharging includes, at least, the steps of, determining the quantity portions of sand core collected in the furnaug, and initiating said step of discharging when a predetermined quantity of portions of sand core is collected in the furnace, discontinuing said step of discharging when less than the predetermined quantity of portions of sand core is collected in the furnace,

38. A method for heat treating a casting with sand core attached thereto and for reclaiming sand from portions of sand core, comprising sand bound by a combustible binder, said method comprising the following steps: introducing the casting into a furnace; heating the furnace including, at least, the step of loosening portions sand core from the casting while the casting is in the furnace; introducing unattached portions of sand core into the furnace, wherefi the unattached portions of sand core are not attached to the casting; and reclaiming, within the furnace, sand of loosened portions of sand :core and san-d of unattached portions of sand core, -wherein said step of reclaiming includes, at least, collecting the portionis of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core to remove binder from the sand of the cores.

39. The method of Claim 38, further comiprising the following steps, prior to said step of introducing unattached portion~s: heating the unattached portions of sand core to above the combustion temperature of the binder; and exposing the heated unattached portions of sand core to an oxygenated atmosphere; whereby binder of the unattached portions of sand core is combusted. An apparatus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: a furnace for receiving the casting therewithin; a furnace heating means for heating said furnace such that portions of sand core are loosened and fall from the casting while the casting is in said furnace; a reclaiming means for reclaiming, within said furnace, sand of loosened portions of sand core, wherein said means for reclaiming includes, at least, a means for contemporaneously exposing loosened portions of sand core to an oxygenated atmosphere and agitating the loosened portions of sand core; collection means disposed within said furnace for collecting the loosened portions of sand core such that collected portions of sand core have .20 a high probability of being recurrently acted on by said reclaiming means; discharge means for discharging reclaimed sand from said furnace; and regulating means for controlling the discharging opjeration of said discharge means such that the length of time that collected portions of sand core are subjected to said reclaiming means is automatically controlled to sufficiently reclaim sand within said furnace to a state reusable for cores. *41. The apparatus of Claim 40, wherein, said furnace includes, at least, a furnace upper portion, and :a furnace lower portion, said collection means includes, at least, a hopper including, at least, a hopper inlet defining an opening in the furnace lower portion that is oriented such that the loosened portions of sand core fall into said hopper inlet, a hopper outlet defining an opening below said hopper inlet, and a hopper wall connecting said hopper inlet to said hopper outlet such that a hop per interior is defined and a passage exists through said hopper interior from said hopper inlet to said hopper outlet, wherein said hopper wall is angled such that, under the force of gravity, the collected portions of sand core tend to accumulate toward said hopper outlet, said discharge means is connected to said hopper outlet, said regulating means includes, at least, measurement means for determining the amount of collected portions of sand core within said hopper interior, and signal means for generating a signal when said measurement means determines that a predetermined amount of collected portions of sand core are within said hopper interior, and said discharge means is responsive to said signal of said signal means to effect discharge of the reclaimed sand, wherein the reclaimed sand passes from said hopper interior and is discharged fromn said furnace.

42. A method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within :the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core :therein, into a furnace; heating the furnace to a temperature in excess of the combustion temperature of the binder material; containing the casting, with the at least a portion of the sand core a..therein, within the heated flul'nace; 25combustLing binder material of at least a portion of the sand core disposed within the casting, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting; fluidizing the collected portions of the sand core in the furnace within a flow 'f air to remove binder from the sand of the cores whereby sand is at least partially reclaimed from the collected portions of the sand core, wherein the flow of air is directed into the furnace; and wherein the flow of air is oxygenated and contributes to the creatiomn of an oxygenated atmosphere within the furnace, which oxygenated atmosphere facilitates, at least in part, -the conbusting step; and 38/1 conveying the at least partially reclaimed sand away from the furnace.

43. The method of Claim 41, wherein the flow of air is cool, and wherein the method further comprises a step of cooling the at least r'eclaimned sand with the flow of air.

44. The method of Claim 41, further comprising a step of heating the flow of air to above the combustion temperature of the binder material whereby the fluidizing step includes a steps of comibusting binder material of the fluidized portions of the sand core, and whereby the fluidizing step contributes to the heating of the furnace. The method of Claim 41, wherein the step of fluidizing includes steps of exposing the collected portions of the sand core to an oxygenated atmosphere, and heating the collected portions of the sand core to above the combustion temperature of the binder, whereby binder material of the collected portions of the sand core is comnbus ted.

46. The mnethod of Claim 45, further comprising a step of regulating the duration of the fluidizing step, whereby the amount of fines and the amount of binder material that are included with the at least partially reclaimed sand conveyed away from the furnace are selectively controlled.

47. The method of Claim 45, wherein the step of fluidizing causes the V. collected portions of the sand core to be suspended and act like a turbulent

48. The method of Claim 47, wherein the step of fluidizing further includes a step of abrading combustion by-products off of the collected portions of the sand core, whereby binder material combustion is enhanced. 39

49. The me thod of claim 41, wherein the collecting step includes a step collecting the fallen portions of the sand core to define a bed of the collected portions of the sand core, and wherein the fluidizing step includes a step of fluidizing the bed of the collected portions of the sand core, The method of Claim 49, wherein the step of fluidizing further includes a step of heating the bed of the collected portions of the sand core to above the combustion temperature of the binder, whereby binder material of the bed of the collected portions of the sand core is conibusted.

51. The method of Claim 49, wherein the collecting step and the fluidizing step are carried out within the furnace. *52. A method for heat treating a casting having a sand core and reclaimning sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace systemn, wherein the furnace system defines a heat treating region, and a reclaiming region disposed below the heat treating region and in heat and gaseous communication with the heat treating region, wherein the furnace systemn includes a support assembly for supporting the casting within the heat treating region, and wherein the introducing step includes a step of placing the casting upon the support assembly; heat treating the casting while the casting is disposed within the heat treating region; dislodging portions of the sand core from the casting while the casting is disposed within the heat treating region, wherein the dislodging step includes a step of combusting binder material of the portion of the sand core; causing the dislodged portions of the sand core to fall from the casting and the support assembly into the reclaiming region; reclaiming, at least partially and within the reclaiming region, sand from the fallen portions of the sand core, wherein the reclaiming step includes a step of furthaer conbusting binder material of the fallen portions of the sand core, wherein the further comibusting step includes a step of agitating the fallen portions of sand core within anl oxygenated atmosphere; and conveying the reclaimed sand away from the furnace system, whereby heat treatment, core removal, and at least partial sand reclamation are accomplished in an integrated process associated with a single furnace system.

53. The method of Claim 52, wherein the heat treating region and the reclaiming region are both disposed within a single furnace.

54. The method of Claim 52, wherein the further comibusting step includes a step of fluidizing the fallen portions of the sand core, and wherein the fluidizing step includes the agitating step. The method of Claim 52, wherein thle method further comprises a step of maintaining the released sand core portions in a heated state during the time between the dislodging step and the reclaiming step. *56. The method of Claim 52, wherein the step of reclaiming is carried out prior to any activity intended to substantially cool the dislodged portions of the sand core.

57. The method of Claim 52, wherein the heat treating region and the reclaiming region are vertically aligned. 58s. The method of Claim 52, wherein the dislodged portions of the sand *.~core free fail from casting and the support assembly into thle reclaiming region.

59. The method of Claim 52, wherein the reclaiming step further includes 20 steps of: collecting the fallen portions of thle sand core within the reclaiming region to define a bed of fallen portions of the sand core, and fluidizing the bed of the fallen portions of the sand core, wherein the fluiidizing step includes the agitating step.

60. The method of Claim 59, wherein the step of reclaiming is carried out prior to any activity intended to substantially cool the dislodged portions of the sand core. and wherein the heat treating region and the reclaiming region are both disposed within a single furnace.

61. The method of Claim 52, wherein the comnbusting step of thle dislodging step includes a step of exposing the casting and at least a portion of the sand core therein to anl oxygenated and heated atmosphere, and wherein the further comibusting step further includes a step of suspending, within the oxygenated and heated atmosphere, at least some of the fallen portions of the sand core. 62, The method of Claim 61, wherein the further combusting step includes a step of fluidizing at least some of the fallen portions of the sand core, wherein the fluidizing step includes the suspending step and the agitating ste p.

63. The method of Claim 61, wherein the suspending step includes steps of: providing a screen disposed beneath the casting and the support assemibly, argersuspending on the screen fallen portions of the sand core which are lrgerthan apertures defined by the screen, to allow further combustion of binder material therefrom, and releasing the suspended portions of the sand core subsequent to the combustion of binder material therefrom. 6. The method of Claim 63, wherein the released portions of the sand core are subjected to the agitating step. The method of Claim 52, wherein the further comibusting step of the reclainling step further includes a step of suspending, within anl oxygenated and heated atmosphere, at least somne of the fallen portions of the sand core such that binder material is coinbusted from the suspended portions of the 20 sand core, and wherein the combusting step of the dislodging step includes a step of exposing the casting and at least a portion of the sand core therein to the oxygenated and heated atmosphere,

66. The method of Claim 62, wherein the further combusting step includes a step of fidizing at least some of the fallen portions of thie sL ore, and wherein the fluidizing step includes the suspending step and the agitating s tep.

67. The method of Claim 65, wherein the suspending step includes steps of: providing a screen disposed beneath the casting and the support assembly, suspending on the screen fallen portions of the sand core which are larger than apertures defined by the screen, to allow further combustion of binder material therefrom, and releasing the suspended portions of the sand core subsequent to the combustion of binder material therefrom.

68. The method of Claim 67, wherein the released portions of the sand core are subjected to the agitating step.

69. The method of Claim 52, wherein the further comibusting step of the reclaiming step further includes a step of suspending, within an oxygenated atmosphere, at least some of the portions of the sand core which have falle'.- from the casting and the support assembly such that binder material is combus ted from the suspended portions of the sand core. The method of Claim 69, wherein the further combusting step includes a step of fluidizing at least some of the fallen portions of the sand core, wherein the fluidizing step includes thle suspending step and the agitating step.

71. The method of Claim 69, wherein thle suspending step includes stce-ps of: providing a screen disposed beneath the casting and the support assembly, l'grsuspending on the screen fallen portions of the sand core which are labiner thnapertures defined by the screen, to allow further combustion of bidrmaterial therefrom, and releasing the suspended portions of the sand core subsequent to the combustion of binder material therefrom.

72. The method of Claim 71, wherein the suspending step includes steps of: providing a screen disposed beneath the casting and the support assembly, suspending onl the screen fallen portions of the sand core which are larger than apertures defined by the screen, to allow further combustion of binder material therefrom, releasing the portions of the sand core suspended upon the screen subsequent to the combustion of binder material therefrom, and fluiclizing thle released portions of the sand core.

73. The method of Claim 69, wherein the heat treating region and the reclaiming region are both disposed within a single furnace.

74. The miethod of Claim 39, wherein the stp of suspending is carried out prior to any activity that substantially cools tile released sand core portions. The method of Claim 69, wherein the comibusting step of the dislodging step includes a step of exposing the casting and at least a portion of the *and care therein to the oxygenated atmosphere.

76. The method of Claim 69, wherein the support assembly includes a roller hearth assembly; wherein the introducing step includes steps of placing the casting into a basket; and -icing the basket, with the casting therein, upon the roller hearth assembly; and wherein the dislodged portions of the sand core fall from the casting, the basket, and the roller hearth assembly prior to the suspending step.

77. A method for heat treating a casting having a sand core and reclaiming sand from Vize sand core, the sand core comiprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: providing an oxygenated atmosphere which is heated to a temperature in excess of the combustion temperature of the binder material; thriintroducing the casting, with at least a portion of the sand core theein into the heated oxygenated atmosphere; wherein the introducing step includes a step of placing the casting upon a support assembly within the heated oxygenated atmosphere; wherein the casting is exposed to the heated oxygenated atinosphere to permit binder material to combust; and 25wherein portions of the sand core are loosened from and fall from the cavity of the casting and the support assembly while the casting is within the furnace; collecting, distant from the casting and the support assembly, the portions of the sand core which fall from the support assembly prior to all of the binder material being comubusted therefrom; maintaining the collected portions of the sand core within the heated oxygenated atmosphere to combust binder material from the collected portions of the sand core, -wherein the maintaining step includes a step of agitating the colected portions of the sand core within the heated oxygenated atmosphere, whereby sand is at least partially reclaimed from the collected portions of thme sand core; and 44 conveying the at least partially reclaimed sand away from 'he heated oxygenated atmiosphere, and removing binder from the sand of the cores.

78. The method of Claim 77, wherein the maintaining step fur~aiier includes a step of suspending the collected portions of the sand core within the oxygenated atmosphere.

79. The method of claim 78, wherein the suspending step includes steps of providing a screen disposed beneath the casting and the support assembly; suspending on the screen fallen portions of the sand core which are larger than apertures defined by the screen, to allow further combustion of binder material therefrom; and releasing the suspended portions of the sand core subsequent to the comnbus tion of binder material therefrom. The method of claim 78, wherein the steps of suspending and agitating comprise a step of fluidizing the collected portions of the sand core wi thin the oxygenated atmosphere. :81. The method of claim 80, wherein the method further comprises steps of providing a screen disposed beneath the casting and the support assembly; suspending on the screen fallen portions of the sand core which are larger than apertures defined by the screen, to allow further combustion of :binder material therefrom; and releasing the suspended portions of the sand core subsequent to tije combustion of binder material therefrom.

82. The method of claim 80, wherein the furnace defines a plurality of zones that are spatially displaced from one another; and wherein the mnethod further comprises a step of conveying the casting along a path through the plurality of zones.

83. A method for heat treating a casting having a sand core and :reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the furnace to a temperature in excess of the combustion temperature of the binder material; containing the casting, with the at least a portion of the sand core therein, within the heated furnace; coinbusting binder material of at least a portion of tlie sand core disposed within the casting, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting; fluidizing the collected portions of the sand core inside the furnace within a flow of heated gas to remove binder from the sand of the cores -such that sand is a] least partially reclaimed from the collected portions of the sand core; wherein the flow of heated gas is directed into the furnace; and wherein the flow of heated gas contributes to the heating of the furnace; and conveying the at least partially reclaimed sand away from the furnace.

84. The method of Claim 83, wherein the flow of heated gas is oxygenated and contributes to -the creation of an oxygenated atmosphere within the furnace, which oxygenated atmosphere facilitates, at least in part, the com~busting step. A method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing a casting with at least some sand core therein into a furnace; csigwherein the furnace includes a support assembly for supporting the within a heat treating region of the furnace; and wherein the introducing step includes a step of placing the casting upon the support assembly; heating the heat treating region to a temperature sufficient to heat treat the casting and sufficient to comnbust the binder material of the sand core; burning binder material of the sand core within the heat treating region to release sand core portions from the casting, wh'verein the released sand core portions fall from the cavity of the casting and the support assembly whik the casting is within the furnace; 45/1 reclaiming, at a reclaiming region distant from the casting and the support assembly, at least some sand from portions of the fallen sand core portions; wherein the reclaiming step includes a step of burning binder material of portions of the fallen sand core portions, the burning step including *e S a S 6 o *5go *o o oo contemporaneous steps of agitating and exposing the fallen sand core portions to an oxygenated atmosphere; and wherein the reclaiming region and the heat treating region are proximately located such that heat passes between the reclaiming region and the heat treating region; and thereafter conveying sand and any attached binder material away from the Furniace,

86. The method of Claim 85, wherein gasses are transferred between the reclaiming region and the heat treating region.

87. The method of Claim 85, wherein the step of reclaiming is carried out prior to any activity intended to substantially cool the released sand core portions. :88. The method of Claim 85, wherein the step of introducing the casting into the furnace is performed prior to any mechanical shaking intended to 15i remove meaningful portions of the sand core, whereby mechanical shaking for core removal is avoided. 89, The method of Claim 85, wherein the reclaiming region is below the support assembly such that the released sand core potions fall, under the force 20 of gravity, from the support assembly to the reclaiming region.

90. The method of Claim 85, wherein the reclaiming step includes a step of fluidizing the fallen sand core portions, wherein the fluidizing step includes the contemporaneous steps of agitating and exposing. *91. The method of Claim 90, wherein the reclaiming step further includes a step of collecting a bed of the fallen sand core portions; and wherein the fluidizing step further includes a step of fluidizing the bed of the fallen sand core portions.

92. The method of Claim 90, wherein the step of fluidizing further includes a step of heating the fallen sand core portions

93. The method of Claim 90, wherein the step of fluidizing Contributes to the heating of the furnace.

94. The method of Claim 90, further comprising a step of controlling the duration of the fluidizing, whereby the amount of fines and the amount of binder material that are included with the sand conveyed away from the furnace are controlled.

95. A method for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the furnace to a temperature in excess of the comnbustion temperature of the binder material; providing anl oxygenated atmosphere within the furnace; containing the casting, with the at least a portion of the sand core therein, within the oxygenated atmosphere in the heated furnace to permit binder material to combust, whereby portions of the sand core are loosened and fall from the cavity of the casting while the casting is within the furnace; collecting the portions of the sand core which fall from the casting prior to the binder material being combustedi therefrom to form a bed of :loosened portions of sand core within the oxygenated atmosphere; 15 fluidizing the bed of loosened portions of sand core such that sand is at least partially reclaimed from the bed of loosened portions of sand core, the fluidizing step including a step of burning binder material from the bed of loosened portions of sand core, whereby fumes are generated; capturing and at least partially incinerating the fumes within the furnace; 20 and conveying the at least partially reclaimed sand away from the furnace.

96. The method of Claim 95, further comprising a step of controlling the duration of the fluidizing, whereby the amount of fines and the amount of binder material that are included with the at least partially reclaimed sand are selectively controlled.

97. The method of Claim 95, wherein the step of fluidizing further includes steps of: heating the bed of loosened portions of sand core to above the comibustionl temperature of the binder; and exposing the bed of loosened portions of sand core to anl oxygenated atmosphere, whereby binder material of the bed of loosened portions of sand core is comibusted.

98. The method of Claim 97, wherein the step of fluidizing at least partially oxygenates the atmosphere within the furnace.

99. The method of Claim 97, wherein the step of fluidizing at least partially heats the furnace.

100. A furnace system for heat treating a casting having a sand core and reclaiming sand from the sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the furnace system comprising: a heat treating region for receiving the casting therewithin; a support assembly for supporting the casting within the heat treating region; and a heating means for heating said heat treating region to a temperature sufficient to loosen portions of the sand core from the casting while the casting is in said heat treating region; a reclaiming region disposed below said heat treating region and in lheat and gaseous communication with said heat treating region, wherein the loosened portions of the sand core fall under the force of gravity from the casting and said support assembly into said reclaiming region; and a fluidizer for fluidizing and reclaiming sand from the fallen portions of the sand core disposed within said reclaiming region, by removing binder from the sand of the cores.

101. The furnace system of Claim 100, further comprising a conveyer downstream from said reclaiming region for conveying the reclaimed sand away from the reclaiming region.

102. The furnace system of Claim 100, wherein said fluidizer is constructed and arranged to defiia and fluidize a bed of the fallen portions of the sand core.

103. The furnace system of Claim 100, wherein the furnace system defines a work chamber; wherein said heat treating region and said reclaiming region are both disposed within said work chamber; and wherein said fluidizer is constructed and arranged to define and fluidize, within said work chamber, a bed of the fallen portions of the sand core.

104. The furnace system of Claim 100, wherein said heat treating region and said reclaiming region are vertically aligned.

105. The furnace system of Claim 104, wherein the furnace system defines a work chamber; and wherein said heat treating region and said reclaiming region are both disposed within said work chamber.

106. The furnace system of Claim 104, wherein said furnace system further defines a vertically extending passage between said heat tr-eating region and said reclaiming region, wherein said passage allows the loosened portions of the sand core to fall substantially vertically from said heat treating region to said reclaiming region; and wherein said passage facilitates said gaseous and heat communication.

107. The furnace system of Claim 100, wherein the furnace system further comprises a hopper defining a hopper interior and including: a hopper inlet that is oriented such that the loosened portions of the sand core fall int said hopper inlet and into said hopper interior; and a hopper outlet defining an opening below said hopper inlet; wherein said hopper outlet is constructed and arranged to pass the fallen portions of the sand core from said hopper interior; and 1 108. wherein said fluidizer is proximate to said hopper outlet. to said The furnace system of Claim 107, wherein said fluidizer is connected tosi hopper proximate to said hopper outlet.

109. The furnace system of Claim 108, wherein said fluidizer is directly connected to said hopper outlet. :110. The furnace system of Claim 108, wherein the furnace system defines 20 a work chamber; and wherein said hopper is at least partially disposed within said work chamber and said hopper outlet is further constructed and arranged to pass the fallen portions of the sand core from said work chamber.

111. The furnace system of Claim 110, wherein said heat treating region and said reclaiming region are vertically aligned.

112. The furnace systemn of Claim ill, wherein said furnace system further defines a vertically extending passage between said heat treating region and said reclaiming region; wherein said passage allows the loosened portions of the sand core to fall substantially vertically from said heat treating region to said reclaiming region; and wherein said passage facilitates said gaseous and heat communication.

113. The furnace system of Clainm 107, wherein said fluidizer includes a source of pressurised gas; and a fluidizer conduit which defines a hollow conduit interior, wherein said fluidizer conduit extends from a first enrl that is in communication with said source of pressurised gas and terminates at a second end in a manner that causes fluidization of the fallen portions of the sand core.

114. The furnace system of Claim 113, wherein said fluidizer further includes a heater for heating the fallen portions of the sand core to a temperature above the combustion temnperature of the binder material of the fallen portions of the sand core; and wherein said source of pressurised gas includes a source of oxygen, whereby binder material of the fallen portions of the sand core is combusted.

115. The furnace system of Claim 113, wherein said fluidizer further 10 includes a fluidizing ring connected to said second end of said fluidizer conduit, wherein said fluidizing ring includes a ring frame at least partially bounding a central open area and defining, a hollow ring interior in communication with the conduit interior of said fluidizer conduit; and '15 a plurality of fluidizing portals communicating between the central open area and the ring interior,

116. The furnace system of Claim '115, wherein said fla.idizing ring is disposed such that fallen portions of the sand core pass from said hopper outlet and through said central open area defined by said ring frame; and wherein said fluidizing portals are angled steeply enough so that fallen portions of the sand core which pass through tile central open area cannot easily migrate up, through the fluidizing portals into the ring interior.

117. The furnace system of Claim 113, wherein said fluidizer is constructed and arranged to fluidize the fallen portions of the sand core within said hopper interior.

118. The furnace system of Claim 1-17, wherein the furnace system defines a work chamber and said heat treating region is disposed within said work chamber; wherein the furnace system further comlprises: a level means for controlling the level of fallen portions of the sand core within said hopper interior, said level means including; a measurement means for determining thle amiount of fallen portions of tile sand core within said hopper interior; and a signal means for generating a signal when said measurement means determines that a first amount of fallen portions of the sand core is within said hopper interior; and a discharge means for discharging reclaimed sand from said work chamber; wherein said discharge means is responsive to said signal of said signal means to effect discharge of fallen portions of the sand core; and wherein during said discharge, fallen portions of the sand core pass from said hopper interior and are discharged froin said work chamnber through said hopper outlet; and wherein the amount of fallen portions of the sand core that collect within sad hopper interior is controlled by said level means and said discharge means such that the length of time that fallen portions of the sand core remain in said hopper interior and are subjected to said fluidizer is controlled, whereby the amount of binder material and fines contained with :the reclaimed sand discharged from said work chamber is controlled.

119. The furnace system of Claim 118, wherein said fluidizer interacts with thle fallen portions of thle sand core within said hopper interior to define a back-pressure in said conduit interior of said fluidizer conduit, wherein thle back-pressure increases as the depth of the fallen portions of the sand core within said hopper interior increases; *~wherein said measurement m-eans includes a gauge in communication with said conduit interior for determining the back-pressure; and wherein said signal means generates a signal when the back-pressure reaches a first level; a whereby a specified amount of fallen portions of the sand core is maintained wi thin said hopper interior.

120. The furnace systemn of Claim -118, wherein said signal means includes a signal adjustment means for selectively specifying the back-pressure at which said signal means generates said signal, whereby the amount of fallen portions of the sand core that collect within said hopper interior is selectively controlled, whereby the length of time that fallen portions of the sand core remain in said hopper interior and are subjected to said fluidizer is selectively controlled, whereby the amount of binder material and fines contained with the reclaimed sand discharged fromn said work chamber is selectively controlled.

121. Thle furnace system of Claim 118, wherein said measurement means inclides a sensor disposed at a height above said hopper outlet, wherein said signal means generates a signal when the fallen portions of the sand core in said hopper interior define a level of fallen portions of the sand core that is at or above said height of said sensor,

122. Furniace system of Claim 118, wherein said measurement means includes a plurality of sensors, wherein each sensor of said plurality of sensors is disposed at a different oiie of a plurality of different heights above said hopper outlet, wherein each of said plurality of different heights corresponds to a desired amount of fallen portions of the sand core in said hopper interior; and said signal mneans further includes selector mieans for selectively specifying one sensor of said plurality of sensors as controlling, wherein, as the level of fallen portions of the sand core in said hopper interior rises to the height of said sensor of said plurality of sensors that is controlling, said signal means generates said signal, whereby the amount of fallen portions of the sand core that collect within said hopper interior is selectively controlled.

123. A method for reclaiming sand from a sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising the steps of: introducing the casting, with at least a portion of the sand core :20 therein, into a furnace; heating the casting and the sand core in the furnace to a temperature in excess of the combustion temperature of the binder material, whereby binder material of the sand core comnbusts and portions of the sand core are loosened from the cavity of the casting while the casting is within the furnace; and fluidizing, in the furnace, the loosened portions of thie sand core within a flow of gas that is directed into the furnace to remove binder from 0 the sand of the cores.

124. The method of Claim 123, wherein the method further comprises a ;step of collecting the loosened portions of Che sand core within the furnace; wherein the fluidizing step includes a step of fluidizing the collected portions of sand core; and wherein the method further comprises a step of discharging loosened portions of the sand core from the collected portions of the sand core and the furnace diuring steps of heating and fluidizing. 52//

125. The method of Claim 123, wherein the flow of gas is oxygenated.

126. The method of Claim 125, wherein the fluidizing step at least partially contributes to the creation of an oxygenated atmosphere within the furnace, *o a which oxygenated atmosphere at least partially facilitates the combustion of the binder material.

127. The method of Claim 125, wherein the method further comprises the steps of: conveying the casting through the furnace; wherein the furnace defines a plurality of zones that are spatially displaced from one another, wherein the conveying step includes a step of sequentially conveying the castings through zones of the plurality of zones, and wherein the distribution of the loosened portions of the sand core ,material across the plurality of zones is varied; and defining a plurality of beds of loosened portions of sand core, wherein each bed of the plurality of beds defines a level, and wherein the fluidizing step includes a step of fluidizing beds of the plurality of beds; maintaining a first level of loosened portions of sand core material within a first bed of the plurality beds; and maintaining a second level of loosened portions of sand core material within a second bed of the plurality beds, wherein the step of maintaining a first level is independent of the step of maintaining a second level,

128. The method of Claim 125, wherein the method further comprises a step of defining a bed of loosened portions of sand core; and wherein the fluidizing step includes a step of fluidizing the bed of loosened portions of sand core.

129. The method of im 128, wherein the bed defines a level, and wherein the ir.t>.od further comprises a step of at least generally maintaining the level.

130. The method of Claim 128, wherein the fluidizing step includes the step of combusting binder material of the bed of loosened portions of sand core, whereby the fluidizing step at least partially reclaims sand from the loosened portions of the sand core.

131. The method of Claim 130, further comprising the step of controlling the fluidizing so that the amount of fines and the amount of binder that are included with the reclaimed sand are controlled.

132. The method of Claim 130, wherein the bed defines a level, and wherein the method further comprises the step of controlling the level so that thle amount c~f fines and the amount of binder that are included with the reclaimed sand are controlled.

133. The method of Claim 128, wherein the method further comprises the steps of: conveying casting through the furnace; wherein the furnace defines a plurality of zones that are spatially displaceed from one another; wherein the conveying step includes a step of sequentially conveying the castings through zones of the plurality of zones; and wherein the distribution of the loosened portions of the sand core *0 material across the plurality of zones is varied; and compensating for the varied distribution of sand core materials. :134. The method of Claim 133, wherein the compensating step includes a step of varying the fluidizing between zones of the plurality of zones. *135. The method of Claim 123, further comprising the steps of: V. introducing unattached portions of sand core into the furnace, wherein the unattached portions of sand core are not attached to the casting; and subjecting the unattached portions of sand core to the fluidizing step.

136. A mnethod of processing a casting, comprising the steps of: introducing thle casting into a furnace, which casting, when introduced :into the furnace, has a sand core associated therewith comp;-sing sand bonded together by a binder; removing portions of the sand core from the casting while the casting is in the furnace; fluidizing within the furnace removed portions of sand core; and wvhile performing the removing and fluidizing steps, at least partially heat treating the casting within the furnace.

137. The method of Claim *136, further comprising the step of heating the removed portions of sand core to a temperature sufficiently hig>. to disintegrate the binder. -138. The miethod of Claim '136. wherein the step of heating the removed portions results in combustion of at least some of the binder.

139. The method of Claim 136, wherein the fluidlizing step includes the step of fluidizing the removed portions of sand core with heated air directed at the removed portions.

140. The method of Claim 136, wherein the fluidizing step includes the step of: fluidizing within the furnace a bed including sand core material therein; continually collecting additional removed portions of sand core remnoved fromn time to time from the casting; and fluidizing within the furnace the bed including the additional removed portions of sand core therein.

141. A method for heat treating a casting with sand core, comprising sand bound by a binder, attached thereto and for reclaiming sand from the sand core, said method comprising the following steps: introducing the casting into a furnace; healing the furnace such that portions of sand core are loosened from the casting while the casting is in the furnace; and rbclaimning, within the furnace, sand of loosened por~ions of sand core, wherein said step of reclaiming includes, at least, collecting loosened portions of sand core within the furnace, and fluidizing within the furnace the collected portions of sand core to remove binder from the sand of the cores. 20 142. The method of Claim 141, wherein the reclaiming step further comiprises the step of heating the binder to a temperature sufficiently high to disintegrate binder material; and the fluidizing step includes the step of fluidizing the collected portions of sand core within a flow of heated gas such that sand is at least partially reclaimed from the collected portions of the sand core; wherein the flow of heated gas is directed into the furnace; and wherein the flow of heated gas contributes to the heating of the binder.

143. The method of Claim 141, wherein the reclaiming step further coniprises the step of comnbusting a binder material; and the fluidizing step includes the step of fluidizing collected portions of sand core within a flow of heated gas such that sand is at least partially reclaimned from the collected portions of the sand core; W 55/1 wherein the flow of air is directed into the furnace; and wherein the flow of air is oxygenated and contributes to the creation of an oxygenated atmosphere within the furnace, which oxygenated atmosphere facilitates, at least in part, the combusting step. o *o

144. The method of Claim 141, wherein the fluidizing step includes a step of disintegrating binder material in the loosened portions of sand core, whereby fumes are generated; and wherein the method further includes the steps of capturing and at least partially incinerating the fumes within the furnace, and conveying the at least partially reclaimed sand away from the furnace,

145. A method for reclaiming sand from a sand core, the sand core comprising sand particles bound together by a binder material, the sand core defining a cavity within the casting, and the method comprising the steps of: introducing the casting, with at least a portion of the sand core therein, into a furnace; heating the casting and the sand core therein to a temperature in :excess of the combustion temperature of the binder material, whereby a binder material of the sand core combusts and portions of the sand core are loosened 15 from the cavity of the casting while the casting is within the furnace; and fluidizing the loosened portions of the sand core within a flow of gas that is directed into the furnace. *146. The method of Claim 145, wherein the method further comprises a step of collecting the loosened portions of the sand core within the furnace; wherein the fluidizing step includes a step of fluidizing the collected portions of the sand core; and wherein the method further comprises a step of discharging loosened portions of the sand core from the collected portions of the sand core and the furnace during steps of heating and fluidizing.

147. The method of Claim 145, wherein the flow of gas is oxygenated.

148. The method of Claim 147, wherein the fluidizing step at least partially contributes to the creation of an oxygenated atmosphere within the furnace, which oxygenated atmosphere at least partially facilities the combustion of the binder material.

149. The method of Claim 147, whereimn the method further comprises the steps of: conveying the casting through the furnace, wherein the furnace defines a plurality of zones that are spatially displaced fromn one another; wherein the conveying step includes a step of sequentially conveying the castings through zones of a plurality of zones; and defining a plurality of beds of loosened portions of sand core, wherein each bed of the plurality of beds defines a level; and wherein the fluidizing step includes a step of fluidizing beds of the plurality of beds; maintaining a first level of loosened portions of sand core material within a first bed of the plurality of beds; and maintaining a second level of loosened portions of sand core material within a second bed of the plurality beds, wherein the step of maintaining a first level is independent of the step of maintaining a second level.

150. The method of Claim 147, wherein the method further comprises a step of defining a bed of loosened portions of sand core; and wherein the fluidizing step includes a step of fluidizing the bed of loosened portions of sand core. :151. The method of claim 150, wherein the bed defines a level; and wherein the method further comprises a step of at least generally maintaining the level. *152. The method of claim 150, wherein the fluidizing step includes the step of combusting binder material of the bed of loosened portions of sand core; whereby the fluidizing step at least partially reclaims sand from the loosened portions of tI e sand core.

153. The method of claim 152, further comprising the step of controlling the fluidizing so that the amount of fines and the amount of binder that are P uded with the reclaimed sand are controlled.

154. The method of claim 152, wherein the bed defines a level; and wherein the method further comprises the step of controlling the level so that the amount of fines and the amount of binder that are included with the reclaimed sand are controlled.

155. The method of claim 150, wherein the method further comprises the steps of: conveying the casting through the furnace; wherein the furnace defines a plurality of zones that are spatially displaced from one another; wherein the conveying step includes a step of sequentially conveying the castings through zones of the plurality zones; .wherein the distribution of the loosened portions of the sand core material across the plurality of zones is varied; and compensating for the varied distribution of sand core materials,

156. The method of claim 155, wherein the compensating step includes a step of varying the fluidizing between zones of the plurality of zones.

157. The method of any one of claim 145 156, further comprising the steps of: introducing unattached portions of sand core into the furnace, wherein the unattached portions of sand core are not attached to the casting; and subjecting the unattached portions of sand core to the fluidizing step.

158. The method of any one of claims 145 156, wherein the fluidizing is carried out within the furnace.

159. Apparatus as claimed in any one of claims 1 to 23, or 40 to 41 and •substantially as hereinbefore described with reference to and as shown in the drawings.

160. A method as claimed in any one of claims 24 to 39, 42 to 99, or 123 to 15 135 and substantially as hereinbefore described.

161. A furnace system as claimed in any one of the claims 100 to 122 and substantially as hereinbefore described with reference to and as shown in the drawings. DATED this nineteenth day of February 1997 CONSOLIDATED ENGINEERING COMPANY, INC Patent Attorneys for the Applicant: F.B. RICE CO.