JP2822884B2 - Method and apparatus for recovering foam gas from foam insulation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating unnecessary foamed heat insulating material used in refrigerators and the like, and more particularly to a method and a processing apparatus for degassing and recovering foamed gas from the foamed heat insulating material. Things.

[0002]

2. Description of the Related Art Conventionally, foamed heat insulating materials to be discarded have been roughly crushed and landfilled or incinerated together with other waste materials. Recently, collection of foamed gas has been studied from the viewpoint of environmental protection or resource recovery.

[0003] For example, with respect to hard foamed polyurethane, foamed gas is exhausted from the heat insulating material by compressing a roughly crushed piece having a size of several tens of mm with a cylinder press or the like.
There is a method of adsorbing and degassing this with activated carbon or the like and recovering it.
(For example, DE 40 16 512 A1) However, according to the experimental results by the inventors, it is impossible to deaerate even if a load of about 5 tons is applied to a 50 mm cubic rigid foamed polyurethane insulation, and it is practically difficult to deaerate with simple compression. It was judged. This is because the strength of rigid foamed polyurethane is increasing due to improvements in resin materials and manufacturing technology, and the same level of degassing from waste a decade or more ago to waste material generated in recent manufacturing processes has been achieved. Is difficult only by the compression work.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to an entire recovery system. The problems to be solved are also a pretreatment step for removing foamed heat insulating material from a refrigerator, a degassing step for degassing foamed gas, and degassing. It is all of the post-processing steps of the foamed insulation material. In other words, the pre-treatment step is to efficiently and almost completely exfoliate the foamed heat insulating material attached to the steel plate or plastic constituting the refrigerator with a labor-saving device, and to separate only the separated foamed heat insulating material. Then, the foaming gas is completely degassed, and in the post-processing step, the volume of the resin fine powder constituting the foamed heat insulating material is reduced so as to be convenient for subsequent transportation and the like. The degassing step will be described below. In order to degas the foamed gas from the foamed heat insulating material formed of closed cells, it is necessary to break the foam film. At this time, destruction by compression requires a high load as described above, and there is a method of heating the resin as a means of weakening the breaking strength, but it is difficult to heat uniformly because it is a heat insulating material, and the foaming gas is heated. It will also be decomposed. On the other hand, it is conceivable that the heat insulating resin is embrittled by cooling to a low temperature in order to avoid thermal decomposition, but uniform cooling is difficult because the heat insulating material is used. The above is a description of only the deaeration step. However, an object of the present invention is to provide a recovery method and apparatus which achieve a high foaming gas recovery rate and labor saving for the entire system as described above.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a casing having an uneven surface formed on the inner wall side, a plurality of hammers connected to a rotor rotating in the casing, and a grid provided at a discharge port. Then, the rotor is rotated at a speed at which the impact force can be applied to the thrown input member by the hammer, and a shear force having an impact force is applied to the thrown member by collision with the hammer and the uneven surface. Into the crushing machine, a material piece composed of foamed heat insulating material and another member to which the foamed heat insulating material is fixed is separated and crushed,
A mixture of crushed pieces in which the foamed heat insulating material and other members are separated from each other is obtained, and the crushed pieces of the foamed heat insulating material and the crushed pieces formed of the other members are separated from the mixture. The aggregate of the crushed pieces of the foamed heat insulating material thus obtained is crushed to release and collect the foaming gas trapped in the crushed pieces. Further, in the present invention, an adsorbent may be further provided to adsorb and collect the foaming gas generated in the peeling / crushing.

[0006]

In the crushing machine, the above-mentioned pieces of material are subjected to impact crushing and crushing action, whereby the components are separated while being crushed. That is, the foamed heat insulating material is fragmented by crushing and is separated from other members such as plastic. As a result, a mixture of crushed pieces of foamed heat insulating material and crushed pieces of plastic or the like is obtained. Since the crushed pieces of the foamed heat insulating material from which the crushed pieces of plastic or the like are separated are extracted from the mixture, an aggregate composed of almost all the crushed pieces of the soft foamed heat insulating material is obtained. Since this aggregate can be pulverized by a method suitable for the above softness, almost all closed cells in the foamed heat insulating material can be destroyed, and as a result, a high value can be obtained as the recovery rate of the foamed gas. In addition, a higher recovery rate can be obtained by recovering the foaming gas generated in the separation and crushing by the adsorbent.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a conceptual diagram of the apparatus. A refrigerator or the like using a foamed heat insulating material is roughly crushed by a crusher A and then put into a crusher B. The crusher B includes a high-speed rotating rotor 5 having a plurality of hammers 4 and a casing 6 surrounding the rotor and having an uneven surface on an inner wall surface. Most of the foamed heat insulating material before being put into the crusher B is in a state of being attached to plastic or the like.
It is sandwiched between the rotor and the casing, and is separated from the fixed plastic or the like by an impact crushing and crushing action. Small pieces of the separated crushed pieces pass through the gap of the grid 8 of the discharge port 7 and directly enter the input port 10 of the wind separator 9 in the next process, but large crushed pieces that cannot pass through the above-mentioned gap are crushed. It remains on the machine B and is more completely peeled off. In the experiments by the inventors, 98% or more of the foamed heat insulating material adhered to plastic or the like could be peeled off.

Next, details of the wind separator will be described with reference to FIG. The wind separator 9 has a structure in which the wind of the blower 11 passes through the wind tunnel to the screen 12. The inclination angle θ of the wind tunnel portion is larger than the wall friction coefficient between the bottom plate 13 of the wind tunnel portion and the plastic or metal piece 15 or the like. This is an angle of inclination that allows sliding without stagnation.
Therefore, the plastic or the like slides downward on the inclined surface and is collected in the collection box 16 of the plastic or the like. On the other hand, the foamed heat insulating material 17 moved to the leeward side is sent to the next pulverizing section. Most of the crushed pieces put into the wind separator are plastic and the like peeled off from the foamed heat insulating material, and the direction of the surface of this plate is parallel to the bottom plate 13 of the wind tunnel. The resistance to wind rising in the wind tunnel is reduced, and the difference between the bulk foam insulation and the ease of flying against the wind is increased. Hereinafter, this will be described in comparison with a conventional machine.

In a conventional wind separator, for example, in the separator shown in FIG. 3, when the surface of the plate-shaped plastic is parallel to the wind direction, the plate-shaped plastic or the like is less likely to fly than the foamed heat-insulating material having a specific gravity smaller than that of the plastic or the like. However, when the surface of the plate is perpendicular to the wind direction, it is easy to fly, as in the case of the foamed heat insulating material. On the other hand, in the wind separator according to the present invention, since the surface of the plate is parallel to the wind direction as described above, the separation becomes highly accurate. FIG. 4 shows the results of experiments on the mixture of crushed pieces of plate-like plastic and bulk foam insulation, and the inventors determined the recovery rate and the mixing ratio of plastic in the recovered foam insulation by experiment. Black and white circles indicate the recovery rates of the present invention and the conventional machine, respectively, and black and white triangles indicate the mixing rate. In the wind separator of the present invention, at the wind speed (4.8 m / s) indicated by the solid arrow a (4.8 m / s), 100% of the recovery rate and the mixing rate of 0% can be ideally separated. At b (5.1 m / s), the recovery rate is about 80%.
In addition, the wind speed is increased by arrow c (5.8 m / s) to increase the recovery rate.
When the recovery rate is raised to 95%, the recovery rate becomes 95%, but the mixing rate becomes about 40%. In the conventional machine, there is no wind speed that makes the recovery rate and the mixing rate compatible.

Next, the height h (FIG. 2) of the wind tunnel of the present sorting machine will be described below. If the feed rate of the mixture is increased by the present separator, a large number of plastics will slide on the floor surface, thereby reducing the wind speed near the floor surface. As a result, the foam insulation that moves upwards near the floor also lands on the floor, further reducing the wind speed near the floor, and finally the foam insulation slides down and is collected by the plastic collection section, where it is collected. To reduce the recovery rate. In this case, since the air volume in the wind tunnel is constant, a decrease in the wind speed near the floor increases the wind speed in the center of the wind tunnel, which is higher than that. At this time, if the height of the wind tunnel is too high with respect to the particle diameter of the foamed heat insulating material, the foamed heat insulating material slides downward on the floor surface due to the reduced wind speed near the floor surface, but if the height is limited to a low level, the lower side may be disturbed. Since the foamed heat insulating material to be slid moves upward due to the wind at the center of the wind tunnel away from the floor, it is possible to prevent a reduction in the recovery rate of the foamed heat insulating material even when the supply amount increases.

FIG. 5 shows the wind speed at which the above-mentioned reduction in the recovery rate occurs when the processing amount is fixed. The wind speed on the horizontal axis indicates the test material such as a foamed heat insulating material. This is a value measured at the center of the wind tunnel in the height direction before it is put into the wind tunnel. In addition, each of the symbols painted black indicates that the foamed heat insulating material was rapidly collected in the collection section of 16 plastics or the like due to the decrease in the wind speed near the floor surface as described above. 3. Wind speed in the figure
Focusing on 9 m / s, the recovery rate is 96% when the height of the wind tunnel is twice the maximum particle size of the foam insulation, but it is about 90% at 2.5 times and 55% at 5 times. Is declining. From this, it can be seen that the effect is obtained when the height of the wind tunnel is set to 2.5 times or less the maximum particle size of the foamed heat insulating material. Further, since the maximum particle size of the foamed heat insulating material targeted in the present invention is about 60 mm, the height of the wind tunnel is 150 mm or less in specific dimensions.

The foamed heat insulating material separated by the above-described wind separator is passed through a vertically long hopper A and a screw feeder 20 having two rotary valves 19 as shown in FIG. Is sent to the crusher 21 which is the process of the above. The crusher degass the foaming gas, and a gas mixture of the degassed foaming gas and air entering the crusher together with the foaming heat insulating material is sent to the condenser 27. In this case, the higher the concentration of the foaming gas, the better the condensation efficiency. The rotary valve is for preventing excess air from entering the pulverizer and for preventing the degassed foam gas from flowing back and leaking out of the system from the screen 12 or the like. The crusher 21 includes a sawtooth-shaped fixed blade 22 and a plate-shaped rotary blade 23 as shown in FIG. The foamed heat insulating material 17 is provided between the tip of the rotary blade and the fixed blade (about 1 to 2 m).
m), and is crushed by shearing force accompanied by torsion and impact. When the foam insulation is hard foamed polyurethane, considering the velocity gradient obtained by dividing the peripheral speed of the tip of the rotary blade by the gap between the tip of the rotary blade and the fixed blade as equivalent to the shearing force, the magnitude of this speed gradient is considered. The thickness is 1000 / s or more, preferably 5000 / s to 50,000 / s.
In the example of FIG. 6, the necessary shearing force can be obtained by setting the rotating blade to about 3000 rpm.

The crusher need not be limited to a rotary type. For example, an impact crusher of a system in which a pair of rotors each having a rotary blade on the outer periphery are arranged in parallel and an impact force is applied to the heat insulating material between the rotary blades. Any material can be used as long as a dynamic external force can act on the heat insulating material. FIG. 7 shows an example of the relationship between the particle size of the foamed heat insulating material after the pulverization performed by the inventors using a pulverizer and the foamed gas to be degassed.
When it is crushed to about mm, that is, to about the closed cell diameter of the foamed heat insulating material, it is almost completely degassed.

A pressure fluctuation wave is generated in the tank 24 and the screw feeder portion of FIG. 1 by the impact of the pulverization. The pressure fluctuation wave propagates to the hopper A, and as a result, the degassed foam gas flows backward. There is a possibility that the water will flow out of the system from the screen 12 of the wind separator. However, in this regard, the shape of the hopper A is vertically long, and the foamed heat insulating material inside serves as a cushioning material. The rotary valve 19 described above greatly reduces the amplitude of the pressure fluctuation wave. By being sucked by the compressor 26 described later, the flow out of the system is prevented.

The foaming gas generated in the pulverizer 21 is compressed by the compressor 26 through the bag filter 25 together with the entrained air, liquefied in the condenser 27 and collected in the collection tank 28.

Next, the compression device 30 for the fine powder 29 of the foamed heat insulating material pulverized by the pulverizer will be described with reference to FIGS. 8, 31 is a hopper B, 32 is a cylinder, 3
Reference numeral 3 denotes a driven piston whose straight body is longer than the opening A of the cylinder, and reference numeral 34 denotes a driven piston which receives a reaction force when the fine powder 29 of the foamed heat insulating material is compressed by the driven piston. The fine powder of the foamed heat insulating material is filled into the cylinder 32 via the hopper B by its own weight. At this time, the driven piston 34 is in contact with the end face of the cylinder at the point B, and when the driven piston is moved to the left, the foamed gas in the gap between the fine powder in the cylinder and the fine powder is moved upward to the hopper side as shown by the arrow. While releasing, the tip of the driving piston is compressed until it passes through the opening (broken line C). Thereafter, as shown in FIG. 9, since the diameter of the tip of the driving piston is small, the foaming gas is discharged to the hopper B as shown by the arrow, and when the driving piston is sealed by the sealing material 35 such as an O-ring as shown in FIG. Compression is complete. Next, FIG.
1, the driving piston and the driven piston are simultaneously moved to the left, and the compressed fine powder 36 of the foamed heat insulating material is discharged to the discharge port 3.
Eject from 7 out of the system.

FIG. 12 shows the details of the compression device. The leakage of the foaming gas to the outside of the system can be prevented by the seal member 35, the packing 38 and the dust seal member 39. When the compressed foamed heat insulating material is discharged, an anti-adhesion material 4 such as a fluorine resin is used.
By affixing 0 to the end face of the piston, it can be easily separated from the piston.

Although the crusher 21 may generate heat due to the crushing action, the temperature of the unrecovered chlorofluorocarbon gas remaining without being condensed in the condenser 27 is sufficiently low. Returning to the state shown by the broken line in FIG. 1 can suppress the heat generation of the crusher 21. Further, by returning the unrecovered Freon gas to the pulverizer 21, the Freon recovery rate can be further improved.

When the fine powder of the foamed heat insulating material is compressed by the compression device shown in FIG. 1, a small amount of a mixed gas of the foaming gas and air is present in the gap between the fine powder and the gas and is discharged out of the system as it is. Since this gap depends on the compression load of the piston, when the compression load is the same, the lower the concentration of the foaming gas, the smaller the amount of the foaming gas discharged out of the system. In this embodiment, air is blown from the outside into the compression device of FIG. 1 to lower the concentration of the foaming gas contained in the compressed fine powder of the foamed heat insulating material, thereby reducing the foaming gas discharged. FIG. 13 shows a cross-sectional view of the cylinder. FIG. 13 shows that the fine powder 29 in the cylinder 32 has the valve 4
Air is blown in by a nozzle 39 having 0. The other crushing section, wind separation section, crushing section, condensing section, and the like shown in FIG.

FIG. 14 shows another embodiment in which an exhaust port 41 and an adsorbent 42 are installed in a crusher B of No. 3, in which the foamed heat insulating material is partially crushed when the foamed heat insulating material is peeled off. The foamed gas deaerated in the step is fixed to the adsorbent from the exhaust port. Therefore, by periodically heating and desorbing the adsorbent, the recovery rate of the foaming gas can be further increased. Since the amount of Freon gas degassed by the crusher 21 is large, the concentration of Freon gas in the tank 24 is high, and direct liquefaction is possible. However, the amount of Freon gas generated in the crusher B is small, so the Freon gas concentration is small. And direct liquefaction is difficult. For this reason, it is practical to collect by adsorption and desorption by the adsorbent 42. The other components such as the wind separator, the pulverizer, and the condenser shown in FIG.

[0021]

According to the present invention, the foamed heat insulating material can be easily and efficiently separated into the foamed gas and the heat insulating resin without deteriorating, and each of them can be recovered at a high recovery rate.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a first embodiment.

FIG. 2 is a detailed front view of the wind separator of FIG. 1;

FIG. 3 is a diagram showing the structure of a conventional wind separator.

FIG. 4 is a diagram comparing the performance of a wind separator included in the present invention with the performance of a conventional wind separator.

FIG. 5 is a diagram illustrating the influence of the height of the wind tunnel of the wind power classifier included in the present invention.

FIG. 6 is a cross-sectional view of a main part of the pulverizing unit of FIG.

FIG. 7 is a graph showing the particle size and degassing rate of the foamed heat insulating material pulverized in the pulverizing section of the present invention after pulverization.

FIG. 8 is a sectional view of a cylinder, a piston, and the like for explaining the operation of the compression device of the present invention.

FIG. 9 is a sectional view of a cylinder, a piston, and the like for explaining the operation of the compression device of the present invention.

FIG. 10 is a sectional view of a cylinder, a piston, and the like for explaining the operation of the compression device of the present invention.

FIG. 11 is a sectional view of a cylinder, a piston, and the like for explaining the operation of the compression device of the present invention.

FIG. 12 is a detailed sectional view of FIG. 11;

FIG. 13 is an explanatory view of the second embodiment and is a cross-sectional view of the eleventh embodiment.

FIG. 14 is an explanatory diagram of the third embodiment, showing the configuration of the entire system.

[Explanation of symbols]

2 ... crusher A, 3 ... crusher B, 4 ... hammer, 5 ... rotor, 6 ... casing, 7 ... outlet, 8 ... grid, 9 ... wind separator, 10 ... inlet, 11 ... blower, 12 ... Screen, 13: Bottom plate of wind tunnel, 14: Plastic, 15 ...
Metal, 16: Collection box of plastic, etc., 17: Foam insulation, 18: Hopper A, 19: Rotary valve, 20 ...
Screw feeder, 21: crusher, 22: fixed blade, 2
3 ... rotary blade, 24 ... tank, 25 ... bag filter, 26
... compressor, 27 ... condenser, 28 ... collection tank, 29 ... pulverized foam insulation, 30 ... compression device, 31 ... hopper B, 32 ... cylinder, 33 ... driven piston, 34 ... driven piston, 35 ... Sealing material, 36: compressed foam insulation material, 37: discharge port, 38: packing, 39: dust seal material, 40: anti-adhesion material, 41: suction port, 42: adsorbent.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C09K 3/00 111 B09B 5/00 ZABQ B29K 105: 04 105: 26 (72) Inventor Kazuo Sakaguchi 502 Kandachicho, Tsuchiura-shi, Ibaraki Prefecture Hitachi, Ltd.Mechanical Research Laboratory Co., Ltd. (72) Inventor Yoshiyuki Takamura 794, Higashi-Toyoi, Kazamatsu City, Yamaguchi Prefecture Incorporated Hitachi, Ltd. Inside the Kasado Plant (72) Inventor Kazuo Makino 794, Higashi-Toyoi, Kazamatsu City, Yamaguchi Prefecture Hitachi, Ltd. Inside the Kasado Plant, Hitachi Ltd. (56) References JP-A-5-147040 (JP, A) JP-A-5-146703 (JP, A) JP-A-5 147039 (JP, A) United States Patent 4531950 (US, A) (58 ) investigated the field (Int.Cl. ^6, DB name) B29B 17/00 - 17/02 B02C 21/00 C08J 11/00 - 11/06 B09B 5/00

Claims (8)

(57) [Claims] 1. A casing having an uneven surface formed on an inner wall side.
Several connected to a rotor rotating in this casing
Hammers and a grid at the outlet
From foam insulation and other members to which this foam insulation is fixed
The material piece consisting of
At a speed at which an impact force can be applied by a hammer,
The material is rotated and the hammer and irregularities
Shear force with impact force is given by collision with surface
This allows the piece of material to pass through the grid spacing
Crushed to the size and the above impact force
The adhesion is released and the foam insulation and the other members peel off.
Is, the the foam insulation and crusher and other member generates a mixture of the separated fragments together, the mixture was passed through the grid, composed of fragments and the other members of the foam insulation crushing A separation unit that separates the foam into pieces; a crusher that crushes the crushed pieces of the foamed heat insulating material to release the foaming gas trapped in the crushed pieces; and a collection that collects the foaming gas generated in the crusher. An apparatus for recovering foamed gas, comprising: a container. 2. The apparatus for recovering foamed gas according to claim 1, wherein said recovering device includes a compression device for compressing and crushing the crushed material of the crushed pieces of the foamed heat insulating material. 3. A casing having an uneven surface formed on an inner wall side.
Several connected to a rotor rotating in this casing
The hammer and the grid provided at the discharge port.
An impact force is applied to the inserted input member by the hammer.
The rotor is rotated at a speed that can be
Impact force due to collision of the input member with the hammer and uneven surface
A crusher that gives a shearing force with
Insert and place this piece of material through the grid
Crushed to the point and the above-mentioned fixation by the above-mentioned impact force
The foam insulation and the other members are peeled off,
A step of generating a mixture of crushed pieces in which the foamed heat insulating material and other members are separated from each other; anda step of separating the crushed pieces of the foamed heat insulating material and the crushed pieces formed of the other members from the mixture. Foaming, comprising: crushing the crushed pieces of the foamed heat insulating material to release the foaming gas trapped in the crushed pieces; and recovering the foaming gas released in the releasing step. Gas recovery method. 4. The method for recovering foamed gas according to claim 3, wherein the step of recovering includes a step of compressing and crushing the crushed pieces of the crushed pieces of the foamed heat insulating material. 5. A mixture of crushed pieces obtained by separating and crushing a piece of material made of a foamed heat insulating material and another member to which the foamed heat insulating material is fixed, so that the foamed heat insulating material and the other member are separated from each other. A crusher that generates a crusher, an adsorbent that is connected to the crusher, and that adsorbs a foaming gas that is degassed from the foam insulating material during peeling and crushing, and a crushed piece of the foam insulating material from the mixture and the other A separating unit for separating crushed pieces made of a member from each other; a crusher for crushing the crushed pieces of the foamed heat insulating material to release a foaming gas trapped in the crushed pieces; and a foaming gas generated in the crusher. And a recovery device for liquefying and recovering the gas. 6. The apparatus for recovering foamed gas according to claim 5, wherein said recovering device includes a compression device for compressing and crushing the crushed material of the crushed pieces of the foamed heat insulating material. 7. A mixture of crushed pieces obtained by separating and crushing a material piece comprising a foamed heat insulating material and another member to which the foamed heat insulating material is fixed, so that the foamed heat insulating material and the other member are separated from each other. Generating a mixture of crushed pieces, and adsorbing a foaming gas generated in the step of generating a mixture of crushed pieces with an adsorbent; and crushing pieces of the foamed heat insulating material and crushed pieces made of the other members from the mixture. Separating the foamed heat insulating material from each other; crushing the crushed pieces of the foamed heat insulating material to release the foaming gas trapped in the crushed pieces; and liquefying and recovering the foamed gas released in the releasing step. A method for recovering a foamed gas, comprising: 8. The method for recovering a foamed gas according to claim 7, wherein the step of recovering includes a step of compressing and crushing the crushed pieces of the crushed pieces of the foamed heat insulating material.