JPH0725085B2 - Method for manufacturing long ceramic board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is to continuously produce a raw material containing a clay mineral as a main component in an arbitrary shape, such as a flat plate or a continuous body extruded with a hollow body, without causing deformation and cracks. The present invention relates to a method for producing a long ceramic plate which is quickly dried in a short time of about 1 to 30 minutes without being generated.

[Conventional technology]

Roof tiles, tiles, etc. are cut into short pieces at the exit of the extruder, sent to the process of waste heat and natural drying, dried for about 1 day to 1 week, and then sent to the glaze and baking process. Was manufactured by.

[Problems to be solved by the invention]

For ceramic plates, such as roof tiles and tiles, the extruded molded body is soft and it is difficult to move to the drying step without deformation, so that a long dried body without deformation or cracks could not be obtained. Moreover, since the conventional drying process is a method of evaporating water only from the outer surface of the extrusion molded body, it has to be dried slowly because it may be cracked or deformed significantly if it is heated rapidly, and it may take a long time. There were problems of drying, cost increase due to it, low productivity, and large-area storage.

[Means for solving problems]

In order to eliminate such drawbacks, the present invention allows the extruded body to remain continuous and pass through the atmosphere of the microwave and the far infrared heater while moving at the extrusion speed, and in particular, in the hollow body, dry air is internally provided. Is fed parallel to the extrusion direction, and air, dry air, warm air, etc. are blown to remove steam from the front and back of the extruded body so that continuous extrusion does not deform or crack more quickly. Then, dry it on a straight line, and then cut it to a fixed length to improve the ventilation of dry air in the hollow part to efficiently evaporate moisture and elongate a longer ceramic plate, for example, 0.5 to 5 m. It is intended to provide a method for producing by drying rapidly, at high efficiency, and continuously at low cost.

〔Example〕

An embodiment of the method for producing a long ceramic plate according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view showing an outline of an apparatus used for carrying out the present invention.
In the figure, reference numeral 1 denotes clay which is obtained by mixing several kinds of raw materials with chamotte or the like through a kneader (not shown), and this is extruded by a vacuum extruding machine 2, for example, from a die 3 to a second It is extruded in the cross-sectional shape shown in FIGS. If necessary, the die 3 may be a core 4 for an extruded hollow body, for example, as shown in FIGS. 3 (a) to 3 (c).
And a tube 5 for inhaling or exhausting gas inside the hollow body is attached to the core 4 or to each lattice 4a, and the cross-sectional area of the lattice 4a increases from the root to the outlet. The configuration described above is preferable in terms of extrusion resistance. Furthermore, the control valve 6 is supplied to the pipe 5 to supply a required gas,
In order to quickly dry the inside of the continuous extrusion-molded body A by connecting the exhaust gas suction / exhaust device 7 and moving the steam inside the hollow body so as to discharge it to the extrusion-molded body A. belongs to. The continuous extrusion-molded body A is a long body until it is dried, and thereafter is cut into regular lengths. Clay 1 is a natural product and has different components depending on each producing area. By utilizing these features and weak points mutually, a predetermined mixed clay is obtained. As an example of the clay 1, pottery stone, feldspar, kaolinite, halosite, metahalosite, kibushi clay, frog eyes clay, Shigaraki clay and the like are crushed, and water is added and kneaded. If necessary, the clay 1 may be ironed by a magnet. Reference numeral 8 denotes a conveyer in which one or more kinds of a flea roller 9, a drive belt 10 and the like are arranged at the same level as the outlet of the mouthpiece 3 and linearly arranged along the extrusion direction. In addition, it is for transporting to the next step at the extrusion speed. Reference numeral 11 is a microwave heating device, in which the microwave α penetrates into the extruded product A to convert the microwave α into heat energy without requiring time for heat conduction, and heat is generated in a few seconds to a few minutes to generate heat in the clay 1. It is for evaporating the water content of. In addition, the water content in the extruded product A is a weight ratio.
22 to 15% is included, of which, for example, 5 to 10%
It has the ability to evaporate. In particular, the volume of the seed extruded product A shrinks until the water content becomes about 5 to 8%, but when the water content is less than that, the volume shrinkage does not occur. Therefore, the microwave heating device 11 will be specifically described with reference to FIGS. 4A and 4B (cross-sectional view taken along the line EE in FIG. 4A). A waveguide 12 that guides the oscillated microwave α to a required location, a reflecting plate 13 that reflects the guided microwave α, a rotary blade 14 that stirs the reflected microwave α, and an extruded body A. While moving at a pushing speed, a large amount of suction is performed from the heated space 18 such as a conveying portion 15 composed of a fli roller having a structure that causes a dielectric but does not spark, a large amount of β such as the inlets and outlets 16 and 17 of the extruded body A and air β. An air supply port 19 for supplying the heated space 18 and an enclosure 20 surrounded by the microwave α so as not to leak to the outside. The inlets and outlets 16 and 17 are formed to have a structure and length that also function as a filter that prevents the microwave α from leaking to the outside. The heated space 18 for heating the extruded body A varies depending on the purpose, but is, for example, 1 to 5 m.
It is a place. Further, the conveying unit 15 absorbs the microwaves α, air β, etc. evenly radiated or blown onto the extruded product A, and shrinks about 10% of the entire extruded product A when it is dried. However, the extruded product A can be conveyed. As shown in FIGS. 5 (a) and 5 (b), an example of the fixed core rod is shown.
It is composed of a pipe-shaped fli roller 21 made of Teflon 20 and a core rod support 22 as shown in FIG.
To further explain, in FIG. 5 (a), the width of the fli roller 21 is divided into, for example, three parts, and the resistance when passing through the extruded product A is further reduced.
21a. Further, the core rod support 22 is provided with a through hole 22a so that the microwave α is also radiated from the back surface of the extrusion molded body A. Further, the air supply port 19 is connected to an air cycle prime mover 23 capable of blowing or sucking air (including dry air, warm air, hot air air) such as a compressor and a ring blower, and the front and back sides of the extrusion molded body A. It helps to more efficiently remove the water vapor existing in the surface layer and promote evaporation of the water vapor. The carrier 8 corresponds to the same level as the carrier 15 and is arranged in series. A far infrared heater device 24 is effective for drying the central portion of the extruded product A to the surface layer in a short time. For example, the water content of clay 1 is 8 to 10% and the water content is 1 to 0%. This is to reduce the shape and enhance the shape retention. The structure is composed of a conveying section 25 of a fli roller, a plurality of far infrared ray heaters 26, an enclosure 27, and a supply / exhaust port 28 provided if necessary, and in particular, the surface layer portion of the extruded body A is further heated to remove moisture. It is to be reduced and dried. In addition, air β
Is a steam extruded product A that is agitated by a fan or the like not shown.
Can be more efficiently evaporated from the surface.

Next, a method for manufacturing a long ceramic plate according to the present invention will be described. First, as the clay 1, for example, a raw material composed of Shigaraki clay, chamotte water reducing agent, and water is prepared. The weight% is Shigaraki clay 61.5%, chamotte 20%, water reducing agent 0.5%.
(Trade name: Cell Flow: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and 18% of water was kneaded with a clay kneader (MP-100 type manufactured by Miyazaki Tekko Co., Ltd.). As the extruder 2, a model name MV-FM-A-1 type (manufactured by Miyazaki Tekko Co., Ltd.) having an extrusion capacity of 100 to 150 l / hr was used. The gas suction and exhaust system was set to exhaust at 2 HP. Also,
The microwave heating device 11 has a frequency of 2450 MHZ, an output of 5 KW, and the heater heating space 18 has a length of 3 m.
A large amount of air is supplied to the enclosure 18 from the air supply port 19 of the enclosure 20, and the steam β'generated during heating is discharged to the outside from the inlets / outlets 16 and 17, and the steam pressure in the heated space 18 is reduced to The heating object and the inner wall of the enclosure 20 are configured so that dew condensation water can be prevented from being generated, and the transport unit 15 is a free roller made of a Teflon pipe. In addition, it is assumed that the microwave heating evaporates the water content of the extruded product A from 18% (% by weight) to 7% (% by weight). Further, as far-infrared heater device 24 , ten far-infrared panel heaters having a wavelength of 4μ to 400μ are arrayed for 10 meters as far-infrared heater 26, and moisture in extrusion molding zone A is diffused to the surface for quick dehydration. The water content can be reduced to 1 to 0%. Further, the air is agitated by the fan in the far infrared heater device 24 , so that the water vapor on the surface of the extruded product A is more easily diffused.
Therefore, it is assumed that the extruded body A of the ceramic plate having the cross section shown in FIG. 2 (a) is continuously extruded at a thickness of 20 mm at 0.5 to 10 m / min, here 400 mm / min. The extruded continuous molded body A is conveyed linearly from the die 3 through the conveyor 8 at the extrusion speed without deformation or cracks,
It is fed to the microwave heating device 11 and the extruded body A 22 to 18
% Moisture is reduced to an average of 7-5% in about 5-10 minutes, then fed to the far-infrared heater device 24 in a continuous form to evaporate the remaining moisture in about 1-10 minutes. It is a dried product.
At this time, the water vapor β ′ is discharged to the outside at the same time as the air β and the like as being injected from the inlet / outlets 16 and 17 of the microwave heating device 11 and the inlet / outlet of the far infrared heater device 24 . This wipes off the water vapor that has come out on the surface of the extruded body A, and the water vapor β ′ inside the hollow body is released to the outside by the dry air, so that the evaporation of the water vapor is further enhanced. Note that evaporation is further promoted by the synergistic effect of the flow of air and the movement of the extruded product A in the traveling direction. Also,
As a comparative example, if air is not supplied to the microwave heating device 11 , water vapor is saturated in the enclosure, and vaporization is about 1/3 of that in the case where air is supplied, and a disadvantage due to dew condensation occurs.

What has been described above is merely one example of the method for manufacturing a long ceramic plate according to the present invention, and the waste heat of the firing furnace not related to the microwave heating device 11 and the far infrared heater device 24 can be used. .

〔The invention's effect〕

As described above, according to the method for producing a ceramic plate according to the present invention, the extrusion molded body made of clay is not deformed, and cracks are not generated rapidly, efficiently and efficiently at low cost. It has the feature that it can be sent to the process.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the outline of an apparatus used for carrying out the method for producing a long ceramic plate according to the present invention, and FIGS.
(S) is an explanatory view showing an example of a cross section of a long ceramic plate,
3 (a) to 3 (c) are perspective views showing an example of the core, and FIG.
Drawing (a), (b), Drawing 5 (a), (b), and Drawing 6 are explanatory views showing an example of a microwave heating device. 1 ... Clay, 2 ... Extruder, 4 ... Core, 7 ... Gas suction / exhaust device, 11 ... Microwave heating device.

Claims (1)

[Claims] 1. A raw material made of clay mineral is continuously extruded from an outlet of an extruder by a flat plate or a hollow body having an arbitrary shape corresponding to a die, and the continuously extruded extruded body is passed through a conveyer. The microwave heating device and the far-infrared heater device are moved in parallel in that order and conveyed at a speed corresponding to the extrusion speed, and dry air is fed to the inner wall of the hollow portion of the extruded body that is continuous during the conveyance in the direction of travel of the extruded body. Dry air is supplied from all cores while controlling the amount, humidity, and temperature, and at least the steam on the front and back surfaces of the continuous extruded body in the microwave heating device is removed by forced blowing. A method for producing a long ceramic plate, characterized in that a continuous extruded body is rapidly and uniformly dried to about 1 to 0% in about 1 to 30 minutes from extrusion of water to drying.