JPS6369745A - Quick drying apparatus for clay formed body - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is a method of extruding an extruded molded product, which is made by continuously extruding a raw material mainly composed of clay into a predetermined shape, by microwave treatment in a short period of about 10 minutes to 1 hour. This invention relates to a quick drying device for clay molded bodies that can be dried by using far infrared rays and air in combination due to their synergistic effect.

[Conventional technology]

In general, inner and outer wall materials and roof tiles made of clay are extruded into a predetermined shape, and then immediately cut into short lengths, for example, 10 to 30 cm, and then cut into short lengths of about 1 to 30 cm using waste heat from a kiln. 3
It was common to use a device configured to reduce the moisture content to 1 to 0% within a few days and then supply it to the kiln.

[Problem that the invention seeks to solve]

Conventional drying equipment for clay molded bodies not only takes several days to dry, but also makes it impossible to transport longer clay molded bodies without using an underboard, resulting in lower productivity and increased costs. It also required a large area of land. Furthermore, when drying time is shortened by one day using conventional drying equipment that applies heat from the surface to dry, the surface layer dries first, causing roof tiles, tiles, and exterior wall materials to twist or warp due to internal water vapor pressure. It has been very difficult to shorten the drying time because of the disadvantages of drying, cranking, and breaking. In addition, instead of drying by heating from the surface, drying by internal heating devices such as microwave heaters and far-infrared heaters can be considered, but if each device is simply used, the former will allow the material to be dried to reach a temperature of about 130°C. It is difficult to raise the temperature, rapid heating can lead to explosion, and the latter can damage the equipment,
Energy costs were high. In addition, although the latter takes longer to reach the inside of the material to be dried than the former, it is much more advantageous in raising the internal temperature than the former, so each drying device has its advantages and disadvantages. In addition, the above two devices have various problems in preventing condensation of a large amount of water vapor generated during drying, and in the conveying structure when drying objects to be dried, such as deformation due to frictional resistance between the objects to be dried and the conveyor belt, and long There was non-uniform heating of the microwave to the ulnar body.

[Means for solving problems]

In order to eliminate these drawbacks, the present invention uses an extrusion molding machine, followed by a microwave heater that has good penetration into the inside of the extruded product, and then an infrared (far infrared) heat source that increases the temperature of the material to be dried. In addition to arranging far-infrared heater devices linearly in this order, a large amount of air is supplied to the space to be heated by microwave heating, and a large amount of water vapor generated during drying is supplied to or sucked out of the space to be heated. The continuum of clay extrudates can be continuously dried in a short period of about 10 minutes to 1 hour by releasing air using air to eliminate condensation on the surface of the extrusion and adhesion of condensed water to the inner wall of the heating space. Moreover, the present invention proposes a rapid drying device for clay molded bodies that is significantly more compact than the conventional device and can quickly dry the material to be dried without cranking, warping, twisting, or exploding.

〔Example〕

EMBODIMENT OF THE INVENTION Below, one Example of the quick drying apparatus of the clay molded object based on this invention is demonstrated in detail using drawing. Figure 1 (a
) and (b) are explanatory diagrams showing a typical example of the above device. In the figure, ■ indicates that an extrusion molding machine is used to continuously extrude a clay-based raw material, for example, into an extrusion molded body A having a cross-sectional shape shown in Figure 2 (al to (Jl). , depending on the width, 200 to 2000+
+n/min. Note that clay is a natural product and has different components depending on its production area, and these advantages and disadvantages are offset to obtain a predetermined mixed clay. Specific examples include pounding pottery stone, feldspar, kaolinite, halozite, metahalosite, Kibushi clay, Frogme clay, Shigaraki clay, chamotte, etc., and kneading them by adding water. In addition, iron may be removed from this clay using a magnet if necessary.

Reference numeral 2 denotes a transfer mechanism, for example, a free roller or at least one drive belt (not shown) synchronized with the extrusion speed.
It is made of seeds and is used to feed the extruded product A to the next process at the same extrusion speed without deformation. The main type is a microwave heating machine with a continuous oven structure, which converts microwaves into thermal energy without penetrating the inside of extruded product A and requiring time for heat conduction, which lasts from a few seconds to a few minutes. This is to generate heat and evaporate the water in the clay. The extruded product A contains about 22 to 15% water by weight, and has the ability to evaporate, for example, 5 to 10% of this water. In particular, this type of extruded product A shrinks in volume until the moisture content reaches about 5 to 8%, but when the moisture content falls below that, the volume does not shrink. Therefore, to explain the microwave heating unit in detail, it includes a waveguide 4 that guides microwaves oscillated from a microwave oscillator (not shown) to a required location;
A reflecting plate 5 that reflects the guided microwaves B, a rotary blade 6 that stirs the reflected microwaves, and an extruded body A
a conveyor section 7 consisting of a free roller that is dielectric but does not cause sparks to move at an extrusion speed;
The inlet and outlet 8.9 and a large amount of air etc. C are heated in the heated space 12.
It is composed of an air supply port 13 for sucking air from the air and supplying it to the heated space 12, and an enclosure 14 that surrounds the microwave B to prevent it from leaking to the outside. Note that the inlet and outlet 8.9 are formed to have a structure and length that also function as a filter to prevent the microwave B from leaking to the outside. Further, the space to be heated 12 in which the extrusion molded product A is heated varies depending on the purpose, but is, for example, about 1 to 5 m. Furthermore, in the conveying section 7, the microwave B, air, etc.
The structure is such that the extrusion molded product A can be transported without absorbing this. An example of this is shown in Figure 3 (a), (
As shown in b), it is composed of a fixed core rod 7a, a pipe-shaped free roller 7b made of Teflon, a core rod support 10 as shown in FIG. 4, and a shielding plate 11 provided as necessary. It is. To explain further, in the figure (a), the width of the free roller 7b is divided into three parts to reduce the resistance when the extruded body A passes through, and in the figure fb), the free roller 7b is composed of one piece. In addition, the core rod support 10 is provided with a passage hole 10a so that the microwave B can be irradiated from the back side of the extrusion molded body A as well. In addition, the shielding plate 11
When the extruded body A is a long body, it is useful for suppressing the physically high density at the upper and both ends in the longitudinal direction and achieving uniform heating. In addition, air supply port 13
is air from a compressor, ring blower, etc. (dry air,
Reference numeral 616 connected to the air cycle prime mover 15 capable of blowing or suctioning warm air (including air) is a far-infrared heater device that uses infrared rays, especially far infrared rays, as a heat source, The temperature of the extruded product A is raised to 130°C or higher in order to reduce the temperature to 1 to 0%. Its structure consists of a conveyance mechanism 17 consisting of free rollers and a drive belt, a far-infrared heater 18, and a heat-retaining box 19, and the heating zone is about 2 to 10m. Of course, the heating zone depends on the thickness, width, and
It varies depending on the size and conveyance speed.

Next, the operation will be explained.

First, clay consisting of Shigaraki clay, chamotte, water reducing agent, and water is prepared as raw materials. The weight percentage is, for example, 61.5% Shigaraki clay, 8% Chamonite, 0.5% water reducing agent (product name: Celluflo, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and 20% water in a clay kneading machine (MP-100). It was mixed using a mold (manufactured by Miyazaki Tekko Co., Ltd.). In addition, the extrusion molding machine 1 has an extrusion capacity of 100
~150I! /hr type name MV-FM-A-1 type (manufactured by Miyazaki Tekko Co., Ltd.) was used. The transfer mechanism 2 includes a free roller and a drive belt conveyor arranged in this order, and the microwave heating unit has a frequency of 2450 MHz and an output of 5 k.
The length of the space to be heated 12 is 3 m, and if necessary, a large amount of air or the like C is fed into the space to be heated 12 from one wall of the enclosure 14, and water vapor C generated during heating is supplied from an outlet 8.9. ' to the outside, lowering the water vapor pressure in the heated space 12, and preventing dew condensation from forming on the heated object and the inner wall of the enclosure 14. It was made into a free roller made of manufactured pipes. Further, the far-infrared heater device 16 includes a plurality of far-infrared heaters 8, approximately three
They were arranged in a zone of ~10 m, and their output was, for example, 20 m. In addition, in the microwave heating machine 1, the moisture content of extrusion molded body A was reduced to 18% (weight %) to 5% (weight %).
The remaining water was evaporated by the far-infrared heater device 16. Further, the extrusion speed of the extrusion molding machine 1 was 300 to 10,001 m/min, and here it was set to 400 mm/min. Others, extrusion molded product A
(Here, it is a continuous molded product) The pass lines of the extruded molded product A are set at the same height, and the extruded molded product A is fed to the microwave heating machine 1 by a drive belt at the same extrusion speed of the extrusion molding machine 1.
Although the volume shrinks due to moisture evaporation on the free roller of the conveying section 7 in the microwave heating machine 1, the difference in speed due to this shrinkage is absorbed. Therefore, the clay supplied to the extrusion molding machine 1 is sent out from the outlet in a continuous body having a cross section shown in FIG. 2(g). The delivered extrusion molded product A is fed to the microwave heating machine 1 via the transfer mechanism 2, and while passing through the heated space 12 of the main microwave heating machine, the moisture content of the extrusion molded product A is reduced to 5% (weight ratio). ) in 5 minutes, and fed from the outlet to the far-infrared heater device 16, where the water content was evaporated to 1% (weight ratio) in about 10 minutes and dried. As a result, the extruded product A, which had a continuous band extending from the exit of the extrusion molding machine 1 to the far-infrared heater device 16, could be sent to the next process as a dry product in about 15 to 20 minutes.

The following effects can be obtained by releasing the water vapor C' in the heated space 12 in the direction of the arrow from the exit 8.9. That is, the release of air from the heated space 12 prevents the water vapor pressure in the heated space 12 from increasing, prevents the extruded product A from overheating and breaking due to rapid heating, and prevents the air etc. C from being heated. By providing a flow to the air layers near the front and back surfaces of the extrusion molded product A inside the extrusion molded product A, the exposed surface of the extrusion molded product A is cooled, and together with this, overheating is suppressed and drying time is shortened, and the extrusion molding This prevents dew condensation from forming on the exposed surface of the body A and the inner wall of the heated space 12. Then, this dried continuous band-shaped extrusion molded product A is cut into regular lengths by a running force/vine 20 and sent to a glazing process or a firing process (not shown).

What has been described above is only one embodiment of the quick drying device for clay molded bodies according to the present invention. Cut or microwave heating machine 1, as shown by the two-dot chain line.
It is also possible to supply warm air or hot air to the far-infrared heater device 16 (only the far-infrared heater device 16 is shown) to further shorten the drying time. Further, as shown by the dashed line in the microwave f>o% machine main 1 section in FIG. 1(a), it is also possible to provide an air cycle line in addition to or in place of the air supply port 13.

〔Effect of the invention〕

As described above, according to the quick drying device for clay molded bodies according to the present invention, a clay extrusion molded body (short length) containing about 22 to 15% water (weight ratio) and a continuous body thereof are subjected to a two-stage heating process. By suppressing water vapor and its rise in the heating space, there is no cracking, explosion, warping, or twisting, and the drying time can be shortened to 1/100 to 300 times of the conventional drying time. Further, although the volume of the extruded body shrinks by 10% or more compared to when it is extruded, there is an advantage that the transport speed due to this shrinks without any adverse effect on the extruded body and can be absorbed and transferred to the next process.

Furthermore, in the present invention, since the processes from extrusion to drying are arranged in series, a long band or continuous band can be dried quickly. Furthermore, since the water vapor in the space to be heated is released to the outside, it is possible to prevent an adverse effect on the inner wall of the space to be heated and the surface of the object to be heated, to prevent condensation, and to prevent a decrease in the evaporation speed. Furthermore, by irradiating the heated object with microwaves from below, concentrating on the weak heating part, etc., drying can be made uniform and adverse effects during drying can be prevented.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are schematic diagrams showing an embodiment of the rapid drying device for clay molded bodies according to the present invention and a cross-sectional view taken along the line E, and FIGS. 2(a) to fj) are extruded molded bodies. 3(a) and 4 are explanatory diagrams showing the configuration of the conveying section of the microwave heating machine. ■...Extrusion molding machine, 1!...Micro Wave heating machine, 7.
...Conveyance section, 13...Air supply port, 16...Far infrared heater device, A...Extrusion molded product, B...Microwave, C...Air, C'...Water vapor. Figure 1 (Illusion Figure 2 (α) f8 (b) , A (c), A (ddon (A Ce) f to 12 staves = go = = down =) Figure 1 to f''>) ～Hero (I ~Ha (Me) I Go (Ha 3rd Figure 6) (l:l) Yumichichi Figure 10

Claims (1)

[Claims] (1) An extrusion molding machine that continuously extrudes clay-based raw materials into a predetermined shape, and a continuous oven-type microwave heating machine that quickly reduces moisture in the extruded product sent out from the extrusion molding machine. and far-infrared heater devices that mainly raise the temperature of the extruded product passed through the microwave heating machine, and air supply ports are provided on the outer circumferential surface of the microwave heating machine other than the exit and inlet. 1. A quick drying device for clay molded bodies.