JPH0359357B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a firing furnace for performing calcination synthesis of ceramic raw materials, firing of ceramic molded bodies, and the like.

(Prior Art) Furnaces such as tunnel-type continuous firing furnaces, batch-type firing furnaces, and rotary kilns have conventionally been used for calcination synthesis of ceramic raw materials, firing of ceramic molded bodies, and the like.

The above-mentioned tunnel type continuous firing furnace has a tunnel-shaped furnace body 1 arranged horizontally, as shown in FIG.
The preheating zone 1a, the firing zone 1b and the cooling zone 1c each have a temperature distribution as shown by the polygonal line _h1 in FIG. 3b.

When a ceramic molded body is burned in a tunnel furnace having the above-mentioned configuration, the ceramic molded body 2 to be fired is packed vertically or horizontally into a box-shaped firing box 3, as shown in FIG. This firing box 3 is loaded on the base plate 4 as shown in FIG. 3a,
First, it is automatically pushed into the preheating zone 1a of the furnace body 1 as shown by arrow _A1 using a pusher (not shown). After burning the binder (molding aid) in the ceramic molded body 2 in this preheating zone 1a (binder removal process), the base plate 4 is moved to the furnace body 1.
The ceramic molded body 2 is heated at a temperature of 1200°C to 1350°C for 2 to 3 hours.
Bake for an hour. When this firing is completed, the ceramic molded body 2 is pushed into the cooling zone 1c of the furnace body 1 and cooled, and then pulled out from the furnace body 1 as shown by arrow _A2 .

In the batch type firing furnace, ceramic molded bodies 2 are packed vertically or horizontally in a firing box 3 similar to the one shown in Fig. 4, and this firing box 3 is loaded on a base plate 4, and fired by so-called batch processing. Do this.

The tunnel-type continuous firing furnace and batch-type firing furnace described above both require firing furnace materials such as the firing box 3 and the base plate 4, and the thermal efficiency is low due to the heat capacity of these firing furnace materials. There was a problem in that the equipment required for the unit processing amount of molded bodies also became large. Further, the ceramic molded body 2 inside the firing box 3 is heat-treated while maintaining the shape packed in the firing box 3, but a temperature difference occurs between the center and the outer circumference of the firing box 3, and the firing box 3 The ceramic molded bodies 2 packed in different positions are subjected to different thermal histories. This difference in thermal history is the difference between firing box 3
This problem is noticeable when the ceramic molded bodies 2 are packed in multiple rows in multiple stages or when the firing boxes 3 are stacked in multiple stages for firing, and there is also a problem that large variations occur in the properties of the ceramic molded bodies 2 after firing. Ta.

Furthermore, rotary kilns are a typical equipment for cement synthesis, but the equipment costs are high, and
Small-sized devices had problems such as a small throughput per facility area.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems in firing furnaces, and has a low equipment area and equipment cost per unit processing amount of materials to be fired. The object of the present invention is to provide a firing furnace in which preheating, firing, and cooling are performed during the process of flowing down to the furnace, and the object to be fired is fired continuously and uniformly with high efficiency.

(Structure of the Invention) For this reason, the present invention is provided with a hopper section in the upper part of the furnace body, which serves as a preheating zone in which the charged object to be fired is preheated. A plurality of partition walls are formed which define slits that open to the hopper section at the upper part and open to the bottom of the furnace body at the lower part, and fixed blades protrude diagonally downward from the wall surface, The upper part of the partition wall has a firing zone in which a heating element is placed in a space formed inside the partition wall, and the lower part of the partition wall has a partition wall with a heat-insulating structure that has no internal space. and a quantitative discharge means disposed in the opening at the bottom of the furnace body, through which the fired material is discharged in a fixed amount while flowing down the slit in a meandering manner by the fixed blades. It is characterized by

(Effects of the Invention) According to the present invention, preheating, firing,
As it passes through each cooling zone, the material to be fired is automatically preheated, fired, and cooled as it flows from top to bottom. As it flows down the narrow slit formed between the walls, it is fired by receiving heat from the heating element inside the partition wall, so it does not require a firing box with a large heat capacity like a conventional tunnel furnace. First, thermal efficiency is high and energy saving can be achieved, and the shape of the firing furnace can also be made smaller. Furthermore, according to the present invention, since each object to be fired is fired in the process of being stirred by fixed blades and continuously flowing down, the firing conditions for each object to be fired are almost constant, which eliminates variations in quality. It is possible to obtain a fired product with less.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a ceramic raw material calcining furnace for calcining and synthesizing ceramic raw materials.

The ceramic raw material calcination furnace shown in FIG. 1 has a vertically elongated box-shaped furnace body 12 whose upper portion serves as a hopper portion 11 into which ceramic raw materials to be calcined are introduced. As shown in FIG. 2, a plurality of partition walls 13, 13, . . . are provided below the hopper portion 11 of the furnace body 12.
are arranged at an interval d. The furnace body 12
The partition walls 13, 13, . . . are all porous and made of an alumina (Al ₂ O ₃ )-based refractory, a silicon carbide (SiC)-based refractory, or the like. The above-mentioned furnace body 12 and partition walls 13, 13,...
For example, it can be manufactured by molding the above-mentioned refractory material by a method such as plaster casting and then firing it.

A cavity 15 is formed inside each of the partition walls 13, 13,..., and each cavity 1 of the partition wall 13, 13,...
Inside the furnace body 12, a plurality of heating elements 16, 16, . . . are arranged at intervals in the vertical direction so that the inside of the furnace body 12 has a predetermined temperature distribution. Above partition wall 1
Although not specifically shown, a cavity similar to the above is formed inside the side wall 12a (see FIG. 1) of the furnace body 12 for 3, 13, . . . , and a plurality of heating elements are arranged inside the cavity. has been done. The above heating element 1
As 6, 16,..., silicon carbide (SiC)-based rod-shaped heating elements can be used, but panel-shaped heating elements or other heating elements can also be used depending on the use and purpose of the kiln. can.

Each of the partition walls 13, 13, . . . is also provided with fixed blades F, F, . Further, although not specifically shown, fixed blades similar to those described above are also provided on the inner wall surface of the side wall 12a of the furnace body 12.

The slits 14, 14, . . . having a width d formed between the partition walls 13, 13, .
The upper portions of the partition walls 13, 13, . . . open into the hopper portion 11, and the lower portions of the partition walls 13, 13, . A slope 13a is formed at the upper end of the partition walls 13, 13, . . . for guiding the ceramic raw material 17 charged into the hopper portion 11 to the slits 14, 14, . The side wall 12a of the furnace body 12 also has a slope similar to the above (not shown).
is formed. The above slits 14, 14,...
Quantitative discharge devices 18, 18, . . . such as rotary valves are disposed at the bottom opening of the furnace body 12.

In the ceramic raw material calcining furnace whose structure has been explained above, as shown in FIG. A preheating zone 21a is configured to preheat the ceramic raw material 17 (see Fig. 2) introduced into the slit 1.
Cavity 1 of partition walls 13, 13, ... in 4, 14, ...
5, 15, . . . (see FIG. 2) constitutes the firing zone 21b. Further, the lower part of the firing zone 21b serves as a cooling zone 21c for the ceramic raw material 17 that has been calcined.

As shown in FIG. 2, the ceramic raw material 17 that has been charged into the hopper section 11 of the furnace body 12 and preheated is discharged by the quantitative discharge device 18 as the ceramic raw material 17 that has been calcined is discharged. They are successively guided to slits 14, 14, . . . formed between partition walls 13, 13, . The ceramic raw material 17 is heated to a heating element 1 within the slits 14, 14, .
6, 16, . . . Above slit 1
The ceramic raw materials 17 in 4, 14, .
8, as a certain amount is discharged from the bottom of the furnace body 12, the fixed blades F, F,... provided on the partition walls 13, 13... meander through the slit 1.
4, 14, ... flows down. In this process, the ceramic raw material 17 is stirred by the meandering motion and heated by the heating elements 16, 16, . . . , and calcining synthesis proceeds. The synthesis degree of the calcination synthesis of the ceramic raw material 17 in the calcination zone 21b is controlled by controlling the temperature of the heating elements 16, 16, . This can be done by

The ceramic raw material 17 that has been subjected to calcination synthesis in the calcination zone 21b is guided from the calcination zone 21b to the cooling zone 21c, and after being cooled in the cooling zone 21c, it is transferred to the furnace body 1 by the quantitative discharge device 18.
2 is discharged to the outside.

In the above embodiment, the ceramic raw material 17 was granulated in advance in order to flow down the slits 14, 14, . . . in a meandering manner. If you do this,
The ceramic raw material 17 is passed through the slits 14, 14,...
The ceramic raw material 17 flowing down inside the slits 14, 14, etc. is heated almost uniformly, and the ceramic raw material 17 of good quality is temporarily heated. You can get pottery.

The present invention is not limited to a calcination furnace for ceramic raw materials, but can also be applied to a main calcination furnace for ceramic molded bodies that have been formed.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the firing furnace according to the present invention, FIG. 2 is a partially enlarged sectional view showing the internal structure of the firing furnace of FIG. 1, and FIG. 3a is an explanatory diagram of a conventional firing furnace. , FIG. 3b is a temperature distribution diagram of the firing furnace of FIG. 3a,
FIG. 4 is a perspective view of a firing box used in the firing furnace of FIG. 3a. 11... Hopper part, 12... Furnace body, 13... Partition wall, 14... Slit, 15... Cavity, 16...
Heating element, 17...Ceramics raw material, 18...Quantitative discharge device, F...Fixed vane.

Claims (1)

[Claims] 1 The upper part of the furnace body is equipped with a hopper part that serves as a preheating zone in which the charged object to be fired is preheated, and the hopper part is arranged at a predetermined interval in the furnace body at the lower part of this hopper part, and the hopper part A plurality of partition walls are formed at the bottom to define slits that open to the bottom of the furnace body, and fixed blades protrude obliquely downward from the wall surface. There is a firing zone in which a heating element is placed in the formed space, and a cooling zone in the lower part of the partition wall, which is made up of a partition wall with an insulating structure that does not have any internal space. 1. A firing furnace comprising: a quantitative discharge means disposed in the opening, through which the fired material is discharged in a fixed amount while flowing down the slit in a meandering manner by the fixed blades.