JPH0359356B2 - - 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 fired in a tunnel furnace having the above-mentioned configuration, the ceramic molded body 2 to be fired is packed vertically or horizontally in 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 firing boxes 3 similar to those shown in FIG. 4, and the firing boxes 3 are loaded on a base plate 4.
Firing is performed by so-called batch processing.

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. 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, 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 at the upper part to define a slit which opens into the hopper part and which opens into the bottom of the furnace body at the lower part. The firing zone consists of a heating element arranged in a space formed by a heating element, and the cooling zone consists of a partition wall of an insulating structure with no internal space at the lower part of the partition wall. The present invention is characterized in that it is provided with a metering discharge means which is disposed in the slit and discharges a metered amount of the fired material during the process of flowing down the slit.

(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 through the narrow slits formed between the walls, it receives heat from the heating element inside the partition walls and is fired, so there is no need for a firing box with a large heat capacity like in conventional tunnel furnaces, resulting in improved thermal efficiency. It is possible to achieve high energy savings, and the shape of the firing furnace can also be made smaller. Furthermore, according to the present invention, since the individual objects to be fired are fired in the process of flowing continuously down the furnace,
The firing conditions for each object to be fired are almost constant, and fired objects with less variation in quality can be obtained.

(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.

Partition walls 13, 13, ... and these partition walls 13, 1
3, ... Cavities 15 are formed inside the side walls 12a of the opposing furnace bodies 12, respectively, and the partition walls 13, 1
3,... and in each cavity 15 of the side wall 12a, 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. . The heating element 16,1
6. For example, a silicon carbide (SiC)-based rod-shaped heating element can be used, but a panel-shaped heating element or other heating element can also be used depending on the use and purpose of the kiln. .

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, . A slope 13a similar to the above is also formed on the side wall 12a of the furnace body 12. Furnace body 1 of the slits 14, 14,...
Quantitative discharge devices 18, 18, . . . such as rotary valves are disposed in the bottom opening of 2.

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, ...
The portion facing 5, 15, ... is the firing zone 21b.
Configure. 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, .
As it is discharged from the bottom of the furnace body 2 in a fixed amount by 8, it flows down through the slits 14, 14, . . . . In this process, the ceramic raw material 17 is 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, . It can be carried out.

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 is granulated in advance in order to flow down through the slits 14, 14, . . . by its own weight, and the width d of the slits 14, 14, . By setting it narrowly, the slit 14,1
The entire ceramic raw material 17 falling through the chambers 4, . . . was heated almost uniformly, and a calcined ceramic raw material 17 of good quality could be obtained.

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.

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 opening to the bottom of the furnace body, and a heating element is arranged in the space formed inside the partition walls at the upper part of the partition walls. A cooling zone is provided at the lower part of the partition wall, which is composed of a partition wall with an insulating structure that does not have any space inside. A firing furnace characterized in that it is equipped with a quantitative discharge means for discharging a fired object in a quantitative manner.