JPH04300239A - Method for sintering ceramic product - Google Patents

Abstract

PURPOSE:To sinter large-seized ceramic product and a large amount of ceramic product at once and in uniformly stabilized quality. CONSTITUTION:A required space part is formed between a truck and lattice-like sintering table 6 framed on upper face of the truck and whole outer peripheral wall of ceramic product group 2 set on the sintering table is encircled with fire shield 7 and the ceramic product group 2 is subjected to high temperature oxidation sintering under uniform temperature distribution by a heating flame kept so as to communicate to the upper face of the truck from above in each fire shield.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for firing ceramic products that can uniformly fire a large amount of ceramic products at once.

0002

[Prior Art] For example, ceramic products such as beta alumina tubes used as solid electrolyte tubes in sodium-sulfur batteries are fired in an oxidizing atmosphere at a temperature of 1,500 to 17
The sintering process is performed at a high temperature of 00°C.

However, when performing high-temperature oxidation firing as described above, it is difficult to obtain a uniform temperature distribution within the firing furnace, so it is difficult to obtain a uniform temperature distribution within the firing furnace. was forced to use it. As a result, there are problems in that it is not possible to sinter large-sized ceramic products with a long overall length, and in that it is not possible to uniformly sinter a large number of ceramic products at once.

0004

[Problems to be Solved by the Invention] The present invention solves the above-mentioned conventional problems, achieves uniform temperature distribution in the furnace, and uniformly processes large ceramic products or large quantities of ceramic products at once. This was completed with the aim of providing a method for firing ceramic products that can be sintered in a timely manner and has excellent workability.

[0005]

[Means for Solving the Problems] The method for firing ceramic products of the present invention, which has been made to solve the above problems, is as follows:
A necessary space is formed between the trolley and a lattice-shaped firing table framed on its upper surface, and the entire outer peripheral wall except the upper surface of the ceramic products set on the firing table is surrounded with a fire shield, and the inside of the kiln is The heating frame is configured to flow through the fire shield from above to the upper surface of the trolley to perform high-temperature oxidation firing of the group of ceramic products set on the firing stand.

The present invention will be explained in detail below with reference to the drawings. FIG. 1 shows an example of high-temperature oxidation firing of a large number of ceramic products 2 using a gas kiln 1, which has a capacity of 1 m<3>. Furthermore, the present invention can be applied to a single gas kiln or a continuous gas kiln for high-temperature oxidation firing with a larger capacity, and it is also possible to fire large ceramic products or a large number of ceramic products.

[0007] A large number of the ceramic products 2 are arranged on a firing table 6 supported by a support material 5 such as an alumina brick so as to have a space 4a between the ceramic products 2 and the cart 3, and as shown in FIG. Each ceramic product 2
The heating frame is arranged so that the porosity with respect to the baking table 6 is 50% or more so that the heating frame can flow through the gap. Further, it is preferable to arrange the ceramic product 2 so that the gap in the center of the firing table 6 is larger than that in other parts, since a more uniform temperature distribution can be obtained. As shown in FIG. 3, the firing table 6 is a combination of a plurality of beams 6a made of recrystallized SiC, for example, in a lattice shape, and a heating frame is arranged between it and the space 4a. It is secured.

The entire outer peripheral wall of the ceramic products arranged on the firing table 6 as described above is made of recrystallized Si except for the upper surface so as to be open toward the upper space 4b.
The heating flame from the burner 8 is surrounded by the fire shield 7 made of C, and the heating flame from the burner 8 is surrounded by the fire shield 7 while ensuring a flow path for the heating flame between the space 4a and the space 4b. This effectively prevents intensive contact only with the outermost peripheral wall portion.

As shown in FIG. 2, about 10 ceramic products 2 are arranged on a firing plate 9 and then placed on the firing table 6. This is preferable since the handling of the ceramic product 2 can be improved. Further, as shown in FIG. 4, it is also possible to stack the ceramic products 2 in two stages and fire them, or to stack them in a larger number of stages and fire them. Furthermore, it goes without saying that the ceramic products 2 arranged in this manner can be fired not only in a single kiln but also in a continuous kiln.

Ceramic product 2 arranged in this way
Since the entire outer peripheral wall is surrounded by the fire shield 7, it is possible to prevent the heating frame of the burner 8 from heating only the outermost peripheral wall part of the ceramic product group, and
The heating frame flows vertically between the space 4b in the upper surface and the space 4a in the lower part of the firing table 6, so that the entire interior of the gas oven 1 has a uniform temperature distribution. As a result,
Due to the heating gas flame flowing in the vertical direction, all the ceramic products 2 are fired efficiently and with stable quality under almost the same temperature conditions despite the large number of ceramic products 2. Similarly, the finished product will be fired to a stable quality.

[0011]

[Example 1] Using an LPG gas furnace with a capacity of 1 m3, as shown in Fig. 1, a beam 6a made of recrystallized SiC is placed on a cart 3 measuring 1670 x 1430 mm with a gap of 350 mm in height. A firing table 6 was prepared, and 100 cylindrical ceramic products 2 with an outer diameter of 68 mm, an inner diameter of 60 mm, and a total length of 510 mm were set on the firing table 6 as shown in FIG. 2 (porosity: 55%), and the outer periphery was The entire wall was surrounded by a fire shield made of recrystallized SiC measuring 280 x 280 x 6 mm at a height of 500 mm. As a result of oxidizing and firing this according to the heat curve shown in Fig. 5, the temperature distribution inside the furnace at 1650°C was found to be extremely uniform within the range of 1643 to 1653°C as measured by nine pairs of thermocouples 10. It was confirmed that the obtained ceramic products were of excellent quality and stable.

0012

[Example 2] Using the same gas kiln as in Example 1, as shown in FIG.
A firing table 6 of 1180 x 880 mm was prepared using a beam 6a made of recrystallized SiC with a gap of 00 mm.
On the baking table 6, there is a plate having an outer diameter of 43 mm, an inner diameter of 36 mm, and a total length of 34 mm.
5mm cylindrical ceramic product 2 is placed in the upper row 224
A total of 422 books, 198 books in the lower row (porosity 5
9%) and the entire outer peripheral wall is 280 x 280 x 6
It was surrounded by a fire shield made of recrystallized SiC with a height of 370 mm. As a result of oxidizing and firing this according to the heat curve shown in Fig. 5, the temperature distribution inside the furnace at 1650°C was determined from the temperature measurements of 25 pairs of thermocouples (12 pairs on the upper stage, 13 pairs on the lower stage). 1642-1652℃
It was confirmed that the ceramic product was in an extremely uniform state within the range of 100%, and the obtained ceramic product was also of excellent quality and stable.

[0013]

[Effects of the Invention] As is clear from the above explanation, the present invention achieves uniform temperature distribution in the furnace and oxidizes large ceramic products and large quantities of ceramic products at high temperature with uniform and stable quality. It can be fired and has excellent workability, and furthermore, it has the advantage of being extremely economical without requiring any improvements to the kiln used. Therefore, the present invention greatly contributes to the development of industry as a method for firing ceramic products that eliminates the conventional problems.

[0014]

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an example of the firing process of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a plan view showing a firing table.

FIG. 4 is a partially cutaway front view showing a firing process using multi-stage stacking according to the present invention.

FIG. 5 is a heat curve in an example of the present invention.

[Explanation of symbols]

1 Gas kiln 2 Ceramics products 4a Space part 4b Space part 6. Baking stand 7 Fire Shield

Claims (1)

[Claims] Claim 1: A necessary space is formed between the trolley and a lattice-shaped firing table framed on its upper surface, and the entire outer peripheral wall except the upper surface of the ceramic products set on the firing table is covered with a fire shield. A method for firing ceramic products, characterized in that a group of ceramic products set on a firing stand are subjected to high-temperature oxidation firing, with the heating frame inside the kiln flowing through the fire shield from above to the top surface of the trolley.