JPH0547796U - Struts for firing ceramic products - Google Patents

Abstract

(57) [Summary] [Constitution] 5 wt% to 2% of high-purity cordierite is added to a base material made of silica-alumina-based material such as mullite.
Struts for firing ceramic products made of refractory containing 5% by weight. [Effect] The vent resistance can be maintained and the spall resistance can be improved, and as a result, it is possible to suppress the occurrence of cracks or the like of the columns standing upright on the carriage as much as possible.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a strut for firing a ceramic product, and more particularly to a strut for firing a ceramic product in which an embedded strut used in a so-called under-fired loading truck for placing an object to be fired is made of a specific material.

[0002]

[Prior Art]

 In a trolley-type tunnel furnace in which a trolley loaded with ceramic products such as tiles and roof tiles (hereinafter referred to as the object to be fired) is run along a rail laid in the tunnel furnace to fire the object to be fired continuously. In general, a so-called under-firing method is adopted in which a space is formed between the upper surface of the trolley and the material to be fired and the combustion flame from the burner is sent into the space. A truck applied to such a combustion method has a large number of hollow columns made of refractory lined upright on the upper surface of a frame framed by a steel material, and a fibrous heat insulating material is filled between the columns. Moreover, it has a structure in which a shelf bar is inserted between the columns.

[0003]

[Problems to be solved by the device]

 BACKGROUND ART Conventionally, as a material of a refractory strut, a mullite-like material has been used in order to increase the strength by placing importance on durability against a load such as an object to be fired. However, the pillar made of mullite has a problem that cracks and breaks due to spalling occur at the boundary between the portion embedded in the heat insulating material and the other portion during firing, and eventually breakage occurs.

[0004]

[Means for Solving the Problems]

Therefore, as a result of intensive studies on the above-mentioned conventional problems, the present inventor has found that the above problems can be solved by improving the material of the column, and has completed the present invention. That is, according to the present invention, a large number of hollow refractory struts are aligned and erected on the upper surface of a frame framed by a steel material, and a fibrous heat insulating material is filled between the struts, and In a trolley for placing a material to be fired, which is constituted by inserting refractory shelf bars between columns, the columns are made of a refractory containing 5 wt% to 25 wt% of high-purity cordierite in a base material. A strut for firing a ceramic product is provided. In the present invention, it is preferable to use high-purity cordierite containing 0.5% by weight or less of Fe ₂ O ₃ . In the present invention, the base material is preferably made of silica / alumina-based material, and particularly preferably made of mullite.

[0005]

[Action]

 The present invention specifies a material for a pillar for firing a ceramic product. That is, the pillars are made of a refractory material containing 5 wt% to 25 wt% of high-purity cordierite in a base material preferably made of silica-alumina-based material such as mullite. In the trolley for placing the object to be fired in which the fibrous heat insulating material is filled between the columns, since the columns are embedded, its characteristic is that it has only bend resistance against conventional loads. It also requires spall resistance.

Cordierite is very effective in improving spall resistance, but the addition of cordierite causes a decrease in strength, which inevitably results in a decrease in bend resistance. It has not been considered in the past to add cordierite to mullite, which is a material that does. However, when the present inventor repeated examinations and experiments from various points of view, mullite contained high-purity cordierite containing Fe ₂ O ₃ as an impurity in a predetermined amount or less within a range of 5 wt% to 25 wt%. By doing so, it was possible to improve spall resistance while maintaining bend resistance.

In the present invention, when the content of high-purity cordierite is less than 5% by weight, the effect of improving the spray resistance cannot be obtained, and when the content of high-purity cordierite exceeds 25% by weight, This leads to a decrease in strength and a decrease in bend resistance. The high-purity cordierite used in the present invention preferably contains Fe ₂ O ₃ as an impurity in an amount of less than 0.5% by weight. When the content of Fe ₂ O ₃ is 0.5% by weight or more, the strength is lowered and the bend resistance may be insufficient.

Next, the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view showing a part of a trolley for placing an object to be burned. Although not shown, the frame is assembled by framing a steel material, and the upper surface of the frame is made of many refractory materials. The hollow columns 10 are aligned and erected. A fibrous heat insulating material 15 is filled between the columns 10, and each column 10 is embedded in the heat insulating material 15. Although not shown, wheels are attached to the lower surface of the frame to form a carriage. On the other hand, a support seat 11 is placed on the upper end of each of the columns 10, a refractory support rod 12 is provided on the upper surface of each support seat 11, and a refractory shelf bar 13 is provided on the top surface thereof. . Then, the sagger 14 containing the article 16 to be fired such as a tile is placed on the shelf bar 13.

[0009]

【Example】

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. (Examples 1 to 7 and Comparative Examples 1 and ₂ ) As shown in Table 1, Fe ₂ was added to a base material containing mullite (3Al ₂ O ₃ .2SiO ₂ ) as a main component and alumina and clay mixed. Hollow struts were made using raw materials containing various kinds of cordierite with different O ₃ contents in various proportions. Also, of the 42 columns that stand upright on one truck, the four columns that are provided at the four corners that are the most strict in terms of conditions were used as test columns. The firing was performed in an oxidizing atmosphere at a firing temperature of 1250 ° C. The firing schedule was a temperature rising rate of 80 ° C./hr, a keeping time of 1 hour, and a cooling rate of 110 ° C./hr.

Under the above conditions, the truck was sent to the tunnel furnace and fired by the under-firing method, and the cracks of the test column and the state of crack generation were investigated. The survey was conducted every 5 times when the number of kilns was 1 to 50, and every 10 times when the number of kilns was 51 to 200, and up to 200 times. The results are shown in Table 1.

[0011]

[Table 1]

(Examples 8 to 11 and Comparative Examples 3 to 6) As shown in Table 1, when the base material was changed and high-purity cordierite was included or not, cracks and cracks of the test column were not formed. The situation was investigated. Other firing conditions, the kiln method, etc. were the same as those in Examples 1-5. The results are shown in Table 2.

[0013]

[Table 2]

As is clear from the above Examples and Comparative Examples, it can be seen that when the material of the present invention is different, cracks occur in the support columns.

[0015]

[Effect of the device]

 As described above, according to the ceramic product firing post of the present invention, since the material thereof is specified, it is possible to maintain the bend resistance and improve the spall resistance, and as a result, to stand on the bogie. It is possible to suppress the occurrence of cracks in the supported columns as much as possible.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a part of a truck for placing an object to be fired.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Supports 11 Supporting seats 12 Receiving rods 13 Shelf rods 14 Sash bowls 15 Fibrous heat insulating materials 16 Fired materials

Claims (4)

[Scope of utility model registration request] 1. A large number of refractory hollow support columns are aligned and erected on the upper surface of a frame framed with steel material, and a fibrous heat insulating material is filled between the support columns, and between the support columns. In a trolley for placing an object to be fired, which is constructed by inserting shelf rods made of refractory, the columns are made of refractory containing 5 wt% to 25 wt% of high-purity cordierite in a base material. Struts for firing ceramic products. 2. The strut for firing a ceramic product according to claim 1, wherein the high-purity cordierite contains 0.5% by weight or less of Fe ₂ O ₃ . 3. The strut for firing a ceramic product according to claim 1, wherein the base material is made of a silica / alumina-based material. 4. The base material is made of mullite.
A pillar for firing a ceramic product according to any one of 3 to 3.