JPH0381074B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is applicable to ceramics, roof tiles, ceramics for electronic parts,
This relates to a plate-shaped kiln packing tool that is used to place products in a firing furnace or the like for firing sintered electromagnetic parts such as ferrite or annealing metal products. (Prior art) Recently, in industries that use thermal energy, such as firing ceramics and various ceramic objects, and annealing metal products, attempts have been made to shorten the firing time as an energy-saving measure, but in this case, the kiln Refractories used as tools are exposed to harsh conditions of rapid heating and cooling. Various proposals have been made for this situation,
Although the material has been improved, there are still material constraints such as having sufficient strength and corrosion resistance at high temperatures, and it is still insufficient to withstand the harsh conditions of rapid heating and cooling. . For this reason, it has been proposed to improve the shape of the refractory shelf material by forming a plurality of cuts in it to improve spalling resistance against rapid heating and cooling. (Jitsukai 49-46044
(No. Publication) In this invention, it was considered that it was practically impossible to manufacture the cut if the width of the cut was less than 0.5 mm, so cutters with a width exceeding 0.5 mm have been used. However, this type of refractory shelf material has drawbacks such as top grain, etc., which is used to prevent reactions between fired products and the shelf material, from falling down from the notches and adhering to products loaded on the lower shelf. There is a proposal to fill these incisions with fire-resistant filler to prevent the top sand from falling. (Utility Model Application Publication No. 51-127948) This idea is an excellent idea, and almost eliminates the drawbacks of the conventional ones. However, after using the shelf material dozens of times, Thermal expansion and thermal contraction and permanent shrinkage due to sintering gradually progress, but due to the difference in shrinkage rate, there is a tendency to create a gap between the shelving material and the filling material, and from this gap, the shelving material as well as the filler material There are disadvantages that damaged particles of the filler and filler fall, and that the coating layer in that area tends to peel off. Furthermore, when a product placed on the notch is fired, unevenness may occur on the lower surface of the placed product, that is, on the surface where the product and the shelf material come into contact, resulting in product defects. (Problems to be Solved by the Invention) The kiln packing tool of the present invention solves the difficult problems as described above, and the
It maintains spalling resistance like the fire-resistant shelving material described in Publication No. 51-127948, and also prevents sand, filler, etc. from falling under the shelving material, and prevents it from falling over the gaps between the shelving materials. The objective is to obtain a kiln packing tool that is a shelf material made of refractory material that does not cause unevenness even when products are placed thereon. (Structure of the Invention) (Means for Solving the Problems) The kiln filling tool of the present invention fills the gap between the plates, which is 0.5 mm or less and enters from the flat surface of the plate made of refractory material. A fire-resistant coating layer with a thickness of 0.1 to 1.0 mm must be provided on the surface of the board, extending inward from the edge or in the diagonal direction of the corner for a length of 20 to 70% of the width. The gap is created by inserting a thin organic combustible material such as a thin plastic film or thin paper during molding, or by inserting and firing an easily melted metal foil that melts and washes away during product firing, or by processing the fired product. It is something. The gap entering from the flat surface of the shelf material may enter from one flat surface and lead to the other flat surface, or may remain in the shelf material. Also, things that are straight when viewed from the flat surface,
Any curved one is acceptable. It is desirable that the tip of the gap extending inward from the edge is rounded. When a gap enters from both flat plate surfaces, it is possible that the two sides do not communicate and the gap appears to be misplaced when viewed from the edge surface of the shelf material, and the gap stops in the middle. They may be located at the same front and back positions, and both may be stopped midway.
The direction in which the gap progresses inward from the edge is preferably substantially perpendicular to the edge, but it may also proceed at an oblique angle. It is desirable that the total depth of the gaps from the flat plate surface is at least half the thickness of the shelf material. The material of the refractory coating layer may be the same or different from that of the shelf material, but alumina, mullite, zircon, zirconia, etc. are preferable. This coating layer may be applied to one side of the flat plate, but it is preferable to apply it to both sides.As shown in Figs. The layers may be embedded in the interstices or may be cross-linked. If the length of this gap is less than 20% of the width, the spalling resistance will not be much different from that without the gap, and the effect of providing the gap will not be significant. Moreover, if it exceeds 70%, cracks tend to propagate from the gaps and the life of the shelf material will be shortened. If the width of the gap exceeds 0.5 mm, it will be difficult to make the top surface flat when a fire-resistant coating layer is applied, and when the product is placed and fired, the bottom surface of the product will be uneven. The refractory coating layer must be thick. However, if the thickness of the fire-resistant coating layer exceeds 1.0 mm, it will easily peel off due to the difference in thermal expansion coefficient during repeated use.
If it is less than that, depending on the location of the shelf material, the material of the shelf material and the product may react and fuse, making it impossible to function as a coating layer, which is not preferable. Most preferably, the thickness of the refractory coating layer is between 0.2 mm and 0.6 mm. (Function) The kiln filling tool of the present invention has a space provided therein.
A gap of 0.5 mm or less that extends from the flat surface of the shelf material is provided inward from the edge of the shelf material or in the diagonal direction of the corner at a length of 20 to 70% of the width. A fire-resistant coating layer with a thickness of 0.1 to 1.0 mm is provided on the surface of the material, preventing foreign objects from falling through the gaps and preventing unevenness from forming on the product even if the product is placed over the gaps. There is no need to fill this gap with a fire-resistant filler, the fire-resistant coating layer does not peel off, and the gap maintains sufficient spalling resistance. (Example) Example Hereinafter, the manufacturing method of each sample of the kiln filling tool which is the refractory shelf material of the present invention and the test method thereof will be explained. Sample 1: One polyethylene sheet with a thickness of 0.2 mm was set inside a rectangle at almost right angles from each side of a formwork with dimensions of 400 mm in length and 350 mm in width, and silicon carbide was the main component. The clay was homogeneously filled and formed into a plate measuring 400 mm x 350 mm x 10 mm as shown in Figure 1, dried and fired to produce a refractory shelf material. The width of the gap that entered from the flat plate surface of this refractory shelf material was 0.2 mm, and it progressed from each edge to a length of 22% of the width, and as shown in Figure 2, both flat plate surfaces There is a single gap that passes through the gap. The tip of the gap that progressed inward on the flat plate surface became a hole with a diameter of approximately 0.5 mm. This refractory shelf material had an alumina coating layer approximately 0.5 mm thick on both flat plate surfaces. Sample 2: One polyethylene sheet with a thickness of 0.1 mm and a width of 7 mm was set inside a rectangle at a nearly right angle from the 400 mm side of a formwork with dimensions of 400 mm in length and 350 mm in width, and silicon carbide was mainly applied to this. Fill the clay ingredients homogeneously and make 400mm x 350mm as shown in Figure 3.
A refractory shelf material was produced by forming a board with dimensions of 10 mm, drying, and firing. The width of the gap entered from the flat plate surface of this refractory shelf material is 0.1 mm, and it extends from the two edges to a length of 22% of the width, and as shown in Figure 4, one of the gaps has a width of 0.1 mm. It penetrates from the flat plate surface to a depth of about 2/3 of the plate thickness, and stops there. This refractory shelf material had an alumina coating layer approximately 0.5 mm thick on both flat plate surfaces. Sample 3: A strip of antimony-tin-lead low melting point alloy with a thickness of 0.4 mm and a width of 0.4 mm is placed under the formwork inside the rectangle at almost right angles from each side of the formwork with dimensions of 400 mm in length and 350 mm in width. One of each was set on the mold, and it was uniformly filled with clay containing silicon carbide as the main component, and the above-mentioned angular strips were formed on the upper surface of the molded body slightly shifted near the position where the lower mold was set. and press-fit with the upper mold while
As shown in the figure, a plate with dimensions of 400 mm x 350 mm x 10 mm is molded, and after drying, this molded body is pretreated at a low temperature to prevent the reaction between the metal and silicon carbide at high temperatures during firing, and the metal After washing away the waste, it was fired to produce a refractory shelf material. The width of the gap that entered from both flat plate surfaces of this refractory shelf material was 0.4 mm, and it progressed from each edge to a length of 22% of the width, and as shown in Figure 6, both flat plate 2/3 between faces
It penetrates to a depth of 2, stops halfway, and when viewed from the cross section, it has a mismatched shape. This refractory shelf material had an alumina coating layer approximately 0.5 mm thick on both flat plate surfaces. Sample 4: A 0.3 mm thick high-strength, high-wear resistant thin cemented carbide sheet was placed in a formwork with dimensions of 400 mm in length and 350 mm in width.
Set one on each side of the rectangle at almost right angles from the two sides of 400 mm, fill it homogeneously with clay whose main component is silicon carbide, and make a 400 mm x A refractory shelf material was produced by forming a board with dimensions of 350 mm x 10 mm, drying and firing. The width of the gap entered from the flat plate surface of this refractory shelf material is 0.3 mm.
It extends from the two edges to a length of 22% of the width, and forms a single gap penetrating between both flat plate surfaces, similar to the one shown in Figure 2. The tip of the gap that progressed inward on the flat plate surface has a diameter of approximately
It has a 0.5mm hole. This refractory shelf material had an alumina coating layer approximately 0.5 mm thick on both flat plate surfaces. Sample 5: One 0.4 mm thick high-strength, highly wear-resistant cemented carbide thin plate was set inside a rectangle at almost right angles from each side of a formwork with dimensions of 400 mm in length and 350 mm in width. This was homogeneously filled with clay whose main component was silicon carbide, and the size was 400mm x 350mm as shown in Figure 5.
A refractory shelf material was produced by forming a board with dimensions of 10 mm, drying, and firing. The width of the gap entered from the flat plate surface of this refractory shelf material is 0.4 mm, and it extends from each edge to a length of 22% of the width, and as shown in Figure 6, the gap between both flat plate surfaces is 0.4 mm. It is stopped on the way. This refractory shelf material has a thickness of approximately 0.45 mm on both flat surfaces.
An alumina coating layer of mm was applied. Sample 6: One 0.35 mm thick high-strength, highly wear-resistant cemented carbide thin plate was set inside a rectangle at almost right angles from each side of a formwork with dimensions of 400 mm in length and 350 mm in width. This was homogeneously filled with clay whose main component was silicon carbide, and the size was 400 mm x 350 mm as shown in Figure 7.
A refractory shelf material was produced by forming a board with dimensions of 10 mm, drying, and firing. The width of the gap that entered from the flat plate surface of this refractory shelf material was 0.35 mm, and it progressed from each edge to a length of 22% of the width, and as shown in Figure 6, the gap between both flat plate surfaces They stop in the middle and intersect with each other, creating a total of eight gaps, each with a depth of 1/2 and 3/8 of the thickness of the plate. This refractory shelf material had an alumina coating layer approximately 0.2 mm thick on both flat plate surfaces. Sample 7: Using a rectangular formwork with a length of 650 mm and a width of 350 mm, a flat plate-shaped fireproof shelf with dimensions of 650 mm x 350 mm x 14 mm was manufactured. The distance between both flat plate surfaces is 0.5mm.
Then, two pieces each from the long side and one piece each from the short side are cut inward at almost right angles to a length of about 22% of the width using a laser beam. An alumina coating layer with a thickness of 0.2 mm was provided. Comparison sample: A 2.4 mm wide cut penetrates between both flat plate surfaces in a fireproof shelf material measuring 400 mm x 350 mm x 10 mm, progressing inward from each edge to a length of 22% of the width. The notch is filled with a refractory filler. Both flat plate surfaces have a thickness on one side.
0.45 mm, and an alumina coating layer with a thickness of 0.2 mm on the other side. Usage test In an actual tunnel kiln for firing tiles, three samples were used for each sample, and each time a new 350 mm x 350 mm square tile was formed and dried on a fireproof shelf placed on a trolley. Each piece of fire-resistant shelving material is passed through a tunnel kiln a total of 90 times to determine the degree of spalling of the fire-resistant shelving material, the presence or absence of foreign matter that has fallen onto the tiles stacked on the lower level of the shelving material used, and the shelf material. When examining the product deformation to see if the tiles piled up on the material would have unevenness where they hit the notches or gaps in the shelving material, it was found that the fire-resistant shelving material passed through the tunnel kiln 90 times and spalled. Although none of the samples of the present invention or comparative samples were tested, the results of falling foreign matter and product deformation were as shown in the table. (Effect of the invention) The kiln filling tool of the present invention has a spacing provided therein.
A gap of 0.5 mm or less and entering from the flat plate surface of the shelf material is provided inward from the edge of the shelf material or in the diagonal direction of the corner at a length of 20 to 70% of the width thereof, Since a fire-resistant coating layer with a thickness of 0.1 to 1.0 mm is provided on the surface of the shelf material, this narrow gap maintains sufficient spalling resistance.

【table】

[Table] In addition to having the advantage of satisfying the basic performance as a material, it eliminates the drawbacks of the conventional material, prevents foreign objects from falling through the gap, and allows the product to be placed over the gap. The present invention has the practical advantages of not causing unevenness on the product and eliminating the need to fill the gaps with a refractory filler, and the present invention greatly contributes to the development of industry. It's a big thing.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a refractory shelf material according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of the refractory shelf material shown in FIG. FIG. 4 is a schematic cross-sectional view of the refractory shelf material shown in FIG. 3; FIG. 5 is a perspective view showing a refractory shelf material according to an embodiment of the present invention; FIG. 6 is a schematic cross-sectional view of the refractory shelf material shown in FIG. 5, and FIG. 7 is a perspective view showing another embodiment of the refractory shelf material of the present invention. 8 is a schematic cross-sectional view of the refractory shelf material shown in FIG. 7, and FIG. 9 is a perspective view showing another embodiment of the refractory shelf material of the present invention.
FIGS. 10, 11, and 12 are explanatory diagrams showing the relationship between coating layers and gaps. 1: Refractory plate material, 2: Gap, 3: Edge,
4: Coating layer.

Claims (1)

[Claims] 1. A gap with a spacing of 0.5 mm or less and entering from the flat plate surface of a refractory plate material, from 20 to 70% of the width inward from the edge of the plate material or in the diagonal direction of a corner. A kiln packing tool characterized by having a fireproof coating layer with a thickness of 0.1 to 1.0 mm on the surface of the plate material.