JPH0712880Y2 - Struts for baking furnace shelves - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention is a column for a shelf assembly of a baking furnace in which a plurality of pieces are erected at intervals in a baking furnace to support a shelf plate in a horizontal state. Regarding

(Prior Art) For example, when firing ceramic products such as tiles and roof tiles in a tunnel kiln, a shelf assembly is provided on a trolley,
By this shelf assembly, the article to be fired is supported in a state where a space through which the flame passes is secured between the article to be fired and the carriage. In this case, as shown in FIG. 3, a plurality of cylindrical refractory struts 21 are erected at intervals on the carriage, and the refractory shelves are hung between the struts 21. Board 22
Is supported horizontally, and the product to be fired is placed on this shelf board.

(Problems to be solved by the invention) By the way, this type of refractory product for shelving has a problem that spalling occurs due to repeated heating and cooling during use, and cracks occur and eventually break. There is. In particular, in the pillar 21 as described above,
While supporting the load of the placed object from above,
There is a circumstance in which the crack 23 tends to extend obliquely with respect to the vertical direction as shown in FIG. When a crack 23 extending in an oblique direction is generated in this way, a force in a displacement direction along the crack 23 acts on both side portions divided by the crack 23. Therefore, a force in the direction indicated by arrow A acts on the upper portion of the crack 23, and the portion is broken as shown in FIG. 3 (b), and as a result, as shown in FIG. 3 (c). There was a risk of a collapse of a large shelf.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a column for a shelf assembly of a firing furnace that can prevent a collapse accident as much as possible.

[Structure of the Invention] (Means for Solving the Problem) The shelf-supporting column of the firing furnace of the present invention is formed of a refractory material into a hollow cylindrical shape, and a plurality of shelves are erected at intervals in the firing furnace. The plate is supported in a horizontal state, and is characterized in that a bottomed groove extending vertically is formed on a peripheral surface of a hollow cylinder.

(Operation) The thermal expansion and thermal contraction associated with the heating and cooling of the stanchions mainly act as tensile and compression forces in the circumferential direction on the surface of the stanchions.

According to the above means, it is possible to absorb the pulling force and the compressing force in the circumferential direction at the time of thermal expansion and contraction by expanding and contracting the bottomed groove in the width direction. Therefore, the occurrence of cracks due to spalling can be suppressed as much as possible.

Even if cracks are unavoidable, cracks first occur in the bottomed groove portion, which has the weakest strength, and are unlikely to occur in other portions. In this case, the columns support the vertical load from above, while cracks are generated by extending vertically as they are guided by the bottomed grooves. A vertical force acts on both of them, and a force in a displacement direction along the crack does not act on them, and as a result, the column is less likely to be damaged.

Therefore, it is possible to prevent as much as possible the collapse accident of the shelf assembly due to the generation of cracks due to spalling.

Also, since the groove is a bottomed groove, the pillar can be maintained in a circumferentially connected state in the left and right portions of the bottomed groove until the use as the pillar is started. It is possible to prevent inconvenience that a step is generated in the vertical direction and the radial direction in the left and right parts of the, and, in turn, the dimensional accuracy can be kept good.

(Example) An example in which the present invention is applied to a tunnel kiln will be described below.
A description will be given with reference to the drawings.

FIG. 2 schematically shows a state of the tunnel kiln 1 which is a firing furnace when firing a ceramic product. Here, the tunnel kiln 1 is formed in a tunnel shape by a furnace bottom 2, a furnace wall 3 and a ceiling 4 made of refractory, respectively. A burner 5 is provided at a main part of the furnace wall 3. In this case, the lower burner 5 is mounted at a position slightly higher than the height of the firing carriage 6, and the upper burner 5 is mounted near the ceiling 4.

The firing carriage 6 is configured by providing wheels 8 for moving on the furnace bottom 2 below a rectangular base 7 made of refractory. On the pedestal 7, a product 9 to be fired, such as a tile or tile, is placed in a state of being supported by a shelf assembly 10 described later. As a result, a so-called fire duct 11 through which the combustion gas from the burner 5 passes is secured between the base 7 and the article to be fired 9, and in this state the firing truck 6
Is a tunnel kiln 1 that has been set to a high temperature atmosphere by a burner 5.
The product 9 is sequentially moved inside, and the article 9 to be fired is heated and fired.

The shelf assembly 10 is configured as follows. That is, on the firing carriage 6, a plurality of columns 12 according to the present embodiment are erected at intervals with their upper ends positioned at the same height. Pillar seats 13 are mounted on the upper ends of the pillars 12, respectively, and further, receiving rods 14 and shelf bars 15 as shelf boards are mounted in a substantially horizontal state so as to be hung between the adjacent pillars 12. .
The products 9 to be baked are stacked on the shelf bar 15 while being housed in the H-shaped bowl 16. Thus, the article to be fired 9 is supported by the firing carriage 6 in a state where the so-called fire duct 11 is secured by the columns 12.

The pillar 12 is made of a refractory material and is formed in a hollow cylindrical shape as shown in FIG. In this case, for example, the length dimension is 300 to 500 mm, the outer diameter dimension is 77 mm, and the wall thickness dimension is 10 mm.
Is formed into a cylindrical shape. A bottomed groove 17 is formed on the outer peripheral surface of the support column 12 so as to extend over the entire vertical direction. In this case, as the dimensions of the bottomed groove 17, it is desirable to set the width dimension to 0.5 to 5 mm and the depth dimension to 5 to 95% of the wall thickness. In the present embodiment, the width dimension is 2 mm and the depth dimension is 5 mm
Is formed in a V-shaped cross section. The column 12 is manufactured by forming a refractory material into a cylindrical shape, drying and firing it. The bottomed groove 17 is formed during molding or after firing. In this case, since the columns 12 are connected in the circumferential direction by forming the bottomed groove 17, unlike the case of forming a groove penetrating in the thickness direction, the bottomed groove 17 is formed at the time of molding. Even in this case, no deformation occurs in the subsequent drying and firing steps.

The refractory material of the pillar 12 may be, for example, an alumina material, a mullite material, a cordierite material, or a silicon carbide material, and is not limited to these. It can be arbitrarily selected according to the cooling speed and the like.

Next, the operation of the above configuration will be described.

The refractory pillars 12 are repeatedly heated and cooled as they are used, and the thermal expansion and thermal contraction are repeated accordingly. The thermal expansion and the thermal contraction are mainly caused by pulling in the circumferential direction on the surface portion of the column 12.
Acts as a compressive force. However, since the bottomed groove 17 is formed in the support column 12, the expansion and contraction of the bottomed groove 17 in the width direction must absorb the tensile force and compression force in the circumferential direction during thermal expansion and thermal contraction. You can Therefore, the occurrence of cracks in the columns 12 due to spalling can be suppressed as much as possible.

Then, even if a crack is generated, the crack is generated so as to penetrate the bottomed groove 17 having a weak strength in the thickness direction. Since the bottomed groove 17 is formed so as to extend in the up-down direction, that is, the vertical direction, cracks will also occur in the vertical direction, and will not easily occur in other portions and in other directions. In this case, the column 12 receives a vertical load from above, while the crack also extends in the vertical direction, a vertical force acts on both side portions divided by the crack, and along the crack. It is possible to prevent the force in the direction of displacement from acting, and as a result, the column 12 is less likely to be damaged.

Thus, according to the pillar 12 of the present embodiment, as compared with the conventional one, the occurrence of cracks due to spalling is suppressed as much as possible, and further, unlike the conventional one in which the cracks are generated in an oblique direction, a crack is generated. Will be guided in the most harmless vertical direction in which the columns 12 are less likely to be damaged. As a result, the collapse accident of the shelf assembly 10 due to the occurrence of cracks can be prevented as much as possible, and the service life can be extended.

The present invention is not limited to the above-described embodiment, and for example, the bottomed groove may be formed in a U-shaped cross section and can be used in various firing furnaces not limited to the tunnel kiln. Various changes can be made without departing from the scope.

[Effects of the Invention] As is clear from the above description, according to the shelf support column of the firing furnace of the present invention, since the bottomed groove extending in the vertical direction is formed on the peripheral surface, it is caused by the occurrence of cracks. It is possible to prevent the collapse of the shelves as much as possible, and it is possible to achieve a long service life.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a perspective view of a column, and FIG. 2 is a longitudinal sectional view schematically showing a state of a tunnel kiln during firing, 3 (a), (b), and (c) show a conventional example, and are diagrams sequentially showing how a rack assembly collapse accident occurs when a crack is generated in a column. In the drawing, 1 is a tunnel kiln (firing furnace), 6 is a trolley, and 9
Is a product to be fired, 10 is a shelf, 12 is a pillar, and 17 is a groove with a bottom.

Claims (1)

[Scope of utility model registration request] 1. A refractory material which is formed into a hollow cylindrical shape and a plurality of which are erected at intervals in a firing furnace to support a shelf plate in a horizontal state. A column for a shelf assembly of a firing furnace, characterized in that a bottomed groove extending to the bottom is formed.