JPS6143198Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a roller hearth kiln used for firing small and lightweight ceramic products such as tiles.

(Conventional technology) Conventional roller hearth kilns for firing small and lightweight ceramic products such as tiles, for example,
Inside the furnace body, which is maintained at 1200 degrees, there are many rollers with a diameter of about 20 to 25 φ for transferring the fired products.
The surface speed is 20 by the chain driving each roller.
Firing was carried out by rotating the product at a speed of about mm/second and transporting the product from the entrance to the exit of the furnace body by friction between the roller surface and the product.
(For example, Publication of Utility Model Publication No. 57-44315) (Problems to be solved by the invention) However, in the conventional roller hearth kiln using such small diameter rollers, the weight of the roller and the product to be fired are reduced at high temperatures. Since the load acts on the roller 30, the center part of the roller 30 bends downward as shown in FIG. The following phenomenon occurs, making it difficult to automatically carry out the fired product 20 at the furnace outlet, and when directly firing tiles, etc., the intervals between the tiles, etc. in the firing zone become uneven, and the flow of firing gas becomes difficult. There were various problems such as irregularities, warping of the tiles, pecking, and other quality variations.
Such a phenomenon is considered to be unavoidable in roller hearth kilns using small diameter rollers, and an effective solution to this essential drawback of roller hearth kilns has been strongly sought after.

(Means for solving the problem) The present invention was completed in order to solve the problems of the conventional method. and a tapered roller having a central shaft diameter larger than the shaft diameters at both ends.

(Embodiment) Next, the present invention will be explained in detail with reference to an embodiment shown in FIGS. There are rollers for transporting the fired products that are arranged in parallel inside the container 1. Most of the rollers 2 are regular rollers 2a with a uniform shaft diameter.
, but some of it has a central shaft diameter.
The tapered roller 2b has d ₁ larger than the shaft diameter d ₀ of both ends, and the intermediate portion thereof is a tapered portion. Generally, it is preferable that the shaft diameter d ₀ at both ends of the tapered roller 2b is equal to the shaft diameter of the normal roller 2a, but conversely, the shaft diameter d ₁ at the center is equal to the shaft diameter of the normal roller 2a. You may. The shaft diameter d ₁ at the center varies depending on the type of product 20 to be fired, the conveyance speed, etc., but is generally 1.1 of the shaft diameter d ₀ at both ends.
It is preferable to set it to about 1.3 times, and when the deflection amount ε at the center of the normal roller 2a, d ₁ =
It is preferable to set it to d ₀ +2ε. Note that the lengths of the central portion and the tapered portion may be appropriately determined depending on the size of the product 20 to be fired. Such taper rollers 2b are arranged in series between the ordinary rollers 2a, or are arranged in a uniformly distributed manner. Since the transport distance correction value is given by the following equation, the required number of rollers n can be easily determined by back calculation.

Transfer distance correction value = d ₁ - d ₀ /d ₁ × p × n (p is the roller pitch, n is the number of tapered rollers) Note that 5 is a drive chain for rotating each roller 2 at the same rotation speed. .

(Function) In the device configured as described above, a to-be-fired product 20 such as a tile is placed on the upper surface of rollers 2 for transporting to-be-fired products arranged in parallel inside the furnace body 1, and each roller 2 is Firing is carried out while transporting the article 20 to be fired by rotating it at the same number of rotations by the drive chain 5, but the delay in the article 20 at the center, which is unavoidably caused by the deflection of the roller 2, is This problem is solved by providing a feed rate higher than that of the fired product 20 passing through the center by the tapered roller 2b in which the shaft diameter d ₁ at the center is larger than the shaft diameter d ₀ at both ends. There is almost no disturbance of the rows as shown. for example,
150 x 150 x 10 ^t tiles are produced using a roller hearth kiln with a total length of approximately 10 m and a 25φ roller.
When firing while transferring at a speed of 0.9 m/min, conventionally the product to be fired in the center was delayed by about 250 mm from both ends, but the tapered roller 2b with d ₁ = 30 mm and d ₀ = 25 mm
When placed in a normal roller 2a, the delay of the product to be fired 20 in the center was 30 mm or less, facilitating automatic unloading and preventing quality variations such as warping and pecking of the tiles.

(Effects of the invention) As is clear from the above explanation, the present invention can prevent delays in the progress of the fired products in the center caused by the deflection of the rollers, and can automatically carry out the fired products at the furnace exit. It has succeeded in making the process easier and preventing variations in the quality of the fired products, so it has great practical value as it eliminates the problems of conventional roller hearth kilns.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a plan view of its main parts, Fig. 3 is a cross-sectional view showing a conventional roller hearth kiln, and Fig. 4 is a plan view of its main parts. be. 1: Furnace body, 2: Roller, 2a: Normal roller, 2b: Tapered roller, d ₀ : Shaft diameter at both ends,
d ₁ : Axis diameter at the center.

Claims (1)

[Claims for Utility Model Registration] 1. The rollers 2 for transferring the fired products installed in parallel inside the furnace body 1 are different from the normal roller 2a and the central shaft diameter.
A roller hearth kiln comprising a tapered roller 2b having a diameter d ₁ larger than a shaft diameter d ₀ at both ends. 2. The roller hearth kiln according to claim 1, in which the shaft diameter d ₀ of both ends of the tapered roller 2b is equal to the shaft diameter of the ordinary roller 2a. 3. The roller hearth kiln according to claim 1, wherein the shaft diameter d ₁ of the central portion of the tapered roller 2b is equal to the shaft diameter of the ordinary roller 2a.