TWI390044B - Dust prevention device in roller hearth type heat treatment furnace - Google Patents

Description

Dust-proof device in roller hearth type heat treatment furnace

The present invention relates to, for example, a dustproof device for preventing dust from intruding into a Roller Hearth type heat treatment furnace for heat-treating a glass substrate used in a manufacturing step of a plasma display panel or the like. A processed product of the intermediate processed product.

In the dustproof device, the hearth roller for handling the product is passed through the side wall of the furnace body so that the end portion protrudes from the side, and the two sealing rings are arranged side by side in the direction of the roller axis at the protruding end of the hearth roller. And the mutually opposing side faces are fitted to each other, wherein one of the seal rings on the side closer to the side wall of the furnace body is fixed to the outside of the side wall of the furnace body in an intimate manner, and the other seal ring is directed toward the roller. The axial direction is free to move and is biased toward the seal ring close to one of the springs by a spring, and is well known (for example, refer to Patent Document 1).

The conventional dustproof device has the following problems. First, there is difficulty in the heat resistance of the material of the seal ring. Second, dust is generated from the roller penetration portion of the side wall of the furnace body. Third, the gap between the roller and the seal ring cannot be completely avoided, and the dust is intruded into the furnace from outside the furnace through the gap. The construction of the two seal rings and springs on the side walls of the furnace body and the hearth rollers is quite complicated and costly.

[Patent Document 1] Japanese Patent Laid-Open No. Hei 6-265273

SUMMARY OF THE INVENTION An object of the present invention is to provide a dustproof device in a roller hearth type heat treatment furnace which has a simple structure for preventing dust from intruding into the furnace.

In the dustproof device of the present invention, a roller hearth type heat treatment furnace is formed in the side wall of the furnace body for forming a roller through which the workpiece is conveyed, and the end portion thereof protrudes from the side surface. The sub-through hole is placed above the side of the furnace body, and a clean air duct is installed on the outer side of the side wall of the furnace body, and on the clean air duct, a downward air blowing port is provided, and the air blowing port is covered from the side to clean the air. The catheter is provided with a shield.

In the dustproof device of the present invention, the space around the outer open end of the roller through hole faces the space surrounded by the clean air duct and the shield, and is filled in the space by the clean air blown from the air outlet. The dust does not intrude into the same space. Even if the air outside the furnace invades from the peripheral surface of the roller through hole and the outside of the hearth roller, the air is only clean air and does not contain dust. Therefore, dust can be prevented from intruding into the furnace.

Further, when the lower edge portion of the shield is located lower than the protruding end portion of the hearth roller, and the lower edge portion of the shield is formed with a notch through which the protruding end portion of the hearth roller penetrates, The periphery of the sub-through hole becomes widely covered by the shield, and thus the effect of preventing dust intrusion is large.

Further, when a metal or heat-resistant glass protective sleeve is inserted between the circumferential surface of the roller through hole and the outer surface of the hearth roller, the roller through hole of the side wall of the furnace body formed of the usual heat insulating material can be prevented. Dust is generated on the circumference.

According to the present invention, a simple configuration can be used to prevent dust from intruding into the furnace.

The form of the present invention will be described with reference to the drawings.

In the following description, the left and right sides are based on the first figure, and the left and right sides are referred to as left and right.

The roller hearth type heat treatment furnace is provided with a furnace body 11 having a square cross section. The furnace body 11 is composed of a top wall 21, a bottom wall 22, and two side walls 23. The top wall 21, the bottom wall 22 and the two side walls 23 are formed of a heat insulating material. Further, a heater (not shown) is provided on the top wall 21, the bottom wall 22, and the both side walls 23. Moreover, the inner surfaces of the top wall 21, the bottom wall 22, and the both side walls 23 are covered with a heat-resistant glass dustproof wall (not shown).

The roller through holes 31 are formed at a plurality of positions in the longitudinal direction of the both side walls 23 so as to be concentric everywhere. A metal protective sleeve 32 is inserted into each of the roller through holes 31. The material of the protective sleeve 32 can also be replaced by heat-resistant glass instead of metal.

The hearth roller 33 for conveyance of the ceramic horizontal round bar-shaped workpiece is passed through the protective sleeve 32 to penetrate the roller through hole 31, and the end portion thereof protrudes from the side.

A clean air duct 41 having a square cross section is attached to the outer side surfaces of the side walls 23 so as to be positioned above the left and right roller through holes 31, respectively. The two clean air ducts 41 are configured such that the left and right directions are opposite and the same. Hereinafter, the cleaning air duct 41 on the right side will be described.

A clean air supply pipe 42 is connected at a suitable portion of the top wall of the clean air duct 41. On the bottom wall of the clean air duct 41, the downward air blowing port 43 is provided at a certain interval in the longitudinal direction. On the clean air duct 41, a side wall on the opposite side of the furnace body 11 is provided with a vertical plate-shaped Teflon (registered trademark) guard plate 44. The lower edge portion of the shield 44 is located below the protruding end of the hearth roller 33. A notch 45 that penetrates the protruding end portion of the hearth roller 33 is formed at a lower edge portion of the shield 44. The notch 45 is formed in an inverted U-shaped outline, and the upper portion has an arc-shaped portion. There is a gap between the arcuate portion and the upper half of the outer surface of the hearth roller 33. This gap is preferably a small gap to the extent that air is not allowed to flow.

The clean air blown from the air blowing port 43 is filled in the lower open space partitioned by the furnace body side wall 23, the clean air duct 41, and the shield 44. Even if air is intruded into the furnace body 11 from the gap between the hearth roller 33 and the protective sleeve 32, the air is clean air, so there is no fear that dust outside the furnace body 11 intrudes into the furnace body 11. Especially in the heat treatment furnace, heating up. In the debonding agent zone, although the negative pressure is maintained by the exhaust in the furnace body 11, the dust outside the furnace body 11 is invaded into the furnace. However, the cleaning air in the same space can be used to resolve the doubt. Further, although fibrous or particulate dust forming the heat insulating material of the furnace body 11 is generated from the circumferential surface of the through hole 31, the protective sleeve 32 can prevent it from scattering.

In the above, the shapes of the clean air duct, the air outlet, the guard, and the notch are not limited to those shown. The gap can also be replaced, for example, by a round hole. In addition, the material of the shield can also be replaced by heat-resistant plastic (T-River (registered trademark)).

11. . . Furnace body

twenty one. . . Top wall

twenty two. . . Bottom wall

twenty three. . . Side wall

31. . . Roller through hole

32. . . Protective casing

33. . . Hearth roller

41. . . Clean air duct

42. . . Clean air supply pipe

43. . . Air outlet

44. . . Guard

45. . . gap

Fig. 1 is a cross-sectional view showing the dustproof device and the roller hearth type heat treatment furnace of the present invention at the same time.

Fig. 2 is a cross-sectional view showing a part of Fig. 1 in an enlarged manner.

Fig. 3 is a perspective view of a portion shown in Fig. 2.

twenty three. . . Side wall

31. . . Roller through hole

32. . . Protective casing

33. . . Hearth roller

41. . . Clean air duct

42. . . Clean air supply pipe

43. . . Air outlet

44. . . Guard

45. . . gap

Claims (5)

A dustproof device which is formed in a roller hearth type heat treatment furnace for forming a roller through hole of a roller for conveying a workpiece to be conveyed on a side wall of a furnace body, and is located at a side of the furnace body so as to be located at a specific roller Install the clean air duct on the outer side of the side wall of the same furnace body, and set the air outlet port downwards on the clean air duct, and install a guard plate on the clean air duct to cover the air from the side. The outlet, the clean air duct is cantilevered with respect to the outer side surfaces of the two side walls, the clean air duct is arranged along the length direction of the side wall of the furnace body, and the clean air supply pipe is connected to the top wall of the clean air duct, and the clean air is supplied to the clean air supply tube for cleaning. The air duct is blown downward from the air outlet by cleaning the inside of the air duct. For example, in the dustproof device of claim 1, the clean air duct and the guard plate area are used to draw out the open space below. The dustproof device of claim 1, wherein the lower edge portion of the shield is located lower than the protruding end portion of the hearth roller, and the protruding end of the hearth roller is formed at the lower edge portion of the shield The gap that runs through the department. The dustproof device of claim 2, wherein the lower edge portion of the shield is located lower than the protruding end of the hearth roller, and the protruding end of the hearth roller is formed at the lower edge portion of the shield The gap that runs through the department. A dustproof device according to any one of claims 1 to 4, wherein a metal or heat-resistant glass protective sleeve is inserted between the circumferential surface of the roller through hole and the outer surface of the hearth roller.