JP2000240904A - Supporting structure of furnace shell protruding section of radiant tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the slide resistance of a radiant tube on the bung side by supporting a burner or a recuperater main body through a rotating body on the furnace shell protruding side of a radiant tube of a heat treatment furnace, and combining the section going through the furnace wall of the burner or the recuperater with a flexible combining body. SOLUTION: A resistance is eliminated by adopting a flexible combining body (bellows made of fabric) 4, and in order to reduce the deforming resistance of a connecting tube, the connecting tube is replaced by a flexible tube 5, and the resistance is reduced. For a rotating body (rolling body) 8 between a burner support 6 and a bearing fitting 7 on the bung side, a cylindrical roller is used. For the rolling body 8, article other than the cylindrical roller may be used as long as the slide resistance of which is small, and which can perform a positioning. Since the rolling body 8 is attached to the outside of a burner 82, the environmental condition is comparatively favorable. Even when a seizure occurs on a radiant tube support 11, a radiant tube 1 can freely extend to a burner 2 side. Therefore, a thermal stress is softened, a bending deformation is reduced, and life can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for supporting a radiant tube on a bang side (furnace shell projecting side) of a radiant tube used in a heat treatment furnace and used as a radiant heat source.

[0002]

2. Description of the Related Art In general, W-type and U-type radiant tubes installed in a heat treatment furnace and used as a radiant heat source are supported as shown in FIG. 8, and the radiant tube 1 on the side of the burner 2 and the bang 9 are slightly spaced from each other, as shown in FIG. The bellows 13 is attached to prevent leakage of the internal atmosphere gas and to release the thermal expansion of the radiant tube 1.

As a special example, as shown in FIG. 10 and FIG. 11, as shown in Japanese Utility Model Publication No. 57-58187, a roller is provided on a telescopic side of a straight tube type radiant tube so as to absorb thermal expansion. Some technologies have been developed.

[0004]

In the conventional support structure of the W-shaped radiant tube 1, as shown in FIG.
By smoothly sliding the support 11 on the thermal expansion of the radiant tube 1, thermal stress can be reduced as shown in FIG. 9B. However, if the radiant tube 1 is used for a while in the actual furnace, the support 1
As a result, the radiant tube 1 tends to extend toward the bang 9 side. At this time, in the conventional support structure, the recuperator 3 side is fixed by welding, and the burner 2 side cannot slide smoothly for the following reason.
As shown in (c), the radiant tube is bent due to an increase in thermal stress, and the life is shortened.

[0005] The reason why the sliding of the burner 2 is hindered is that the clearance between the radiant tube 1 and the bang 9 is small, and the contact is caused by thermal expansion, thereby causing resistance, and receiving a reaction force from the metal bellows 13.

[0006] Japanese Utility Model Publication No. 57-58187 discloses a technique for supporting the expansion / contraction side of a straight tube type radiant tube as shown in FIG.
As shown in FIG. 0, means for providing a rolling element 8 and absorbing thermal expansion has been proposed. This technology has the following problems,
It cannot completely absorb thermal expansion. That is, since the short pipe 14 has the bellows (shielding film) 13 inside, it cannot receive the reaction force at the time of expansion and contraction to completely absorb the thermal expansion. In addition, in order to install the rolling element 8 inside the short pipe 14,
The function check and repair cannot be performed easily. further,
Seizure is likely to occur due to the structure of the rolling elements 8 and the environment inside the short pipe 14. This is because the temperature inside the short tube is 200 ° C or more,
This is because the diameter of the shaft supporting the load of the rolling elements 8 is small, so that the contact surface pressure increases.

An object of the present invention is to provide a technique in which such disadvantages are improved.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its technical means is that a burner or a recuperator is provided with a rotating body on the side of a radiant tube of a heat treatment furnace at which a furnace shell protrudes. A support structure for a furnace shell projection of a radiant tube, characterized in that a portion through which a burner or a recuperator body penetrates a furnace wall is connected by a flexible coupling body. That is, the following components were arranged to reduce the sliding resistance on the bang side.

(1) The metal bellows is changed to a cloth bellows to reduce the stretching resistance.

(2) The gap between the radiant tube and the bang is widened to prevent contact.

(3) Smooth sliding can be obtained by attaching a burner support to the side surface of the burner, attaching a receiving hardware to the bang, and arranging a rolling element between the burners. Since this rolling element is not high in temperature, a roller with a shaft can be used.

(4) The connecting pipe connecting the burner and the recuperator is changed from a pipe to a flexible tube to reduce sliding resistance.

[0013]

FIG. 1 shows an embodiment in which the present invention is applied to only the burner 2 as one of the embodiments, but is also applicable to the recuperator 3. According to the present invention, smooth sliding could be obtained by eliminating the following factors that hinder the thermal expansion of the radiant tube 1 toward the bang 9 side.

(A) As shown in FIG. 3, the contact resistance between the radiant tube 1 and the bang 9 is widened to prevent the contact by positioning by the burner support 6. FIG. 3 is a detailed view of a portion B in FIG.

(B) The expansion and contraction resistance of the bellows 13 is reduced. That is, as shown in FIG. 3, the resistance is eliminated by adopting the cloth bellows 4, and as shown in FIG.
In order to reduce the deformation resistance of the conventional connecting pipe 12 shown in FIG.
This was replaced with a flexible tube 5 to reduce the resistance.

FIG. 1 is a view showing one embodiment of the present invention, and FIG. 2 is a view taken on line AA of FIG. This is an example in which the present invention is applied to the burner 2 side.
Even when seizure occurs in one part, the radiant tube 1 can freely expand toward the burner 2 side, so that thermal stress is relaxed, bending deformation is reduced, and the life can be extended. In addition to the U-type and W-type radiant tubes, the present invention can be applied to the telescopic side of a straight tube type radiant tube.

In the embodiment, as shown in FIGS. 4 and 5, a cylindrical roller is used for the rolling element 8 between the burner support 6 and the metal fitting 7 on the bang 9 side. The rolling element 8 is not limited to the cylindrical roller, and may be any element that has a small sliding resistance and can be positioned. Since the rolling elements 8 are mounted outside the burner 2, environmental conditions are relatively good.

[0018]

According to the present invention, the sliding resistance of the radiant tube on the bang side is reduced, thereby alleviating the thermal stress generated in the radiant tube, preventing the shortening of the life due to deformation, and improving the life. In addition, by arranging the rolling element at a position that can be seen from the outside, inspection and repair can be facilitated, and the effect can be continuously exhibited.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a front view of the embodiment of the present invention (a view taken along the line AA in FIG. 1).

FIG. 3 is a burner side sectional view showing details of a portion B in FIG. 1;

FIG. 4 is a detailed view of a burner support unit.

FIG. 5 is a perspective view of a burner support section.

FIG. 6 is a side view of the prior art.

FIG. 7 is a detailed view of a portion D in FIG. 6;

FIG. 8 is a view of a part E in FIG. 6;

FIG. 9 (a) Radiant tube at normal temperature, (b) Elongation when radiant tube support moves normally,
(C) It is explanatory drawing which shows the deformation | transformation when a radiant tube support is baked.

FIG. 10 is an overall view of the related art.

11 is a view as viewed from the direction of the arrow F in FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiant tube 2 Burner 3 Recuperator 4 Cloth bellows 5 Flexible tube 6 Burner support 7 Bang side metal fittings 8 Rolling element 9 Bang 10 Furnace shell 11 Radiant tube support 12 Connecting pipe 13 Metal bellows 14 Short pipe 15 Stopper 16 Rolling element holding frame 21 Stretch 22 bends

Claims (1)

[Claims] 1. A burner or a recuperator main body is supported via a rotating body on a side of a radiant tube of a heat treatment furnace where a furnace shell protrudes, and a portion where the burner or the recuperator body penetrates a furnace wall is connected by a flexible coupling body. The support structure of the protruding part of the furnace shell of the radiant tube characterized by the following.