JP3819278B2 - Heating furnace seal structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing structure of a heating furnace that is required to be heated in a state where the inside of the furnace is kept airtight like a vacuum heating furnace.
[0002]
[Prior art]
For example, in the vacuum heating furnace sealing structure, the technique disclosed in Japanese Patent No. 2531496 is known. In this technique, in order to keep the inside of the vacuum heating furnace airtight, a seal member (rubber O-ring) is used to seal between the outer cylinder flange portion of the radiant tube burner attached to the heating furnace and the furnace body. Yes. In addition, since a high temperature combustion gas, a vapor | steam, etc. flow in the inside of a radiant tube burner, the cooling means for protecting an O-ring from the heat | fever is taken in. As this cooling means, the outer cylinder flange portion is brought into contact with a water-cooling jacket provided on the heating furnace side and cooled to prevent high temperature heat from being transmitted from the outer cylinder flange portion to the O-ring. .
[0003]
[Problems to be solved by the invention]
However, in the seal structure disclosed in the above publication, since the O-ring is interposed between the outer cylinder flange portion of the radiant tube burner and one of the water cooling jackets, Adhesion with water-cooled jacket will be lost. Therefore, the cooling function of the mounting flange by the water cooling jacket is lowered, and high heat is transmitted to the O-ring. Further, since the O-ring is disposed near the radiant tube burner, it is easily affected by heat such as high-temperature combustion gas or steam flowing in the burner. As a result, the O-ring is likely to deteriorate due to the heat effect from the radiant tube burner.
[0004]
The present invention is intended to solve the above-mentioned problems, and the object thereof is to promote the cooling effect of the mounting flange in a heat source body such as a radiant tube burner, to reduce the conduction heat to the seal member, and to be possible from the heat source body. By disposing the seal member at a position as far as possible, the deterioration of the seal member due to the heat effect from the heat source body is eliminated and durability is provided.
[0005]
[Means for Solving the Problems]
The present invention is for achieving the above object, and the invention according to claim 1 is a sealing structure for keeping the inside of the heating furnace airtight, and is provided with a cooling means and a fastening provided on the heating furnace side. An attachment flange formed on the heat source body attached to the heating furnace is located between the members . And an outer periphery of the mounting flange, the sealing member is disposed between the wall portions provided in the cooling means or clamping member at a position opposed to the outer periphery. And with that contacting the mounting flange and the cooling unit of the heat source body planar surface of each other, are set to apply a compressive force to the sealing member by a fastening member.
In this way, by eliminating the seal member from the contact surface between the mounting flange of the heat source body and the cooling means to enhance mutual adhesion, the cooling effect of the mounting flange is promoted and the conduction heat to the seal member is reduced. be able to. Further, since the seal member is disposed on the outer periphery of the mounting flange as far as possible from the heat source body , the deterioration of the seal member due to the heat effect from the heat source body is eliminated, and stable sealing performance is maintained. In addition, by directly compressing the sealing member with the fastening member, it is possible to design the fastening member so that the fastening force of the fastening member is not applied to the mounting flange of the heat source body. As a result, even when the outer shell of the heat source body is formed of a ceramic material or the like, the situation where the mounting flange is damaged by the tightening force is solved.
[0006]
The invention described in claim 2 is the sealing structure of the heating furnace described in claim 1, wherein the cooling means is provided with a stopper for receiving and positioning the outer periphery of the mounting flange of the heat source body .
Thus, by providing a stopper in the cooling means, the position of the mounting flange in the heat source body is stabilized, and as a result, the sealing performance by the seal member disposed between the mounting flange and the wall portion is also stabilized.
[0008]
The invention according to claim 3 is the sealing structure of the heating furnace according to claim 1, wherein the cooling means or the fastening member is provided with a slope that compresses the seal member in a direction to press the outer periphery of the mounting flange. It has been.
This inclined surface improves the sealing function of the sealing member.
[0009]
The invention according to claim 4 is the sealing structure of the heating furnace according to claim 1 , wherein a compression force is applied to the seal member by the tightening member. A slight gap is set between them.
Even when the tightening member is tightened and an appropriate compressive force is applied to the seal material due to the gap, the tightening load acting on the mounting flange becomes zero, and the mounting flange such as a ceramic material may be damaged by the tightening load. It will be resolved.
[0010]
A fifth aspect of the present invention is the heating furnace seal structure according to the fourth aspect , wherein a spacer is interposed in a gap between the mounting flange of the heat source body and the fastening member.
According to this configuration, the contact load between the mounting flange and the tightening member can be managed by selecting the thickness of the spacer. This prevents an excessive load from being applied to the mounting flange even if there is some variation in the dimensional accuracy of the fastening member and other members.
[0011]
The invention according to claim 6 is the sealing structure of the heating furnace according to claim 3 , wherein the slope that compresses the seal member in a direction to press the seal member against the outer periphery of the mounting flange is at a position facing the outer periphery of the mounting flange. It also serves as a wall .
This can simplify the seal structure.
[0012]
The invention according to claim 7 is the sealing structure of the heating furnace according to claim 1, 2, 3, 4, 5 or 6 , wherein the heat source body is a radiant tube burner provided with a mounting flange. At the same time, the cooling means is a water cooling jacket, and a sealing member for sealing between the mounting flange and the water cooling jacket is disposed on the outer periphery of the mounting flange.
Thereby, the cooling effect of the mounting flange in the radiant tube burner is promoted, and the deterioration of the seal member due to the heat effect of the combustion gas flowing inside the radiant tube burner is prevented.
[0013]
The invention described in claim 8 is the sealing structure of a heating furnace described in claim 1, 2, 3 , 4 , 5 , 6 or 7 , wherein the fastening member is a water cooling jacket.
Thereby, the cooling effect of a mounting flange is further accelerated | stimulated and the thermal deterioration of a sealing member is prevented effectively.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
First, the first embodiment will be described with reference to FIGS. FIG. 1 is a sectional view showing a mounting portion of a radiant tube burner which is a heat source body of a vacuum heating furnace. As shown in this drawing, a radiant tube burner 20 (hereinafter abbreviated as RTB 20) is located from the outside to the inside of the heating furnace 10 with respect to the fixed flange 13 integral with the furnace wall 12 constituting the outer shell of the heating furnace 10. It is attached in a state of being inserted. That is, the RTB 20 is attached to the fixed flange 13 of the furnace wall 12 with the heat radiation tube 21 inserted into the furnace 11, and is used to heat a predetermined treatment in the non-oxidizing (vacuum) furnace 11. High temperature heat can be radiated.
[0015]
Here, the structure and function of the RTB 20 will be briefly described.
The RTB 20 shown in the drawing is of a single end type, and the heat radiation tube 21 is constituted by an inner cylinder 22 and an outer cylinder 24 made of a heat-resistant material (alloy steel or ceramic). In the inner cylinder 22, a base end portion thereof is fixed inside the burner body 28 located outside the heating furnace 10, and a distal end portion is opened inside the outer cylinder 24. Inside the inner cylinder 22 is a burner nozzle 30, to which gas is supplied through a gas pipe 32. The burner body 28 includes a spark plug 34 for igniting the pilot burner, an air supply port 36 and other necessary parts.
[0016]
The gas supplied to the burner nozzle 30 is preliminarily mixed with the air taken in from the air supply port 36, ignited by the pilot burner, and burned at the burner nozzle 30. The interior 11 of the furnace is heated by the radiant heat from the outer surface of the outer cylinder 24 accompanying this combustion. Further, the combustion gas is reversed upward at the tip opening of the inner cylinder 22, then flows through the space between the inner cylinder 22 and the outer cylinder 24, and is discharged to the outside from the gas discharge port 38 of the burner body 28.
[0017]
At the location where the RTB 20 is attached to the fixed flange 13 of the furnace wall 12, the outside of the heating furnace 10 and the vacuum furnace 11 are sealed so that the inside of the furnace 11 is hermetically sealed, and further, between the inside of the furnace 11 and the inside of the outer cylinder 24. It is necessary to maintain airtightness and at the same time keep the temperature below the temperature at which the seal member is protected from thermal degradation by cooling. Therefore, a water cooling jacket 14 used as one of the cooling means is provided between the fixed flange 13 and the mounting location of the RTB 20. The space between the water cooling jacket 14 and the mounting flange 26 of the outer cylinder 24 of the RTB 20 is sealed with a rubber O-ring 40 (seal member).
[0018]
The water cooling jacket 14 has an annular shape in which an outer cylinder 24 is positioned at the center opening, and cooling water circulates through the hollow interior. A heat-resistant wall 18 fixed to the furnace wall 12 is located outside the outer cylinder 24 in a predetermined range outside the furnace.
[0019]
FIG. 2 is an enlarged cross-sectional view of a part of FIG. As is apparent from this drawing, a step portion 15 is provided on the upper surface of the water cooling jacket 14, and a wall portion 16 is formed on the outer peripheral portion of the water cooling jacket 14 by the step portion 15. A mounting flange 26 of the outer cylinder 24 is positioned on the upper surface of the water cooling jacket 14 inside the wall portion 16, and an O-ring 40 is disposed between the outer periphery of the mounting flange 26 and the inner periphery of the wall portion 16.
[0020]
A fastening member 42 is located between the water cooling jacket 14 (mounting flange 26) and the burner body 28. The fastening member 42 enters between the outer periphery of the mounting flange 26 and the inner periphery of the wall portion 16 from above. A protruding portion 44 is provided. A compressive force is applied to the O-ring 40 between the protruding portion 44 and the water cooling jacket 14. As a result, the space between the water cooling jacket 14 and the mounting flange 26, that is, between the inside of the furnace 11 and the outside of the furnace and between the inside of the furnace 11 and the inside of the outer cylinder 24 is sealed. There is a gap between the mounting flange 26 and the fastening member 42, and a spacer 46 using a copper plate or the like is interposed here.
[0021]
The mounting flange 26 of the outer cylinder 24 is heated by conduction heat such as high-temperature combustion gas or steam flowing through the heat radiation tube 21. Therefore, in order to avoid the deterioration of the O-ring 40 due to the heat effect from the mounting flange 26, the mounting flange 26 is cooled (heat exchange with cooling water) by the water cooling jacket 14. In the sealing structure, the water cooling jacket 14 and the mounting flange 26 are brought into direct contact with each other to improve mutual adhesion. As a result, the cooling effect of the mounting flange 26 is promoted, and the thermal influence on the O-ring 40 is naturally reduced. The O-ring 40 is disposed on the outer periphery of the mounting flange 26 as far as possible from the high-temperature gas flowing in the heat radiation tube 21. As a result, the deterioration of the O-ring 40 due to the thermal effect from the RTB 20 is eliminated.
[0022]
The O-ring 40 is adapted to receive a necessary compressive force by the projecting portion 44 of the fastening member 42, whereby a load for applying a compressive force to the O-ring 40 is applied to the mounting flange 26 of the outer cylinder 24. There is no need. Therefore, by arbitrarily selecting the thickness of the spacer 46, the load applied from the fastening member 42 to the mounting flange 26 can be managed.
[0023]
Further, instead of providing the spacer 46, by leaving a gap between the mounting flange 26 and the fastening member 42 so as not to cause any other trouble, the load applied to the mounting flange 26 from the fastening member 42 can be reduced to zero. In any case, regardless of variations in the dimensional accuracy of the fastening member 42 and the like, an excessive load is not applied to the mounting flange 26, and for example, a situation in which the ceramic mounting flange 26 is damaged by the tightening load can be solved.
[0024]
Next, the second embodiment will be described with reference to FIG. FIG. 3 is a sectional view showing the seal structure and its cooling means in the second embodiment in correspondence with FIG. As shown in this drawing, in the second embodiment, the fastening member 42 of the first embodiment is replaced with a water cooling jacket 50. The water cooling jacket 50 includes a protruding portion 52 that enters from the upper side between the outer periphery of the mounting flange 26 and the inner periphery of the wall portion 16. A compressive force is applied to the O-ring 40 between the protruding portion 52 and the water cooling jacket 14 to maintain the sealing function. A spacer 46 using a copper plate or the like is interposed between the water cooling jacket 50 and the mounting flange 26.
[0025]
In the second embodiment, the mounting flange 26 heated by conduction heat such as high-temperature combustion gas or steam flowing in the heat radiation tube 21 is cooled from both sides by the water cooling jackets 14 and 50. Therefore, this cooling effect is further enhanced, and the thermal influence on the O-ring 40 is effectively suppressed.
In the second embodiment, members that are considered to be the same as or equivalent to those in the first embodiment are denoted by the same reference numerals in the drawings, and redundant description is omitted. Similarly, the description of the third and fourth embodiments to be described next is omitted.
[0026]
Next, Embodiment 3 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing the seal structure of the third embodiment and its cooling means corresponding to a part of FIG. 2 or FIG. In the third embodiment, the contact surface with the O-ring 40 in the protruding portion 44 (52) of the fastening member 42 (or the water cooling jacket 50) is the inclined surface 60. When the O-ring 40 is compressed by the inclined surface 60, the O-ring 40 is deformed in a direction in which it is pressed against the outer periphery of the mounting flange 26. Therefore, the sealing function by the O-ring 40 is further enhanced.
[0027]
Next, the fourth embodiment will be described with reference to FIG. FIG. 5 is a sectional view showing the seal structure of the fourth embodiment. The step portion 72 of the water-cooling jacket 70 according to the fourth embodiment includes a stopper 78 that protrudes from a wall portion 74 formed on the outer peripheral portion thereof to a position for receiving the outer periphery of the mounting flange 26. A slope 76 is formed between the wall 74 and the stopper 78. An O-ring 40 is disposed between the slope 76, that is, between the outer periphery of the mounting flange 26 and the inner periphery of the wall portion 74.
[0028]
Further, the projecting portion 44 (52) of the fastening member 42 (or the water cooling jacket 50) enters between the outer periphery of the mounting flange 26 and the inner periphery of the wall portion 74, and is compressed into the O-ring 40 between the inclined surface 76. Power is applied. Due to the inclination of the inclined surface 76, the O-ring 40 is deformed in the direction in which the O-ring 40 is pressed against the outer periphery of the mounting flange 26, as in the case where the inclined surface 60 is provided on the protruding portion 44 (52) in the third embodiment. Therefore, the sealing function by the O-ring 40 is enhanced. Of course, the slope 76 and the slope 60 of the protruding portion 44 (52) can be used in combination.
[0029]
Further, in the fourth embodiment, by receiving the outer periphery of the mounting flange 26 by the stopper 78, the position of the mounting flange 26, that is, the centering position of the water cooling jacket 70 and the outer cylinder 24 is stabilized, and as a result, the O-ring. The sealing performance by 40 is also stable.
[0030]
Next, a fifth embodiment will be described with reference to FIG. FIG. 6 is a sectional view showing the seal structure of the fifth embodiment. In the fifth embodiment, the protruding portion 44 (52) is omitted from the fastening member 42 (or the water cooling jacket 50) in the seal structure of the fourth embodiment (FIG. 5). Moreover, the function of the wall portion 74 for positioning the O-ring 40 at a position where the inclined surface 79 of the water-cooling jacket 70 faces the outer periphery of the mounting flange 26, and the function of deforming the O-ring 40 so as to press the outer periphery of the mounting flange 26. Is also used. The stopper 78 of the stepped portion 72 in the water cooling jacket 70 of the fifth embodiment fulfills the same function as that of the fourth embodiment.
[0031]
Next, the sixth embodiment will be described with reference to FIG. FIG. 7 is a sectional view showing the seal structure of the sixth embodiment. In the seal structure of the sixth embodiment, for example, the water cooling jacket 70 of the fourth and fifth embodiments is changed to the water cooling jacket 80 of FIG. This water cooling jacket 80 is only provided with a stopper 84 having the same function as the stopper 78 of the fourth and fifth embodiments at the step portion 82. On the other hand, the fastening member 42 (or the water cooling jacket 50) includes a slope 86 at a position facing the outer periphery of the mounting flange 26. An O-ring 40 is disposed between the slope 86 and the outer periphery of the mounting flange 26. Therefore, the slope 86 has both a function of a wall portion for positioning the O-ring 40 at a position facing the outer periphery of the mounting flange 26 and a function of deforming the O-ring 40 so as to press the outer periphery of the mounting flange 26.
[0032]
As described above, in the seal structure in each of the above-described embodiments, the seal member such as the O-ring 40 is excluded from the contact portion between the mounting flange 26 of the RTB 20 that is the heat source body of the heating furnace 10 and the water cooling jacket. To improve the adhesion. Thereby, the mounting flange 26 is effectively cooled, and the deterioration of the seal member due to the thermal influence from the mounting flange 26 to the seal member is eliminated.
[0033]
In each of the above-described embodiments, the case where the single-ended RTB 20 is used as the heat source body of the heating furnace 10 has been described, but it is naturally possible to replace this with a radiant tube burner of another type. Other types of radiant tube burners are known, such as a straight type, a U type, and a W type.
Further, the water cooling jackets 14, 70, 80 used as the cooling means or the water cooling jacket 50 serving also as a fastening member can be replaced with a plate formed of a steel material having high thermal conductivity. In this case, cooling of the mounting flange 26 is promoted by the heat radiation action from the plate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a mounting portion of a radiant tube burner with respect to a vacuum heating furnace.
2 is an enlarged cross-sectional view of a part of FIG.
FIG. 3 is a cross-sectional view illustrating a seal structure according to a second embodiment.
4 is a cross-sectional view illustrating a seal structure according to Embodiment 3. FIG.
FIG. 5 is a cross-sectional view showing a seal structure according to a fourth embodiment.
6 is a cross-sectional view illustrating a seal structure according to Embodiment 5. FIG.
7 is a cross-sectional view showing a seal structure according to Embodiment 6. FIG.
[Explanation of symbols]
10 Heating furnace 14 Water cooling jacket 16 Wall 20 Radiant tube burner (heat source)
26 Mounting flange 40 O-ring (seal member)

Claims (8)

A sealing structure for keeping the inside of the heating furnace airtight, and a mounting flange formed on a heat source body attached to the heating furnace is located between the cooling means provided on the heating furnace side and the fastening member. , and an outer periphery of the mounting flange, at a position opposed to the outer periphery is arranged a seal member between the wall portion provided in the cooling means or clamping member, the flat a mounting flange and cooling means of the heat source body mutual A sealing structure for a heating furnace that is set to contact with a surface and is configured to apply a compressive force to the sealing member by a fastening member . The sealing structure for a heating furnace according to claim 1, wherein the cooling means is provided with a stopper for receiving and positioning the outer periphery of the mounting flange of the heat source body . The sealing structure of a heating furnace according to claim 1, wherein the cooling means or the fastening member is provided with a slope that compresses the sealing member in a direction to press the sealing member against an outer periphery of a mounting flange. The heating furnace sealing structure according to claim 1 , wherein a slight gap is set between the fastening member and the mounting flange in a state where a compressive force is applied to the sealing member by the fastening member. The heating furnace seal structure. The sealing structure for a heating furnace according to claim 4 , wherein a spacer is interposed in a gap between the mounting flange of the heat source body and the fastening member. It is the sealing structure of the heating furnace described in Claim 3 , Comprising: The slope which compresses a sealing member in the direction which presses on the outer periphery of a mounting flange serves as the wall part provided in the position facing the outer periphery of a mounting flange . Heating furnace seal structure. The heating furnace sealing structure according to claim 1, 2, 3, 4, 5, or 6 , wherein the heat source is a radiant tube burner having a mounting flange, and the cooling means is a water cooling jacket. A sealing structure for a heating furnace in which a sealing member for sealing between the mounting flange and the water cooling jacket is disposed on the outer periphery of the mounting flange. The heating furnace sealing structure according to claim 1, 2, 3 , 4 , 5 , 6, or 7 , wherein the fastening member is a water-cooling jacket.

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