JP2000329472A - Heat treatment apparatus with special heat-resisting filter, and special heat-resisting filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment apparatus which can realize an environment being clean and having higher temperature, and a filter used therefor. SOLUTION: A clean oven has an opening frame 2 forming an opening 1, a filter 3 of which the filter part 31 is surrounded by a filter frame 32 constituted of ferrite-series special heat-resisting steel having a composition enhancing heat resistance, a packing 4, short tightening shafts 5 between P1-P2, nuts 5a, retainer plate 19, etc. According to this constitution, the filter frame is kept from rust, although it is constituted of the ferrite-series material. Since the filter frame 32 is constituted of the same ferrite-series material as that of an inner tank 6, a thermal expansion difference between the filter frame 32 and the opening frame 2 on the opposite sides of the packing 4 is eliminated and the sealing properties of this part are made excellent. Since the tightening shafts 5 are short, a change in the amount of compression of the packing is small and deterioration of the sealing properties can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a special filter for a heat treatment apparatus and a heat treatment apparatus equipped with the same, and in particular, to a high temperature for providing a clean environment of a high temperature of about 500.degree. Conveniently used for heat treatment equipment.

[0002]

2. Description of the Related Art In a heat treatment apparatus for heat-treating a work such as an electric or electronic part, a heat treatment and various performance tests of the work are performed under a high temperature of about 200 ° C. to 300 ° C. and in a clean environment free of dust. A high-performance filter that satisfies such thermal conditions and its mounting structure are employed.

That is, as shown in FIG. 7, for example, an opening 1 for passing hot air is provided in an inner tank 6 of a clean oven as a heat treatment apparatus.
Is provided as a tank internal structure, and a tightening shaft 5 ′ made of austenitic stainless steel such as SUS304 is extended therefrom to form a screw portion at the tip thereof. Filter 3
The filter press plate 19 ', which is in contact with the front end surface 32b' of the filter frame 32 ', can be tightened with the nut 5a', and the packing 4 interposed between the opening frame 2 and the rear end surface 32a 'of the filter frame. By applying an appropriate pressing force to the opening frame, the sealing property between the opening frame and the filter is maintained. The inner tank 6 is made of a heat-resistant ferritic steel having a small coefficient of thermal expansion, including the opening frame, to prevent thermal deformation.

[0004]

According to the above-mentioned structure, the filter has no rust due to the high corrosion resistance of the austenitic stainless steel and has good clean performance. Also, since the filter frame and the shaft for tightening the same are made of the same material, even if the temperature inside the tank fluctuates and these members expand or contract, the amounts of the members are almost the same, so that the pressure contact force of the packing changes. In addition to maintaining good sealing properties, thermal distortion of the internal structure of the tank is suppressed.

However, in such a structure, the coefficient of thermal expansion of the austenitic stainless steel forming the filter frame 32 is larger than that of the heat-resistant ferritic steel forming the opening frame 2, so that the temperature when the temperature of the clean oven rises and falls is reduced. Due to a temperature difference or a temperature difference between when the operation is performed and when the operation is stopped, a difference in thermal expansion occurs between the filter frame and the opening frame, and the packing interposed therebetween receives a shearing force, thereby causing a gap between the filter frame and the packing. It was found that the sealability deteriorated due to a shift in the seal, the peeling of the packing from the opening frame, the deterioration of the packing by repeated stress, and the like.

In particular, recently, a high-temperature specification of about 500 ° C. has been introduced as a production oven for electronic parts and a clean oven for testing and research. This is an important issue.

Accordingly, the present invention provides a heat treatment apparatus which solves the above-mentioned problems in the prior art, improves the sealing performance of a filter mounting portion, and particularly realizes a clean and higher temperature environment, and a filter used therefor. That is the task.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is provided with an opening for a filter through which air for heat treatment supplied to a processing chamber is formed. A peripheral member, a filter including a structural member surrounding the filter portion, and a seal interposed between the peripheral member and one surface of the structural member that is on the upstream side in the air-passing direction. A member, and a pulling member for pulling the opposite end of the one side in the direction of the one side so that the one surface is pressed against the sealing member, and passes through the filter from the opening. In the heat treatment apparatus in which the air for heat treatment is supplied to the treatment chamber, the structural member is made of a ferritic special heat resistant steel having a composition for increasing heat resistance among ferritic heat resistant steels, and the tensile member is Previous Characterized in that it is fixed in a position close to the opposite end.

According to a second aspect of the present invention, there is provided a filter which is mounted on a heat treatment apparatus provided with a peripheral member so as to form an opening for the filter, the filter including a structural member surrounding the filter portion. In a filter which is mounted such that the one surface is pressed against a seal member interposed between the one surface and the peripheral member which is on the upstream side in the direction of passing air, the structural member is It is characterized by being made of ferritic special heat-resistant steel having a composition that enhances heat resistance among ferritic heat-resistant steels.

According to a third aspect of the present invention, in addition to the above, in the heat treatment apparatus, the opposite end of the one side is pulled in the direction of the one side so that the one surface is pressed against the seal member. A pulling member is provided, and the pulling member is fixed at a position near the opposite end.

[0011]

1 and 2 show a configuration example of a filter mounting portion in a clean oven to which the present invention is applied, and FIG. 3 shows a schematic overall structure of the clean oven.
A clean oven as a heat treatment apparatus includes an opening frame 2 as a peripheral member provided to form an opening 1 for a filter, and a filter frame 32 as a structural member surrounding a filter portion 31, and is commonly called a HEPA filter. that high-performance filter 3, a packing as a sealing member interposed between the rear end surface 32a is a surface on one side Y ₁ direction of the filter frame 32 and the opening frame 2 4, the rear end face 32a to the packing 4 Y ₁ direction opposite Y ₂ direction of the end portion at which the tip end face 32b of the fastening shaft 5 as tensioning member for pulling the Y ₁ direction so as to press, etc. have, from the opening 1 as indicated by the arrow This is a device in which air for heat treatment is circulated and supplied to the inner tank 6, which is a processing chamber, through the filter unit 31.

The material of the filter frame 32 is a heat resistant ferritic steel, which is a special heat resistant ferritic steel having a composition for increasing heat resistance. If such a special steel is indicated as A, the special steel A is manufactured as having a composition as shown in Table 1 below, for example. In this table, SUS43, which is a representative of ferritic stainless steel, is used for comparison.
The composition of 0 is also shown.

[0013]

[Table 1] This special steel A was developed as a material for automobile exhaust gas purification equipment and heating equipment, and has mechanical properties similar to those of SUS430, but has a higher chromium content than SUS430 and contains aluminum. Therefore, it is excellent in oxidation resistance especially at high temperatures, and is an excellent ferritic heat-resistant steel with little scale peeling even with repeated heating and cooling, and is suitable as a material of the filter frame 32 which is an object of the present invention. It is. The thermal expansion coefficient of this material is 10.0 × 10 ⁻⁶ (0-100 ° C.)-1 ° C.
2.8 × 10 ⁻⁶ (0-800 ° C.), SUS304
Etc. are sufficiently smaller than the coefficient of thermal expansion of austenitic stainless steel.

FIGS. 4 and 5 show test examples of high-temperature oxidation characteristics performed as a material test of the above-mentioned special steel A. FIG. 4 shows a long-term cycle test in a high-temperature exhaust gas atmosphere, and FIG. There is a short cycle test in air. As shown in these figures, special steel A
It can be seen that it is extremely excellent in oxidation resistance as compared with the same ferrite-based SUS430. The inventors conducted a test in which a clean oven, which is an apparatus to which the present invention is applied, was repeatedly used between a high-temperature environment and a normal-temperature atmospheric environment. According to the results, it was confirmed that rust was immediately generated in SUS430, but no rust was generated in the special steel A.

[0015] clamping shaft 5, as a position close to the position P ₁ of the front end face 32b, and is fixed from the position P ₂ of the opening frame 2 in block 7 in sufficiently separated P ₃ located in Y ₂ direction. The block 7 is attached to the intermediate frame 8. In this example, the ceiling 6a, floor 6b, both side walls 6c, etc. of the inner tank 6 are also made of the above-mentioned ferritic special heat-resistant steel.

In addition to the above-described structure around the filter, the clean oven has, as a usual configuration, an air conditioner in which a heat insulating wall 9, a heater 10a provided below the inner tank 6 in this example, a circulating blower 10b, and the like are arranged. It has a chamber 10, a duct portion 11 in which a cooler 11a for temperature control and rapid cooling in the tank is arranged, and the like.
Reference numeral 9a denotes a door and 10c denotes a motor for a circulation blower. The air conditioning room 10 and the duct portion 11 are partitioned by a reinforcing plate 12 that connects to the opening frame 2 and reinforces the opening frame 2, and the air for heat treatment circulates through the opening 13 therebetween. The opening frame 2 and the intermediate frame 8 are attached to the ceiling 6a, the floor 6b, and the side wall 6c of the inner tank 6, and are reinforced by the reinforcing plates 12, 14, and the like.

As the mounting structure of the filter 3, in addition to the opening frame 2 and the intermediate frame 8, the support bases 15 and 16 forming two rows of ridges supported on the floor 6b, and the protrusions mounted on the side wall 6c. A support plate 17 forming a strip is provided. or,
A protective wire mesh 18 is provided on the front side of the filter. Usually, four tightening shafts 5 are provided on both upper and lower sides, and a screw is cut on the tip end side, and a nut 5a is screwed into the screw.
Reference numeral 19 denotes a holding plate interposed between the nut 5a and the tightening shaft 5.

In the above-described clean oven, the filter 3 is mounted as follows, and exerts its function and effect in various use states of the clean oven. Filter 3
Are mounted on the support bases 15 and 16, and both side surfaces 32 c of the filter frame 32 are positioned and supported by the support plate 17. In this state, the holding plate 19 is inserted into the tips of the four tightening shafts 5 through holes formed at both ends of the two holding plates 19,
Abutting it to the front end face 32b of the filter frame 32, fitted with a nut 5a to screw the fastening shaft 5, press the Y ₁ direction by tightening the filter frame 32 through the pressing plate 19, the rear end surface 32a of the filter frame The filter 3 is pressed against the packing 4 to complete the mounting of the filter 3. Due to this pressure contact, the packing 4 is pushed in, for example, by about 3 mm from the state before the pressure contact, and an appropriate surface pressure is generated between the rear end 32a of the filter frame 32 and the packing, so that a sufficient seal is formed.

When the clean oven is operated, hot air heated to a high temperature of, for example, 500 ° C. by a heater is sent from the air conditioning room 10 through the duct 11 and the filter 3 to the inner tank 6 by a blower. Circulate. At this time,
The inner tank 6 together with the filter 3 is exposed to hot air of about 500 ° C. However, since the filter frame 32 and the respective parts of the inner tank 6 are formed of ferritic special heat-resistant steel, rust is generated due to good corrosion resistance at high temperatures. Without, a clean environment is maintained.
Also, since this material has a small coefficient of thermal expansion, even if the temperature rise is large at a high temperature, the thermal distortion of each part is small and a good structure with reduced thermal stress is obtained.

On the other hand, in the filter mounting portion, since the distance between P _{2 and} P ₃ is made longer and the distance between P _{3 and} P ₁ is made sufficiently shorter, of the width B of the filter frame 32 in the Y ₁ -Y ₂ direction, The length of each part of the inner tank 6 and the reinforcing plate made of the same ferrite material as the frame is long, and the length of the fastening shaft 5 made of an austenitic material different from the filter frame is sufficiently short. Therefore, there is no large difference in thermal expansion between the two when the temperature rises. That is, for example, if the compression ratio of the packing 4 is set to 3 mm at normal temperature when each structural portion has the dimensional ratio shown in FIG. 1, when the temperature rises to 500 ° C., this value becomes about 2. Although it is 8 mm, the good sealing property of the packing portion does not decrease when the thickness is about this.

Even if the tightening shaft 5 is shortened, the tightening force F by this shaft acts on the distal end surface 32b of the filter frame 32 via the holding plate 19, and as shown in FIG. F
Are dispersed via the highly rigid packing frame 32 and act as substantially uniformly distributed loads on the packing 4 on the rear end face 32a. Therefore, in this respect, similar to the conventional device, the tightening force is dispersed and the pressure on the sealing surface is made uniform by a simple operation of tightening only four tightening portions under a simple tightening structure. The sealing performance can be improved.

Since the opening frame 2 and the filter frame 32 are made of the same material, the two members sandwiching the packing 4 have the same thermal deformation, so that there is a problem as shown by a two-dot chain line in FIG. No condition occurs. That is, as in the conventional apparatus, when the opening frame 2 and the filter frame 32 are each composed of a combination of different materials of a ferrite-based material and an austenitic-based material, if the frames 2 and 32 are in a solid line state at room temperature, At 500 ° C., the filter frame 32 relatively extends in the width X direction and the height Z direction to the position indicated by the two-dot chain line, and the packing 4 is deformed as shown by the two-dot chain line.
Between the packing 4 and the rear end face 32a of the filter frame which is in contact with the filter frame, and the packing 4 is peeled off from the adhesive surface of the opening frame 2 so that the sealing performance in these portions cannot be maintained. Adoption eliminates all such problems.

In the above, an example in which the filter is mounted on the opening frame using the tightening shaft 5 has been described. However, a filter frame having a seat for attachment to the opening frame 2 is formed at the rear end face 32a. And a filter may be mounted by compressing the packing at the seat portion.

In the above description, an example was shown in which the material of the fastening shaft 5 was made of austenitic stainless steel, which is a normal shaft material. However, this was changed to a ferritic heat-resistant special steel like the filter frame and the inner tank material. It is also possible. In that case,
The fastening shaft 5 may be attached to the opening frame 2 to make it longer. In this case, rust is generated on the shaft using SUS430, but rust can be avoided on the ferritic heat-resistant special steel.

[0025]

As described above, according to the present invention, in the first aspect of the present invention, the heat treatment apparatus includes a peripheral member having a predetermined configuration, a filter, a seal member, and a pull member, and the structural member of the filter is provided. Is formed of ferritic special heat-resistant steel with a composition that enhances heat resistance among ferritic heat-resistant steels, and the tensile member is fixed at a position near the end of the structural member opposite to the side that is pressed against the seal member Therefore, even under a high-temperature heat treatment condition, it is possible to prevent the filter from rusting, maintain the cleanliness, and eliminate the troubles caused by thermal expansion.

That is, since the structural member of the filter is made to have a special composition for increasing heat resistance, the corrosion resistance is also improved due to an increase in the content of Cr, etc., and although it is a ferritic heat-resistant steel, it is sufficiently higher than 500 ° C. In addition to having heat resistance, no rust is generated even under such high temperature use conditions.
Then, the heat treatment apparatus can be used as a high-temperature clean oven.

Since a ferritic stainless steel is usually used in the processing chamber of the heat treatment apparatus to reduce thermal stress and the like, by using the same ferritic material for the structural members of the filter, these thermal expansion strains can be reduced. Can be about the same. As a result, even if there is a frequent temperature change between a high temperature and a normal temperature, the contact state around the seal member interposed between the filter and the surrounding member for the filter opening constituting the structural part in the processing chamber does not change, and the sealing performance is not changed. Can be favorably maintained.

Further, in order to uniformly press the periphery of the structural member of the filter against the seal member, a structure is employed in which the pull member pulls the position opposite to the contact position of the structural member to the seal member toward the seal member. However, since the tensile member is usually formed as a tensile shaft, and austenitic stainless steel, which is a general shaft material, is generally used as the material, unlike the ferrite-based filter structural member, the thermal expansion coefficient of the tensile member increases. Since the fixing position of the tension member is set to a position close to the tension position, the length is sufficiently short, and the difference in thermal expansion between the structural member and the tension member can be sufficiently reduced.
As a result, even when a temperature difference between high and low temperatures occurs, the pressing force of the structural member against the seal member is maintained, and the sealing performance is maintained in a good state.

According to the second aspect of the present invention, in a filter which is mounted such that one surface of a structural member of the filter is in pressure contact with a peripheral member provided so as to form an opening for the filter, Since it is made of ferritic special heat resistant steel with a composition that enhances heat resistance among ferritic heat resistant steels, it provides a filter for high temperature heat treatment equipment that can maintain cleanliness without rusting and has good sealing performance. be able to.

According to the third aspect of the present invention, the structure member is pressed against the seal member by a pull member,
Since the tension member is fixed at a position close to the tension position at the tip of the structural member, even if the material of the structural member and the material of the tension member are different, the influence of thermal expansion is sufficiently reduced. Then, the filter can be uniformly pressed against the seal member by a simple tightening structure and a simple tightening operation, so that the sealing property therebetween can be maintained well.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration example of a filter mounting portion of a clean oven which is a heat treatment apparatus to which the present invention is applied.

FIGS. 2A and 2B are a plan view and a front view of the device.

FIG. 3 is a side view showing an example of the overall configuration of the clean oven.

FIG. 4 is a curve diagram showing test results of high-temperature oxidation characteristics of ferritic special heat-resistant steel (special steel A).

FIG. 5 is a curve diagram showing test results of other high-temperature oxidation characteristics of the special steel A.

FIG. 6 is an explanatory diagram of a state when a filter is mounted in the above-described device.

FIG. 7 is an explanatory view showing a state in which a packing mounting portion of a conventional device is thermally expanded.

FIG. 8 is a side view showing a configuration example of a filter mounting portion of a clean oven which is a conventional heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Opening 2 Opening frame (peripheral member) 3 Filter 4 Packing (seal member) 5 Tightening shaft (pulling member) 6 Inner tub (processing chamber) 31 Filter part 32 Filter frame (structural member) 32a Rear end surface (one side surface) ) 32b Tip surface (opposite end)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tsutomu Hirata 3-5-6 Tenjinbashi, Kita-ku, Osaka-shi, Osaka Prefecture F-term (reference) 4D019 AA01 BA02 CB01 CB04 4K050 AA02 BA16 CA04 DA00

Claims (3)

[Claims] 1. A filter provided with a peripheral member provided to form an opening for a filter through which air for heat treatment supplied to a processing chamber passes, a filter including a structural member surrounding a filter portion, and a surface of the structural member. A sealing member interposed between the one surface facing the upstream side in the air passing direction and the peripheral member, and the opposite of the one side so that the one surface is pressed against the sealing member. A heat-treating device, comprising: a pulling member for pulling a side end in the one-side direction; and supplying air for heat treatment to the processing chamber through the filter through the opening. Is a ferrite-based special heat-resistant steel having a composition that enhances heat resistance among ferritic heat-resistant steels, and the tensile member is fixed at a position near the opposite end. 2. A filter mounted on a heat treatment apparatus equipped with a peripheral member so as to form an opening for the filter, the filter including a structural member surrounding a filter portion, and a surface of the structural member through which air passes. A filter that is mounted so that the one surface is pressed against a seal member interposed between the one surface and the peripheral member that is the upstream side in the direction, wherein the structural member is made of a heat-resistant ferritic steel. A filter comprising a special heat-resistant ferritic steel having a composition that enhances heat resistance. 3. The heat treatment apparatus further includes a pulling member for pulling the opposite end of the one side in the direction of the one side so that the one surface is pressed against the sealing member. The filter according to claim 2, wherein a member is fixed at a position near the opposite end.