JPH0569163U - Hot gas shutoff valve - Google Patents

Abstract

(57) [Summary] [Objective] To provide a gas shutoff valve capable of stably maintaining a high degree of sealing property for a long period of time even in a high temperature gas such as an exhaust gas discharged from a CVD facility. It is in. [Structure] A rotatable valve shaft and a valve body fixed to the valve shaft via an arm, and a tubular body provided on the front side of a metal body of the valve body so as to project toward the shutoff port side. A heat resistant cloth to be pressed against the portion is fixed, and at least the valve shaft and the arm have a fluid cooling structure having a refrigerant flow passage therein.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas shutoff valve suitable for shutting off exhaust gas that is extremely harmful to the human body, such as exhaust gas discharged from so-called CVD equipment.

[0002]

[Prior art]

As a method of manufacturing a high silicon steel sheet, a so-called CVD method (Chemical Vapor Deposition method) is known as a Si diffusion and permeation treatment. Usually, the production of high silicon steel sheet by this CVD method is carried out in a facility equipped with a steel sheet heating zone, a CVD zone, a soaking zone, and a cooling zone first, after heating the steel sheet to a predetermined temperature in the heating zone. , Si compound such as SiCl ₄ by CVD band hot containing (hereinafter, illustrating a SiCl ₄ as an example) (usually after about 1200 ° C. before) siliconizing treatment in a non-oxidizing gas atmosphere (CVD process) By soaking, Si was permeated from the surface of the steel sheet, and then in a soaking zone, the steel sheet was subjected to soaking diffusion treatment in a non-oxidizing gas atmosphere containing no Si compound, and the permeated Si was diffused into the steel sheet. Then, it cools in a cooling zone. In the above CVD band, always a certain amount of SiCl ₄ gas to enhance the purity of the SiCl ₄ gas is bubbler, and discharge (exhaust gas) by and blower a certain amount of the in-furnace gas. Since this exhaust gas is hot, it is cooled by a gas cooler and then passed through a dust collector.

[0003]

[Problems to be solved by the device]

The main composition of the exhaust gas, N ₂ (carrier gas), SiCl ₄ (reaction gas), when is a F eCl ₂ (reaction product gas), FeCl ₂ (iron chloride) drops temperature up to 670 ° C. or less solid And then adheres to the inner surface of the exhaust gas duct path, and this adhered material gradually grows. Therefore, it is necessary to periodically shut off the exhaust gas duct path from the CVD zone and clean the exhaust gas duct path.

[0004] Such shutoff of the exhaust gas duct path is usually performed on the inlet side of the gas cooler, etc., but the shutoff valve for this purpose is exposed to high temperature exhaust gas for a long period of time, and it has been used conventionally. Such a shutoff valve does not provide sufficient durability. In particular, the exhaust gas from the CVD equipment contains high-temperature components that are extremely harmful to the human body, so extremely high sealing performance is required to shut off the gas. It is difficult to maintain such sealability stably over a long period of time.

The present invention has been made in view of such a conventional problem, and maintains a high level of sealing stability for a long time even in a high temperature gas such as exhaust gas discharged from a CVD equipment. It is intended to provide a gas shutoff valve that can

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the gas cutoff valve of the present invention comprises a rotatable valve shaft and a valve body fixed to the valve shaft via an arm, and a metal body of the valve body. A heat-resistant cloth to be pressed against the tubular portion protruding toward the shutoff side is fixed to the front surface of the valve, and at least the valve shaft and the arm have a fluid cooling structure having a refrigerant flow passage therein. Is its characteristic. In the gas cutoff valve of the present invention, the heat resistant cloth attached to the valve body is preferably made of a ceramic fiber.

[0007]

[Action]

 The valve body of the gas shutoff valve opens and closes with respect to the shutoff opening as the valve shaft rotates. The shut-off opening of the valve body is closed by pressing the heat resistant cloth on the front surface of the valve body against the tubular portion projecting on the shut-off opening side. The surface pressure of the heat resistant cloth against the blocked opening is performed by, for example, a counter weight attached to the valve shaft. Since the heat-resistant cloth is pressed against the tubular portion on the side of the blocked port with a predetermined surface pressure, the blocked port can be closed with a high degree of sealing property.

Further, since the arm holding the valve shaft and the valve body has a fluid cooling structure such as water cooling, and the seal portion of the valve body is made of a heat resistant cloth, even if it is exposed to high temperature gas for a long period of time, Stable durability can be obtained. Further, particularly by using a ceramic fiber as the heat resistant cloth, long-term durability can be obtained even against high temperature exhaust gas such as SiCl ₄ exhausted from the CVD equipment.

[0009]

【Example】

 1 to 5 show an embodiment in which the gas cutoff valve of the present invention is provided inside a gas cooler in an exhaust gas treatment path of a CVD equipment. A U-shaped gas flow path is formed inside the gas cooler body 1, and an exhaust gas inlet 100 is formed on the upper side of one side X and an exhaust gas outlet 101 is formed on the upper side of the other side Y thereof. Has been done. The gas shutoff valve 3 of the present invention is provided so that the inlet 100 can be closed from the inside of the cooler as shown in FIGS.

The gas cutoff valve 2 includes a valve shaft 4 that is rotatably provided so as to penetrate through both upper side walls on the one side X side, and a valve fixed to the valve shaft 4 via an arm 5. It consists of body 6. FIG. 5 shows a cross-sectional structure of the valve body 6, in which a flange portion 8 is provided on the outer periphery of the front surface of the metal body 7 of the valve body 6, and a proper thickness is provided in a recess 9 inside the flange portion 8. The heat-resistant cloth 10 is placed on the metal main body 7 by fixing means 11 composed of bolts and nuts.

The heat-resistant cloth 10 is usually made of a material such as ceramic fiber, but in particular, the one made of ceramic fiber containing alumina and silica as the main components is most preferable in terms of heat resistance and corrosion resistance. preferable. In addition, in this embodiment, asbestos layer 12 is provided inside heat-resistant cloth 10 instead of heat-resisting cloth entirely in recess 9 for the purpose of cost reduction. On the other hand, the inner pipe 13 is fitted inside the inlet 100, and the tip of the inner pipe 13 projects into the gas flow path by an appropriate length.

A counter weight 15 is attached to one end side of the valve shaft 4 protruding outside the machine via an arm 14. When the shut-off valve is closed, the counter weight 15 secures the surface pressure in the seal portion. I have to. During normal operation, the gas shutoff valve 3 is retracted to the position shown by the phantom line in FIG. 3, and therefore, as shown in FIG. 4, at the end of the valve shaft 4, An arm 16 having a pin insertion hole 17 and extending in the opposite direction to the arm 14 is provided, and a pin locking hole 18 is provided on the gas cooler body 1 side, and fixed to the pin insertion hole 17 and the pin locking hole 18. By inserting the pin 19, the gas cutoff valve 3 can be held in an open state against the action of the counterweight 15.

Further, as shown in FIG. 1, the valve shaft 4 and the arm 5 have a fluid cooling structure having therein a coolant passage a such as cooling water. A refrigerant supply pipe 31 and a discharge pipe 32 are connected to each end of the valve shaft 4, and a refrigerant flow path a in the valve shaft 4 and a cooling medium flow path a in the arm 5 are connected to the communication pipes 33, 33. The refrigerant such as the cooling water is connected to the refrigerant through the supply pipe 31 → the one refrigerant passage a of the valve shaft 4 → the communication pipe 33 → the refrigerant passage a of the arm 5 → the communication pipe 33 ′ → the valve shaft 4 The other refrigerant flow path a-> the discharge pipe 32 flows.

Explaining other configurations inside the gas cooler, first, a dust receiving bucket 25 is arranged at the U-shaped bottom portion Z of the gas flow path. By making the gas passage in the machine U-shaped in this way, the dust contained in the exhaust gas is dropped to the U-shaped bottom (received by the dust receiving bucket 25), and the cooling pipe on the downstream side of the gas passage is provided. The amount of dust reaching the swarm can be reduced. A cooling pipe group A including a large number of cooling pipes 2 is arranged on the downstream side of the gas flow channel, that is, on the other side Y side of the U-shaped gas flow channel. The respective cooling pipes 2 constituting the cooling pipe group A are arranged so as to horizontally traverse the gas passage in the vertical direction.

In the gas cooler provided in the exhaust gas treatment system of the CDV equipment, dust is remarkably attached to the cooling pipe portion, and when dust attachment and growth progress in this portion, the gas cooler is eventually blocked and the line The operation has to be stopped. Therefore, in this embodiment, the cooling pipe group A is provided with a mechanism capable of easily removing the dust adhering to the cooling pipe portion even during operation.

The dust removing mechanism has a plurality of insertion holes into which the cooling pipes 2 can be slidably inserted or loosely inserted, and the cooling pipes 2 are inserted into the respective insertion holes of the plurality of cooling pipes 2. Is composed of a dust removing plate 20 attached by being inserted or loosely inserted, and a moving mechanism 21 for moving the dust removing plate in the axial direction of the cooling pipe.

In this embodiment, the cooling pipe group A is divided into a plurality of (five) groups in the vertical direction, and the dust removing plates 20a to 20e are attached to the cooling pipe groups of these groups. Each of the dust removing plates 20a to 20e has a large number of insertion holes 200 on the entire surface, and the cooling pipes 2 are slidably inserted or loosely inserted into the insertion holes 200, whereby the cooling pipes are inserted. It is slidably attached to the group in the axial direction (horizontal direction).

The moving mechanism 21 is composed of a slide shaft 22 connected to the dust removing plates 20a to 20e. That is, the tip of the slide shaft 22 inserted into the machine is connected to each of the dust removing plates 20a to 20e via a seal composed of a gland packing 26 and a gas sealing bush 27, and this slide By slidingly moving the shaft 22 in the longitudinal direction, the dust removing plates 20a to 20e can be slidably moved in the cooling pipe tube axial direction. The movement of the slide shaft 22 can be performed manually or by a drive mechanism such as a cylinder device.

The inside of the wall 24 of the gas cooler body 1 has a fluid cooling structure in which a coolant flow path a for cooling water or the like is formed. In addition, in the other drawings, 30 is an opening / closing lid for taking out the dust receiving bucket 25 to the outside at the time of collecting dust, and 34 is an exhaust gas conduit connected to each of the inlet 100 and the outlet 101. Further, in the present embodiment, the counterweight 15 and the fixing pin 19 are used as means for applying the surface pressure to the shutoff port side to the valve body 6 and holding the valve body in the open state, but instead of this, Any mechanism such as an opening / closing mechanism in which a spring and an air cylinder device are combined can be adopted.

6 and 7 show an example in which a drive device 23 (cylinder device) is used for the moving mechanism 21, and a plurality of slide shafts 22 extending outside the machine are connected by a connecting plate 35. The connecting plate 35 is connected to the rod of the cylinder device which is the drive device 23. The other configurations are similar to those of the above-described embodiment, and therefore, the same reference numerals are given and the description thereof is omitted.

According to the gas cooler having the structure shown in FIG. 1 to FIG. 5, or FIG. 6 and FIG. 7, the exhaust gas discharged from the CVD equipment or the like is supplied from the inlet 100 into a U-shaped gas passage in the machine. It is introduced into the upper part on the side X on one side, cooled in the process of passing through the cooling pipe group A on the side Y on the other side U, and then discharged from the discharge port 101 and sent to the dust collector side.

The gas cutoff valve 3 is in a state shown by a phantom line in FIG. 3 because the counterweight 15 is locked by the fixing pin 19 during normal operation. When shutting off the exhaust gas from the CVD zone for cleaning the inside of the exhaust gas treatment system, the fixing pin 19 is pulled out, the valve body 6 is rotated downward by the action of the counterweight 15, and the valve body 6 is introduced. The mouth 100 is closed. The shut-off valve that closes the inlet 100 in this way has a high sealing property because the heat resistant cloth 10 is pressed against the tip of the inner pipe 13 attached to the inlet 100 by the action of the counterweight 15. Further, particularly when the heat-resistant cloth 10 made of ceramic fiber is used, long-term durability can be obtained even against high temperature exhaust gas such as SiCl ₄ discharged from the CVD equipment. In addition, since a cooling medium such as cooling water flows inside the arm 5 that holds the valve shaft 4 and the valve body 6, long-term durability can be obtained in these portions as well.

To explain the operation of the other configuration, during normal operation, the dust removing plates 20a to 20e are retracted to the positions shown in FIG. 2 or 6. The gas cooler is operated for a certain period of time, and when dust adheres to the cooling pipe group A to some extent, it is driven by the slide shaft 22 constituting the moving mechanism 21 (in the case of FIGS. 6 and 7, the slide shaft 22 is driven by the drive mechanism 23). ) Sliding the dust removing plates 20a to 20e in the cooling pipe tube axial direction (horizontal direction). Since each cooling pipe 2 is inserted or loosely inserted into the insertion hole 200 of the dust removal plates 20a to 20e, the dust attached to the surface of the cooling pipe 2 is moved by the movement of the dust removal plates 20a to 20e. Be paid off. The dust that has been blown off falls into the dust receiving bucket 25 below the cooler, and at the stage when an appropriate amount of dust has accumulated, the gas shutoff valve 3 temporarily closes the inlet 100 and opens the open / close lid 30. Remove the dust receiving bucket 25 to the outside of the machine and collect the dust.

FIG. 8 shows an exhaust gas treatment flow of a CVD treatment facility for manufacturing a high silicon steel sheet to which the gas cooler shown in FIGS. 1 to 5 or 6 and 7 is applied. In the figure, 40 is a continuous processing furnace, which comprises a heating zone 42, a CVD zone 43, a soaking zone 44 and a cooling zone 45. The exhaust gas processing system 41 cools, collects, and collects the exhaust gas discharged from the CVD zone 43. From its upstream side, a gas cooler 46, a dust collector 47 (bag filter), an exhaust gas processor 48, and a suction blower. The gas shutoff valve 3 of the present invention is provided inside the gas cooler 46. Incidentally, in this flow, the gas cooler 46 is provided in each of the two exhaust gas conduits 34 arranged in parallel.

As described above, the gas shutoff valve of the present invention is a shutoff valve suitable for a treatment route of exhaust gas that is extremely harmful to the human body at high temperature such as exhaust gas discharged from a CVD equipment, and has an excellent seal. It is applicable not only to CVD equipment but also to any equipment that handles high-temperature gas because of its durability and durability.

[0026]

[Effects of the Invention] According to the gas shutoff valve of the present invention described above, it is possible to stably maintain a high level of sealing performance for a long period of time even in high temperature gas such as exhaust gas discharged from a CVD facility. it can.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a vertical sectional view of a gas cooler having a gas cutoff valve attached thereto.

FIG. 2 is a partially cutaway side view of the gas cooler shown in FIG.

FIG. 3 is a sectional view of the gas cooler shown in FIG. 1 taken along the line III-III.

FIG. 4 is a partial cross-sectional plan view partially showing the counterweight of the embodiment shown in FIG. 1 and its periphery.

5 is a longitudinal sectional view of the valve body of the embodiment shown in FIG.

FIG. 6 is a partially cutaway side view showing another embodiment of a gas cooler to which the gas cutoff valve of the present invention is applied.

7 is a horizontal sectional view partially showing a cooling pipe portion of the gas cooler shown in FIG.

FIG. 8 is an explanatory diagram showing an exhaust gas treatment flow of a CVD treatment facility to which the gas cutoff valve of the present invention is applied.

[Simple explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas cooler main body, 2 ... Cooling pipe, 3 ... Gas cutoff valve, 4 ... Valve shaft, 5 ... Arm, 6 ... Valve body, 7 ... Metal body, 8 ... Flange part, 9 ... Recessed part, 10 ... Heat resistant cloth, 11 ...
Fixing means, 12 ... Asbestos layer, 13 ... Inner tube, 14 ... Arm,
15 ... Counter weight, 16 ... Arm, 17 ... Pin insertion hole, 18 ... Pin locking hole, 19 ... Fixing pin, A ... Cooling pipe group

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F27D 17/00 105 G 6977-4K

Claims (2)

[Scope of utility model registration request] 1. A gas shutoff valve used for shutting off high-temperature gas, comprising a rotatable valve shaft and a valve body fixed to the valve shaft via an arm, and the metal of the valve body. A heat-resistant cloth to be pressed against a tubular portion protruding toward the blocked opening side is fixed to the front surface of the main body, and at least the valve shaft and the arm have a fluid cooling structure having a refrigerant passage therein. High temperature gas shutoff valve. 2. The high temperature gas cutoff valve according to claim 1, wherein the heat resistant cloth is made of ceramic fiber.