JP2009250264A - Safety valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety valve which is of a space-saving design, of a simple structure, and cost effective. <P>SOLUTION: The safety valve 2, which is operated by both of positive pressure and negative pressure in internal and external relative pressure of a box portion 24 functioning as a gas passage, comprises: a flat plate portion 11, which constitutes a part of the box portion 24 and in which a main ventilation hole 14 for ventilating air is formed; a main valve plate 12, which is formed in such a size as to cover the main ventilation hole 14 of the flat plate portion 11 and in which sub-ventilation holes 15 for ventilating air are formed inside from a range overlapping the main ventilation hole 14; a sub-valve plate 13, which covers the sub-ventilation holes 15 of the main valve plate 12; a plurality of main guide shafts 19, which are passed through the peripheral portion of the main valve plate 12 and the flat plate portion 11 at equal intervals; a plurality of main springs 20, through which each main guide shaft 19 is passed to urge the main valve plate 12 to the flat plate portion 11 in a contact state; a sub-guide shaft 16, which is passed through the center portion of the main valve plate 12 and that of the sub-valve plate 13; and a sub-spring 17, through which the sub-guide shaft 16 is passed to urge the sub-valve plate 13 to the main valve plate 12 in a contact state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a safety valve that operates with both positive and negative relative pressures inside and outside a gas flow path.

  As a cleaning apparatus for cleaning semiconductors and electronic devices with a solvent, there is an apparatus that exhausts exhaust gas at a specific timing in one cycle by using a solvent in a part of one cycle process such as a cleaning / drying process. Such an apparatus discharges exhaust gas intermittently by repeating the process of one cycle. At the time of discharge, a large amount of exhaust gas is discharged in a short time.

  An exhaust gas treatment device is connected to the cleaning device by piping. The exhaust gas treatment apparatus sucks and takes in the exhaust gas with a suction pump or the like, and removes the solvent in the exhaust gas.

  For example, in an abnormal state where exhaust gas exceeding the specified amount is discharged from the cleaning device or the exhaust gas from the exhaust gas treatment device is not in time, the internal pressure of the pipes connecting the devices is excessive relative to the external pressure. High pressure (positive pressure) may cause the pipe to burst and break.

  Also, when the internal pressure of the pipe becomes excessively low (negative pressure) due to suction of the exhaust gas treatment device, the pipe may be crushed and damaged.

  For this reason, it is necessary to attach a safety valve to prevent the internal pressure of the pipe from becoming excessively high or low.

  For example, Patent Literature 1 discloses an atmospheric discharge valve that discharges an internal fluid to the outside. This atmospheric release valve releases the internal fluid to the outside by moving the valve main body which becomes the lid of the container along the groove of the guide.

  Patent Document 2 discloses a safety valve that operates with both positive pressure and negative pressure. In this safety valve, a cylindrical valve body having a floating plate coupled to an end thereof is urged so as to protrude outward from the pressure vessel by a large-diameter coil spring surrounding the periphery. Further, in this safety valve, the top-like valve element disposed inside the cylindrical valve element is urged toward the inside of the pressure vessel by the small diameter coil spring. The small-diameter coil spring surrounds the periphery of the guide rod, and the guide rod is guided by a through hole opened in the center of the floating plate.

  In this safety valve, when the inside of the pressure vessel becomes higher in pressure than the elastic force of the small-diameter coil spring, the coma-shaped valve body operates so as to move to the outside of the pressure vessel, and the high-pressure fluid is discharged to the outside. Further, when the inside of the pressure vessel becomes lower than the elastic force of the large coil spring, the cylindrical valve body operates so as to move to the inside of the pressure vessel, and external gas flows into the pressure vessel.

JP 58-50373 A JP 2004-132528 A

  When the atmospheric release valve shown in the conventional Patent Document 1 is arranged in a pipe that becomes a gas flow path, it operates only when the internal pressure of the pipe becomes high (positive pressure). For this reason, it is necessary to mount another safety valve for operating when the internal pressure of the pipe becomes a low pressure (negative pressure). For example, it is conceivable to arrange the safety valve of Patent Document 1 on the inside of the pipe. However, the use of two safety valves has the problem of requiring twice as much space for arrangement.

  In addition, the safety valve disclosed in Patent Document 2 has a problem that it is expensive because the shape of the cylindrical valve body, the top-shaped valve body, and the like is complicated.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an inexpensive safety valve that is space-saving and has a simple structure.

  The safety valve according to claim 1, which has been made to achieve the above object, is a safety valve in which the relative pressure inside and outside the gas flow path operates with both positive pressure and negative pressure, A flat plate portion that constitutes a part of the wall surface of the gas flow path and has a main vent hole for ventilation, and a size that covers the main vent hole of the flat plate portion, and is formed in the main vent hole. A main valve plate in which a sub vent hole for ventilation is formed inside an overlapping range, a sub valve plate that covers the sub vent hole of the main valve plate and is smaller than the main vent hole, and the main vent plate A plurality of main guide shafts that are inserted through the periphery of the main valve plate covering the pores and the flat plate portion at equal intervals, and are inserted into the main guide shafts so that the main valve plate is in close contact with the flat plate portion. A plurality of main springs to be urged are inserted through the central portion of the main valve plate and the central portion of the sub valve plate. And the sub guide shaft, characterized in that it is constituted by a secondary spring that biases in close contact with the inserted through the sub guide shaft sub valve plate to the main valve plate.

  The safety valve according to claim 2 is the safety valve according to claim 1, wherein an inner periphery of the main vent plate contacting the main valve plate and / or the main valve plate contacting the flat plate portion is provided. An annular main seal member is attached to the peripheral portion, and an annular sub seal is provided on the outer peripheral portion of the sub vent hole that contacts the sub valve plate and / or the inner peripheral portion of the sub valve plate that contacts the main valve plate. A seal member is attached.

  A safety valve according to a third aspect is the one according to the first aspect, wherein the flat plate portion is detachably disposed in the gas flow path.

  An exhaust gas treatment apparatus according to a fourth aspect is characterized in that the safety valve according to any one of the first to third aspects is disposed in an introduction pipe for introducing exhaust gas by suction with a suction pump.

  According to the safety valve of the first aspect, the main valve plate covers the main vent hole formed in the flat plate portion, the sub valve plate covers the sub vent hole for ventilation formed in the main valve plate, and the main guide shaft and The main valve plate is urged to the flat plate portion by the main spring, and the sub valve plate is urged to the main valve plate by the sub guide shaft and the sub spring. For this reason, two valves are arranged in the space of one valve. Therefore, the safety valve that operates at positive pressure and negative pressure can be made space-saving.

  Further, the flat plate portion, the main valve plate, and the sub-valve plate are all plate-shaped and have a simple shape as compared with a three-dimensional valve. Also, the main guide shaft, the sub guide shaft, the main spring, and the sub spring have a simple shape. For this reason, since a manufacturing cost can be made cheap, it can be set as a cheap safety valve.

  According to the safety valve of the second aspect, the annular seal member is attached to the outer peripheral portion of the main vent hole contacting the main valve plate and / or the inner peripheral portion of the main valve plate contacting the flat plate portion. By attaching an annular seal member to the outer peripheral portion of the sub vent hole that contacts the valve plate and / or the inner peripheral portion of the sub valve plate that contacts the main valve plate, the flat plate portion and the main valve plate are connected to each other. The valve plate and the auxiliary valve plate can be reliably sealed.

  According to the safety valve of the third aspect, since the flat plate portion is detachably disposed on the wall surface of the gas flow path, the safety valve can be removed by removing the flat plate portion. For this reason, it can be easily replaced with a positive spring or a secondary spring having different elastic forces. Therefore, the pressure at which the main valve plate and the sub valve plate start operating can be easily adjusted.

  According to the exhaust gas processing apparatus of claim 4, exhaust gas is excessively discharged by disposing the safety valve according to any one of claims 1 to 3 in the introduction pipe for introducing the exhaust gas by suction with a suction pump. Even when the suction pipe is excessively sucked by the suction pump, the introduction pipe can be reliably prevented from being broken.

Preferred form for carrying out the invention

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

  FIG. 1 is a block diagram showing an embodiment of a safety valve to which the present invention is applied.

  A safety valve unit 1 shown in FIG. 1 is a unit for arranging a safety valve 2 in the middle of a pipe serving as a gas flow path. The safety valve 2 is arranged in the opening on the upper surface of the box portion 24 so that it is hollow as a whole. It is formed in a box shape. Cylindrical connection portions 25 for connecting pipes are formed on both side surfaces of the box portion 24. By connecting the pipes to the connection parts 25, 25, the internal cavity of the box part 24 becomes a part of the gas flow path. The safety valve 2 operates both when the relative pressure inside and outside the gas flow path becomes excessively positive and excessively negative, thereby preventing the pipe from being ruptured or crushed. .

  As shown in FIG. 2, the safety valve 2 includes a flat plate portion 11, a main valve plate 12, a sub valve plate 13, three (only one is shown in the drawing) main guide shafts 19, three (only one is shown in the drawing). A main spring 20, three main springs 21 (only one is shown in the figure), a sub guide shaft 16, a sub spring 17, and a sub nut 18.

  The flat plate part 11 constitutes a part of the wall surface of the gas flow path. The flat plate portion 11 is a metal flat plate and is formed in a square shape. The flat plate portion 11 is formed with a circular main ventilation hole 14 for ventilation at the center thereof. In the flat plate portion 11, communication holes 75 are formed in the periphery of the main vent hole 14 at three equal intervals so as to communicate with the main valve plate 12 and through which a column portion 72 of the main guide shaft 19 described later can be inserted. . Further, attachment holes for screwing and fixing to the box portion 24 are formed at the four corners of the flat plate portion 11.

  An annular main seal member 50 is bonded and fixed to the flat plate portion 11 at the outer peripheral portion of the edge of the main vent hole 14 in contact with the main valve plate 12 and inside the three communication holes 75. . As an example, the main sealing material 50 is fixed to the flat plate part 11 with a rubber lip in an annular shape by vulcanization adhesion or adhesive.

  The main valve plate 12 is a circular plate made of metal. The main valve plate 12 is formed in a size that covers the main vent hole 14. A central hole 77 is formed in the central portion of the main valve plate 12 so as to communicate with the central portion of the sub-valve plate 12 and into which a column 62 of the sub-guide shaft 16 described later can be inserted. The main valve plate 12 is formed with a sub-ventilation hole 15 constituted by three holes for ventilation inside the range overlapping with the main vent hole 14 and excluding the central portion. The main valve plate 12 communicates with the communication hole 75 of the flat plate portion 11 when the main vent hole 14 is covered at three locations at equal intervals around the main valve plate 12, and the screw portion 73 of the main guide shaft 19 can be inserted through the main valve plate 12. A communication hole 76 is formed.

  The sub-valve plate 13 is a circular plate made of metal. A central hole 78 is formed in the central portion of the sub valve plate 13 so as to communicate with the central hole 77 in the central portion of the main valve plate 11 and into which the screw portion 63 of the sub guide shaft 16 can be inserted. The sub valve plate 13 covers the sub vent hole 15 formed in the main valve plate 12 and is formed in a size smaller than the main vent hole 14.

  An annular secondary seal member 51 is bonded and fixed to the secondary valve plate 13 on the inner peripheral portion of the edge contacting the primary valve plate 12. As an example, the sub seal material 51 is fixed to the sub valve plate 13 with a rubber lip in an annular shape by vulcanization adhesion or adhesive.

  The auxiliary guide shaft 16 is, for example, a stepped hexagon bolt, and a hexagonal head portion is provided with a flange 61, and the columnar column portion 62 has a smaller diameter at the tip thereof. The screw part 63 is attached and formed. The auxiliary spring 17 is a spring spring and has an elastic force. The auxiliary spring 17 has a diameter that can be inserted through the column portion 62 of the auxiliary guide shaft 16 and can be locked by the flange 61 of the auxiliary guide shaft 16. The sub-nut 18 is formed with a diameter capable of being engaged with the sub-guide shaft 16 and locking the sub-spring 17.

  The main guide shaft 19 is, for example, a stepped hexagon bolt, and a hexagonal head portion is provided with a flange 71, and the columnar column 72 has a smaller diameter at the tip thereof. The screw part 73 is attached and formed. The main spring 20 is a spring spring and has an elastic force. The main spring 20 has a diameter that can be inserted through the column portion 72 of the main guide shaft 19 and can be locked by the flange 71 of the main guide shaft 19. The main nut 21 is formed with a diameter capable of being engaged with the main guide shaft 19 and locking the main spring 20.

  As shown in FIG. 2, the auxiliary guide shaft 16 through which the auxiliary spring 17 is inserted is inserted from the main valve plate 12 side into the central hole 77 and the central hole 78 of the auxiliary valve plate 13, and the auxiliary valve is engaged with the auxiliary nut 18. Tightened from the plate 13 side. At this time, the auxiliary spring 17 is compressed. In this case, the column portion 62 of the sub guide shaft 16 passes through the center hole 77 of the main valve plate 12. The step at the boundary between the column portion 62 and the screw portion 63 abuts on the auxiliary valve plate 13, and the auxiliary nut 18 is screwed to the screw portion 63 via the auxiliary valve plate 13, so that the auxiliary guide shaft 16 becomes the auxiliary valve plate. 13 is fixed.

  The main guide shaft 19 inserted through the main spring 20 is inserted into the communication hole 75 and the communication hole 76 of the main valve plate 12 from the flat plate portion 11 side, and is tightened from the main valve plate 12 side with the main nut 21. At this time, the main spring 20 is compressed. In this case, the support column 72 of the main guide shaft 19 passes through the communication hole 75 of the flat plate portion 11. The step at the boundary between the support column 72 and the screw portion 73 abuts on the main valve plate 12 and is screwed to the screw portion 73 with the main nut 21 via the main valve plate 12 so that the main guide shaft 19 is moved to the main valve plate. 12 is fixed. In FIG. 2, only the assembled state of one main guide shaft 19 is shown, but the main guide shaft 19, the main spring 20, and the main nut 21 are similarly attached to the remaining two locations.

  As shown in FIG. 1, the combined safety valve 2 is fixed with screws 22 at the four corners of the flat plate portion 11 to constitute the upper surface of the box portion 24. Thus, the flat plate part 11 is detachably fixed to the box part 24 by the screws 22.

  FIG. 3 shows a cross-sectional view taken along the line AA of the top view shown in FIG.

  As shown in FIG. 3, the main valve plate 12 and the sub-valve plate 13 are brought into close contact with each other by being biased by the elastic force of the sub-spring 17. Further, the flat plate portion 11 and the main valve plate 12 are in contact with each other by being biased by the elastic force of the three main springs 20. As a result, the main vent hole 14 and the sub vent hole 15 are closed. In this case, since the main seal member 50 is attached to the flat plate portion 11 and the sub seal member 51 is attached to the sub valve plate 13, the flat plate portion 11 and the main valve plate 12, the main valve plate 12 and the sub valve plate 13 are connected. Each is securely sealed.

  For this reason, the gas inside the box part 24 is not leaked from the safety valve 2 to the outside, and the outside gas is kept from entering the box part 24 through the safety valve 2. Further, the main guide shaft 19 protrudes only in three places inside the box portion 24. These are thin rods, and even if gas flows at high speed inside the box portion 24, there is almost no gas resistance.

  Next, the operation of the safety valve 2 will be described.

  For example, as shown in FIG. 6, the safety valve unit 1 is disposed in the middle of an introduction pipe 3 of an exhaust gas treatment device 4 that introduces exhaust gas. In this case, the introduction pipe 3 becomes a gas flow path in the present invention.

  The exhaust gas generator 40 cleans and drys electronic equipment and the like with a solvent, and intermittently discharges a large amount of exhaust gas (an example of gas). The exhaust gas generator 40 includes a cleaning / drying chamber 41 and an aeration tank 42 for recovering a part of the solvent by bubbling the exhaust gas discharged from the cleaning / drying chamber 41.

  The exhaust gas treatment device 4 includes an introduction pipe 3, an introduction means 5, a storage tank 6, a vacuum pump 7, and a condenser 8 arranged in this order from the exhaust gas generation device 40 side. In this exhaust gas treatment device 4, the suction of the vacuum pump 7, which is a suction pump, brings the storage tank 6 into a depressurized state during a period when the exhaust gas is not discharged, and the exhaust gas is introduced into the storage tank 6 at once when the exhaust gas is discharged. To do. In order to operate in this way, the introducing means 5 is arranged upstream of the storage tank 6.

  The introduction pipe 3 is connected to an exhaust gas generator 40 that generates exhaust gas. The introduction pipe 3 is provided with a safety valve unit 1 in the middle and a differential pressure sensor 38.

  The introduction means 5 includes a manual valve 31 and a solenoid valve 32 attached to a pipe 35 connecting the introduction pipe 3 to the storage tank 6 inside the apparatus, and further to a bypass pipe 37 that bypasses the manual valve 31 and the solenoid valve 32. A manual valve 33 is provided. The manual valve 33 limits the gas flow rate flowing through the bypass pipe 37 to a smaller amount than the gas flow rate flowing through the pipe 35.

  The control unit 10 detects the discharge of exhaust gas based on the differential pressure between the pressure in the introduction pipe 3 and the external pressure output from the differential pressure sensor 38. The control unit 10 immediately opens the solenoid valve 32 when it detects exhaust gas emission due to a decrease in the differential pressure. Further, the control unit 10 controls the electromagnetic valve 32 to be closed when the end of the discharge is detected due to an increase in the differential pressure. For this reason, during a period when exhaust gas is not discharged, only a small amount of gas is sucked through the bypass pipe 37, and the inside of the storage tank 6 is in a decompressed state. When the exhaust gas is discharged, the control unit 10 immediately opens and controls the electromagnetic valve 32, so that the exhaust gas passes through the pipe 35 (electromagnetic valve 32) and is immediately introduced into the depressurized storage tank 6.

  The condenser 8 cools the exhaust gas sent from the vacuum pump 7, condenses the solvent in the exhaust gas, and cleans the exhaust gas. The condensed solvent is discharged from the discharge valve 39 and collected.

  In the safety valve unit 1 arranged as described above, first, an operation when the internal pressure of the introduction pipe 3 becomes excessively higher (positive pressure) than the external pressure will be described.

  For example, when exhaust gas emission detection by the control unit 10 of the exhaust gas treatment device 4 is delayed, the opening control of the electromagnetic valve 32 is delayed, and the pressure of the introduction pipe 3 is excessively increased. Therefore, the pressure in the safety valve unit 1 (box portion 24) becomes excessively high relative to the external pressure.

  In this case, as shown in FIG. 4, the main valve plate 12 of the safety valve 2 is guided by the main guide shaft 19 due to a pressure difference and moves away from the flat plate portion 11. For this reason, a gap is formed between the flat plate portion 11 and the main valve plate 12, and the exhaust gas is discharged to the outside from the main vent hole 14 as indicated by a thick arrow in the drawing. Therefore, the pressure in the box part 24 (introduction piping 3) falls, the pressure difference inside and outside the introduction piping 3 becomes small, and the rupture breakage of the introduction piping 3 can be prevented.

  When the pressure in the box portion 24 is reduced, the main valve plate 12 is brought into close contact with the flat plate portion 11 by the elastic force of the main spring 20, and the emission of exhaust gas is stopped.

  The pressure (relative pressure) at which the main valve plate 12 is actuated to start emission of exhaust gas is determined by the elastic force of the three main springs 20. Therefore, by changing the elastic force of the main spring 20, it can be adjusted so that the exhaust gas starts to be released at an arbitrary pressure.

  Next, the operation when the internal pressure of the introduction pipe 3 becomes excessively lower (negative pressure) than the external pressure will be described.

  For example, when the exhaust gas generator 40 does not discharge the exhaust gas for a long time or when the vacuum pump 7 of the exhaust gas treatment device 4 is excessively operated, the pressure in the introduction pipe 3 is excessively reduced. Therefore, the pressure in the safety valve unit 1 (box portion 24) becomes excessively low with respect to the external pressure.

  In this case, as shown in FIG. 5, the auxiliary valve plate 13 of the safety valve 2 is guided by the auxiliary guide shaft 16 due to the pressure difference and moves away from the main valve plate 12. For this reason, a gap is formed between the main valve plate 12 and the sub valve plate 13, and as shown by a thick arrow in the drawing, the sub vent hole 15 of the main valve plate 12 and the main vent hole 14 of the flat plate portion 11. Through this, outside air is introduced into the box 24. Therefore, the pressure in the box part 24 (introduction piping 3) rises, the pressure difference inside and outside the introduction piping 3 becomes small, and the collapse of the introduction piping 3 can be prevented.

  When the pressure difference between the inside and outside of the box portion 24 becomes small, the auxiliary valve plate 13 is brought into close contact with the main valve plate 12 by the elastic force of the auxiliary spring 17, and the introduction of outside air is stopped.

  The pressure (relative pressure) at which the auxiliary valve plate 13 is activated to start the introduction of outside air is determined by the elastic force of the auxiliary spring 17. Therefore, by changing the elastic force of the auxiliary spring 17, it is possible to adjust so as to start introduction of outside air at an arbitrary pressure. The pressure at which the sub valve plate 13 starts operating can be adjusted independently of the pressure at which the main valve plate 12 starts operating.

  Thus, according to the safety valve 2, the main vent plate 14 covers the main vent hole 14 formed in the flat plate portion 11, and the sub vent hole 15 for ventilation formed in the main valve plate 12 serves as the sub valve plate 13. The main valve plate 12 is urged to the flat plate portion 11 by the three main guide shafts 19 and the main springs 20, and the sub valve plate 13 is urged to the main valve plate 12 by the sub guide shafts 16 and the sub springs 17. Therefore, the two valves are constituted by a single valve space. Therefore, it is not necessary to separately arrange safety valves that operate with positive pressure and negative pressure, and only one place is required, so that space can be saved.

  The flat plate portion 11, the main valve plate 12, and the sub-valve plate 13 are all plate-shaped and have a simple shape as compared with a three-dimensional valve. The main guide shaft 19, the sub guide shaft 16, the main spring 20, and the sub spring 17 also have a simple shape. For this reason, since a manufacturing cost can be made cheap, it can be set as the cheap safety valve 2. FIG. Further, since the flat plate portion 11, the main valve plate 12, and the sub valve plate 13 are all plate-like and thin, they can be configured in a space-saving manner.

  Furthermore, according to this safety valve 2, the safety valve 2 can be easily removed by removing the flat plate portion 11 because the flat plate portion 11 is detachably disposed on the box portion 24 serving as a gas flow path. For this reason, it can be easily replaced with the positive spring 20 and the secondary spring 17 having different elastic forces. Therefore, the pressure at which the main valve plate 12 and the sub valve plate 13 start operating can be easily adjusted.

  As shown by a broken line in FIG. 6, a collection box 55 is arranged around the safety valve unit 1, and the exhaust gas discharged to the outside by the operation of the safety valve unit 1 is collected, and the cleaning / drying chamber 41. You may return to.

  Next, another embodiment of the safety valve to which the present invention is applied will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure similar to the already demonstrated structure, and description is abbreviate | omitted.

  A safety valve 2a is attached to the safety valve unit 1a shown in a sectional view in FIG. In the safety valve 2a, the sub guide shaft 16 through which the sub spring 17 is inserted is inserted from the sub valve plate 13 side into the center hole 78 and the center hole 77 of the main valve plate 12, and the sub nut 18 is used to close the main valve plate 12 side. It is tightened from. That is, the auxiliary spring 17 is disposed on the inner side of the box portion 24. In this case, the center hole 78 is formed with a hole diameter through which the column part 62 is inserted, and the center hole 77 is formed with a hole diameter through which the screw part 63 is inserted. About another structure, it is comprised similarly to the safety valve 2 of FIG.

  Even in the safety valve 2a, when the pressure inside the box portion 24 becomes excessively low relative to the external pressure, the auxiliary valve plate 13 is guided by the auxiliary guide shaft 16 due to the pressure difference and away from the main valve plate 12. Moving. Therefore, a gap is formed between the main valve plate 12 and the sub valve plate 13, and outside air is introduced into the box portion 24 through the sub vent hole 15 of the main valve plate 12 and the main vent hole 14 of the flat plate portion 11. As a result, the pressure difference between the inside and outside becomes small. Therefore, it is possible to prevent the introduction pipe 3 from being crushed and broken.

  When the pressure inside the box portion 24 becomes excessively higher than the external pressure, the box 24 operates in the same manner as the safety valve 2.

  In this safety valve 2a, since the auxiliary guide shaft 16 and the auxiliary spring 17 do not protrude outside the box portion 24, further space saving can be achieved. Only the main guide shaft 19 and the sub guide shaft 16 protrude from the box portion 24 at three locations. These are thin rods, and even if gas flows at high speed inside the box portion 24, there is almost no resistance.

  The safety valve to which the present invention is applied can be arranged not only in the direction shown in FIG. 3 but also in the direction shown in FIG. 8, that is, in the opposite direction.

  In the safety valve unit 1b shown in a sectional view in FIG. 8, the safety valve 2 is disposed in the opening of the box portion 24 from the inside. In the safety valve unit 1 already described, as shown in FIG. 3, the safety valve 2 is fixed in a direction in which the auxiliary guide shaft 16 protrudes outward from the outside of the opening of the box portion 24 (upper side in the drawing) In the safety valve unit 1 b, as shown in FIG. 8, the safety valve 2 is fixed with screws 22 in a direction in which the main guide shaft 19 projects outward from the inside of the opening of the box portion 24. The box portion 24 is configured to be separable so that the safety valve 24 can be fixed from the inside.

  In the safety valve unit 1b, when the pressure inside the box portion 24 becomes excessively high with respect to the external pressure, the auxiliary valve plate 13 of the safety valve 2 is guided to the auxiliary guide shaft 16 by the pressure difference and is operated as the main valve. Move away from the plate 12. Thereby, gas, such as exhaust gas, is discharged | emitted from the inside of the box part 24 to the exterior, and a pressure difference is eliminated.

  When the pressure inside the box portion 24 becomes excessively low relative to the external pressure, the main valve plate 12 of the safety valve 2 is guided by the main guide shaft 19 due to the pressure difference and moves away from the flat plate portion 11. To do. Thereby, outside air is introduced into the inside from the outside of the box part 24, and the pressure difference is eliminated.

  In the safety valve unit 1b, the safety valve 2 is fixed from the inside of the box portion 24. However, the safety valve 2 may be fixed from the outside of the box portion 24 in that direction. Further, the safety valve 2a described with reference to FIG.

  In the above description of the safety valve 2 (2a), the example in which the flat plate portion 11 is formed in a quadrangular shape has been described, but it may be formed in a circular shape or a polygonal shape. Further, the main valve plate 12 and the sub valve plate 13 can be formed in a rectangular shape or a polygonal shape instead of a circular shape.

  Moreover, although the example which formed the sub ventilation hole 15 of the main valve plate 12 by three holes was demonstrated, the shape and number of holes can be changed suitably. For example, the sub vent hole 15 can be formed by forming a large number of thin slits.

  Furthermore, although the example in which the main guide shaft 19 is disposed at three positions has been described, this number can be changed as appropriate, such as four or five positions. Moreover, although the example which comprised the main guide shaft 19 and the sub guide shaft 16 with the stepped hexagon bolt with the flange was demonstrated, there exists a flange and protrusion for latching a spring and a board by rod shape near both ends. Anything can be used.

  Moreover, although the example which attached | subjected the main seal member 50 to the flat plate part 11 was demonstrated, the same seal member can also be attached | subjected to the main valve plate 12 of the position contact | abutted to this main seal member 50, and the main valve plate. A similar sealing member may be attached only to the 12 side. Moreover, although the sub seal member 51 is attached to the sub valve plate 13, a similar seal member can be attached to the main valve plate 12 at a position in contact with the sub seal member 51, or on the main valve plate 12 side. Only the same sealing member may be attached.

  In addition, the example in which the safety valve 2 (2a) is arranged in the introduction pipe 3 of the exhaust gas treatment device 4 has been described, but it can be applied as long as the internal pressure of the gas flow path is higher or lower than the external pressure. It can prevent rupture and collapse of piping.

It is an external view of the safety valve unit incorporating the safety valve to which the present invention is applied. It is an assembly drawing of the safety valve to which the present invention is applied. It is sectional drawing of a safety valve unit. It is sectional drawing of the safety valve unit which showed the operating state by the positive pressure of a safety valve. It is sectional drawing of the safety valve unit which showed the operating state by the negative pressure of a safety valve. It is a block diagram which shows the use condition of a safety valve unit. It is sectional drawing of the safety valve unit which shows another embodiment of the safety valve to which this invention is applied. It is sectional drawing of the safety valve unit which shows embodiment of the safety valve to which this invention is applied.

Explanation of symbols

  1, 1a, 1b are safety valve units, 2, 2a are safety valves, 3 is an introduction pipe, 4 is an exhaust gas treatment device, 5 is an introduction means, 6 is a storage tank, 7 is a vacuum pump, 8 is a condenser, 10 is a control unit , 11 is a flat plate portion, 12 is a main valve plate, 13 is a sub valve plate, 14 is a main vent hole, 15 is a sub vent hole, 16 is a sub guide shaft, 17 is a sub spring, 18 is a sub nut, and 19 is a main guide. Shaft, 20 is a main spring, 21 is a main nut, 22 is a screw, 24 is a box part, 25 is a connection part, 31 and 33 are manual valves, 32 is a solenoid valve, 35 is piping, 37 is bypass piping, and 38 is differential Pressure sensor, 39 is a discharge valve, 40 is an exhaust gas generator, 41 is a washing and drying chamber, 42 is an aeration tank, 50 is a main seal material, 51 is a sub seal member, 55 is a collection box, 61 and 71 are flanges, 62 , 72 are struts, 63, 73 are screw parts, and 75, 76 are in communication. , 77 and 78 is the center hole.

Claims (4)

  A safety valve that operates with both positive and negative relative pressures inside and outside the gas flow path, and forms a part of the wall surface of the gas flow path, and is formed with a flat plate portion having a main ventilation hole for ventilation; A main valve plate having a size covering the main vent hole of the flat plate portion and having a sub vent hole for ventilation inside a range overlapping the main vent hole; and A plurality of main guide shafts that pass through the sub-valve plate that covers the sub-ventilation hole and is smaller than the main vent hole, and the peripheral portion of the main valve plate that covers the main vent hole and the flat plate portion at equal intervals. A plurality of main springs that are inserted through the main guide shafts and urge the main valve plate in close contact with the flat plate portion, and a central portion of the main valve plate and a central portion of the auxiliary valve plate are inserted. An auxiliary guide shaft that is inserted into the auxiliary guide shaft and biases the auxiliary valve plate in close contact with the main valve plate A safety valve, characterized in that it is constituted by a spring.   An annular main seal member is attached to the outer peripheral portion of the main vent hole that contacts the main valve plate and / or the inner peripheral portion of the main valve plate that contacts the flat plate portion, and also contacts the sub valve plate. The safety valve according to claim 1, wherein an annular sub seal member is attached to an outer peripheral portion of the sub vent hole and / or an inner peripheral portion of the sub valve plate in contact with the main valve plate.   The safety valve according to claim 1, wherein the flat plate portion is detachably disposed in the gas flow path.   An exhaust gas treatment apparatus, wherein the safety valve according to any one of claims 1 to 3 is disposed in an introduction pipe for introducing exhaust gas by suction with a suction pump.

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