JP2013170623A - Gas supply device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas supply device and a method capable of suppressing the lowering of pressure when a backup device starts to operate.SOLUTION: A gas supply device includes: a gas supply path 12 for supplying gas from a supply gas source to a gas using destination at pressure equal to or higher than first set pressure; a backup path 15 for supplying gas from a backup device 13 to the gas supply path 12; a backup valve 18 provided in the backup path 15; a pressure detector 17 for detecting pressure in the gas supply path 12; and a pressure regulating means 16 for regulating the pressure in the gas supply path 12 to second set pressure. The gas supply device further includes a backup valve control means for fully opening the backup valve 18, and also operating the fully-opened backup valve 18 gradually in a closing direction when the supply gas source stops gas supply.

Description

  The present invention relates to a gas supply apparatus and method, and more particularly, to an apparatus for supplying gas from a supply gas source such as an air separation apparatus or a gas supply apparatus to a user, from the supply gas source to the user. The present invention relates to a gas supply device that replenishes gas from a backup device when the amount of gas to be supplied is reduced and continuously supplies gas to a user at a predetermined pressure and flow rate, and a control method at the time of starting the gas supply device.

  For example, when nitrogen gas produced by an air separation device is continuously supplied to a user, a backup device is attached to the air separator according to fluctuations in demand for nitrogen gas at the user. This back-up device can liquefy part of the nitrogen gas and store it in a liquefied nitrogen storage tank when the demand for nitrogen gas in use is small compared to the amount of nitrogen gas produced by the air separation device. The amount of nitrogen gas produced by evaporating the liquefied nitrogen stored in the liquefied nitrogen storage tank of the backup device and replenishing it from the backup path to the gas supply path when there is a great demand for nitrogen gas at the usage site. To make up for the shortage.

  The conventional general backup device controls the opening degree of the backup valve according to the pressure detected by the pressure detector provided in the gas supply path or the backup path (hereinafter also referred to as normal PID control). In order to operate the backup device, the first set pressure when the air separation device supplies the user through the gas supply path and the second set pressure when the backup device starts operating are set. However, if the air separation device stops and the pressure in the gas supply path suddenly drops below the second set pressure, the operation of the backup device is stabilized. Therefore, the pressure of the gas supplied to the user may be greatly reduced temporarily. For this reason, even if the gas pressure drops temporarily at the start of the backup device operation, the set pressure is set high so that the gas can be supplied at a pressure exceeding the lower limit pressure required by the user, Control is performed to suppress the pressure drop (for example, see Patent Document 1).

JP 2002-181444 A

  However, when the set pressure is increased, the power cost required for the compressor that boosts the gas is greatly increased, and in order to perform complex control, many devices such as various detectors and various control valves are required. Therefore, an increase in cost is inevitable.

  Therefore, the present invention has a simple device configuration and can suppress a pressure drop when the backup device starts operating in response to a sudden pressure drop in the gas supply path, and continuously uses a gas at a predetermined pressure or higher. An object of the present invention is to provide a gas supply apparatus and method that can be supplied to a gas generator.

  In order to achieve the above object, a gas supply apparatus according to the present invention includes a gas supply path for supplying a gas from a supply gas source at a pressure equal to or higher than a first set pressure set in advance for a gas use destination, and the gas supply path. A backup path for replenishing gas from the backup device, a backup valve provided in the backup path, a pressure detector for detecting the pressure in the gas supply path, and a pressure in the gas supply path are preset. In the gas supply apparatus comprising a pressure adjusting means for adjusting to the second set pressure, the backup valve is fully opened and the backup valve is fully opened when the supply gas source stops gas supply. Back-up valve control means for gradually operating the opening in the closing direction.

  Further, in the gas supply device of the present invention, the backup valve is urged in the opening direction by the urging means, and is urged in the closing direction by the valve driving gas supplied from the valve driving gas supply path. A valve that opens and closes by adjusting a gas supply amount. The valve-driven gas supply path includes a first path switching unit, a second path switching unit, and a flow rate control path connected to the second path switching unit. The first path switching means supplies a valve driving gas supply side for communicating the primary side valve driving gas supply path and the secondary side valve driving gas supply path, and supplies the valve driving gas to the backup valve. The second path switching means is a valve drive that supplies valve driving gas to the first path switching means at a relatively large flow rate, and is configured to be switched to a gas discharge side that discharges the driving gas from the backup valve. Gas supply It is characterized in that it is switchable formed on the flow control path side supplied to the first path switching means relatively small flow in the valve driving gas through the flow control path to the side.

  Furthermore, in the gas supply device of the present invention, the supply gas source is an air separation device, the gas supplied to the gas user is the product gas of the air separation device, and the backup device is incorporated in the air separation device. It is characterized by being.

  The gas supply method of the present invention is a gas supply method using the gas supply apparatus having the above-described configuration, wherein the backup valve control means is configured to perform the above operation when the detected pressure of the pressure detector is equal to or higher than the first set pressure. When the backup valve is held in a fully closed state and the supply gas source stops supplying gas, the backup valve is fully opened, and then the opening degree of the fully opened backup valve is gradually operated in the closing direction. After that, the pressure adjusting means controls the detected pressure of the pressure detector to the second set pressure.

  Furthermore, in the gas supply method of the present invention, the backup valve is urged in the opening direction by the urging means, and is urged in the closing direction by the valve driving gas supplied from the valve driving gas supply path. A valve that opens and closes by adjusting a gas supply amount. The valve-driven gas supply path includes a first path switching unit, a second path switching unit, and a flow rate control path connected to the second path switching unit. When the detected pressure of the pressure detector is equal to or higher than the first set pressure, both the first path switching means and the second path switching means are switched to the valve driving gas supply side, and the valve driving gas supply path When the valve driving gas is supplied from the second path switching means to the backup valve through the first path switching means, the backup valve is held in the fully closed state, and the supply gas source stops the gas supply. As a first step, the first path switching means is switched to the gas discharge side to cut off the supply of the drive gas from the valve drive gas supply path to the backup valve and to discharge the drive gas from the backup valve. As a second stage after the backup valve is fully opened by the biasing force of the biasing means and the backup valve is fully opened, the first path switching means is switched to the valve driving gas supply side, and the first The two-path switching means is switched to the flow rate control path side, and the first path switching means is controlled in a state where the valve driving gas in the valve driving gas supply path is controlled to be smaller in the flow rate control path than in the valve driving gas supply side. Is supplied to the backup valve via the valve, the backup valve gradually operates in the closing direction, and the second path switching means switches to the valve driving gas supply side. As a third step after being the detected pressure of the pressure detector operates said pressure adjusting means is characterized in that it is adjusted to the second set pressure.

  The first path switching means may be switched to the valve drive gas supply side after a preset time has elapsed after being switched to the gas discharge side, and the second path switching means may After switching to the control path side, the valve driving gas supply side is switched after a preset time has elapsed.

  According to the present invention, when the supply gas source stops the gas supply, the backup valve is fully opened to supply a large amount of gas from the backup device to the gas supply path through the backup path. The pressure is not greatly reduced. In addition, by gradually operating the backup valve in the fully open state in the valve closing direction and adjusting the pressure in the gas supply path to the second set pressure, the gas pressure can be reduced without causing hunting in the product pressure. In a stable state, a gas having a predetermined pressure or higher can be continuously supplied.

1 is a system diagram showing a first embodiment of a gas supply device of the present invention. It is a figure which shows an example of the operation | movement procedure of a control part. It is a figure which shows an example of a pressure fluctuation. It is a systematic diagram which shows the 2nd example of a gas supply apparatus of this invention.

  The gas supply apparatus shown in the first embodiment of FIG. 1 is an apparatus for supplying nitrogen gas of a product manufactured by the air liquefaction separation apparatus 11 to a gas user, and is an air liquefaction separation apparatus that is a supply gas source. 11, a gas supply path 12 connected to a gas use destination is provided. Although not shown in the drawings, the gas use destination is provided with a secondary pressure control valve that adjusts the pressure of the gas supplied from the gas supply path 12 to a constant pressure suitable for use in the gas use destination. The pressure of the gas supplied from the gas supply path 12 is required to be equal to or higher than the pressure (lower limit pressure) at which the secondary pressure can be adjusted to a constant pressure by the secondary pressure control valve.

  To supply the gas supply path 12 with nitrogen gas extracted from a liquefied nitrogen storage tank 14 serving as a backup gas supply source and vaporized by an evaporator (not shown) as a backup device 13. Backup path 15 is connected. In the backup path 15, gas is supplied by detecting the pressure in the backup path 15 as pressure adjusting means 16 for adjusting the pressure of nitrogen gas supplied from the backup path 15 to the gas supply path 12 by normal pressure control. A pressure detector 17 for detecting the pressure of the nitrogen gas supplied to the gas user from the path 12 and a backup valve 18 that opens when supplying the nitrogen gas from the backup path 15 to the gas supply path 12 are provided. Is provided.

  The backup valve 18 is urged in an opening direction by an urging means such as a spring, and is a pneumatic valve whose valve opening is adjusted by a valve driving gas supplied through a positioner 19, usually instrumentation air. The so-called fail-open type valve (FO valve) is used.

  The backup valve 18 and the positioner 19 are connected by a valve driving gas supply path 20 through which the instrumentation air flows. The valve driving gas supply path 20 shown in this embodiment has a backup valve control means 21 as a backup valve control means 21. A first three-way switching electromagnetic valve 22 serving as a first path switching means is provided on the 18th side, and a second three-way switching electromagnetic valve 23 serving as a second path switching means is provided on the positioner 19 side. Further, a speed which is a flow rate control means for reducing the gas flow rate is provided between the second three-way switching solenoid valve 23 and the valve driving gas supply path 20 on the first three-way switching solenoid valve 22 side of the second three-way switching solenoid valve 23. A flow control path 25 having a controller 24 is provided. The first three-way switching solenoid valve 22 and the second three-way switching solenoid valve 23 are provided with a control unit 26 that outputs signals S1 and S2 for operating the solenoid valves. The control unit 26 is provided with a receiving unit for receiving the detected pressure signal S3 from the pressure detector 17 and the nitrogen gas production stop signal S4 from the air liquefaction separation apparatus 11.

  The first three-way switching solenoid valve 22 and the second three-way switching solenoid valve 23 are both in a non-excited state when the signals S1 and S2 from the control unit 26 are not present, and the valve driving gas supply path 20 on the valve primary side and the valve secondary side. When the signal S1 is input from the control unit 26 to the first three-way switching solenoid valve 22, the first three-way switching solenoid valve is switched to the valve driving gas supply side (in the direction of arrow A). 22 is in an excited state, and shuts off the supply of instrumentation air from the valve drive gas supply path 20 to the backup valve 18 and switches to the gas discharge side (in the direction of arrow B) for discharging the instrumentation air from the backup valve 18. Further, when the signal S2 is input from the control unit 26 to the second three-way switching electromagnetic valve 23, the second three-way switching electromagnetic valve 23 enters an excited state, and the instrumentation air in the valve drive gas supply path 20 is passed through the flow control path 25. It is switched to the flow rate control path side (arrow B direction) supplied to the first three-way switching electromagnetic valve 22 side with a small flow rate.

  Next, when the gas liquefying / separating apparatus 11 serving as a supply gas source stops supplying nitrogen gas by the gas supply apparatus configured as described above, nitrogen gas having a predetermined pressure or higher is continuously supplied in a stable state at the gas use destination. An example of the supply operation will be described. As each set pressure, the first set pressure during normal operation for supplying nitrogen gas from the air liquefaction separation apparatus 11 to the gas user through the gas supply path 12 is 8.1 barA (0.81 MPa), and the backup valve 18 is opened. It is assumed that the second set pressure at which the backup device operates is set in advance to 7.8 barA (0.78 MPa). During normal operation, the signals S1 to S4 are off, the backup valve 18 is fully closed, and the first three-way switching solenoid valve 22 and the second three-way switching solenoid valve 23 are both in a non-excited state. It is on the driving gas supply side.

  During normal operation, when the amount of nitrogen gas used in the gas usage destination gradually increases beyond the amount of nitrogen gas produced by the air liquefaction separation apparatus 11, the pressure of the nitrogen gas in the gas supply path 12 gradually decreases. . When the detected pressure of the pressure detector 17 decreases to the second set pressure of 7.8 barA, the backup valve 18 is operated in the opening direction by normal pressure control to increase the replenishment amount of nitrogen gas from the backup path 15. The supply pressure of nitrogen gas to the gas user is maintained at 7.8 barA which is the second set pressure.

  When the amount of nitrogen gas used at the gas destination decreases and the pressure detected by the pressure detector 17 gradually increases, the backup valve 18 is fully closed and the backup device 13 stops operating. Thereafter, the pressure of nitrogen gas supplied from the air liquefaction separation apparatus 11 to the gas user through the gas supply path 12 is adjusted on the air liquefaction separation apparatus side so that the first set pressure is 8.1 barA. Return to the state.

  FIG. 2 shows an example of the operation procedure of the control unit 26 when the operation of the air liquefaction separation device 11 is stopped. During the operation of the air liquefaction separation device 11, the signals S1 and S2 are output from the control unit 26. First, the first three-way switching solenoid valve 22 and the second three-way switching solenoid valve 23 are switched to the valve driving gas supply side (step 51). During operation, the operation state of the air liquefaction separation apparatus 11 is constantly monitored in step 52, and when the control unit 26 receives the signal S4 indicating that the air liquefaction separation apparatus 11 has stopped operation, the process proceeds to step 53, where the signal S1 is sent from the control unit 26. Is output, the first three-way switching electromagnetic valve 22 is excited and switched to the gas discharge side, and the first timer starts counting. As a result, the first three-way switching electromagnetic valve 22 is switched to the gas discharge side, the supply of instrumentation air from the valve drive gas supply path 20 to the backup valve 18 is shut off, and the instrumentation air is discharged from the backup valve 18 to the outside. As a result, the backup valve 18 is instantly fully opened. Thereby, the set pressure of the liquefied nitrogen storage tank 14, for example, nitrogen gas set to 9.2 barA is instantaneously supplied from the backup path 15 to the gas supply path 12 through the fully opened backup valve 18 from the backup device 13. Thus, the supply of nitrogen gas having a lower limit pressure, for example, 7.0 barA or higher is continued without greatly reducing the pressure of nitrogen gas supplied from the gas supply path 12 to the gas user.

  The output of the signal S1 from the control unit 26 continues until the first timer reaches the preset first set time in step 54, and the fully opened state of the backup valve 18 is maintained for a predetermined time, for example, about 10 seconds. . Thereby, the nitrogen gas from the backup device 13 is spread over the entire length of the gas supply path 12, and the nitrogen gas can be supplied at a pressure equal to or higher than the lower limit pressure required by the gas user.

  When the first timer reaches the first set time in step 54, the process proceeds to step 55, the output of the signal S1 from the control unit 26 is cut off, and at the same time, the signal S2 is output and the second timer starts counting. To do. As a result, the first three-way switching solenoid valve 22 is switched to the non-excited state and switched to the valve driving gas supply side, and the second three-way switching solenoid valve 23 is switched to the excited state by the signal S2 from the control unit 26. Switch to the route side. Since the second three-way switching electromagnetic valve 23 is switched to the flow rate control path side, the first three-way switching solenoid valve supplied to the backup valve 18 is reduced to a small flow rate through the flow rate control path 25. The backup valve 18 is supplied via 22. Therefore, the backup valve 18 is gradually urged in the valve closing direction by the inflow of a small flow of instrumentation air. When the backup valve 18 is gradually closed, the flow rate of nitrogen gas supplied from the backup path 15 to the gas supply path 12 is reduced in accordance with the decrease in the opening degree of the backup valve 18, and the pressure is increased accordingly. The detection pressure of the detector 17 also gradually decreases. The output of the signal S2 from the control unit 26 continues until the second timer reaches the second set time set in advance in step 56. For example, the backup valve 18 gradually moves in the valve closing direction for about 10 seconds. The operating state is continued.

  When the second timer reaches the second set time in step 56, the process proceeds to step 57, where the output of the signal S2 from the control unit 26 is cut off and the second three-way switching solenoid valve 23 becomes non-excited to supply valve driving gas. Switched to the side. As a result, the instrumentation air flows through the valve driving gas supply path 20 via the first three-way switching solenoid valve 22 and the second three-way switching solenoid valve 23 that are both on the valve driving gas supply side. Returning to normal pressure control that adjusts the valve opening degree of the backup valve 18 according to the detected pressure, the gas supply pressure of nitrogen gas is adjusted to the second set pressure of 7.8 barA. Thereafter, when the air liquefaction separation apparatus 11 resumes operation, the pressure of the nitrogen gas supplied to the gas user through the gas supply path 12 is adjusted on the air liquefaction separation apparatus side so that the first set pressure is 8.1 barA. Then, the operation of the backup device 13 is stopped and the process returns to the state of step 51.

  FIG. 3 shows a pressure detector when the pressure control is performed only by the normal PID control which is a conventional backup method and the change in the detected pressure of the pressure detector 17 when the backup valve control means 21 is used (Example). And the change in the detected pressure. As is apparent from FIG. 3, in the case of only the conventional PID control, there is a time difference from when the pressure detector detects a pressure drop until the backup valve opens to a predetermined opening, so supply to the gas user. The pressure of nitrogen gas to be temporarily reduced greatly.

  On the other hand, when the operation of the air liquefaction separator 11 is stopped, the backup valve control means 21 forcibly opens the backup valve 18 to supply a large amount of nitrogen gas from the backup device 13 to the gas supply path 12. Therefore, the pressure drop of the nitrogen gas supplied to the gas user can be surely prevented as compared with the conventional method. Therefore, in this embodiment, the supply pressure of nitrogen gas may be lower than the lower limit pressure of 7.0 barA only with normal PID control, but by using the backup valve control means 21, the pressure is always higher than the lower limit pressure. Nitrogen gas can be supplied. As a result, each set pressure can be reduced by 0.1 to 0.3 barA, and the power cost of the compressor for boosting the product nitrogen can be reduced.

  Also, a control unit having a simple configuration including two three-way switching solenoid valves, a pipe having a simple speed controller for restricting the flow rate, a part for processing four signals S1 to S4, and two timers is added. As a result, the initial cost is slightly increased as compared with those using complicated equipment, and the operating cost and maintenance cost can be greatly reduced. In addition, the timing which makes each three-way switching solenoid valve 22 and 23 a non-excitation state can employ | adopt another method irrespective of a timer, for example, based on the detection pressure of the pressure detector 17, It is also possible to switch to normal pressure control after monitoring the opening of the backup valve 18 and confirming that the backup valve 18 has been closed to the opening assumed during normal pressure control (normal PID control).

  FIG. 4 shows a second embodiment of the gas supply apparatus of the present invention, in which the flow rate of nitrogen gas supplied to the gas user is large, and the gas supply path 12 and the backup path 15 are compared with the first embodiment. An example of a device configuration suitable for a large-diameter case is shown. In the following description, the same components as those of the gas supply apparatus shown in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The pressure adjusting means 16 in this embodiment is composed of a pressure detector 17 for performing normal PID control and a backup valve 18 as in the first embodiment, and the backup valve control means 21 is a valve drive gas supply path. 20 is a first three-way switching pneumatic valve 31 serving as a first path switching means provided on the backup valve 18 side, and a second three-way serving as a second path switching means provided on the positioner 19 side of the valve drive gas supply path 20. The switching solenoid valve 23 and the third three-way switching solenoid valve 33 provided in the second valve drive gas supply path 32 that supplies instrumentation air for driving the first three-way switching pneumatic valve 31 in the closing direction. doing.

  The back-up valve 18 in the present embodiment is a pneumatic valve that has a larger diameter than the back-up valve used in the first embodiment and uses a large amount of instrumentation air energized in the valve closing direction. As the three-way switching pneumatic valve 31, a pneumatic valve having a diameter capable of discharging a large amount of instrumentation air that urges the backup valve 18 in a fully closed state in a short time is used. The second three-way switching solenoid valve 23 and the third three-way switching solenoid valve 33 are solenoid valves that have the same or slightly larger aperture than the second three-way switching solenoid valve used in the first embodiment.

  In the backup valve control means 21 having such a configuration, during normal operation, the first three-way switching pneumatic valve 31 and the second three-way switching electromagnetic valve 23 are both valve primary gas and valve secondary gas drive gas supply paths 20. Is switched to the valve drive gas supply side (in the direction of arrow A) that communicates with each other, and the third three-way switching solenoid valve 33 transfers the instrumentation air in the second valve drive gas supply path 32 to the first three directions. It is in the state switched to the valve drive gas supply side (arrow A direction) supplied to the switching pneumatic valve 31.

  For example, when the control unit 26 receives a signal S4 indicating that the operation of the air liquefaction separation apparatus 11 has stopped, the control unit 26 outputs a signal S1 to the third three-way switching electromagnetic valve 33, and the third three-way switching electromagnetic valve 33 The excited state is switched to the gas discharge side (in the direction of arrow B) by S1, the instrumentation air supplied from the valve drive gas supply path 32 to the first three-way switching pneumatic valve 31 is shut off, and the first three-way switching pneumatic valve The air for instrumentation is discharged from 31. As a result, the first three-way switching pneumatic valve 31 is switched from the valve drive gas supply side to the gas discharge side (in the direction of arrow B), and the supply of instrumentation air to the backup valve 18 is cut off and the instrumentation air is supplied from the backup valve 18. Is discharged, and the backup valve 18 is instantly fully opened.

  After the backup valve 18 is fully opened, the control unit 26 stops the signal S1 and outputs the signal S2 in the same manner as in the first embodiment, so that the third three-way switching electromagnetic valve 33 is switched to the valve driving gas. The first three-way switching pneumatic valve 31 is switched to the valve driving gas supply side by the instrumentation air passing through the third three-way switching electromagnetic valve 33 and the second three-way switching electromagnetic valve 23 is controlled by the signal S2. Switch to the side (arrow B direction). Therefore, the instrumentation air supplied to the backup valve 18 is supplied to the second three-way switching electromagnetic valve 23 through the flow rate control path 25 so as to be reduced to a small flow rate, and the backup valve 18 is gradually attached in the valve closing direction. Be forced. Thereafter, the normal PID control by the pressure detector 17 and the backup valve 18 is started in the same manner as in the first embodiment, and the pressure of nitrogen gas supplied from the backup path 15 to the gas supply path 12 is set to a preset pressure. Adjusted.

  When the large-diameter backup valve 18 is used, it is possible to exhaust the instrumentation air from the backup valve 18 even if a general-diameter electromagnetic valve is used, but to exhaust a large amount of instrumentation air. Therefore, it may take time for the backup valve 18 to change from the fully closed state to the fully open state. On the other hand, as shown in the present embodiment, the small-diameter third three-way switching electromagnetic valve 33 using a general-diameter electromagnetic valve is switched to the gas discharge side by a signal S1, and the third three-way switching electromagnetic valve 33 is switched. From the first three-way switching pneumatic valve 31 with the medium diameter, the instrumentation air of the first three-way switching pneumatic valve 31 with the medium diameter is discharged, the first three-way switching pneumatic valve 31 is switched to the gas discharge side, and switched to the gas discharge side. By exhausting the instrumentation air of the large-diameter backup valve 18, the instrumentation air can be quickly exhausted from the large-diameter backup valve 18, and the large-diameter backup valve 18 is fully opened in a short time. Is possible.

  The supply gas source is not limited to the air liquefaction separation device, and can be used for various gas production facilities and various gas supply facilities, and an appropriate backup device can be adopted as the backup device. In addition, the type of gas supplied to the gas user is arbitrary, and can be similarly applied to devices supplying various gases including oxygen gas and argon gas, and the supply pressure is also arbitrarily set can do.

  Furthermore, the backup path is divided into two systems in the middle, and a first backup valve and a second backup valve are provided in parallel in each branch system, and the first backup valve is operated by normal PID control by a pressure detector, Similarly to the above-described backup valve, the second backup valve can be formed so as to be once fully opened and then gradually closed when the backup device is operated. Further, the backup valve control means can be operated by a signal from the gas supply destination.

  DESCRIPTION OF SYMBOLS 11 ... Air liquefaction separation apparatus, 12 ... Gas supply path, 13 ... Backup apparatus, 14 ... Liquefied nitrogen storage tank, 15 ... Backup path, 16 ... Pressure control means, 17 ... Pressure detector, 18 ... Backup valve, 19 ... Positioner, DESCRIPTION OF SYMBOLS 20 ... Valve drive gas supply path, 21 ... Backup valve control means, 22 ... 1st three-way switching solenoid valve, 23 ... 2nd three-way switching solenoid valve, 24 ... Speed controller, 25 ... Flow control path, 26 ... Control part, 31 ... First three-way switching pneumatic valve, 32 ... Second valve drive gas supply path, 33 ... Third three-way switching solenoid valve

Claims (7)

  A gas supply path for supplying a gas from a supply gas source at a pressure equal to or higher than a first preset pressure set in advance to a gas use destination; a backup path for supplying gas from the backup device to the gas supply path; and the backup path A gas provided with a backup valve provided in the pressure sensor, a pressure detector for detecting the pressure in the gas supply path, and a pressure adjusting means for adjusting the pressure in the gas supply path to a preset second set pressure. In the supply device, when the supply gas source stops gas supply, the backup valve is fully opened, and the backup valve control means for gradually operating the opening degree of the backup valve in the fully open state in the closing direction A gas supply device comprising:   The backup valve is energized in the opening direction by the energizing means, and is energized in the closing direction by the valve driving gas supplied from the valve driving gas supply path, and is opened and closed by adjusting the supply amount of the valve driving gas. The valve driving gas supply path is provided with a first path switching means, a second path switching means, and a flow rate control path connected to the second path switching means, and the first path switching means The valve drive gas supply side for connecting the valve drive gas supply path on the primary side and the valve drive gas supply path on the secondary side, and the supply of the valve drive gas to the backup valve is shut off and the drive gas is discharged from the backup valve The second path switching means is configured to be switchable between a valve driving gas supply side for supplying valve driving gas to the first path switching means at a relatively large flow rate and the flow rate control path. Gas supply device pair to claim 1, characterized in that the switchable formed on a flow control path side supplied to the first path switching means a valve driving gas with a low flow rate.   The said supply gas source is an air separator, The gas supplied to a gas user is the product gas of the said air separator, The said backup device is integrated in the said air separator. Gas supply device.   3. The gas supply method using the gas supply device according to claim 1, wherein the backup valve control means fully closes the backup valve when the detected pressure of the pressure detector is equal to or higher than the first set pressure. When the supply gas source stops the gas supply, the backup valve is fully opened, and then the opening of the backup valve that has been fully opened is gradually operated in the closing direction. A gas supply method for controlling the detected pressure of the pressure detector to the second set pressure by an adjusting means.   The backup valve is energized in the opening direction by the energizing means, and is energized in the closing direction by the valve driving gas supplied from the valve driving gas supply path, and is opened and closed by adjusting the supply amount of the valve driving gas. The valve-driven gas supply path is provided with a first path switching means, a second path switching means, and a flow rate control path connected to the second path switching means, and is detected by the pressure detector. When the pressure is equal to or higher than the first set pressure, both the first path switching means and the second path switching means are switched to the valve driving gas supply side, and the valve driving gas of the valve driving gas supply path is changed from the second path switching means. When the backup valve is held in a fully closed state by being supplied to the backup valve through the first path switching means, and the supply gas source stops the gas supply, the first step is performed as the first step. The path switching means is switched to the gas discharge side to cut off the supply of driving gas from the valve driving gas supply path to the backup valve, and the driving valve is discharged from the backup valve so that the backup valve is biased by the biasing means. As a second stage after the backup valve is fully opened, the first path switching means is switched to the valve driving gas supply side, and the second path switching means is moved to the flow control path side. The valve driving gas in the valve driving gas supply path is switched to be backed up by being supplied to the backup valve via the first path switching means in a state in which the valve driving gas is controlled to have a smaller flow rate than the valve driving gas supply side in the flow control path. As the third stage after the valve gradually operates in the closing direction and the second path switching means is switched to the valve driving gas supply side, Gas supply method according to claim 4, wherein the force adjustment means adjusts the detected pressure of the pressure detector operating in the second set pressure.   The gas supply method according to claim 4 or 5, wherein the first path switching means is switched to the valve drive gas supply side after a preset time has elapsed after being switched to the gas discharge side.   The gas supply method according to any one of claims 4 to 6, wherein the second path switching means is switched to the valve drive gas supply side after a preset time has elapsed after being switched to the flow rate control path side. .

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