JP2005052757A - Gas supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas supply apparatus capable of following the fluctuation of product gas use without increasing electric power consumption or enlarging the apparatus. <P>SOLUTION: In the gas supply apparatus 1, concentrated oxygen produced in a PSA (pressure swing adsorption) air separation apparatus main body 2 is stored in a buffer tank 10 and supplied to a buffer tank 12 based on a set flow rate value (a) by a controller-attached flowmeter 36. The flow rate of oxygen supplied to the outside from the buffer tank 12 is detected by a flow rate detector 53 and outputted to a controller 5. In the case the detected flow rate value F exceeds the set flow rate value (a), an oxygen supplement valve 42 is opened to supplement the concentrated oxygen in an oxygen bomb 3 to the buffer tank 12. Since the set flow rate value (a) is the amount of maximum production to which the purity required as a product gas of a PSA air separation apparatus 4 can be maintained, the gas supply apparatus 1 can stably supply concentrated oxygen corresponding to the fluctuation of the amount of the product gas used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas supply device, and more particularly to a gas supply device that can follow fluctuations in the amount of product gas used without increasing the size of an air separation device.

  Conventionally, as one type of gas supply device, there is known an air separation device that selectively separates nitrogen or oxygen from the air to produce a product gas, and is incorporated in many devices that continuously consume nitrogen or oxygen. ing. In such an air separation device, the amount of product gas used at the supply destination often fluctuates constantly, and even if the amount of product gas used is small, an air separation device that can follow the maximum amount of product gas must be used. In addition, the size of the apparatus is increased, the power consumption is increased, and it is economically inefficient.

  In order to deal with such a problem, for example, when the amount of product gas used at the supply destination is lower than the amount of product gas generated by the air separation device, the excess product gas generated by the air separation device is liquefied to liquefy the gas. If it is stored in a storage tank and the amount of product gas used at the supply destination exceeds the amount of product gas produced by the air separation device, the liquefied gas stored in the liquefied gas storage tank is vaporized again with an evaporator, and the vaporized gas is removed. A gas supply device for replenishing a supply destination is known (see, for example, Patent Document 1).

  There is also a gas supply device in which an expansion turbine that generates a cooling heat source for a rectifying column in which nitrogen is generated is steadily operated to produce a predetermined amount of nitrogen, and nitrogen for the demand fluctuation is supplemented from the liquid nitrogen storage tank. Known (for example, see Patent Documents 2 and 3). In this gas supply device, the liquid level of the raw material liquid air stored at the bottom of the rectification column varies depending on the fluctuation of the nitrogen demand at the supply destination. The liquid level gauge provided in the tower detects and controls the opening and closing of the valve provided in the nitrogen supply line of the liquid nitrogen storage tank so as to cope with fluctuations in the demand amount of nitrogen.

Further, a gas supply device for supplying oxygen-enriched air to a copper smelting furnace and a copper converter is also known. This gas supply device, when the consumption of oxygen-enriched air at the supply destination (smelting furnace, converter) is small, oxygen generated by the air separation unit and a part of the compressed air generated by the compressor Is stored in the buffer tank, and the supply destination (smelting furnace, converter) consumes a large amount of oxygen-enriched air, the oxygen-enriched air stored in the buffer tank may be replenished to the supply destination. Yes (see Patent Document 4). In this gas supply apparatus, a part of the air compressed by the compressor is processed by the air separation unit to become oxygen. The oxygen is blown into the compressed air supplied to the copper smelting furnace and the copper converter, and is consumed at the supply destination as oxygen-enriched air.
Japanese Patent Publication No. 1-331116 JP-A-4-297780 Japanese Patent Laid-Open No. 10-292987 JP 2002-155321 A

  However, in the gas supply apparatus described in Patent Document 1, expensive equipment such as a liquefier that liquefies a part of the generated oxygen and a heat exchanger that vaporizes the liquefied gas again must be provided in the apparatus. However, there was a problem that the cost was high. In addition to the step of generating the product gas, the gas supply device includes a step of liquefying part of the product gas generated by the air separation device and a step of vaporizing the liquefied product gas. Therefore, there is a problem that the power consumption of the entire gas supply device is increased.

  Moreover, in the gas supply apparatus of patent documents 2 and 3, the demand fluctuation amount of nitrogen gas is judged by the vertical fluctuation of the liquid level of the liquid air stored in the rectification tower, and the air is liquefied and nitrogen is liquefied. Applicable only to the cryogenic liquefaction separation method. However, in the adsorptive separation system that selectively adsorbs nitrogen or oxygen from the air to generate oxygen or nitrogen, the raw material air is not liquefied, so the range of use is limited to a cryogenic liquefaction separation system apparatus. There was a problem.

  In the gas supply device described in Patent Document 4, the buffer tank stores oxygen enriched by mixing oxygen generated by the air separation unit and part of compressed air generated by the compressor. Since it is air, it can be applied to any device that can use even low-purity oxygen, but it cannot be applied to a device that requires high-purity oxygen. In addition, the power source that supplies oxygen-enriched air to the supply destination and oxygen-enriched air to the buffer tank is concentrated in the compressor that generates compressed air that is the raw material for oxygen, increasing the power consumption of the compressor. There was also a problem of causing.

  The present invention has been made to solve the above-described problems, and provides a gas supply device that can follow fluctuations in the amount of product gas used without increasing the size of the device and without increasing power consumption. Objective.

  In order to achieve the above object, the gas supply apparatus according to claim 1 is a gas supply apparatus that supplies a product gas to a supply destination, and is a pressure fluctuation adsorption type that selectively separates nitrogen or oxygen from the air. An air separation device, a gas cylinder in which the same gas as that obtained by the air separation device is stored in advance, a gas supplied at a constant flow rate from a buffer tank of the air separation device, and a gas supplied from the gas cylinder A second buffer tank to be mixed, a solenoid valve interposed in a gas supply line from the gas cylinder, a flow rate detecting means for detecting a flow rate of the product gas supplied from the second buffer tank to the supply destination, And a solenoid valve opening / closing control means for opening the solenoid valve when the product gas flow rate detected by the flow rate detection means exceeds a set flow rate.

  In addition to the configuration of the invention according to claim 1, the gas supply device according to claim 2 is characterized in that the flow rate of the gas supplied from the buffer tank of the air separation device and the set flow rate are product gas. The maximum production amount of the air separation device that can ensure the gas purity required for the above is set.

  The gas supply apparatus according to claim 3 is a gas supply apparatus that supplies a product gas to a supply destination, the pressure fluctuation adsorption air separation apparatus that selectively separates nitrogen or oxygen from the air, and A gas cylinder that is connected to a pipe upstream of the buffer tank of the air separation device and stores the same gas as the gas obtained by the air separation device; pressure detection means for detecting the pressure in the buffer tank; and A solenoid valve interposed in the gas supply line, a flow rate detection means for detecting the flow rate of the product gas supplied from the buffer tank to the supply destination, and the product gas flow rate detected by the flow rate detection means exceeds the set flow rate Or a solenoid valve opening / closing control means for opening the solenoid valve when the pressure in the buffer tank detected by the pressure detection means falls below a set pressure.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the invention, the set flow rate is set to the maximum production amount of the air separation device that can ensure the gas purity required for the product gas. Further, the set pressure is set to a minimum value that does not fall below the product gas pressure specification.

  According to the gas supply device of the first aspect of the present invention, the gas is supplied at a constant flow rate from the buffer tank of the air separation device to the second buffer tank, and the flow rate detecting means supplies the gas from the second buffer tank to the supply destination. The supplied product gas flow rate can be detected. When the detected product gas flow rate exceeds the set flow rate, the solenoid valve opening / closing control means opens the solenoid valve of the gas supply line from the gas cylinder to replenish the gas in the gas cylinder to the second buffer tank. Therefore, even if the product gas flow rate supplied to the supply destination increases, the air separation device only needs to supply the generated gas to the second buffer tank at a constant flow rate, reducing the load on the air separation device. can do. Therefore, the running cost of the gas supply device can be reduced.

  Further, in the gas supply device according to claim 2, in addition to the effect of the invention according to claim 1, the flow rate of the gas supplied from the buffer tank of the air separation device at a constant flow rate and the electromagnetic valve opening / closing control means are electromagnetic. The set flow rate to open the valve is set to the maximum production amount of the air separation device that can ensure the gas purity required for the product gas, so there is no need to generate gas exceeding the maximum production amount of the air separation device, The gas amount exceeding the maximum production amount can be supplemented by a gas cylinder. Therefore, it is possible to efficiently supply a product gas having a stable purity to the supply destination with a minimum amount of energy loss, with the gas generation amount of the air separation device being constant.

  Further, in the gas supply device according to claim 3, when the flow rate detection means detects the product gas flow rate supplied to the supply destination and the detected product gas flow rate exceeds the set flow rate, or the pressure detection means When the pressure in the buffer tank of the air separation device is detected and the detected pressure is less than the set pressure, the solenoid valve opening / closing control means opens the solenoid valve in the gas supply line from the gas cylinder to separate the air Since gas is replenished to the buffer tank of the apparatus, the gas pressure in the buffer tank is always kept at a set pressure or higher, and the product gas holding the set pressure can be stably supplied to the supply destination. Further, since the air separation device does not need to generate gas exceeding the set flow rate, the power consumption of the air separation device is not increased.

  In addition, in the gas supply device according to claim 4, in addition to the effect of the invention according to claim 3, the set flow rate is set to the maximum generation amount of the air separation device that can ensure the gas purity required for the product gas. In addition, since the set pressure is set to the lowest value that does not fall below the product gas pressure specification, the product gas having a stable and efficient purity can be supplied from the buffer tank to the supply destination.

  Hereinafter, a first embodiment of a gas supply device 1 to which the present invention is applied will be described with reference to the drawings. First, the configuration of the gas supply device 1 will be described with reference to FIG. FIG. 1 is a configuration diagram illustrating a configuration of a gas supply device 1 according to the first embodiment. In addition, the gas supply apparatus 1 of 1st Embodiment is an apparatus which produces | generates and supplies the concentrated oxygen mainly utilized for combustion of garbage in a garbage incinerator, and as shown in FIG. 1, a gas supply apparatus The parts constituting 1 are connected by piping. The gas supply device 1 includes a pressure fluctuation adsorption type (PSA) air separation device 4 (from the PSA air separation device main body 2 to the flow meter with controller 36) and an oxygen cylinder 3, and supplements oxygen to replenish deficient oxygen. Concentrated oxygen supplied from the oxygen cylinder 3 at a constant flow rate with the line 9 (from the oxygen cylinder 3 to the solenoid valve 54 and from the oxygen cylinder 3 to the reverse valve 44) and the PSA air separation device 4 are mixed. And a supply line 11 (from the buffer tank 12 to the gas supply port 55) for supplying to the supply destination.

  Next, the configuration of the PSA air separation device 4 will be described. As shown in FIG. 1, a reverse support valve 35 is connected to the PSA air separation device main body 2 that selectively absorbs and separates nitrogen from the air to generate oxygen, and PSA air is disposed downstream of the reverse support valve 35. A buffer tank 10 for temporarily storing the concentrated oxygen produced in the separator main body 2 is connected. The buffer tank 10 is provided with a monitoring pressure gauge 10a for detecting the pressure of the concentrated oxygen inside the tank. Further, as shown in FIG. 1, a flow meter with controller 36 for adjusting the oxygen flow rate to a constant flow rate is connected to the downstream side of the buffer tank 10.

  Next, the supply line 11 will be described. As shown in FIG. 1, on the downstream side of the flowmeter with controller 36, the concentrated oxygen supplied at a constant flow rate from the flowmeter with controller 36 and the concentrated oxygen supplied from an oxygen cylinder 3 described later are mixed. A buffer tank 12 for temporarily storing the mixed concentrated oxygen is connected. The buffer tank 12 is provided with a monitoring pressure gauge 12a for detecting the pressure of the concentrated oxygen inside the tank.

  A stop valve 48 is connected to the downstream side of the buffer tank 12, and a pressure reducing valve 49 is connected to the downstream side of the stop valve 48. A flow rate detector 53 is connected to the downstream side of the pressure reducing valve 49, and the pressure of the concentrated oxygen supplied to the outside as a product gas is connected to a pipe connected between the pressure reducing valve 49 and the flow rate detector 53. A pressure gauge 51 for monitoring that can be detected is provided. The flow rate detector 53 is connected to the controller 5, and the flow rate detection value F at the flow rate detector 53 is output to the controller 5. A solenoid valve 54 is connected to the downstream side of the flow rate detector 53, and a gas supply port 55 for supplying the produced concentrated oxygen as a product gas to the supply destination is provided on the downstream side of the solenoid valve 54. Yes.

  Next, the configuration of the oxygen replenishment line 9 including the oxygen cylinder 3 will be described with reference to FIG. As shown in FIG. 1, the oxygen replenishment line 9 is provided with two oxygen cylinders 3 and 3 in which liquefied oxygen is stored, and original valves 3a and 3a are provided at the outlets of the oxygen cylinders 3 and 3, respectively. Is always open. The downstream sides of the pipes connected to the two oxygen cylinders 3 and 3 are combined into one, and further, the downstream side of the pipe connected to the one is branched into a supply line 60 and a supply line 70. Yes.

  First, a manual stop valve 37 is connected to the pipe branched into the supply line 60, and a pressure reducing valve 38 is connected to the downstream side of the stop valve 37. The other end side opposite to the one end side of the pipe connected to the pressure reducing valve 38 is connected to the electromagnetic valve 54. The pressure reducing valve 38 reduces the oxygen supplied from the oxygen cylinder 3 to the electromagnetic valve 54 to a predetermined pressure. The stop valve 37 is opened when the gas supply device 1 is started, and the concentrated oxygen released from the oxygen cylinder 3 passes through the electromagnetic valve 54 and is supplied to the gas supply port 55. Note that the pressure reduction setting of the pressure reducing valve 38 is set on the assumption of the maximum amount of product gas that is consumed when starting up an externally connected device.

  As shown in FIG. 1, a stop valve 39 is connected to the pipe branched to the supply line 70, and a pressure reducing valve 45 is connected to the downstream side of the stop valve 39. An oxygen replenishing valve 42 is connected to the downstream side of the pressure reducing valve 45, and a pipe connected between the oxygen replenishing valve 42 and the pressure reducing valve 45 is used for monitoring to detect the pressure of concentrated oxygen in the pipe. The pressure gauge 41 is provided. A controller 5 is connected to the oxygen replenishment valve 42. Further, a monitoring flow meter 43 is connected to the downstream side of the oxygen replenishing valve 42, a reverse support valve 44 is connected to the downstream side of the flow meter 43, and piping connected to the downstream side of the reverse support valve 44 is connected. The other end side opposite to the one end side is connected to a pipe connected to the above-described flow meter with controller 36 and the buffer tank 12. The PSA air separation device 4 in the configuration diagram of the gas supply device 1 shown in FIG. 1 corresponds to a “pressure fluctuation adsorption air separation device”, the oxygen cylinder 3 corresponds to a “gas cylinder”, and the buffer tank 12 includes It corresponds to a “second buffer tank”, the oxygen replenishment valve 42 corresponds to a “solenoid valve”, and the flow rate detector 53 corresponds to a “flow rate detection means”.

  Next, the PSA air separation device main body 2 will be described with reference to FIG. FIG. 2 is a configuration diagram showing the configuration of the PSA air separation device main body 2. The PSA (Pressure Swing Adsorption) air separation device main body 2 shown in FIG. 2 concentrates oxygen by selectively adsorbing and separating nitrogen from the air. The adsorbent filled in the first adsorbing cylinder 7 and the second adsorbing cylinder 8 to be described later of the PSA air separation device main body 2 is a zeolite which is a crystalline hydrous aminosilicate, and has a large number of pores. It has the property of adsorbing a large amount of nitrogen. Then, while the operations of pressurization (adsorption) and pressure reduction (desorption) are alternately repeated in the first adsorption cylinder 7 and the second adsorption cylinder 8, target concentrated oxygen is continuously generated. The PSA air separation device main body 2 can generate concentrated oxygen having a purity of about 90%. Further, the PSA air separation device main body 2 has a rising characteristic that the oxygen purity generated at the time of activation is low and the oxygen purity gradually increases with the activation.

  Next, the configuration of the PSA air separation device main body 2 will be described. It should be noted that parts constituting the PSA air separation device main body 2 are connected by piping. As shown in FIG. 2, the PSA air separation device main body 2 is provided with a compressor 15 that compresses external air, and the compressor 15 includes a filter 15b connected to the side from which air is sucked and a pump that compresses air. 15a and a filter 15c for further filtering the compressed air compressed by the pump 15a. Further, a stop valve 16 is connected to the downstream side of the compressor 15, and three filters 17 a, 17 b and 17 c are connected in order to the further downstream side of the stop valve 16. The filters 17a and 17b are mist separator type filters that remove moisture and oil in the air, and the filter 17c removes odorous components in the air.

  As shown in FIG. 2, a monitoring flow meter 18 is connected to the downstream side of the filter 17c, and the pipe connected to the downstream side of the flow meter 18 is branched into two pipes. Each pipe is connected to the air inflow side of the first adsorption cylinder 7 and the second adsorption cylinder 8. The first adsorption cylinder 7 and the second adsorption cylinder 8 are provided with monitoring pressure gauges 7a and 8a for detecting the gas pressure in the cylinder, respectively. A pressure gauge 20 for monitoring is provided in the vicinity of the downstream side of the flow meter 18. Further, electromagnetic valves 23 and 24 are respectively connected between the two pipes branched into two and the two pipes connected to the first adsorption cylinder 7 and the second adsorption cylinder 8. Compressed air is alternately supplied to the adsorption cylinder 7 and the second adsorption cylinder 8.

  Further, as shown in FIG. 2, a pipe is further branched and connected to the middle of the pipe connected to the first adsorption cylinder 7 and the electromagnetic valve 23, and the other end side opposite to the connected one end side. A solenoid valve 25 is connected to the. Further, a pipe is also branched and connected between the pipes connected to the second adsorption cylinder 8 and the electromagnetic valve 24, and an electromagnetic valve 26 is connected to the other end side opposite to the connected one end side. Yes. A single pipe is connected between the solenoid valve 25 and the solenoid valve 26. Further, a pipe is branched and connected to the middle of the pipe connecting the solenoid valve 25 and the solenoid valve 26, and the silencer 22 is connected to the other end side opposite to the connected one end side. A gas exhaust port 28 is provided on the side.

  Further, a pipe is connected to the middle of the pipe interposed between the electromagnetic valve 23 and the electromagnetic valve 25, and further, the pipe is also connected to the middle of the pipe interposed between the electromagnetic valve 24 and the electromagnetic valve 26. Are connected, and the other end opposite to one end connected to the electromagnetic valve 25 or 26 of each pipe is connected to each other with an electromagnetic valve 27 interposed therebetween.

  As shown in FIG. 2, one pipe is connected to the oxygen releasing side of the first adsorption cylinder 7, and an electromagnetic valve 29 is connected to the other end opposite to the connected one end. In addition, one pipe is connected to the oxygen releasing side of the second adsorption cylinder 8, and the electromagnetic valve 30 is connected to the other end side opposite to the connected one end side. One pipe is connected between the solenoid valve 29 and the solenoid valve 30, and one pipe is branched and connected from the middle so that the first suction cylinder 7 and the second suction cylinder are connected from the pipe. The concentrated oxygen produced | generated by 8 is supplied outside. One pipe is connected between the middle of the pipe connected to the first adsorption cylinder 7 and the electromagnetic valve 29 and the middle of the pipe connected to the second adsorption cylinder 8 and the electromagnetic valve 30. The solenoid valve 31 is connected to the middle of the connected pipe. One pipe is connected to the upstream side of the pipe connected to the first adsorption cylinder 7 and the electromagnetic valve 29 and to the upstream side of the pipe connected to the second adsorption cylinder 8 and the electromagnetic valve 30. An orifice 6 is provided in the middle of the connected pipe.

  Next, the controller-equipped flow meter 36 will be described. The flow meter with controller 36 shown in FIG. 1 can freely set the flow rate of the concentrated oxygen supplied from the buffer tank 10 to the buffer tank 12. Here, if the flow rate value is set to a, the set flow rate value a is determined from the maximum production amount of the PSA air separation device main body 2 that can ensure the oxygen purity required as the product gas. Therefore, since the PSA air separation device main body 2 does not need to generate concentrated oxygen in an amount exceeding the set flow rate value a with respect to the buffer tank 12, the PSA air separation device main body 2 can stably concentrate high-purity concentrated oxygen. Can be generated. In the gas supply device 1 of the first embodiment, the set flow rate value a is set to 130 L / min.

  Next, the pressure reducing valve 45 will be described. As shown in FIG. 1, the pressure reducing valve 45 of the supply line 70 of the oxygen replenishment line 9 depressurizes the concentrated oxygen supplied to the oxygen replenishment valve 42 to a predetermined pressure. The pressure of the pressure reducing valve 45 is set on the assumption of the maximum amount of product gas consumed by an externally connected device.

  Next, the operating principle of the PSA air separation device main body 2 will be described with reference to FIG. As shown in FIG. 2, when the PSA air separation device main body 2 is activated, the pump 15a of the compressor 15 is activated, and external air is sucked through the filter 15b and further filtered through the filter 15c. The compressed air is supplied into the air separation device main body 2. Next, the sucked compressed air passes through the open stop valve 16 and further passes through the filters 17a, 17b and 17c, and moisture, oil and odor components are removed. The filtered compressed air passes through the flow meter 18 and flows into pipes branched in two directions, the first adsorption cylinder 7 and the second adsorption cylinder 8.

  Then, the solenoid valve 23, the solenoid valve 29, and the solenoid valve 26 shown in FIG. 2 are opened, and the solenoid valve 24, the solenoid valve 30, and the solenoid valve 25 are closed, whereby compressed air is supplied to the first adsorption cylinder 7. . At this time, the first adsorption cylinder 7 is in a pressurized state, and the second adsorption cylinder 8 is in a reduced pressure state. The nitrogen in the compressed air supplied to the first adsorption cylinder 7 is adsorbed and separated by the adsorbent, the oxygen in the first adsorption cylinder 7 is concentrated, passes through the electromagnetic valve 29 and releases the concentrated oxygen toward the buffer tank 10. Is done. Further, part of the concentrated oxygen released from the first adsorption cylinder 7 passes through the orifice 6 and flows into the second adsorption cylinder 8. Next, due to the concentrated oxygen flowing from the orifice 6, the gas in the second adsorption cylinder 8 is discharged through the electromagnetic valve 26, and at the same time, the nitrogen adsorbed by the adsorbent in the second adsorption cylinder 8 is removed. It is desorbed (purged) and discharged from the gas exhaust port 28. Note that the silencer 22 provided on the upstream side of the gas exhaust port 28 reduces the exhaust sound of the gas generated when the electromagnetic valve 25 and the electromagnetic valve 26 installed in the vicinity of the gas exhaust port 28 are switched.

  Next, the electromagnetic valve 24, the electromagnetic valve 30, and the electromagnetic valve 25 shown in FIG. 2 are opened, and the electromagnetic valve 23, the electromagnetic valve 29, and the electromagnetic valve 26 are closed, so that the first adsorption cylinder 7 and the second adsorption cylinder 8 Adsorption and desorption of are switched. At this time, in order to prevent sudden pressure changes in the first adsorption cylinder 7 and the second adsorption cylinder 8, the electromagnetic valve 27 and the electromagnetic valve 31 are opened for a predetermined time (about 10 seconds) from the time of switching of the electromagnetic valves. . Then, compressed air is supplied to the second adsorption cylinder 8, similarly, concentrated oxygen is generated, and the generated concentrated oxygen is supplied to the buffer tank 10 through the electromagnetic valve 30. Similarly, in the first adsorption cylinder 7, the gas in the first adsorption cylinder 7 is discharged by the concentrated oxygen passing through the orifice 6, and at the same time, the nitrogen adsorbed by the adsorbent in the first adsorption cylinder 7 is desorbed. (Purge) and exhausted from the gas exhaust port 28. Therefore, in the 1st adsorption cylinder 7 and the 2nd adsorption cylinder 8, the adsorption process which carries out adsorption separation of nitrogen in the air, and produces | generates concentrated oxygen, and the desorption process which desorbs nitrogen are repeated alternately, and it is continuous. Concentrated oxygen is generated, and the generated concentrated oxygen passes through the reverse valve 35 and is supplied to the buffer tank 10.

  Next, the operation of the gas supply apparatus 1 having the above configuration will be described with reference to FIGS. FIG. 3 is a flowchart showing the control of the oxygen replenishment valve 42 of the controller 5. First, as the gas supply device 1 is activated, the PSA air separation device main body 2 is activated. Due to the rising characteristics of the PSA air separation device main body 2, oxygen having a low purity is generated. Therefore, by manually opening the stop valve 37 of the supply line 60 of the oxygen replenishment line 9, the concentrated oxygen decompressed by the pressure reducing valve 38 is released toward the electromagnetic valve 54, and the electromagnetic valve 54 is opened. The concentrated oxygen is supplied from the gas supply port 55 to the supply destination. Therefore, it is possible to prevent a decrease in the purity of the concentrated oxygen supplied from the gas supply port 55 when the gas supply device 1 is started. Note that the stop valve 37 is opened only for a time (about 30 minutes in the gas supply device 1 of the first embodiment) when the purity of the concentrated oxygen produced by the PSA air separation device body 2 is predicted to reach about 90%. .

  Then, the concentrated oxygen generated in the PSA air separation device main body 2 passes through the reverse support valve 35 and is stored in the buffer tank 10. Further, the concentrated oxygen released from the buffer tank 10 is supplied to the buffer tank 12 and stored by the flow meter with controller 36 at a flow rate of 130 L / min. The concentrated oxygen stored in the buffer tank 12 passes through the open stop valve 48, and the pressure of the concentrated oxygen is reduced by the pressure reducing valve 49. The decompressed concentrated oxygen passes through the flow rate detector 53. At this time, the flow rate detector 53 detects the flow rate detection value F of the concentrated oxygen supplied to the supply destination as the product gas (S1). The detection value F detected by the flow rate detector 53 is output to the controller 5, and the controller 5 determines whether or not the flow rate detection value F exceeds the set flow rate value a (a: 130 L / ml) (S2). ). If the flow rate of the concentrated oxygen exceeds the set flow rate value a (S2: YES), the maximum oxygen oxygen production amount required as the product gas of the PSA air separation device body 2 is exceeded. Requires replenishment.

  Therefore, the controller 5 opens the oxygen replenishment valve 42 (S3). When the oxygen replenishing valve 42 is opened, the liquefied oxygen sealed in the oxygen cylinder 3 is increased in pressure and vaporized by passing through the original valve 3a, passes through the stop valve 39, and is predetermined by the pressure reducing valve 45. Depressurized to pressure. The decompressed concentrated oxygen passes through the opened oxygen replenishment valve 42 and is supplied to the buffer tank 12. By checking the pressure gauge 41 for monitoring, it can be visually determined whether or not the concentrated oxygen passing therethrough is depressurized as predetermined. The concentrated oxygen that has passed through the opened oxygen replenishment valve 42 passes through the monitoring flow meter 43 and the reverse support valve 44 and is supplied from the buffer tank 10 of the PSA air separation device 4 at a constant flow rate by the buffer tank 12. It is mixed with concentrated oxygen and supplied to the supply destination.

  In addition, when the flow rate detection value F is equal to or less than the set flow rate value a (S2: NO), since it is less than the maximum production amount that can be produced by the PSA air separation device main body 2, the oxygen purity required as product gas of 90% or more While being held, the concentrated oxygen is supplied to the buffer tank 12 only from the PSA air separation device 4. Therefore, there is no need to replenish the buffer tank 12 with concentrated oxygen from the oxygen cylinder 3, so the oxygen replenishing valve 42 is closed (S4). The flow rate detector 53 continues to detect the oxygen flow rate of the supplied product gas (S1), and the concentrated oxygen from the oxygen cylinder 3 to the buffer tank 12 according to the amount of concentrated oxygen used on the product gas request side. Is replenished. Note that the controller 5 that executes the determination processing of S3 and S4 in the flowchart shown in FIG. 3 functions as “electromagnetic valve opening / closing control means”.

  As described above, the gas supply device 1 according to the first embodiment includes the PSA air separation device 4 and the oxygen replenishment line 9 that replenishes the buffer tank 12 with the concentrated oxygen from the oxygen cylinder 3. The concentrated oxygen produced by the PSA air separation device main body 2 is stored in the buffer tank 10 and further supplied to the buffer tank 12 by the flow meter with controller 36 based on the set flow rate value a (= 130 L / min). The flow rate of oxygen supplied from the buffer tank 12 to the supply destination as the product gas is detected by the flow rate detector 53, and the detected flow rate F is output to the controller 5. When the flow rate detection value F is less than or equal to the set flow rate value a, only the concentrated oxygen generated by the PSA air separation device 4 is supplied to the buffer tank 12, but the oxygen usage amount on the product gas request side varies greatly, When the set flow rate value a is exceeded, the controller 5 opens the oxygen replenishing valve 42 and replenishes the buffer tank 12 with the concentrated oxygen in the oxygen cylinder 3. Since the set flow rate value a is determined as the maximum production amount that can maintain the purity required as the product gas of the PSA air separation device 4, since the high-purity oxygen is always stored in the buffer tank 12, the gas The supply device 1 can supply concentrated oxygen having a stable and efficient purity according to the amount used on the product gas request side. Furthermore, even if a small PSA air separation device 4 is used for the gas supply device 1, if the number of installed oxygen cylinders 3 is increased, it is possible to cope with fluctuations in the amount of concentrated oxygen used on the product gas request side. The initial investment of the gas supply device 1 can be suppressed, and the installation space for the gas supply device 1 can also be reduced.

  Next, the gas supply apparatus 100 which is the 2nd Embodiment of this invention is demonstrated. First, the configuration of the gas supply device 100 will be described with reference to FIG. FIG. 4 is a configuration diagram illustrating the configuration of the gas supply device 100 according to the second embodiment. Here, the PSA air separation device main body 2 is assumed to be the same as the PSA air separation device main body 2 of the gas supply device 1 described above. As shown in FIG. 4, the gas supply device 100 includes a PSA air separation device 40 (from the PSA air separation device main body 2 to the buffer tank 10) and an oxygen cylinder 3, and an oxygen replenishment line 90 that replenishes deficient oxygen. (From the oxygen cylinder 3 to the solenoid valve 54 and from the oxygen cylinder 3 to the reverse branch valve 44) and the supply line 110 (gas from the stop valve 48) for supplying the concentrated oxygen in the buffer tank 10 of the PSA air separation device 40 to the supply destination. To the supply port 55).

  First, the PSA air separation device 40 will be described. As shown in FIG. 4, a monitoring flow meter 62 is connected to the PSA air separation device main body 2, and the downstream side of the flow meter 62 is generated by the PSA air separation device main body 2 via a reverse support valve 61. A buffer tank 10 for storing concentrated oxygen is connected. The buffer tank 10 is connected to a pressure detector 10b that detects the pressure of the concentrated oxygen inside the tank, and a controller 50 is connected to the pressure detector 10b.

  Next, the supply line 110 will be described. As shown in FIG. 4, a stop valve 48 is connected to the downstream side of the buffer tank 10 of the PSA air separation device, and a pressure reducing valve 49 is connected to the further downstream side of the stop valve 48. A flow rate detector 53 is connected to the downstream side of the pressure reducing valve 49, and the pressure of the concentrated oxygen supplied to the supply destination as a product gas is connected to a pipe connected between the pressure reducing valve 49 and the flow rate detector 53. Is provided. The flow rate detector 53 is connected to the controller 50. An electromagnetic valve 54 is connected to the downstream side of the flow rate detector 53. A gas supply port 55 for supplying concentrated oxygen as a product gas to a supply destination is provided on the downstream side of the electromagnetic valve 54. Note that the buffer tank 12 provided in the gas supply device 1 of the first embodiment is not provided.

  Next, the oxygen replenishment line 90 will be described. As shown in FIG. 4, the configuration of the oxygen replenishment line 90 provided with the oxygen cylinder 3 is the same as that of the oxygen replenishment line 90 of the gas supply device 1 of the first embodiment shown in FIG. 60 and a supply line 70 are branched. The other end of the supply line 70 connected to the reverse support valve 44 is connected to a pipe connected between the reverse support valve 61 of the PSA air separation device 40 and the buffer tank 10. Yes. Note that the pressure detector 10b in the configuration diagram of the gas supply device 100 shown in FIG. 4 corresponds to the “pressure detection means”, and the buffer tank 10 corresponds to the “buffer tank”.

  Next, the pressure detector 10b will be described. The pressure detector 10b shown in FIG. 4 detects the pressure in the buffer tank 10, and outputs the detected pressure detection value D to the controller 50. The pressure detection value D of the pressure detector 10b is used when determining opening / closing of the oxygen replenishment valve 42 of the controller 50, and the controller 50 compares the pressure detection value D with a set pressure value b described later, The opening / closing of the oxygen replenishing valve 42 is controlled.

  Next, the set pressure value b will be described. The set pressure value b is a set value set to determine whether or not to open the oxygen replenishment valve 42 provided in the supply line 70 of the oxygen replenishment line 90, similarly to the set flow rate value a described above. . This set pressure value b is set as a minimum value that does not fall below the pressure value required for the product gas. In the gas supply device 100 of the second embodiment, the set pressure value b is set to 0.45 MPa (megapascal).

  Next, the operation of the gas supply apparatus 100 configured as described above will be described with reference to FIGS. FIG. 5 is a flowchart showing the control of the oxygen replenishment valve 42 of the controller 50. First, as the gas supply device 100 is activated, the PSA air separation device main body 2 is activated. Due to the rising characteristics of the PSA air separation device main body 2, oxygen having a low purity is generated. Therefore, by manually opening the stop valve 37 of the supply line 60 of the oxygen replenishment line 90, the concentrated oxygen depressurized by the pressure reducing valve 38 is released, and by opening the electromagnetic valve 54, the gas supply port 55 is opened. Concentrated oxygen is supplied to the supply destination. Note that the stop valve 37 is opened for about 30 minutes in the same manner as the stop valve 37 of the gas supply device 1 of the first embodiment.

  Next, the concentrated oxygen generated in the PSA air separation device main body 2 passes through the monitoring flow meter 62 and the reverse support valve 61 and is temporarily stored in the buffer tank 10. Then, the pressure detection value D in the buffer tank 10 is detected by the pressure detector 10b provided in the buffer tank 10 (S7), and the detected pressure detection value D is output to the controller 50. The concentrated oxygen stored in the buffer tank 10 passes through the open stop valve 48, and the concentrated oxygen is depressurized by the pressure reducing valve 49. Next, the decompressed concentrated oxygen passes through the flow rate detector 53. The flow rate detector 53 detects the flow rate detection value F of the concentrated oxygen supplied to the supply destination as the product gas (S8), and the detected flow rate detection value F is output to the controller 50. The concentrated oxygen that has passed through the flow rate detector 53 passes through the opened electromagnetic valve 54 and is supplied as a product gas from the gas supply port 55 to the supply destination.

  Then, the controller 50 determines whether the oxygen replenishment valve 42 is opened or closed based on the detected pressure detection value D and the detected flow rate value F (S9, S10). When the pressure detection value D in the buffer tank 10 is less than the set pressure value b (b = 0.45 MPa) (S9: YES), it is below the pressure value required as the product gas, so PSA air separation The apparatus main body 2 is loaded more than the capacity. When a load exceeding the capacity is applied to the PSA air separation device main body 2, the generated oxygen purity is lowered, and the oxygen purity required as the product gas cannot be reached. Therefore, the controller 50 opens the oxygen replenishment valve 42 (S12).

  When the detected pressure value D is equal to or higher than the set pressure value b (S9: NO) and the detected flow rate value F exceeds the set flow value a (S10: YES), the product gas of the PSA air separation device main body 2 is obtained. Therefore, it is necessary to replenish the concentrated oxygen from the oxygen cylinder 3. Therefore, the controller 50 opens the oxygen replenishment valve 42 (S12). When the oxygen replenishing valve 42 is opened under the above conditions, the liquefied oxygen sealed in the oxygen cylinder 3 is increased in pressure and vaporized by passing through the original valve 3a, and is reduced in pressure through the stop valve 39. The pressure is reduced to the set pressure by the valve 45. The decompressed concentrated oxygen passes through the opened oxygen replenishment valve 42 and is supplied to the buffer tank 10.

  Therefore, the oxygen replenishing valve 42 is closed only when the detected pressure value D is not less than the set pressure value b (S9: NO) and the detected flow rate value F is not more than the set flow value a (S10: NO) (S11). If one of the two open / close conditions (S9, S10) of the oxygen replenishing valve 42 set in the pressure detector 10b and the flow rate detector 53 is opened, the oxygen replenishing valve 42 is opened. It has come to be. Then, returning to S7, the flow rate detection value F and the pressure detection value D are continuously monitored. In this way, the gas supply device 1 can always generate concentrated oxygen with high purity according to the required amount of product gas. Note that the controller 50 that executes the determination processing of S11 and S12 in the flowchart of FIG. 5 functions as “electromagnetic valve opening / closing control means”.

  As described above, the gas supply device 100 according to the second embodiment further simplifies the configuration of the gas supply device 1 according to the first embodiment and reduces the production cost of the gas supply device. As a modification of 1, the buffer tank 12 is omitted. The flow rate detector 53 detects the flow rate detection value F, and the pressure detector 10 b connected to the buffer tank 10 detects the pressure detection value D and outputs it to the controller 50. When the detected pressure value D is less than the set pressure value b or when the detected flow value F exceeds the set flow value a, the controller 50 opens the oxygen replenishing valve 42 of the oxygen cylinder 3. The buffer tank 10 is controlled to be replenished with the concentrated oxygen from the oxygen cylinder 3. Here, the set flow rate value a is set in the same manner as the gas supply device 1 of the first embodiment, and the set pressure value b is set to the minimum value of the pressure value required as the product gas. The supplied concentrated oxygen can be supplied to the supply destination while always maintaining the pressure required as the product gas. Further, since the PSA air separation device main body 2 does not need to generate concentrated oxygen exceeding the capacity as in the case of the gas supply device 1 of the first embodiment, it does not increase power consumption and is concentrated with stable purity. Oxygen is obtained. Furthermore, even if a small PSA air separation device 40 is used, if the number of installed oxygen cylinders 3 is increased, it is possible to cope with fluctuations in the amount of concentrated oxygen used on the product gas request side. Initial investment can be suppressed, and the installation space of the gas supply apparatus 100 can also be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the gas supply devices 1 and 100 have been described as devices that generate and supply oxygen, but not only oxygen but also nitrogen can be used. The number of oxygen cylinders 3 may be determined in consideration of the concentrated oxygen generation capacity of the PSA air separation devices 4 and 40 and the maximum usage amount of the product gas at the supply destination, and the gas according to the embodiment of the present invention. There are two oxygen cylinders 3 in the supply devices 1 and 100, but the number may be more or less. The flow meter with controller 36 may be anything as long as it can adjust the amount of gas passing therethrough, and can be changed, for example, as a constant flow valve.

  The present invention can be applied not only to a gas supply device that supplies oxygen as a product gas to a device that consumes oxygen, but also to a gas supply device that supplies various gases such as nitrogen.

It is the block diagram which showed the structure of the gas supply apparatus 1 of 1st Embodiment. 3 is a configuration diagram showing a configuration of a PSA air separation device main body 2. FIG. 4 is a flowchart showing control of an oxygen replenishment valve 42 of the controller 5. It is the block diagram which showed the structure of the gas supply apparatus 100 of 2nd Embodiment. 4 is a flowchart showing control of an oxygen refill valve 42 of the controller 50.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas supply apparatus 2 PSA air separation apparatus main body 3 Oxygen cylinder 5 Controller 10 Buffer tank 12 Buffer tank 36 Flowmeter with controller 42 Oxygen replenishment valve 50 Controller 53 Flow rate detector

Claims (4)

A gas supply device for supplying product gas to a supply destination,
A pressure fluctuation adsorption air separation device that selectively separates nitrogen or oxygen from the air;
A gas cylinder in which the same gas as the gas obtained by the air separation device is stored in advance;
A second buffer tank for mixing the gas supplied at a constant flow rate from the buffer tank of the air separation device and the gas supplied from the gas cylinder;
A solenoid valve interposed in the gas supply line from the gas cylinder;
Flow rate detection means for detecting the flow rate of product gas supplied from the second buffer tank to the supply destination;
A gas supply device comprising: an electromagnetic valve opening / closing control means for opening the electromagnetic valve when a product gas flow rate detected by the flow rate detection means exceeds a set flow rate. The flow rate of the gas supplied at a constant flow rate from the buffer tank of the air separation device and the set flow rate are set to the maximum generation amount of the air separation device that can ensure the gas purity required for the product gas. The gas supply device according to claim 1. A gas supply device for supplying product gas to a supply destination,
A pressure fluctuation adsorption air separation device that selectively separates nitrogen or oxygen from the air;
A gas cylinder that is connected to a pipe line in front of the buffer tank of the air separation device and stores the same gas as the gas obtained by the air separation device;
Pressure detecting means for detecting the pressure in the buffer tank;
A solenoid valve interposed in a gas supply line from the gas cylinder;
Flow rate detection means for detecting the flow rate of the product gas supplied from the buffer tank to the supply destination;
Solenoid valve opening / closing control means for opening the solenoid valve when the product gas flow rate detected by the flow rate detection means exceeds a set flow rate or when the pressure in the buffer tank detected by the pressure detection means falls below a set pressure; A gas supply device comprising: The set flow rate is set to the maximum generation amount of the air separation device that can ensure the gas purity required for the product gas, and the set pressure is set to the lowest value that does not fall below the product gas pressure specification. The gas supply device according to claim 3.

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