JP2019042613A - Gas separation device - Google Patents

Abstract

To improve convenience of a user at a failure time of a gas separation device.SOLUTION: There is provided a gas separation system having pressure detection means for detecting a pressure of compressed gas between a compressed air supply source and an adsorption tank, and a control part for controlling operation according to a detected pressure. In a gas separation device, when the detected pressure falls lower than a first specified value, the control part elongates a time of an adsorption process or stops the compressed air supply source.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure swing adsorption (PSA) gas separation device.

  Patent Document 1 is a conventional pressure swing adsorption (PSA) type gas separation apparatus.

  Patent Document 1 discloses a rapid pressure drop in the adsorption cylinder by providing a main orifice 18 for throttling the amount of flowing gas after adsorption between the lead-out side of the first and second adsorption cylinders and the external use side. , It is possible to prevent an unscheduled shutdown.

  However, as a safety device when the main orifice 18 does not function, the compressor 1, the pressure regulator 3, the drain filter 4, and the mist filter 5 in the order of the compressed air supplied between the drain filter 4 and the mist filter 5 It is described in paragraph numbers 0017 to 0042 that the pressure sensor 6 is provided and it is determined that the operation of the compressor 1 is stopped when the detected pressure becomes lower than the set pressure, and the regeneration operation is stopped. .

JP 2002-143631 A

  In the above conventional gas separation apparatus, the regeneration operation is stopped when the pressure of the compressed gas from the compressor 1 or the pressure regulator 3 is decreased by the pressure sensor 6 regardless of the main orifice 18 not functioning. I did not give a stop instruction. In the case of an abnormality such as a deterioration of the compressor or a pipe leak, the operation of the compressor will be continued and the user may not notice the abnormality.

  In addition, in the above-described conventional gas separation apparatus, the user's convenience is low also because the regeneration operation is suddenly stopped.

  An object of the present invention is to improve the convenience of the user when an abnormality occurs in the gas separation device.

  Although the present invention solves the above-mentioned subject, if a representative example is given, it is as follows.

  A pressure detection means is provided in the path between the air tank storing compressed air and supplied to the adsorption tank, and if the pressure falls below a specified pressure, the adsorption step is lengthened or not only the gas separation apparatus but also compressed air Stop the operation of the supply source.

  According to the present invention, it is possible to improve the convenience of the user when an abnormality occurs in the gas separation device.

FIG. 1 is an overall configuration view showing a gas separation device in a first embodiment. The state of the adsorption tank of each process of Example 1 is shown.

  Hereinafter, the present embodiment will be described.

  Hereinafter, an embodiment according to the present invention will be described based on the drawings.

  FIG. 1 is a block diagram showing a gas separation apparatus according to a first embodiment of the present invention. The gas separation device 1 of the first embodiment shown in FIG. 1 is a PSA type gas separation device. The gas separation apparatus 1 is connected to a compressed air supply source 2 for supplying compressed air and a pipe 3 for flowing the compressed air, and an air filter 4 provided in the middle of the pipe 3 for removing dust and the like from the compressed air. .

  The gas separation apparatus includes an air tank 5 connected to the end of the pipe 3 and storing the compressed air cleaned by the air filter 4 and a pipe 6 for flowing the compressed air.

  The pressure detection means 7 is on the primary side of the adsorption tank, and is provided in the middle of the pipe 6 in the present embodiment. The position of the pressure detection means 7 may be in the pipe 3 but is preferably installed in the air tank 5 or the pipe 6 in consideration of pressure fluctuation.

  A pair of pipes 8 is connected to the end position of the pipe 6. A supply valve 9 for opening and closing the flow path is provided in the middle of each of the pipes 8, and an adsorption tank 10 for adsorbing oxygen molecules and extracting nitrogen gas as a product gas is connected to the terminal. .

  In addition, a pipe 11 is connected to the pair of pipes 8 at a position between the supply valve 9 and the adsorption tank 10, respectively, and an exhaust valve 12 for opening and closing the flow path in the middle is connected to these pipes 11 An exhaust silencer 13 with a filter for silencing is provided. Further, a pipe 14 is connected to the pair of pipes 8 so as to connect the positions of the pipe 11 and the adsorption tank 10 to each other, and the pipe 14 has a pair of lower pressure equalizing valves 15 for opening and closing a flow path. It is provided.

  The pair of adsorption vessels 10 is filled with an adsorbent which is an adsorption means for adsorbing oxygen molecules. Specifically, molecular sieve carbon, zeolite or the like is used as the adsorbent.

  The piping 16 which mutually joins in a terminal position is connected to a pair of adsorption tank 10, respectively. The pipes 17 are connected to the pipes 16 so as to connect the adsorption tank 10 sides with each other, and the pipe 18 is provided with a throttle 18. Further, a pipe 19 is connected to the pair of pipes 16 so as to connect opposite sides of the adsorption tank 10 with each other than the pipes 17, and the pipe 19 is a pair of upper pressure equalizing valves for opening and closing the flow path. 20 are provided. Further, the pair of pipes 16 is provided with a discharge valve 21 for opening and closing the flow path on the opposite side to the adsorption tank 10 with respect to each of the pipes 19.

  A pipe 22 is connected to the joining position of the pair of pipes 16, and a nitrogen tank 23 as a product tank for storing nitrogen gas is connected to an end position of the pipe 22. A pipe 25 whose end position is a discharge port 24 is connected to the nitrogen tank 23. At an intermediate position of the pipe 25, dust and the like are sequentially removed from the nitrogen tank 23 side and the flow rate of gas is adjusted. A filter regulator 26, a discharge valve 27 for opening and closing the flow path, and a flow control valve 28 for adjusting the flow rate of the gas are provided.

  A pipe 29 and a pipe 30 are connected to a position between the filter regulator 26 of the pipe 25 and the discharge valve 24, and the pipe 29 includes an on-off valve 31 for opening and closing the flow path in order from the pipe 29 side. A flow control valve 32 for adjusting the flow rate and a silencer 33 are provided. The pipe 30 is provided with an on-off valve 34 for opening and closing the flow path, a flow rate adjusting valve 35 for adjusting the flow rate of gas, and an oxygen sensor 36 for detecting an oxygen concentration in order from the pipe 30 side.

  The pressure detection means 7 and the oxygen sensor 36 are communicably connected to the control unit 37, and output a detection signal to the control unit 37.

  Also, the supply valve 9, the exhaust valve 12, the lower pressure equalizing valve 15, the upper pressure equalizing valve 20, the outlet valve 21, the discharge valve 27, the flow control valve 28, the on-off valve 31, the flow control valve 32, the on-off valve 34, and the flow control valve 35 Is communicably connected to the control unit 37, and operates in accordance with a command from the control unit 37.

  In the gas separation device 1, the following steps (a) to (d) are sequentially performed. The state of the adsorption tank of each process is shown in FIG.

  (A) Adsorption step: The compressed air compressed by the compressed air supply source 2 and stored in the air tank 5 is introduced into the adsorption tank A10-a filled with the adsorbent by opening the supply valve 9, and The nitrogen gas remaining in the tank 23 is returned to the adsorption tank A10-a by opening the takeout valve 21-a to raise the pressure in the adsorption tank 10-a, and the pressure is used to adsorb the oxygen molecule to the adsorbent Process.

  (B) Take-out step: Continue to introduce compressed air from the air tank 5 to the adsorption tank A10-a continuously from the adsorption step, and at the same time take out nitrogen gas separated and produced by the adsorbent from the adsorption tank A10-a A step of storing in the tank 23;

  (C) Pressure equalization process: pressure equalization after completion of the take-out process is achieved by opening and closing upper pressure equalization valve 20 and lower pressure equalization valve 15, and adsorption efficiency of the next adsorption process is enhanced to generate nitrogen gas of higher purity. Process.

  (D) Regeneration process: By opening the exhaust valve 12-a in the adsorption tank A10-a after completion of the pressure equalization process, the atmosphere is opened via the pipe 11 to desorb the oxygen molecules adsorbed by the adsorbent. Step of regenerating the adsorbent. In this regeneration process, the supply valve 9-a, the lower pressure equalizing valve 15, the upper pressure equalizing valve 20 and the takeout valve 21-a related to the adsorption tank A10-a other than the exhaust valve 12-a are in a closed state.

  The control unit 37 switches these respective steps (a) to (d) for a preset time, or pressure conditions of the air tank 5, the adsorption tank A10-a, the adsorption tank B10-b, the nitrogen tank 23, etc. Supply valve 9-a, b, exhaust valve 12-a, b, lower pressure equalizing valve 15, upper pressure equalizing valve 20, and outlet valve 21-a, which are disposed in adsorption tank A10-a and adsorption tank B10-b. This is done by controlling the opening and closing of, b. Moreover, switching of each step (a) to (d) is repeatedly performed for each adsorption tank, and the steps in each adsorption tank are performed in cooperation, that is, the adsorption step and the extraction step in one adsorption tank. Is completed, and after the regeneration process is completed in the other adsorption tank, the controller 37 controls the pressure equalization process.

  As described above, in the adsorption step (a), compressed air is introduced to the pressure increase of the adsorption tank A10-a, and nitrogen gas is refluxed from the nitrogen tank 23. When the pressure of the compressed air decreases, the reflux from the nitrogen tank 23 increases. Since the amount of compressed air introduced is small, the amount of nitrogen gas generated is small, and the pressure and purity of nitrogen gas in the nitrogen tank 23 are reduced. Further, since the pressure is equalized with the other adsorption tank B10-b in the pressure equalization step, and exhausted in the regeneration step, the more the reflux, the more the generated nitrogen gas is released.

  Therefore, when the primary pressure of the adsorption tank detected by the pressure detection means 7 falls below the specified value for a certain period of time, the control unit 37 determines that it is abnormal and stops not only the gas separation device 1 but also the compressed air supply source 2 .

  The conventional gas separation apparatus stops the discharge of nitrogen gas when the purity of nitrogen gas deteriorates and the specification value is not satisfied. Even in that case, the operation of the gas separation apparatus continues, and when the pressure of the compressed air is low, the useless operation of the compressed air supply source 2 also continues without improving the purity. In the present invention, since not only the gas separation device 1 but also the compressed air supply source 2 is stopped, unnecessary operation can be prevented. In addition, by stopping the gas separation apparatus, it is possible to prevent the decrease in pressure and purity of the purified nitrogen due to the increase of the reflux, and to save energy and shorten the time to take out the nitrogen gas after repair.

  Furthermore, by stopping the compressed air supply source 2 that generates a loud noise, the user can notice abnormal early.

  Immediately after entering the adsorption step, the pressure of the compressed air decreases, but the pressure of the adsorption tank 10 rises and returns to a level before the adsorption step. The time until the stop is, for example, about half of the time of the adsorption step, and when the pressure of the compressed air does not reach the specified value or more, it may be judged as abnormal and the compressed air supply source 2 may be stopped.

  In the present embodiment, a gas separation apparatus will be described in which steps are provided to control specified values of pressure of compressed air. The difference from the first embodiment is that the control unit 37 continues the operation of the gas separation device 1 and the compressed air supply source 2 when the pressure of the compressed air becomes equal to or less than the first specified value, but the gas separation device 1 gives an alarm When the pressure output point and the pressure of the compressed air further decrease and become less than or equal to the second predetermined value (less than the first predetermined value), the gas separation apparatus 1 and the compressed air supply source 2 are stopped as in the first embodiment. It is a point. In this embodiment, two stages are used, but three or more stages may be used.

  By outputting an alarm before stopping the apparatus, it is possible to cope with abnormalities in the compressed air supply source 2, piping abnormalities, etc. in advance, and it is possible to reduce the impact on customers.

  In the first embodiment, the gas separation device 1 and the compressed air supply source 2 are suddenly stopped, but in the present embodiment, a plurality of stages are provided for the pressure of the compressed air at specified values, and adsorption is performed in the stages up to the final stage. Control the process time to be gradually longer.

  The apparatus configuration is the same as in the first and second embodiments, and the control unit 37 sets a stage at the specified value of the pressure of the compressed air as in the second embodiment, so that the compressed air decreases and becomes less than the first specified value. Increase the time of the adsorption step. By lengthening the adsorption step, the pressure in the adsorption tank 10 is increased, and the pressure and purity of nitrogen gas in the nitrogen tank 23 are improved.

  Even so, when the compressed air decreases and becomes less than or equal to the second predetermined value, the control unit 27 stops the gas separation device 1. In the present embodiment, stopping of the compressed air supply source 2 may be added, but this is not an essential configuration.

  About the present Example, the pressure detection means 7 of the structure of Examples 1-3 demonstrates the case where it is a flow volume detection means.

  The apparatus configuration is different from the first to third embodiments in that the pressure detection means 7 is a flow rate detection means, and the specified value of the pressure of the compressed air in the first to third examples is the specified value of the flow rate of compressed air. It is. The same control is performed when the value is less than the specified value.

  In this embodiment, in the gas separation device 1 of the first to fourth embodiments, when the pressure of the air tank 5 does not exceed the specified value at the start of the operation of the gas separation device 1, the operation of the gas separation device 1 is not started. It is This is because it is necessary to drive the compressed air supply source 2 and wait until the air tank 5 is filled with a predetermined pressure. This prevents the wasteful operation of the gas separation device 1 and prevents the discharge of the purified nitrogen tank. In addition, since the gas separation device 1 does not operate, it is possible to discover an abnormality of the compressed air supply source 2 and a forget of the preceding operation.

DESCRIPTION OF SYMBOLS 1 ... Gas separation apparatus, 2 ... Compressed air supply source, 3 ... Piping, 4 ... Air filter, 5 ... Air tank, 6 ... Piping, 7 ... Pressure detection means, 8 ... Piping, 9 ... Supply valve, 10 ... Adsorption tank 11: Piping 12: Exhaust valve 13: Exhaust silencer 14: Piping 15: Lower pressure equalizing valve 16: Piping 17: Piping 18: Squeezing 19: Piping 20: Upper pressure equalizing valve 21 Valve 22 22 piping 23 nitrogen tank 24 discharge port 25 piping 26 filter regulator 27 discharge valve 28 flow control valve 29 piping 30 piping 31 opening and closing valve 32 ... Flow adjustment valve, 34 ... on-off valve, 35 ... flow adjustment valve, 37 ... control unit

Claims (6)

The pressure detection means for detecting the pressure of the compressed gas in the supply path between the compressed air supply source and the adsorption tank, and the control unit for controlling the operation according to the detected pressure,
The gas separation device according to claim 1, wherein the control unit lengthens the time of the adsorption step or stops the compressed air supply source when the detected pressure falls below a first predetermined value. In claim 1,
The compressed gas supply path is provided with an air tank for storing the compressed gas,
The gas separation apparatus, wherein the pressure detection means detects the pressure between the air tank and the adsorption layer tank. In claim 1,
The said separation part stops the operation | movement of a gas separation apparatus, when it becomes less than the 2nd predetermined value lower than the said 1st specification, The gas separation apparatus characterized by the above-mentioned. Gas having a compressed air supply source, an adsorption tank, pressure detection means for detecting the pressure of the compressed gas between the compressed air supply source and the adsorption tank, and a control unit for controlling the operation according to the detected pressure In the separation system
The said control part stops the said compressed air supply source, The gas separation apparatus characterized by the above-mentioned. In claim 4,
The compressed gas supply path is provided with an air tank for storing the compressed gas,
The gas separation apparatus, wherein the pressure detection means detects the pressure between the air tank and the adsorption layer tank. In claim 4,
The said separation part stops the operation | movement of a gas separation apparatus, when it becomes less than the 2nd predetermined value lower than the said 1st specification, The gas separation apparatus characterized by the above-mentioned.

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