JP2016215088A - Gas separator and method for cooling compressor used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas separator capable of improving cooling efficiency by using exhaust gas of an adsorption tank peculiar to the gas separator of PSA type.SOLUTION: A gas separator includes an air supply unit with a compressor to compress air, and a PSA unit with an adsorption tank for separating product gas from the air compressed by the compressor. The gas separator has a structure that the air supply unit and the PSA unit are connected to each other with a partition part interposed therebetween. The gas separator is configured to have a passage through which exhaust gas from the adsorption tank is supplied to a cooling air suction port of the compressor.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a gas separation device having a compressor.

  A PSA (Pressure Swing Adsorption) type is known as a gas separation device. According to the PSA formula, for example, by using air as a raw material and adsorbing oxygen in the air with an adsorbent, for example, nitrogen can be separated and nitrogen gas can be obtained as product gas. The PSA treatment process includes an adsorption process for adsorbing oxygen at a high pressure, and a desorption process for desorbing oxygen at a low pressure from the adsorbent on which oxygen is adsorbed by the adsorption process. Continuous operation is carried out while recovering the adsorption capacity.

  As background art of this technical field, there is JP 2011-251243 A (Patent Document 1). Patent Document 1 discloses a gas separation device including an air supply unit that supplies air and a PSA unit that generates product gas. The air supply unit includes a compressor that compresses air and an air tank (air storage tank) that stores the compressed air. In addition, the PSA unit separates a predetermined gas from the compressed air supplied from the air supply unit, thereby generating a product gas and a nitrogen tank (product gas storage tank) for storing the product gas (nitrogen). have.

JP 2011-251243 A

  Patent Document 1 shows a configuration of a PSA type gas separation device, but does not consider the cooling of the compressor.

  An object of the present invention is to provide a gas separation device capable of improving the cooling efficiency by utilizing the exhaust of the adsorption tank unique to the PSA type gas separation device.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present invention includes a plurality of means for solving the above problems. For example, an air supply unit having a compressor for compressing air and product gas from the air compressed by the compressor are separated. A gas separation device having a structure in which an air supply unit and a PSA unit are connected to each other with a partition portion between the air supply unit and the PSA unit. It is configured to have a supply path.

  ADVANTAGE OF THE INVENTION According to this invention, the gas separation apparatus which can aim at the improvement of cooling efficiency can be provided.

1 is an overall configuration diagram of a gas separation device in Embodiment 1. FIG. 1 is an external view of a scroll compressor body in Embodiment 1. FIG. FIG. 3 is a schematic diagram illustrating a flow of cooling air in the scroll compressor body in the first embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is the whole external appearance figure of the gas separation apparatus in Example 1, and the perspective view seen from the back surface. BRIEF DESCRIPTION OF THE DRAWINGS It is the whole external appearance figure of the gas separation apparatus in Example 1, and the perspective view seen from the front. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall external view of a gas separation device according to a first embodiment and is a perspective view seen from the right side on the back. It is the whole gas-separation apparatus external view in Example 2, and is the perspective view seen from the back surface.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the overall configuration of a PSA type gas separation apparatus in the present embodiment. In FIG. 1, a gas separation device 1 includes an air supply unit 2 that supplies air and a PSA unit 3 that generates product gas. The air supply unit 2 and the PSA unit 3 are stored in the same casing.

  The air supply unit 2 includes a compressor 4 for compressing air, an electric motor 9 for driving the compressor 4, an inverter circuit 10 for performing capacity control, an air tank 5 for storing compressed air, and compressed air. It has an air dryer 6 for dehumidification and a drain filter 7 for removing impurities while collecting the drain water. In the present embodiment, as an example, the compressor 4, the air tank 5, the air dryer 6, and the drain filter 7 are stored in a casing. On the other hand, the PSA unit 3 separates a predetermined gas from the compressed air supplied from the air supply unit 2, thereby generating adsorption tanks 19 </ b> A and 19 </ b> B that generate product gas, and a nitrogen tank that stores product gas (nitrogen) ( Product gas storage tank) 41.

  The compressed air stored in the air tank 5 is supplied to the adsorption tanks 19 </ b> A and 19 </ b> B, and a predetermined gas is separated from the compressed air stored in the air tank 5. In the present embodiment, the case where nitrogen is separated by adsorbing oxygen in the adsorption tanks 19A and 19B will be described. However, other gases may be separated from compressed air other than the atmosphere.

  As the compressor 4, a reciprocating type, screw type or scroll type compressor or the like is generally used. However, in this embodiment, the cooling air from the cooling fan is not taken in from the air intake port of the compressor. For example, assume a scroll compressor having a structure.

  2A and 2B are external views of the scroll compressor body in the present embodiment, where FIG. 2A is a front view, FIG. 2B is a right side view, FIG. 2C is a left side view, and FIG. E) shows a rear view. In FIG. 2, reference numeral 70 denotes a casing constituting the outer shell of the compressor 4, which is formed as a bottomed cylindrical body that is closed on one side in the axial direction and opened on the other side in the axial direction. An orbiting scroll described later is accommodated in the cylindrical portion of the casing 70. The compressor 4 has a fixed scroll as one scroll member fixedly provided on the opening end side of the casing 70. 71 is a plurality of compression chambers defined between the wrap portion of the fixed scroll and the wrap portion of the orbiting scroll, and each compression chamber 71 is configured so that the wrap portion of the orbiting scroll overlaps the wrap portion of the fixed scroll. Has been placed. A pulley 72 is provided at one end of a drive shaft (not shown) and is connected to an output side of an electric motor as a drive source via a belt (none of which is shown) to drive the drive shaft. . The drive shaft causes the orbiting scroll to orbit with respect to the fixed scroll. A motor-integrated scroll air compressor in which the rotation shaft of the motor is integrated with the drive shaft, and the pulley 72 and the belt may be omitted. Reference numeral 80 denotes a suction port provided on the outer peripheral side of the fixed scroll. The suction port 80 sucks air from the outside through the suction filter 81, and this air continues in each compression chamber 71 along with the turning operation of the turning scroll. Compressed.

  That is, the orbiting scroll is driven via a drive shaft by an electric motor (not shown) or the like, and performs an orbiting motion with respect to the fixed scroll. Thereby, the compression chamber 71 on the outer diameter side of the plurality of compression chambers 71 sucks air from the suction port 80 of the fixed scroll, and this air is continuously compressed in each compression chamber 71. And compressed air is discharged toward the exterior from the discharge port 42 located in the center side from the compression chamber 71 of the innermost diameter side. Reference numeral 73 denotes a discharge pipe provided in connection with the discharge port 42 of the fixed scroll. The discharge pipe 73 constitutes a discharge flow path for communicating between a storage tank (not shown) and the discharge port 42. . Reference numeral 74 denotes a fan duct that guides cooling air generated by rotation of a cooling fan described later to the fixed cooling fin 75 of the fixed scroll and the orbiting cooling fin 76 of the orbiting scroll. Reference numeral 77 denotes a fin cover that covers the fixed cooling fin 75.

  FIG. 3 is a schematic view showing the flow of cooling air in the scroll compressor body in the present embodiment, and is a horizontal sectional view of the left side view of FIG. In FIG. 3, the cooling air 90 is sucked in outside air from the cooling air inlet 91 as indicated by an arrow 90-1 by a cooling fan 95 provided on the pulley 72 side of the scroll compressor 4, and indicated by an arrow 90-2. After cooling the fixed cooling fins 75 of the fixed scroll and the turning cooling fins 76 of the orbiting scroll through the fan duct 74 with the cooling air indicated by the arrow 90-3, the cooling air is supplied as indicated by the arrow 90-4. Exhaust from the outlet 96.

  On the other hand, the suction port 80 for taking in the air to be compressed by the compressor 4 sucks air from the outside through the suction filter 81, but the suction port 80 is separated from the cooling air suction port 91 and is further cooled by the cooling fan 95. Since the vicinity of the wind suction port 91 has a negative pressure, the air in the vicinity of the cooling air suction port 91 is structured not to be taken in from the suction port 80 of the compressor.

  Returning to FIG. 1, the air tank 5 is connected to a pipe 16 through which compressed air from the air tank 5 flows, and pipes 17 </ b> A and 17 </ b> B branched into two systems are connected to the terminal position of the pipe 16. Yes. Supply pipes 18A and 18B for opening and closing the flow paths are respectively provided in the pipes 17A and 17B, and adsorption tanks 19A and 19B for adsorbing oxygen molecules and taking out nitrogen gas as product gas are connected to the pipes 17A and 17B, respectively. ing. This adsorption tank has a constant volume. The pipes 17A and 17B are connected to pipes 21A and 21B at positions between the supply valves 18A and 18B and the adsorption tanks 19A and 19B, respectively. Exhaust valves 22A, 22B are provided with an exhaust silencer 23 with a filter for silencing at the terminal. This exhaust silencer may be provided for each adsorption tank 19A, 19B. Further, pipes 25A and 25B are connected to the pipes 17A and 17B so as to connect the positions between the pipes 21A and 21B and the adsorption tanks 19A and 19B. The pipes 25A and 25B are opened and closed. Lower pressure equalizing valves 26A and 26B are provided.

  The adsorption tanks 19A and 19B are filled with, for example, an adsorbent that is an adsorbing means for adsorbing oxygen molecules. Specifically, molecular sieve carbon or zeolite is used as the adsorbent. Pipes 31A and 31B that merge with each other are connected to the adsorption tanks 19A and 19B, respectively. Pipes 32A and 32B are connected to the pipes 31A and 31B so as to connect the adsorption tanks 19A and 19B to each other, and a throttle 33 is provided in the pipes 32A and 32B. Pipes 35A and 35B are connected to the pipes 31A and 31B so that the opposite sides of the adsorption tanks 19A and 19B are connected to the pipes 32A and 32B. Upper pressure equalizing valves 36A and 36B are provided for opening and closing. The pipes 31A and 31B are provided with take-out valves 38A and 38B for opening and closing the flow paths on the opposite side of the adsorption tanks 19A and 19B from the pipes 35A and 35B, respectively. A pipe 40 is connected to a joining position of the pipes 31A and 31B, and a nitrogen tank 41 as a product gas storage tank for storing nitrogen gas is connected to the pipe 40. A pipe 43 provided with a discharge port 42 is connected to the nitrogen tank 41, and a filter that removes dust and the like and adjusts the gas pressure in order from the nitrogen tank 41 side in the middle of the pipe 43. A regulator 44, a discharge valve 45 for opening and closing the flow path, a flow rate adjusting valve 46 for adjusting the flow rate of the product gas, and a flow rate sensor 61 for sensing the flow rate of the product gas are provided. A pipe 48 and a pipe 49 are connected to the pipe 43 between the filter regulator 44 and the discharge valve 45. The pipe 48 has an opening / closing valve 50 for opening and closing the flow path in order from the pipe 43 side, A flow rate adjusting valve 51 for adjusting the flow rate and a silencer 52 are provided. The pipe 49 is provided with an open / close valve 54 that opens and closes the flow path, a flow rate adjustment valve 55 that adjusts the flow rate of gas, and an oxygen sensor 56 that detects the oxygen concentration in order from the pipe 43 side.

  The oxygen sensor 56 and the flow sensor 61 are communicably connected to the control unit 60 and output detection signals to the control unit 60. The control unit 60 receives the detection signal and controls the generation of nitrogen gas in the adsorption tanks 19A and 19B. Specifically, the supply valves 18A and 18B, the exhaust valves 22A and 22B, the lower pressure equalizing valves 26A and 26B, the upper pressure equalizing valves 36A and 36B, the take-off valves 38A and 38B, the discharge valve 45, and the on-off valves 50 and 54 are controlled by the control unit. 60 is communicably connected, and operates in response to a command from the control unit 60.

  The configuration of the gas separation device 1 has been described above. Hereinafter, a gas separation method performed in the gas separation device will be described.

  In the gas separation device 1, the compression process of compressing air by the compressor 4, the storage process of storing the air compressed by the compression process in the air tank 5, the dehumidification process of dehumidifying the compressed air by the air dryer 6, and dehumidification by the dehumidification process A separation step for separating the gas from the air is performed.

In the separation step of the gas separation device 1, the following steps (a) to (d) are sequentially repeated.
(A) Adsorption / refluxing process: The compressed air compressed by the compressor 4 and stored in the air tank 5 is supplied to the adsorption tank 19 filled with the adsorbent by opening the supply valve 18, and the nitrogen tank 41. A step of recirculating the nitrogen gas remaining therein to the adsorption tank 19 by opening the take-off valve 38 to increase the pressure in the adsorption tank 19 and adsorbing oxygen molecules to the adsorbent using the pressure.
(B) Extraction process: Continuing from the adsorption process, the compressed air is continuously supplied from the air tank 5 to the adsorption tank 19, and at the same time, the nitrogen gas separated and generated by the adsorbent is extracted from the adsorption tank 19 and stored in the nitrogen tank 41. Process.
(C) Pressure equalization process: The pressure equalization of the pair of adsorption tanks 19 after completion of the take-out process is achieved by opening and closing the upper pressure equalization valve 36 and the lower pressure equalization valve 26, and the adsorption efficiency of the next adsorption process is increased, resulting in higher purity. For generating nitrogen gas.
(D) Regeneration step: A step of regenerating the adsorbent by desorbing oxygen molecules adsorbed by the adsorbent through the pipe 21 by opening the exhaust valve 22 in the adsorption tank 19 after completion of the pressure equalization step. . In this regeneration process, the supply valve 18, the lower pressure equalizing valve 26, the upper pressure equalizing valve 36 and the take-off valve 38 related to the adsorption tank 19 other than the exhaust valve 22 are closed.

  While the adsorption process / removal process (process (a) (b)) is performed in the adsorption tank 19A, the regeneration process (process (d)) is performed in the adsorption tank 19B. Thereafter, the (c) pressure equalization step is performed simultaneously, and the adsorption tanks 19A and 19B are exchanged to perform the adsorption step / removal step (steps (a) and (b)) and the regeneration step (step (d)).

  Here, the exhaust of the adsorption tank is at a low temperature due to adiabatic expansion. Therefore, in this embodiment, the low-temperature exhaust gas exhausted from the adsorption tank is used as cooling air for the compressor.

  FIG. 4 shows an overall external view of the gas separation device in this example. FIG. 4 shows a perspective view of the gas separation device as seen from the back. In FIG. 4, a compressor 4 that compresses air, an air supply unit 2 that mainly includes an electric motor 9 that drives the compressor 4, adsorption tanks 19 </ b> A and 19 </ b> B that generate product gas, and product gas (nitrogen) The PSA unit 3 whose main constituent is a nitrogen tank (product gas storage tank) 41 that stores the gas) is partitioned by a partition portion 28. Here, the exhaust from the adsorption tanks 19 </ b> A and 19 </ b> B is exhausted from the exhaust silencer 23. The exhaust from the adsorption tank is at a low temperature due to adiabatic expansion. The adsorption tank exhaust 27 flows to the air supply unit 2 side through the ventilation port 29 provided in the partition portion 28 and is taken in from the cooling air suction port 91 by the cooling fan 95 shown in FIG. Then, the fixed cooling fin 75 of the fixed scroll and the turning cooling fin 76 of the orbiting scroll are cooled and then exhausted from the cooling air outlet 96. Thus, it has the path | route which supplies the exhaust_gas | exhaustion from an adsorption tank to the cooling air suction inlet of a compressor. Thereby, the low temperature exhaust gas exhausted from the adsorption tank can be used as cooling air for the compressor.

  The exhaust gas exhausted from the adsorption tank is an exhaust gas when oxygen molecules adsorbed by the adsorbent are desorbed, and thus has a high oxygen concentration. On the other hand, since the PSA unit 3 separates a predetermined gas (for example, nitrogen) from the compressed air supplied from the air supply unit 2, if the oxygen concentration of the compressed air is high, the gas to be separated decreases, and the gas generation efficiency is improved. It gets worse. Therefore, it is necessary to prevent the exhaust gas exhausted from the adsorption tank from being taken in from the suction port 80 of the compressor 4. In this embodiment, the suction port 80 of the compressor 4 is separated from the cooling air suction port 91, and further, the cooling air of the compressor 4 in the middle of the path to the suction port 80 of the compressor 4 for the adsorption tank exhaust gas. Since the suction port 91 has a negative pressure in the vicinity of the cooling air suction port 91 by the cooling fan 95, most of the air near the cooling air suction port 91 is taken in from the cooling air suction port 91, and the suction port of the compressor The possibility of being taken in from 80 is low. Further, since the flow rate of the adsorption tank exhaust gas is smaller than the flow rate from the suction port 80 taken from outside air, the possibility of taking the adsorption bath exhaust gas from the suction port 80 is low.

  FIG. 5 is an overall external view of the gas separation device in the present embodiment, and shows a perspective view seen from the front. The air taken in from the intake port 80 of the compressor performs the compressor intake 82 from the intake hole provided in the housing of the entire panel that covers the gas separation device.

  Thus, according to the present embodiment, the ventilation port is provided between the air supply unit and the PSA unit so that the exhaust gas from the adsorption tank can be sucked by the cooling air suction port of the compressor. Also, by providing a ventilation port near the cooling air intake port of the compressor, the low-temperature exhaust gas exhausted from the adsorption tank can be used as the cooling air for the compressor, and taken in from the intake port of the compressor By adopting such a structure, gas generation efficiency and compressor reliability can be improved.

  FIG. 6 is an overall external view of the gas separation device in the present embodiment, and shows a perspective view seen from the right side of the back surface. FIG. 6 is an external view showing a structure in which the panel covering the gas separation device is removed and the compressor exhaust path is visible. In FIG. 6, reference numeral 96 denotes a cooling air outlet of the compressor. Exhaust air from the adsorption tank is taken in from a cooling air inlet 91 of the compressor through a ventilation port between the air supply unit and the PSA unit, The fixed cooling fins 75 of the fixed scroll and the turning cooling fins 76 of the orbiting scroll are cooled via the duct 74 and then exhausted from the cooling air outlet 96. The exhaust exhausted from the cooling air outlet 96 is exhausted as a gas separation device exhaust 97 through a compressor exhaust path isolated from the compressor intake path. As described above, in the gas separation device according to the present embodiment, the exhaust path of the adsorption tank is shared with the exhaust path of the cooling air of the compressor, thereby exhausting the adsorption tank using the compressor exhaust path. Therefore, since both the adsorption tank and the compressor can be exhausted by one exhaust duct, there is an effect that the exhaust processing can be facilitated.

  Further, since the exhaust path from the adsorption tank is long from the cooling air suction port of the compressor through the cooling air outlet and the compressor exhaust path to the gas separation device exhaust, there is also an effect that sound leakage due to the exhaust can be reduced.

  As described above, this embodiment includes an air supply unit having a compressor that compresses air, and a PSA unit having an adsorption tank for separating product gas from the air compressed by the compressor. A compressor-integrated gas separation device having a structure in which a supply unit and a PSA unit are partitioned by a partition portion, and configured to have a path for supplying exhaust from the adsorption tank to the cooling air intake port of the compressor.

  A compressor cooling method for use in a PSA type compressor-integrated gas separation device comprising a compressor for compressing air and an adsorption tank for separating product gas from the air compressed by the compressor, The compressor is cooled by supplying the exhaust from the tank to the cooling air inlet of the compressor.

  This makes it possible to improve the gas generation efficiency and reliability by improving the cooling efficiency by utilizing the exhaust from the adsorption tank unique to the PSA type gas separation device and using it for cooling the compressor. The exhaust processing can be facilitated while being planned.

  In this embodiment, the capacity control by the inverter circuit 10 is performed. However, the operation and stop of the compressor may be controlled by pressure monitoring without the inverter circuit 10.

  FIG. 7 is an overall external view of the gas separation device in this embodiment, and is a perspective view seen from the back. In FIG. 7, the basic configuration of the apparatus is the same as that of the gas separation apparatus 1 described in the first embodiment, and a description thereof will be omitted. The difference between the present embodiment and FIG. 4 of the first embodiment is that a shielding plate 98 is provided.

  That is, in the first embodiment, the exhaust gas exhausted from the adsorption tank is a gas having a high oxygen concentration, and it is necessary to prevent it from being taken in from the suction port of the compressor. Therefore, a shielding plate 98 is provided between the suction port 80 and the cooling air suction port 91 of the compressor 4, and the exhaust gas exhausted from the adsorption tank is taken in from the cooling air suction port 91 and is compressed. The exhaust gas exhausted from the adsorption tank is shielded by the shielding plate 98 so that it does not flow into the suction port 80 of the compressor 4. Thereby, in addition to the improvement of the reliability of the compressor by improving the cooling effect, the gas generation efficiency can also be improved. The shielding plate 98 reduces the amount of air that was originally taken from the compressor intake air 82 obtained from the intake hole of the gas separation device from the cooling air intake port 91, so a cooling air intake port is separately provided. May be.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications. Moreover, it is not necessarily limited to what has all the structures demonstrated. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1: PSA type gas separation device, 2: Air supply unit, 3: PSA unit, 4: Compressor, 5: Air tank, 6: Air dryer, 7: Drain filter, 9: Electric motor, 10: Inverter circuit, 19A 19B: Adsorption tank, 23: Exhaust silencer, 27: Adsorption tank exhaust, 28: Partition, 29: Ventilation port, 41: Nitrogen tank (product gas storage tank), 42: Discharge port, 70: Casing, 71: Compression Chamber, 72: pulley, 73: discharge pipe, 74: fan duct, 75: fixed cooling fin, 76: swirl cooling fin, 77: fin cover, 80: suction port, 81: intake filter, 82: compressor intake, 90 : Cooling air, 91: Cooling air inlet, 95: Cooling fan, 96: Cooling air outlet, 97: Exhaust gas separator, 98: Shielding plate

Claims (10)

An air supply unit having a compressor for compressing air; and a PSA unit having an adsorption tank for separating product gas from the air compressed by the compressor, wherein the air supply unit and the PSA unit are partitioned. A gas separation device having a structure connected with parts separated,
A gas separation device having a path for supplying exhaust from the adsorption tank to a cooling air suction port of the compressor. The gas separation device according to claim 1,
The said path supplies the exhaust_gas | exhaustion from the said adsorption tank to the cooling air suction inlet of the said compressor through the ventilation port provided in the said partition part, The gas separation apparatus characterized by the above-mentioned. The gas separation device according to any one of claims 1 and 2,
The gas separation device according to claim 1, wherein the compressor has a cooling fan, and cooling air from the cooling fan is not taken in from an intake port that sucks in air compressed by the compressor. The gas separation device according to any one of claims 1 to 3,
The compressor has a suction port for sucking in air to be compressed and a cooling air suction port for sucking cooling air, and the cooling air suction port is in the middle of the path from the adsorption tank to the suction port. Gas separation device. The gas separation device according to claim 4,
The compressor has a cooling fan, and the cooling fan takes in the cooling air from the cooling air inlet through the cooling fan. The gas separation device according to claim 2,
The compressor is a scroll compressor, and the ventilation port is provided at a position closer to a cooling fan of the scroll compressor than a suction port for sucking air compressed by the scroll compressor. Separation device. The gas separation device according to any one of claims 1 to 6,
A gas separation apparatus characterized in that an exhaust path of the adsorption tank is shared with an exhaust path of cooling air of the compressor. The gas separation device according to any one of claims 1 to 7,
The compressor has a suction port for sucking compressed air and a cooling air suction port for sucking cooling air, and a shielding plate is provided between the suction port and the cooling air suction port. Separation device. A compressor cooling method used in a PSA type gas separation apparatus comprising a compressor for compressing air and an adsorption tank for separating product gas from air compressed by the compressor,
The compressor cooling method characterized by cooling the said compressor by supplying the exhaust_gas | exhaustion from the said adsorption tank to the cooling air suction inlet of the said compressor. The compressor cooling method according to claim 9,
Exhaust gas from the adsorption tank is supplied to a cooling air intake port of the compressor through an air vent provided in a partition that separates the compressor and the adsorption tank.

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