Gas compression device

Abstract

To provide a gas compression device of liquid pump type which facilitates maintenance of a cylinder tank inner part, and part replacement.SOLUTION: A gas compression device 10 compresses gas taken into a cylinder tank 1A by a liquid piston. Therein, the cylinder tank 1A includes a barrel plate 1a, a top plate 1b which closes an opening of the one end side of the barrel plate 1a and a bottom plate 1c which closes an opening of the other end side of the barrel plate 1a. The barrel plate 1a has a first flange 71 which extends toward the outer side from an opening periphery of the one end side. The top plate 1b is formed on an end plate and has a second flange 72 which extends toward the outer side from an opening periphery of the end plate. The top plate 1b is attached to the barrel plate 1a by connecting the first flange 71 and the second flange 72 by using a fastener 74.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present invention relates to a gas compression device for compressing gas.

Background Art

[0002] Conventionally, electric air compressors such as screw type, scroll type, rotary vane type, and reciprocating piston type have been widely used. These air compressors are devices that adiabatically compress the inhaled air by a mechanical compression mechanism to produce compressed air at a required pressure. In the mechanical compression mechanism, after a certain operating time has elapsed, leakage of compressed air occurs due to wear of the gas seal part (specifically, rotor tooth groove part, tip seal, slide vane, piston ring, etc.), and a decrease in volumetric efficiency is likely to occur.

[0003] Also, in the adiabatic compression process, the gas phase part holds the compression heat generated by the increase in the kinetic energy of molecules and becomes high temperature, and the air in the compression process tries to expand against compression. Therefore, in this type of air compressor, the specific energy is directly related to the running cost.

[0004] In view of the characteristics of such a mechanical compression mechanism, a liquid pump type gas compression device disclosed in, for example, Patent Documents 1 and 2 has been studied for a long time.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The liquid pump type gas compression device is configured to compress air inside a cylinder tank by sending a liquid (typically water) into the lower part of the cylinder tank into which atmospheric pressure air is taken in, using a liquid pump. That is, the liquid filled inside the cylinder tank serves as a piston, and as the liquid level rises, the compression of the air progresses. The devices disclosed in Patent Documents 1 and 2 have a configuration in which a liquid piston is alternately moved between two cylinder tanks to periodically produce compressed air. During the production of compressed air, an operation control that continuously drives the liquid pump is employed.

[0007] During the air compression process, since the contact surface between the cylinder tank corresponding to the cylinder and the liquid piston is completely sealed, there is no leakage of compressed air, and high volumetric efficiency is maintained. Thus, the cylinder tank corresponding to the cylinder needs to be configured to obtain high sealing performance. On the other hand, from the perspective of the maintainability of the cylinder tank, it is desirable that repairs and component replacements inside the cylinder tank can be easily carried out.

[0008] In view of the above problems, an object of the present invention is to provide a liquid pump type gas compression device with high maintainability that allows for easy repair and component replacement inside the cylinder tank.

Means for Solving the Problems

[0009] The gas compression device according to the present invention is a gas compression device that compresses gas taken into a cylinder tank by a liquid piston. The cylinder tank includes a barrel plate, a top plate that closes an opening on one end side of the barrel plate, and a bottom plate that closes an opening on the other end side of the barrel plate. The barrel plate has a first flange that projects outward from the peripheral edge of the opening on one end side. The top plate is formed on a platen and has a second flange that projects outward from the peripheral edge of the opening of the platen. By joining the first flange and the second flange using a fastener, the top plate is attached to the barrel plate. According to this configuration, it is possible to obtain a liquid pump type gas compression device with high maintainability that allows for easy repair and component replacement inside the cylinder tank.

[0010] More specifically, as the above configuration, the cylinder tank may be configured to include a hinge mechanism that allows one end side of the barrel plate to be opened and closed by moving the top plate around the axis of the rotation fulcrum in a state where the fastener is released. More specifically, as the above configuration, at least two of the cylinder tanks may be provided adjacent to each other laterally, and the axes of the rotation fulcrums in the two cylinder tanks may be arranged to extend in a direction perpendicular to the adjacent direction.

[0011] More specifically, as the above configuration, the axes of the rotation fulcrums in the two cylinder tanks may be arranged to be most separated from each other in the adjacent direction. More specifically, as the above configuration, at least two of the cylinder tanks may be provided adjacent to each other laterally, and the axes of the rotation fulcrums in the two cylinder tanks may be arranged to extend in the same direction as the adjacent direction.

[0012] More specifically, as the above configuration, the axes of the rotation fulcrums in the two cylinder tanks may be arranged on the same side in a direction perpendicular to the adjacent direction. More specifically, as the above configuration, the cylinder tank may be configured to include a davit mechanism that allows the top plate to be lifted away from the barrel plate and slid horizontally in a state where the fastener is released.

[0013] More specifically, as the above configuration, the top plate may be configured to have a fixture for an electrode rod that detects the top dead center of the liquid piston. More specifically, as the above configuration, the top plate may have an exhaust pipe body erected on the top of the platen, the fixture may include a branch pipe penetrating the pipe wall of the pipe body, and the electrode rod may be attached in a state of being horizontally inserted into the internal space of the branch pipe.

[0014] More specifically, as the above configuration, the top plate has an exhaust pipe body erected on the top of the mirror plate, the fixture includes a socket erected on the mirror plate close to the pipe body, the electrode rod is mounted in a state of being inserted vertically into the internal space of the socket and only the tip protruding into the mirror plate, and the socket may be configured to have a communication portion for allowing the internal compressed gas to escape to the pipe body.

[0015] More specifically, as the above configuration, at least two of the cylinder tanks, an intake mechanism and an exhaust mechanism communicating with the upper spaces of the respective cylinder tanks, a first liquid port provided at the lower part of each of the cylinder tanks, a second liquid port provided at the lower part of each of the cylinder tanks, a third liquid port provided at the lower part of each of the cylinder tanks, a liquid pump for transferring liquid from one of the cylinder tanks to the other, a first liquid flow line for communicating the first liquid ports with each other, a second liquid flow line for communicating the second liquid ports with each other, a third liquid flow line for communicating the third liquid ports with each other, a liquid suction line connecting the suction side of the liquid pump to the first liquid flow line, a liquid discharge line connecting the discharge side of the liquid pump to the second liquid flow line, a plurality of first liquid flow control valves provided in the first liquid flow line corresponding to each of the first liquid ports, a plurality of second liquid flow control valves provided in the second liquid flow line corresponding to each of the second liquid ports, a third liquid flow control valve provided in the third liquid flow line, and control means for controlling a process switching element group including the liquid pump, the first liquid flow control valve, and the second liquid flow control valve, wherein the control means controls the process switching element group such that when one of the cylinder tanks is in a control state of performing a compression / exhaust process, the other cylinder tank is in a control state of performing an expansion / intake process, the third liquid flow control valve is a full bore type ball type electric valve or a butterfly type electric valve having a valve body formed of a rotating body rotating in a valve box, and the control means may be configured to stop the liquid pump and open the third liquid flow control valve until a predetermined time after switching between the compression / exhaust process and the expansion / intake process, and drive the liquid pump and close the third liquid flow control valve after the elapse of the predetermined time.

Effect of the Invention

[0016] According to the gas compression device of the present invention, it is possible to provide a liquid pump type gas compression device with high maintainability that facilitates repair and component replacement inside the cylinder tank.

Brief Description of the Drawings

[0017]

Figure 1A

Figure 1B

Figure 1C

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Embodiments for Carrying Out the Invention

[0018] Embodiments of the present invention will be described below by taking the first to fifth embodiments as examples.

[0019] 1. First Embodiment (1) Device Configuration of Gas Compression Device FIG. 1A is a configuration diagram showing a schematic configuration of a gas compression device 10 according to the first embodiment. The gas compression device 10 is a liquid pump type gas compression device.

[0020] As shown in FIG. 1A, the gas compression device 10 includes two cylinder tanks 1A and 1B, an intake mechanism 2, and an exhaust mechanism 3. By sending liquid L from the lower part of each of the cylinder tanks 1A and 1B, the air contained in each of the cylinder tanks 1A and 1B can be compressed. Regarding the type of the liquid L, as will be described later, clean water is preferable, but other types of liquids may be used as long as the gist of the present invention is not deviated from.

[0021] The gas compression device 10 is provided with a pressure sensor Px for detecting the gas phase pressure in each of the cylinder tanks 1A and 1B. The air in the cylinder tank 1A can be discharged by opening the air vent valve 14A as needed, and the air in the cylinder tank 1B can be discharged by opening the air vent valve 14B as needed.

[0022] The intake mechanism 2 communicates with the upper spaces of the respective cylinder tanks 1A and 1B, and includes an intake line 21A provided corresponding to the cylinder tank 1A and an intake line 21B provided corresponding to the cylinder tank 1B. An intake valve 22A is provided in the intake line 21A, and an intake valve 22B is provided in the intake line 21B.

[0023] The intake valve 22A opens (enters an open state) when the internal pressure of the cylinder tank 1A falls below a first pressure, and closes (enters a closed state) when the internal pressure of the cylinder tank 1A exceeds a second pressure that is equal to or higher than the first pressure. The intake valve 22B opens when the internal pressure of the cylinder tank 1B falls below the first pressure, and closes when the internal pressure of the cylinder tank 1B exceeds the second pressure that is equal to or higher than the first pressure. The intake valves 22A and 22B can be constituted by self-operating valves or automatic valves that operate at a required pressure. In the present embodiment, as an example, it is assumed that the intake valves 22A and 22B are constituted by self-operating valves.

[0024] When the intake valves 22A and 22B are self-operating valves, a check valve can be applied as shown in the configuration diagram of FIG. 1. In this case, the check valve opens when the secondary pressure falls below the first pressure (that is, when a negative pressure is generated), and closes when the secondary pressure exceeds the second pressure (that is, when a positive pressure is generated).

[0025] When the intake valves 22A and 22B are automatic valves, an electric drive valve (electromagnetic valve or electric valve) can be applied. In this case, the electric drive valve opens when the detected pressure of the pressure sensor Px falls below the first pressure, and closes when the detected pressure exceeds the second pressure. The first pressure and the second pressure in this case can be set to appropriate values, for example, in the control means 7.

[0026] The exhaust mechanism 3 communicates with the upper spaces of the respective cylinder tanks 1A and 1B. The exhaust mechanism 3 has an exhaust line 31A provided corresponding to the cylinder tank 1A and an exhaust line 31B provided corresponding to the cylinder tank 1B. An exhaust valve 32A is provided in the exhaust line 31A, and an exhaust valve 32B is provided in the exhaust line 31B.

[0027] The exhaust valve 32A is a valve that closes when the internal pressure of the cylinder tank 1A falls below a third pressure and opens when the internal pressure of the cylinder tank 1A exceeds a fourth pressure that is equal to or higher than the third pressure. The exhaust valve 32B is a valve that closes when the internal pressure of the cylinder tank 1B falls below the third pressure and opens when the internal pressure of the cylinder tank 1B exceeds the fourth pressure that is equal to or higher than the third pressure. The exhaust valves 32A and 32B can be constituted by self-operated valves or automatic valves that operate at a required pressure. In this embodiment, as an example, it is assumed that the exhaust valves 32A and 32B are constituted by self-operated valves.

[0028] When the exhaust valves 32A and 32B are self-operated valves, a backpressure valve (primary pressure regulating valve) can be applied as shown in the configuration diagram of FIG. 1. In this case, the backpressure valve closes when the primary pressure falls below the third pressure (a mechanically adjustable set value) and opens when it exceeds the fourth pressure (a mechanically adjustable set value that can be the same value as the third pressure).

[0029] When the exhaust valves 32A and 32B are automatic valves, an electric drive valve (solenoid valve or electric motor valve) can be used. In this case, the electric drive valve opens when the detected pressure of the pressure sensor Px is below the third pressure and closes when it exceeds the fourth pressure. The third pressure and the fourth pressure in this case can be set to appropriate values, for example, in the control means 7.

[0030] In addition, when using the self-operated valve described above, since inhalation and discharge are actively performed without using electric power, from this perspective, it can contribute to the reduction of specific energy. On the other hand, when using the automatic valve described above, by selecting a valve type with a small pressure loss during inhalation and discharge, energy-saving operation with less energy loss becomes possible, and thus, from this perspective, it can contribute to the reduction of specific energy.

[0031] At the lower part of the cylinder tank 1A, a first liquid port 11A and a second liquid port 12A are provided. Also, at the lower part of the cylinder tank 1B, a first liquid port 11B and a second liquid port 12B are provided. A first liquid flow line 41A is connected to the first liquid port 11A, and a first liquid flow line 41B is connected to the first liquid port 11B. A second liquid flow line 51A is connected to the second liquid port 12A, and a second liquid flow line 51B is connected to the second liquid port 12B. The first liquid flow lines 41A and 41B communicate the first liquid ports 11A and 11B with each other, and the second liquid flow lines 51A and 51B communicate the second liquid ports 12A and 12B with each other.

[0032] The gas compression device 10 is also provided with a liquid pump 6. Further, the gas compression device 10 includes a liquid suction line (suction-side common line) 61 that connects the suction side of the liquid pump 6 to the first liquid flow lines 41A and 41B, and a liquid discharge line (discharge-side common line) 62 that connects the discharge side of the liquid pump 6 to the second liquid flow lines 51A and 51B.

[0033] A first liquid flow control valve 42A is provided in the first liquid flow line 41A, and a first liquid flow control valve 42B is provided in the first liquid flow line 41B. A second liquid flow control valve 52A is provided in the second liquid flow line 51A, and a second liquid flow control valve 52B is provided in the second liquid flow line 51B. The first liquid flow control valve 42A can be seen as provided in the first liquid flow line 41A corresponding to the first liquid port 11A, and the first liquid flow control valve 42B can be seen as provided in the first liquid flow line 41B corresponding to the first liquid port 11B. Also, the second liquid flow control valve 52A can be seen as provided in the second liquid flow line 41A corresponding to the second liquid port 12A, and the second liquid flow control valve 52B can be seen as provided in the second liquid flow line 41B corresponding to the second liquid port 12B.

[0034] When one of the first liquid flow control valves 42A and 42B corresponding to one of the cylinder tanks 1A and 1B is in an open state and one of the second liquid flow control valves 52A and 52B corresponding to the other of the cylinder tanks 1A and 1B is in an open state, when the liquid pump 6 is driven, the liquid L is transferred through the first liquid flow lines 41A and 41B corresponding to one of the cylinder tanks 1A and 1B, the liquid suction line 61, the liquid pump 6, the liquid discharge line 62, and the second liquid flow lines 51A and 51B corresponding to the other of the cylinder tanks 1A and 1B. That is, the liquid L is transferred from one of the cylinder tanks 1A and 1B to the other of the cylinder tanks 1A and 1B.

[0035] Also, a liquid feed check valve 611 is provided in the liquid suction line 61, and a flow rate sensor Fx (one form of flow rate detection means) is provided in the liquid discharge line 62. The flow rate sensor Fx may be provided in the liquid suction line 61 or the liquid pump 6 instead of the liquid discharge line 62. The flow rate sensor Fx can detect the end of the expansion of the air inside the cylinder tanks 1A and 1B in the expansion - intake process described later by detecting a predetermined flow rate.

[0036] In the gas compression device 10, instead of using the flow sensor Fx, alternative means may be used. For example, a flow switch (a switch that turns on when the set flow rate is reached or exceeded and turns off when the set flow rate is not reached) or a magnetic sensor (a sensor that detects the rotational speed by attaching a magnet to the drive shaft directly connected to the rotor (such as an impeller or gear) of the liquid pump 6) can be used as an alternative means to the flow sensor Fx.

[0037] In addition, the cylinder tank 1A is provided with a spray nozzle (injector) 13A for spraying the liquid L into its internal space, and the cylinder tank 1B is provided with a spray nozzle 13B for spraying the liquid L into its internal space. Further, the gas compression device 10 is provided with a liquid introduction line 53A that branches from the secondary side of the second liquid flow control valve 52A of the second liquid flow line 51A and guides a part of the liquid being transferred by the liquid pump 6 to the spray nozzle 13A, and a liquid introduction line 53A that branches from the secondary side of the second liquid flow control valve 52B of the second liquid flow line 51B and guides a part of the liquid L being transferred by the liquid pump 6 to the spray nozzle 13B. A liquid introduction control valve 54A is provided in the liquid introduction line 53A, and a liquid introduction control valve 54B is provided in the liquid introduction line 53B.

[0038] In the compression and exhaust process described later, the liquid L is sprayed from the spray nozzle 13A onto the compressed air inside the cylinder tank 1A, and the liquid L is sprayed from the spray nozzle 13B onto the compressed air inside the cylinder tank 1B, thereby realizing an isothermal compression process. The spray nozzles 13A and 13B can use, for example, full-cone type nozzles or hollow-cone type nozzles, and are installed in the cylinder tanks 1A and 1B so as to be able to spray the liquid L onto the compressed air space of the air.

[0039] Each cylinder tank 1A, 1B is provided with a liquid level detection electrode rod Lx (a form of liquid level detection means). By detecting that the liquid level of the liquid L inside the cylinder tanks 1A, 1B has reached a predetermined liquid level with the liquid level detection electrode rod Lx, it is possible to detect the top dead center of the liquid piston in the compression / exhaust process. Note that various forms can be adopted for the installation form of the liquid level detection electrode rod Lx in each cylinder tank 1A, 1B. Specific examples of the installation form of the liquid level detection electrode rod Lx will be described in detail as the third and fourth embodiments described later.

[0040] An air filter 23 is provided upstream of the intake lines 21A, 21B. The air filter 23 can remove contaminants, bacteria, etc. contained in the air during intake.

[0041] A liquid discharge line 81 and a liquid supply line 83 are connected to the first liquid flow line 41A. Note that the liquid discharge line 81 and the liquid supply line 83 may be connected to any one of the cylinder tanks 1A, 1B, the second liquid flow lines 51A, 51B, the liquid suction line 61, and the liquid discharge line 62 instead of the first liquid flow line 41A. A liquid discharge valve 82 is provided in the liquid discharge line 81, and a liquid supply valve 84 is provided in the liquid supply line 83.

[0042] When water is used as the liquid L in the gas compression device 10, for example, there is a possibility that contaminants and bacteria cannot be sufficiently removed by the air filter 23, and water quality contamination and the growth of miscellaneous bacteria due to repeated intake are a concern. In this regard, according to the configuration of this embodiment, it is possible to periodically perform a blowdown of the retained water via the liquid discharge line 81 and the liquid discharge valve 82. Also, after the blowdown, it is possible to supply new water via the liquid supply line 83 and the liquid supply valve 84. Thereby, the liquid piston can be kept in a clean state, and clean compressed air without contamination can be supplied to the load equipment.

[0043] An air separator 91 is provided on the downstream side of the exhaust lines 31A and 31B. The compressed air sent out from the exhaust lines 31A and 31B is separated into gas and liquid by the air separator 91 and then accumulated in a reservoir tank (not shown) arranged on the downstream side. The liquid L separated by the air separator 91 is discharged from a drain trap 92 connected to the liquid accumulation part of the air separator 91.

[0044] The liquid L intermittently discharged from the drain trap 92 is returned to the cylinder tank 1A or the cylinder tank 1B with a lower liquid pressure by utilizing the pressure of the compressed air and the head pressure in the air separator 91. A liquid return check valve 93A is provided in the line for returning the liquid L from the drain trap 92 to the cylinder tank 1A, and a liquid return check valve 93B is provided in the line for returning the liquid L from the drain trap 92 to the cylinder tank 1B. By installing the liquid return check valves 93A and 93B, the loss of the liquid L in these lines is prevented.

[0045] As described above, a reservoir tank (not shown) for accumulating compressed air is installed on the downstream side of the air separator 91. Thereby, similar to the operation control of a general gas compression device, it is possible to control the operation and stop of the gas compression device 10 according to the internal pressure of the reservoir tank. In the gas compression device 10, it is also possible to omit the installation of the air separator 91 and adopt a configuration in which gas-liquid separation is performed by the reservoir tank. In this configuration, the drain trap 92 can be connected to the bottom of the reservoir tank.

[0046] In addition, the cylinder tanks 1A and 1B of this embodiment are configured to be openable and closable so that internal repairs, component replacements, etc. can be performed. Regarding the main configuration related to this opening and closing, FIG. 1B schematically shows the configuration of the cylinder tank 1A as viewed from the front, and FIG. 1C schematically shows the configuration of the cylinder tank 1A as viewed from above. The front-back, left-right, and up-down directions shown in these figures are directions orthogonal to each other. The up-down direction coincides with the vertical direction, and the left-right direction coincides with the direction in which the cylinder tanks 1A and 1B are adjacent to each other (the direction in which the axes of both cylinder tanks 1A and 1B are adjacent to each other). Also, since the configuration of the cylinder tank 1B is basically the same as that of the cylinder tank 1A, the description thereof is omitted here.

[0047] As shown in FIGS. 1B and 1C, the cylinder tank 1A is a vertical pressure vessel centered on an axis (axis center) extending vertically. More specifically, the cylinder tank 1A includes a barrel plate 1a formed in a cylindrical shape centered on an axis extending vertically, a top plate 1b that closes the opening on the upper end side of the barrel plate 1a, and a bottom plate 1c that closes the opening on the lower side of the barrel plate 1a. The top plate 1b and the bottom plate 1c are mirror plates.

[0048] Furthermore, the barrel plate 1a has a first flange 71 that projects outward from the peripheral edge of the opening on the upper end side. The top plate 1b has a second flange 72 that projects outward from the peripheral edge of the opening of its mirror plate. Then, by joining the first flange 71 and the second flange 72 using a fastener 74 (in the example of this embodiment, a bolt 74a and a nut 74b), the top plate 1b is attached to the barrel plate 1a. Therefore, it is possible to easily perform internal repairs, component replacements, etc. of the cylinder tank 1A by appropriately removing the fastener 74 and opening the upper side of the barrel plate 1a. Note that a gasket is interposed between the first flange 71 and the second flange 72 to ensure airtightness.

[0049] Also, both flanges 71 and 72 are connected via a hinge mechanism. This hinge mechanism is a mechanism that allows the top plate 1b to be moved around the axis of the rotation fulcrum 73 to open and close the upper side of the body plate 1a with the above-mentioned fastener 74 released. In the example shown in FIG. 1B, the rotation fulcrum 73 is provided near the right ends of both flanges 71 and 72 such that the rotation axis X extends back and forth. Thereby, as indicated by the dotted arrow in FIG. 1B, the top plate 1b can be rotationally moved to easily open and close the upper side of the body plate 1a.

[0050] Next, the configuration of the main control system of the gas compression device 10 is shown in FIG. 2. As shown in this figure, the gas compression device 10 is provided with control means 7. The control means 7 controls the operations of at least each element of the process switching element group Z shown in FIG. 2 so that the gas compression device 10 operates normally.

[0051] The process switching element group Z includes each element of the liquid pump 6, each valve corresponding to the cylinder tank 1A (the first liquid flow control valve 42A, the second liquid flow control valve 52A, and the liquid introduction control valve 54A), and each valve corresponding to the cylinder tank 1B (the first liquid flow control valve 42B, the second liquid flow control valve 52B, and the liquid introduction control valve 54B). That is, the control means 7 controls the drive / stop of the liquid pump 6, the opening / closing of each of the first liquid flow control valves 42A and 42B, the opening / closing of each of the second liquid flow control valves 52A and 52B, and the opening / closing of the liquid introduction control valves 54A and 54B.

[0052] (2) Control Contents Next, the control contents of the main operations in the gas compression device 10 will be described. FIG. 3 is an explanatory diagram schematically showing the transition of the control state of the gas compression device 10 (particularly, the control states of each cylinder tank 1A and 1B). As shown in this figure, for the control state of the gas compression device 10, after passing through the control states A1 to A5 in order, and then passing through the control states B1 to B5 in order, it returns to the control state A1, and the same control state is repeated. Note that the control states B1 to B5 are equivalent to the control states A1 to A5 when the control states are reversed between the cylinder tank 1A and the cylinder tank 1B.

[0053] Hereinafter, each of the above-described control states will be described in more detail with reference to FIGS. 4 to 9. For each valve shown in FIGS. 4 to 9, those shown in black indicate a closed state, and those shown in white indicate an open state.

[0054] FIG. 4 shows the control state A1. The control state A1 is the state when the compression / exhaust process is completed in the cylinder tank 1A (the left tank in this figure), and the state when the expansion / intake process is completed in the cylinder tank 1B (the right tank in this figure). Here, the liquid pump 6 is stopped, the cylinder tank 1A has reached a predetermined upper liquid level (the top dead center of the liquid piston), and the cylinder tank 1B has reached the lower liquid level (the bottom dead center of the liquid piston). The exhaust from the cylinder tank 1A has ended, and the gas phase part has become equal to or lower than the third pressure. However, compressible air close to the third pressure remains inside the cylinder tank 1A.

[0055] FIG. 5 shows the control state A2. The switching from the control state A1 to A2 is performed by switching the opening and closing of the first liquid flow control valves 42A and 42B and the second liquid flow control valves 52A and 52B by the control means 7. In the control state A2, the expansion / intake process in the cylinder tank 1A is started, and the compression / exhaust process in the cylinder tank 1B is started. That is, the liquid L is sent out due to the expansion of the gas phase part in the cylinder tank 1A, and partial compression and cooling of the gas phase part due to the intake of the liquid L are performed in the cylinder tank 1B.

[0056] With the liquid pump 6 stopped, the transfer of the liquid L from the cylinder tank 1A to the cylinder tank 1B is started. The transfer is performed via the first liquid flow line 41A, the liquid suction line 61, the liquid pump 6, the liquid discharge line 62, and the second liquid flow line 51B. Specifically, the liquid L is sent out by utilizing the expansion of the gas phase part (expansion of the remaining compressed air) and the head pressure of the liquid phase part in the cylinder tank 1A.

[0057] In the cylinder tank 1B, partial compression of the gas phase starts as the liquid level rises. Since the control means 7 controls the liquid introduction control valve 54B to be in an open state while filling the liquid L from the second liquid port 12B, the liquid L is sprayed from the spray nozzle 13B, and the compressed air in the cylinder tank 1B is cooled. The compression heat generated in the gas phase is absorbed by the sprayed liquid L and merges into the liquid L being filled from the lower part of the cylinder tank 1B. That is, the absorption of the compression heat is carried out through both the droplets of the liquid L sprayed from the upper part and the liquid level of the liquid L filled from the lower part. Also, since the inside of the cylinder tank 1A is at a positive pressure (a pressure state exceeding the second pressure), the intake valve 22A remains closed.

[0058] Figure 6 shows the control state A3. In the control state A3, the expansion of the gas phase in the cylinder tank 1A is completed, the partial compression of the gas phase in the cylinder tank 1B is completed, and the overall compression of the gas phase is started.

[0059] When the detected flow rate by the flow rate sensor Fx drops to a predetermined flow rate, the liquid pump 6 in the stopped state is driven by the control means 7. When the expansion of the compressed air remaining in the cylinder tank 1A ends and the head pressure difference is balanced, the liquid pressure acting on the first liquid port 11A of the cylinder tank 1A (the sum of the air pressure in the gas phase and the head pressure in the liquid phase) and the liquid pressure acting on the second liquid port 12B of the cylinder tank 1B are in a balanced state, so the delivery of the liquid L stops and the compression of the air becomes impossible.

[0060] Therefore, in the present embodiment, while the liquid pump 6 is stopped, when the detected flow rate drops to a predetermined flow rate (a set value that is higher than the lower limit flow rate value at which air compression becomes impossible by a differential value), the liquid pump 6 is driven to continue the delivery of the liquid L. As a result, the liquid pump 6 can be driven without delay to produce compressed air. That is, the liquid L flows at a sufficient flow rate with the liquid level in the cylinder tank 1A being higher than the liquid level in the cylinder tank 1B, and the liquid pump 6 is driven in a state where air compression can be performed. As described above, in the present embodiment, the stop of the liquid pump 6 is continued until a predetermined time α during the expansion of the remaining compressed air, and then the liquid pump 6 is driven.

[0061] In the cylinder tank 1B, an isothermal compression process is continuing due to the cooling of the gas phase part (heat absorption into the aqueous phase part). However, before the driving of the liquid pump 6, as the liquid pressure in the cylinder tank 1A decreases, the spray flow rate from the spray nozzle 13B gradually decreases.

[0062] FIG. 7 shows the control state A4. In the control state A4, intake air is started due to the generation of negative pressure in the cylinder tank 1A, and overall compression and cooling of the gas phase part are performed in the cylinder tank 1B.

[0063] When the driving of the liquid pump 6 is continued, the liquid pressure in the cylinder tank 1A becomes lower than the liquid pressure in the cylinder tank 1B. When the gas phase part of the cylinder tank 1A turns into a negative pressure (a pressure state lower than the first pressure), the intake valve 22A is opened, and external air is taken into the cylinder tank 1A through the air filter 23.

[0064] In the cylinder tank 1B, an isothermal compression process is continuing due to the cooling of the gas phase part. After the driving of the liquid pump 6, the spray flow rate from the spray nozzle 13B recovers. Note that this spray flow rate gradually decreases as the head pressure (suction head of the liquid pump) in the cylinder tank 1A decreases.

[0065] Figure 8 shows control state A5. In control state A5, intake air continues to be drawn in due to the generation of negative pressure in cylinder tank 1A, and exhaust starts in cylinder tank 1B due to the set pressure in the gas phase section being reached.

[0066] When pressure sensor Px detects that the gas phase section of cylinder tank 1B has reached the fourth pressure, control means 7 determines that the isothermal compression process has ended, closes liquid introduction control valve 54B to stop the liquid spray from spray nozzle 13B, and at the same time, opens exhaust valve 32B to start discharging compressed air. For the delivery of compressed air, the driving of liquid pump 6 continues.

[0067] The delivered compressed air is separated into gas and liquid by air separator 91 and then accumulated in a reservoir tank (not shown) arranged on the downstream side. The liquid L separated by air separator 91 is discharged from drain trap 92. The liquid L intermittently discharged from drain trap 92 is returned to the cylinder tank with a lower liquid pressure (here, cylinder tank 1A where the liquid level has dropped and the gas phase section is in equilibrium with atmospheric pressure due to intake air) by utilizing the pressure of the compressed air and the head pressure in air separator 91.

[0068] Note that in order to prevent liquid droplets from being entrained in the compressed air, the closing timing of liquid introduction control valve 54B may be made earlier than the opening timing of exhaust valve 32B. That is, liquid introduction control valve 54B may be closed at a set pressure lower than the fourth pressure.

[0069] Figure 9 shows control state B1. In control state B1, the expansion / intake process ends in cylinder tank 1A, and the compression / exhaust process ends in cylinder tank 1B.

[0070] In the cylinder tank 1B, when the top dead center (upper limit liquid level) of the liquid piston is detected by the liquid level detection electrode rod Lx, the control means 7 stops the liquid pump 6. At this time, the exhaust valve 32B is closed. Instead of this, in the cylinder tank 1B, when the detected pressure of the gas phase part by the pressure sensor Px drops to the third pressure (a set value lower than the differential value from the exhaust start pressure value by the differential value), the control means 7 may stop the liquid pump 6. At this time, the exhaust valve 32B is closed.

[0071] As described above, the compression and exhaust process will be completed. As a result, at the end point of this process, compressed air will surely remain in the cylinder tank 1B. As a result, immediately after switching to the expansion and intake process in the cylinder tank 1B, it is possible to send out the liquid L by using the expansion of the gas phase part without driving the liquid pump 6, which contributes to the reduction of specific energy.

[0072] The control state B1 corresponds to the control state A1 (see Fig. 4) when the control states between the cylinder tank 1A and the cylinder tank 1B are reversed. After this, as already described, the control states B2 to B5 (the control states A2 to A5 when the control states between the cylinder tank 1A and the cylinder tank 1B are reversed) are passed through in order and return to the control state A1, and the same control state will be repeated. During the control states B2 to B5, the expansion and intake process is executed in the cylinder tank 1B, and the compression and exhaust process is executed in the cylinder tank 1A.

[0073] As described above, the control means 7 according to the present embodiment controls the process switching element group Z so that when one cylinder tank (one of 1A and 1B) is in a control state of executing the compression / exhaust process, the other cylinder tank (the other of 1A and 1B) is in a control state of executing the expansion / intake process. Further, in the compression / exhaust process, the control means 7 ends the process by stopping the liquid pump 6 with compressed air remaining in the cylinder tanks 1A and 1B. Furthermore, in the expansion / intake process, the control means 7 continues to stop the liquid pump 6 until a predetermined time α during the expansion of the remaining compressed air, and then drives the liquid pump 6. Therefore, according to the gas compression device 10, it is possible to achieve an improvement in specific energy by realizing an operation cycle by the intermittent driving of the liquid pump 6.

[0074] In the expansion / intake process, with the liquid pump 6 stopped, the liquid L filled in the cylinder tanks 1A and 1B is sent out by utilizing at least the expansion of the gas phase portion, and preferably by utilizing the expansion of the gas phase portion and the head pressure of the liquid phase portion. Then, after a predetermined time α during the expansion of the gas phase portion, the liquid pump 6 is driven, and external air is inhaled by utilizing the negative pressure of the gas phase portion generated as the liquid L is further sent out.

[0075] In the compression / exhaust process, with the liquid pump 6 stopped, partial compression of the gas phase portion is performed by taking in the liquid L. Then, when the liquid pump 6 is driven, overall compression of the gas phase portion is performed by taking in the liquid L further. And when the gas phase portion reaches the set pressure, the generated compressed air is discharged.

[0076] Also, in the compression and exhaust process, the liquid pump 6 is stopped with compressed air remaining in the cylinder tank, thereby ending the process. Therefore, immediately after switching to the expansion and intake process, even if the operation of the liquid pump 6 is continued, the liquid L can be sent out by utilizing the expansion of the gas phase part. As a result, the gas compression device 10 according to the present invention periodically produces compressed air while intermittently driving the liquid pump 6. As a result, the specific energy can be significantly improved as compared with the conventional type of device that continuously drives the liquid pump. Further, even if a liquid pump with a high suction and discharge capacity is mounted, an increase in specific energy can be minimized.

[0077] (3) Arrangement of the rotation fulcrum in the hinge mechanism As described above, each of the cylinder tanks 1A and 1B of the present embodiment is provided with a hinge mechanism that enables the upper side of the body plate 1a to be opened and closed by moving the top plate 1b around the axis of the rotation fulcrum 73 (see FIGS. 1B and 1C). The rotation fulcrums 73 of these hinge mechanisms are preferably arranged so that the opening and closing operations of each of the cylinder tanks 1A and 1B can be easily and smoothly performed. Next, an example of a preferable arrangement of the rotation fulcrum 73 will be described.

[0078] FIGS. 10 to 13 schematically show, in a top view, each arrangement example of the rotation fulcrum 73 of the hinge mechanism in the two cylinder tanks 1A and 1B.

[0079] In the examples shown in FIGS. 10 and 11, the rotation fulcrums 73 in each of the two cylinder tanks 1A and 1B are arranged such that the axis X extends in the front-rear direction orthogonal to the left-right direction (the direction in which the cylinder tanks 1A and 1B are adjacent to each other). By arranging the rotation fulcrums 73 in this way, it becomes easy to rotate the top plates 1b of the respective cylinder tanks 1A and 1B without interfering with each other.

[0080] Particularly in the example shown in FIG. 10, rotation fulcrums 73 in the two cylinder tanks 1A and 1B are arranged so as to be most separated in the left - right direction (the direction in which the cylinder tanks 1A and 1B are adjacent to each other). As a result, interference between the top plates 1b of the respective cylinder tanks 1A and 1B is surely avoided, and the top plates 1b of both cylinder tanks 1A and 1B can be opened to both the left and right outer sides, improving workability even when performing repairs and component replacements inside both cylinder tanks 1A and 1B in parallel. In the example shown in FIG. 11, after opening the top plate 1a of the cylinder tank 1A, the top plate 1b of the cylinder tank 1B is opened.

[0081] In the examples shown in FIGS. 12 and 13, rotation fulcrums 73 in the two cylinder tanks 1A and 1B are arranged such that the axis X extends in the left - right direction (the direction in which the cylinder tanks 1A and 1B are adjacent to each other). By arranging each rotation fulcrum 73 in this way, it is also possible to rotate - move the top plates 1b of the respective cylinder tanks 1A and 1B without interference with each other.

[0082] Particularly in the example shown in FIG. 12, rotation fulcrums 73 in the two cylinder tanks 1A and 1B are arranged on the same side in the front - rear direction (the direction orthogonal to the left - right direction in which the cylinder tanks 1A and 1B are adjacent to each other). As a result, the top plates 1b of both cylinder tanks 1A and 1B can be opened to the same side in the front - rear direction (the rear side in the example of FIG. 12), improving workability even when performing repairs and component replacements inside both cylinder tanks 1A and 1B in parallel.

[0083] 2. Second Embodiment Next, the second embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted. Also, in the following description, mainly the configuration of the cylinder tank 1A will be described, but the configuration of the cylinder tank 1B can be considered the same.

[0084] FIG. 14 schematically shows the main configuration related to the opening and closing of the cylinder tank 1A in the second embodiment. As shown in this figure, the cylinder tank 1A is provided with a davit mechanism 76. The davit mechanism 76 is a mechanism that can lift the top plate 1b away from the body plate 1a and slide horizontally in a state where the fastener 74 is released. In the example shown in FIG. 14, the fasteners 74 (bolt 74a and nut 74b) are provided near the four corners in the top view of the second flange portion 72, respectively.

[0085] The davit mechanism 76 illustrated in FIG. 14 has an arm portion 76a, a support portion 76b provided so as to protrude to the right from the body portion 1a and the first flange portion 71, and a lifting portion 76c movably supported in the vertical direction by the arm portion 76a. The support portion 76b supports the arm portion 76 rotatably around an axis extending vertically, and the top plate 1b is fixed to the lower end of the lifting portion 76c.

[0086] Thereby, in a state where the lifting portion 76c is moved upward to lift the top plate 1b, by rotating the arm portion 76a, it is possible to slide the top plate 1b horizontally. Thus, in the second embodiment, since the top plate 1b can be moved using the davit mechanism 76, the upper side of the body plate 1a can be opened and closed very easily, and repairs and component replacements inside the cylinder tank 1A can be easily performed.

[0087] 3. Third Embodiment Next, the third embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted. Also, in the following description, mainly the configuration of the cylinder tank 1A will be described, but the configuration of the cylinder tank 1B can be made the same.

[0088] In the third embodiment, the top plates 1b of the respective cylinder tanks 1A and 1B have the fixtures for the liquid level detection electrode rods Lx as described above. More specifically, the top plate 1b has exhaust lines 31A and 31B (tubular bodies for exhaust) erected at the top of the mirror plate, and the fixture for the liquid level detection electrode rod Lx includes a branch pipe 31x that penetrates the pipe wall of the exhaust lines 31A and 31B. The liquid level detection electrode rod Lx is attached in a state of being horizontally inserted into the internal space of the branch pipe 31x.

[0089] FIG. 15 schematically illustrates the state of the cylinder tank 1A before the attachment of the liquid level detection electrode rod Lx, and FIG. 16 schematically illustrates the state of the cylinder tank 1A after the attachment of the liquid level detection electrode rod Lx. As shown in these figures, an exhaust line 31A is erected at the top of the mirror plate of the top plate 1b, and a branch pipe 31x is provided at a position slightly above the top plate 1b in the exhaust line 31A so as to branch and extend to the right.

[0090] As shown in FIG. 15, it is possible to insert the liquid level detection electrode rod Lx into the branch pipe 31x from the right to the left. When the liquid level detection electrode rod Lx is inserted to the deepest part of the branch pipe 31x, as shown in FIG. 16, the tip of the liquid level detection electrode rod Lx reaches the inside of the exhaust line 31A, and the liquid level detection electrode rod Lx is completely attached and fixed to the branch pipe 31x.

[0091] In the third embodiment, by having the fixture for the liquid level detection electrode rod Lx described above, it becomes easy to set the detection position of the top dead center of the liquid piston in the cylinder tanks 1A and 1B higher. According to this configuration, the discharge amount of compressed air per cycle can be increased, which is advantageous for improving the specific energy of the gas compression device 10. In addition, by making the liquid level detection electrode rod Lx easily detachable from the fixture, the replacement and inspection of the liquid level detection electrode rod Lx become easy and the maintainability is also improved.

[0092] 4. Fourth Embodiment Next, the fourth embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted. Also, in the following description, mainly the configuration of the cylinder tank 1A will be described, but the configuration of the cylinder tank 1B can be made the same.

[0093] As shown in FIG. 17, the top plate 1b of each of the cylinder tanks 1A and 1B in the fourth embodiment has the fixture for the liquid level detection electrode bar Lx described above. More specifically, the top plate 1b has exhaust lines 31A and 31B (tubular bodies for exhaust) erected at the top of its mirror plate, and the fixture for the liquid level detection electrode bar Lx includes sockets 77 erected on the mirror plate in proximity to the exhaust lines 31A and 31B. The liquid level detection electrode bar Lx is attached in a state of being inserted vertically into the internal space of the socket 77 and only the tip protruding into the mirror plate. Further, the socket 77 has a communication portion 78 for discharging the internal compressed gas to the exhaust lines 31A and 31B.

[0094] FIG. 17 schematically illustrates the state of the cylinder tank 1A before the attachment of the liquid level detection electrode bar Lx, and FIG. 18 schematically illustrates the state of the cylinder tank 1A after the attachment of the liquid level detection electrode bar Lx. As shown in these figures, an exhaust line 31A is erected at the top of the mirror plate of the top plate 1b, and a socket 77 is erected on the mirror plate at a position close to the left side of this exhaust line 31A.

[0095] As shown in FIG. 17, it is possible to insert the liquid level detection electrode bar Lx into the socket 77 from above downward. When the liquid level detection electrode bar Lx is inserted to the deepest part of the socket 77, as shown in FIG. 18, the tip of the liquid level detection electrode bar Lx reaches the inside of the mirror plate of the top plate 1b, and the liquid level detection electrode bar Lx is completely attached and fixed to the socket 77.

[0096] Even in the fourth embodiment, by having the fixture for the liquid level detection electrode rod Lx described above, it becomes easier to set the detection position of the top dead center of the liquid piston in the cylinder tanks 1A and 1B higher, which is advantageous for improving the specific energy of the gas compression device 10. Further, by making the liquid level detection electrode rod Lx easily detachable from the fixture, it becomes easier to replace or inspect the liquid level detection electrode rod Lx, and the maintainability is also improved. Furthermore, by providing the communication portion 78 in the socket 77, even when compressed gas in the cylinders 1A and 1B enters the gap between the socket 77 and the liquid level detection electrode rod Lx, this compressed gas can be discharged to the exhaust lines 31A and 31B.

[0097] 5. Fifth Embodiment Next, the fifth embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0098] As shown in the description of the first embodiment, the gas compression device 10 stops the liquid pump 6 until a predetermined time α after switching between the compression / exhaust process and the expansion / intake process, and drives the liquid pump 6 after the elapse of the predetermined time α. Thereby, in a state where the liquid pump 6 is stopped, the transfer of the liquid L using the expansion of the gas phase part in the cylinder tank (preferably, using the expansion of the gas phase part and the head pressure of the liquid phase part), that is, the transfer of the liquid L without power between the two cylinder tanks 1A and 1B (hereinafter, may be referred to as "non-powered water supply") is performed. In non-powered water supply, basically, the liquid L is transferred from the cylinder tank with a high liquid level to the cylinder tank with a low liquid level.

[0099] In the gas compression device 10 of the fifth embodiment, in order to execute such transfer of the liquid L without power in a shorter time, as shown in FIG. 19, a third liquid flow line 55, a third liquid flow control valve 56, and third liquid ports 57A and 57B are provided. The third liquid port 57A is provided at the lower part of the cylinder tank 1A, and the third liquid port 57B is provided at the lower part of the cylinder tank 1B.

[0100] The third liquid flow line 55 has one end connected to the third liquid port 57A and the other end connected to the third liquid port 57B, and communicates these third liquid ports 57A and 57B with each other. The third liquid flow control valve 56 is a valve disposed at an intermediate position of the third liquid flow line 55. From the viewpoint of reducing the pressure loss, a full bore type ball electric valve or a butterfly type electric valve (a valve having a valve body composed of a rotating body that rotates in a valve box) is preferable.

[0101] Also in the fifth embodiment, the control means 7 also controls the opening and closing of the third liquid flow control valve 56. More specifically, the control means 7 stops the liquid pump 6 and opens the third liquid flow control valve 56 until the predetermined time α after switching between the compression / exhaust process and the expansion / intake process, and after the transition of the predetermined time α, drives the liquid pump 6 and closes the third liquid flow control valve 56.

[0102] In this way, the control means 7 opens the third liquid flow control valve 56 from the time of switching between the compression / exhaust process and the expansion / intake process until the predetermined time α (the period during which the liquid pump 6 is stopped). Thereby, non-powered water supply is performed through the third liquid flow line 55. Since the third liquid flow control valve 56 is considered to reduce the pressure loss as described above, the non-powered water supply is performed in a shorter time.

[0103] Also, the control means 7 closes the third liquid flow control valve 56 in order to prevent the liquid L from passing through the third liquid flow line 55 after the transition of the predetermined time α (the period during which the liquid pump 6 is driven). As described above, in the fifth embodiment, the third liquid flow line 55 and the third liquid flow control valve 56 are provided so that non-powered water supply is performed in a shorter time. According to this configuration, the time required for one cycle can be shortened, which is advantageous in improving the specific energy. In the fifth embodiment, non-powered water supply using the third liquid flow line 55 may be performed in parallel with non-powered water supply in the first embodiment (non-powered water supply passing through the stopped liquid pump 6), or the execution of non-powered water supply in the first embodiment may be omitted.

[0104] 6. Others (1) Regarding the cooling means It is desirable to provide the gas compression device 10 with a cooling means for promoting heat dissipation from the liquid piston. In this case, for example, it is advisable to install a cooling heat exchanger in the liquid discharge line 62. The cooling heat exchanger is connected to a cooling tower via a cooling water circulation circuit and cools the liquid L discharged from the liquid pump 6 by heat exchange with the cooling water. When the ambient temperature around the gas compression device 10 becomes higher than the liquid temperature during operation, such as in summer, there is a risk of compression heat accumulating in the liquid piston. However, by operating the circulation pump provided in the circulation circuit, the liquid piston can be kept below the ambient temperature, and the effect of reducing the specific energy can be obtained.

[0105] (2) Regarding the working medium As the above-mentioned liquid L, that is, the working medium for the liquid piston in the gas compression device 10, for example, clean water (preferably pure water (RO water, ion-exchanged water) or softened water) is suitable. Since the specific heat capacity of water is very large compared to other substances, it is particularly suitable as the working medium for the isothermal compression process involving absorption of compression heat. In addition, since clean water is harmless to the human body, it is also suitable as the working medium for the gas compression device for food factories.

[0106] In this embodiment, an air filter 23 is equipped at the air intake of the device, but pollutants and bacteria floating in the air may pass through, and depending on the installation environment of the device, water quality pollution and propagation of miscellaneous bacteria due to repeated intake of air may be a concern. Therefore, it is desirable to perform regular blowdown using the liquid discharge valve 82 and replenish clean water using the liquid supply valve 84.

[0107] In addition, as the working medium, for example, brine (aqueous calcium chloride solution, aqueous sodium chloride solution, etc.), glycerin aqueous solution, ethylene glycol aqueous solution, liquid paraffin, vegetable oil, and synthetic oil can also be preferably used as antifreeze for cold regions. As the working medium for the gas compression device 10 for food factories, any of brine, glycerin aqueous solution, liquid paraffin, and vegetable oil is preferable.

[0108] Also, in cold regions, there is a concern about freezing of water during the stop of the gas compression device 10 in winter. Therefore, from the viewpoint of minimizing this problem, it is desirable to take the following measures. First, as the first measure, regarding the type of the liquid L, even when using clean water in summer and intermediate seasons, it is desirable to replace it with an antifreeze liquid such as the above-mentioned brine in winter. When using such an antifreeze liquid, the installation of the heater and heat insulation material described below is basically unnecessary.

[0109] Also, as the second measure, it is desirable to enclose the entire device with a casing and attach a planar heater to the inner surface of the casing panel. In this case, for example, when the internal temperature of the casing becomes lower than the set temperature, it is advisable to energize the heater to perform heating.

[0110] Furthermore, as the third measure, it is desirable to cover the line through which the liquid L flows in the gas compression device 10 and the liquid pump 6 with a heat insulation material (thermal insulation material), and attach a planar heater to the outer surfaces of the cylinder tanks 1A and 1B. In this case, for example, when the ambient temperature around the cylinder tanks 1A and 1B becomes lower than the set temperature, it is advisable to energize the heater to perform heating.

[0111] (3) Regarding the number of cylinder tanks In the above-described embodiment, the number of cylinder tanks in the gas compression device is two, but the number of cylinder tanks may be three, and three processes including the standby process may be rotated. The significance of this configuration is that during regular replacement of the working medium and maintenance, one of the cylinders during the standby process can be left in a stopped state and the production of compressed air can be continued with the remaining two. In this case, the operation modes of the gas compression device having three cylinder tanks (for convenience, referred to as the first to third tanks) are sequentially switched among three patterns of the first to third operation modes.

[0112] In the first operation mode, the first tank undergoes an expansion / intake process (compression / exhaust process), the second tank undergoes a compression / exhaust process (expansion / intake process), and the third tank undergoes a standby process. In the second operation mode, the first tank undergoes a standby process, the second tank undergoes an expansion / intake process (compression / exhaust process), and the third tank undergoes a compression / exhaust process (expansion / intake process). In the third operation mode, the first tank undergoes a compression / exhaust process (expansion / intake process), the second tank undergoes a standby process, and the third tank undergoes an expansion / intake process (compression / exhaust process).

[0113] It is also possible to have four or more cylinder tanks. However, for example, when the number of cylinder tanks is four, it is usually more desirable to install two gas compression devices each equipped with two cylinder tanks to double the production amount of compressed air per unit time rather than installing four cylinder tanks in one gas compression device.

[0114] 7. Effects, etc. As described above, the gas compression device 10 of each embodiment is a device that compresses the gas taken into the cylinder tanks 1A and 1B by a liquid piston. The cylinder tanks 1A and 1B include a cylinder plate 1a, a top plate 1b that closes the opening on one end side of the cylinder plate 1a, and a bottom plate 1c that closes the opening on the other end side of the cylinder plate 1a. Further, the cylinder plate 1a has a first flange 71 that projects outward from the peripheral edge of the opening on one end side, and the top plate 1b is formed on a mirror plate and has a second flange 72 that projects outward from the peripheral edge of the opening of the mirror plate. Then, by joining the first flange 71 and the second flange 72 using a fastener 74, the top plate 1b is attached to the cylinder plate 1a.

[0115] Therefore, the gas compression device 10 is configured to obtain high sealing performance for the cylinder tanks 1A and 1B, while also enabling easy repair and component replacement inside the cylinder tanks, making it a liquid pump type gas compression device with high maintainability. Also, as is clear from the description of each of the above embodiments, according to the gas compression device 10, it is possible to increase the specific energy during compressed gas production.

[0116] The embodiments of the present invention have been described above. However, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. That is, the above embodiments should be considered as illustrative in all respects and not restrictive. The technical scope of the present invention is shown not by the description of the above embodiments but by the scope of the claims, and it should be understood that all modifications belonging to the meaning and scope equivalent to the scope of the claims are included.

[0117] <Contribution to the United Nations-led Sustainable Development Goals (SDGs)> The air compressor according to the present disclosure improves specific energy by realizing an isothermal compression process and can contribute to the achievement of Goal 7, "Ensure access to affordable, reliable, sustainable and modern energy for all" of the SDGs (Sustainable Development Goals).

Industrial Applicability

[0118] The present invention can be used in a gas compression device for compressing gas.

Explanation of Signs

[0119] 1A, 1B cylinder tanks 1a cylinder plate 1b top plate 1c bottom plate 2 intake mechanism 3 exhaust mechanism 6 liquid pump 7 control means 10 gas compression device 11A, 11B first liquid ports 12A, 12B second liquid ports 13A, 13B spray nozzles 14A, 14B air vent valves 21A, 21B intake lines 22A, 22B intake valves 23 air filter 31A, 31B exhaust lines 31x branch pipe Exhaust valves 32A, 32B First liquid flow lines 41A, 41B First liquid flow control valves 42A, 42B Second liquid flow lines 51A, 51B Second liquid flow control valves 52A, 52B Liquid introduction lines 53A, 53B Liquid introduction control valves 54A, 54B Third liquid flow line 55 Third liquid flow control valve 56 Third liquid ports 57A, 57B Liquid suction line 61 Liquid discharge line 62 First flange 71 Second flange 72 Rotation fulcrum 73 Fastener 74 Bolt 74a Nut 74b Davit mechanism 76 Arm part 76a Support part 76b Lifting part 76c Socket 77 Communication part 78 Liquid discharge line 81 Liquid discharge valve 82 Liquid supply line 83 Liquid supply valve 84 Air separator 91 Drain trap 92 Return liquid check valves 93A, 93B Liquid feed check valve 611 Flow rate sensor Fx Liquid level detection electrode rod Lx Pressure sensor Px Liquid L Process switching element group Z

Claims

1. A gas compression device that compresses the gas taken into the cylinder tank by a liquid piston, wherein the cylinder tank has a barrel plate, a top plate that closes an opening on one end side of the barrel plate, and a bottom plate that closes an opening on the other end side of the barrel plate, the barrel plate has a first flange that projects outward from the peripheral edge of the opening on one end side, the top plate is formed on the mirror plate and has a second flange that projects outward from the peripheral edge of the opening of the mirror plate, A gas compression device in which the top plate is attached to the barrel plate by joining the first flange and the second flange using a fastener.

2. The cylinder tank, The gas compression device according to claim 1, further comprising a hinge mechanism that enables the top plate to be moved around an axis of a rotation fulcrum to open and close one end side of the barrel plate in a state where the fastener is released.

3. At least two of the cylinder tanks are provided adjacent to each other laterally, The gas compression device according to claim 2, wherein the axes of the rotation fulcrums in the two cylinder tanks are arranged so as to extend in a direction orthogonal to the adjacent direction.

4. The gas compression device according to claim 3, wherein the axes of the rotation fulcrums in the two cylinder tanks are arranged so as to be most separated in the adjacent direction.

5. At least two of the cylinder tanks are provided adjacent to each other laterally, The gas compression device according to claim 2, wherein the axes of the rotation fulcrums in the two cylinder tanks are arranged so as to extend in the same direction as the adjacent direction.

6. The gas compression device according to claim 5, wherein the axes of the rotation fulcrums in the two cylinder tanks are arranged on the same side in a direction orthogonal to the adjacent direction.

7. The gas compression device according to claim 1, wherein the cylinder tank includes a davit mechanism that allows the top plate to be lifted away from the barrel plate and slid horizontally in a state where the fastener is released.

8. The gas compression device according to claim 1, wherein the top plate has a fixture for an electrode rod that detects the top dead center of the liquid piston.

9. The top plate has an exhaust pipe body erected on the top of the mirror plate, the fixture includes a branch pipe that penetrates the pipe wall of the pipe body, The gas compression device according to claim 8, wherein the electrode rod is attached in a state of being inserted horizontally into the internal space of the branch pipe.

10. The top plate has an exhaust pipe body erected on the top of the mirror plate. The fixture includes a socket erected on the mirror plate in proximity to the pipe body. The electrode rod is installed in a state where it is inserted vertically into the internal space of the socket and only the tip protrudes into the mirror plate. The gas compression device according to claim 8, wherein the socket has a communication portion for allowing internal compressed gas to escape to the pipe body.

11. At least two of the cylinder tanks, An intake mechanism and an exhaust mechanism communicating with the upper spaces of the respective cylinder tanks, A first liquid port provided at the lower part of each of the cylinder tanks, A second liquid port provided at the lower part of each of the cylinder tanks, A third liquid port provided at the lower part of each of the cylinder tanks, A liquid pump for transferring liquid from one cylinder tank to the other cylinder tank, A first liquid flow line connecting the first liquid ports, A second liquid flow line connecting the second liquid ports, A third liquid flow line connecting the third liquid ports, A liquid suction line connecting the suction side of the liquid pump to the first liquid flow line, A liquid discharge line connecting the discharge side of the liquid pump to the second liquid flow line, A plurality of first liquid flow control valves provided in the first liquid flow line corresponding to each of the first liquid ports, A plurality of second liquid flow control valves provided in the second liquid flow line corresponding to each of the second liquid ports, A third liquid flow control valve provided in the third liquid flow line, Control means for controlling a process switching element group including the liquid pump, the first liquid flow control valve, and the second liquid flow control valve. When one of the cylinder tanks is in a control state of performing a compression / exhaust process, the control means controls the process switching element group so that the other cylinder tank is in a control state of performing an expansion / intake process. The third liquid flow control valve, Is a full bore type ball type electric valve or a butterfly type electric valve having a valve body composed of a rotating body rotating in a valve box. The control means, The gas compression device according to any one of claims 1 to 10, wherein the liquid pump is stopped and the third liquid flow control valve is opened until a predetermined time after switching between the compression / exhaust process and the expansion / intake process, and the liquid pump is driven and the third liquid flow control valve is closed after the elapse of the predetermined time.

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