JP6057348B2 - Energy recovery equipment - Google Patents

Description

  The present invention relates to an energy recovery device for a water treatment system using a reverse osmosis membrane method used for desalination of seawater.

  A reverse osmosis method is known as one method for producing fresh water from seawater. In this reverse osmosis method, salt and fresh water are filtered through a semipermeable membrane (reverse osmosis membrane) in addition to the direction in which the osmotic pressure acts on seawater at a pressure higher than the osmotic pressure of seawater (about 2.5 MPa). Are separated from each other. In this reverse osmosis method, seawater (concentrated seawater) from which fresh water is separated and salts are concentrated flows out of the reverse osmosis membrane module while maintaining high pressure energy. Various energy recovery devices have been put into practical use in order to effectively use the high pressure energy of the concentrated seawater that flows out.

  Conventionally, for example, Patent Document 1 proposes an example of a conventional energy recovery device in a seawater desalination system using a reverse osmosis method. In this patent document 1, each one end of a pair of cylinder apparatus is connected with the water intake pump and the pressure booster pump via the flow-path direction control apparatus comprised by four check valves. The other end of the cylinder device is communicated with an inflow / outflow port of the flow path switching device. The inflow port of the flow path switching device is communicated with the outlet of the high-pressure concentrated seawater of the reverse osmosis membrane module. Furthermore, an outflow port is provided at one end of the flow path switching device.

In this energy recovery device, seawater sent from the intake pump is pressurized with a high-pressure pump and supplied to the reverse osmosis membrane module, and high-pressure concentrated seawater discharged from the reverse osmosis membrane module is supplied to the cylinder device at high pressure. A piston that pushes out seawater is driven, and high-pressure seawater is also sent from the cylinder device to the reverse osmosis membrane module via a pressure increasing pump. The operation of driving the piston that supplies high pressure concentrated seawater discharged from the reverse osmosis membrane module to the cylinder device and pushes the seawater at high pressure is called a pressure feeding process.
In addition, after the pumping process is completed, seawater is supplied from the intake pump to the cylinder device via the flow direction control device, and the operation of filling the seawater while discharging the concentrated seawater by driving the piston in the opposite direction to the pumping process This is called the filling process.
Thus, in this energy recovery device, when the piston of the cylinder device reaches the end of the cylinder, the flow switching device alternately supplies the high-pressure concentrated seawater from the reverse osmosis membrane module to the pair of cylinder devices and the intake pump The control is performed so that the pair of cylinder devices are alternately filled with seawater.

Thus, continuous filtration is possible by repeatedly performing the seawater pumping step and the filling step with two cylinder devices. In this way, by using the high-pressure energy of the concentrated seawater discharged from the reverse osmosis membrane module, the high-pressure seawater is supplied from the two cylinder devices to the pressure-intensifying pump. Energy in the process can be recovered.
Further, the technique of this Patent Document 1 is configured so that the flow path switching timing of the two flow path switching devices that mutually switch between the filling process and the pressure feeding process of the two cylinder devices can be appropriately set. This is an excellent technique improved by reducing the impact caused by sudden pressure fluctuations that occur at the time of switching so that a high pressure is not instantaneously applied to the reverse osmosis membrane module.

JP 2013-86043 A

In the above conventional technique, the following problems remain.
That is, in the above-described conventional technology, when the drain pipe is connected to the downstream side from the outflow port of the flow path switching device, and the downstream tip opening of the drain pipe is located below the water surface of the water tank, or the rising part in the middle of the drain pipe When the filling process is completed, there is a problem that an impact sound is generated when the communication from the outflow / inflow port to the outflow port is blocked at the end of the filling process. Further, there is a problem that an impact sound is generated when the outflow / inflow port and the outflow port communicate with each other even at the start of the filling process.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an energy recovery device that can suppress the generation of impact noise at the end or start of the filling process.

As a result of intensive studies to elucidate this cause, the present inventors have obtained the following knowledge.
In the above filling process, the inflow / outflow port of the flow path switching device is fully opened, the concentrated seawater is discharged from the cylinder device from the outflow port of the flow path switching device to the drain pipe at a constant flow rate, and the inside of the drain pipe moves to the downstream side at a constant pressure. A stable continuous flow is formed. However, at the end of the filling process, the communication between the outflow port and the outflow port is blocked in a short time by the piston of the flow path switching device moving at a constant speed, so that the stable continuous flow moving downstream at a constant pressure. Stops suddenly. For this reason, it turned out that the water hammer accompanying the pressure in a drain pipe falling instantaneously generate | occur | produces and the impact sound is produced as a result.
On the other hand, at the start of the filling process, the inflow and outflow ports and the outflow port are communicated in a short time by the piston of the flow path switching device that moves at a constant speed. It was also revealed that when the high residual pressure was released from the inflow / outflow port, the concentrated seawater spouted out at once and an impact sound was generated. The present inventor has completed the present invention based on the above findings.

  The present invention employs the following configuration in order to solve the above problems. That is, the energy recovery device according to the first invention is a membrane separation that separates high-pressure seawater into fresh water and concentrated seawater using a reverse osmosis membrane, discharges the freshwater into a freshwater pipe, and discharges the high-pressure concentrated seawater into the concentrated water pipe. An energy recovery apparatus connected to the apparatus, wherein one end is connected to the concentrated water pipe through a first flow path switching mechanism that performs communication with the concentrated water pipe and shuts off the concentrated seawater drain pipe. A first cylinder device having a first piston connected to the concentrated water pipe and the drain pipe and reciprocatingly moved in the first cylinder is connected to and disconnected from the concentrated water pipe and communicated to and cut off from the drain pipe. A second cylinder device having a second piston, one end of which is connected to the concentrated water pipe and the drain pipe via a second flow path switching mechanism that performs reciprocating movement in the second cylinder, and the first flow Path switching mechanism and second A path switching mechanism is controlled to switch the connection of the first cylinder device and the second cylinder device to the concentrated water pipe and the drain pipe, and the high-pressure concentrated seawater is supplied to the first cylinder device and the second cylinder device. A control unit having a control function for alternately flowing the concentrated seawater and a control function for alternately discharging the concentrated seawater from the first cylinder device and the second cylinder device, the other end of the first cylinder device, and the second cylinder Connected to the other end of the device, and alternately supplying seawater to the first cylinder device and the second cylinder device, and alternately pushed out from the first cylinder device and the second cylinder device at high pressure A flow path direction regulating mechanism for returning seawater to the membrane separation device via a pressure increasing means, wherein the first flow path switching mechanism and the second flow path switching mechanism are the first cylinder device. Comprises a switching cylinder device for switching between supply and stop of the concentrated seawater to the second cylinder device and discharge and stop of the concentrated seawater from the first cylinder device or the second cylinder device, The switching cylinder device is reciprocally moved in the switching cylinder, the switching cylinder connected to one end of the first cylinder device or the second cylinder device, the drain pipe, and the concentrated water pipe, and the first cylinder apparatus. One end of a cylinder device or the second cylinder device and a drain side piston capable of communicating with and blocking the drain pipe and the concentrated water pipe, and the control unit controls the first flow path switching mechanism. When the one end of the first cylinder device and the drain pipe communicate with each other, the moving speed of the drain side piston is reduced to start communication gently, and the first cylinder device When the communication between one end of the drainage pipe and the drain pipe is cut off, the moving speed of the drainage-side piston is reduced so as to cut off the communication gently, and the second flow path switching mechanism is further controlled to control the second cylinder device When one end of the second cylinder device is communicated with the drain pipe, the movement speed of the drain side piston is reduced to start communication gently, and communication between the one end of the second cylinder device and the drain pipe is interrupted. The movement speed of the drain side piston is reduced to gently cut off the communication.

  In this energy recovery device, the control unit slowly starts the communication by decelerating the moving speed of the drain side piston when one end of the first cylinder device or the second cylinder device and the drain pipe communicate with each other. When the communication between one end of the cylinder device or the second cylinder device and the drain pipe is cut off, the movement speed of the drain side piston is reduced to gently cut off the communication. The residual pressure is gradually released, and at the time of shut-off, the discharge flow rate from the cylinder device is gently reduced to prevent the generation of impact sound.

In order to prevent impact noise at the end of the filling process, it is necessary not to generate a water hammer in the drain pipe. For this purpose, a stable continuous flow that moves downstream in the drain pipe at a constant pressure is suddenly stopped. It is necessary not to let it. Moreover, in order to prevent an impact sound at the start of the filling process, it is necessary to suppress the ejection of concentrated seawater by not releasing the high residual pressure in the cylinder device at once.
Therefore, in the present invention, before the communication between the outflow port and the outflow port is interrupted at the end of the filling process, the moving speed of the drain side piston of the switching cylinder device is reduced, thereby The communication is gradually cut off, and the flow rate of the concentrated seawater discharged to the drain pipe is gradually reduced to suppress a sudden stop of a stable continuous flow in the drain pipe.
Further, at the start of the filling process, the moving speed of the drain side piston of the switching cylinder device is reduced before the drain side piston of the switching cylinder device moves and communication between the outflow port and the outflow port is started. As a result, the communication between the outflow / inflow port and the outflow port is gradually started, and the residual pressure in the cylinder device is gradually released, whereby the ejection of the concentrated seawater can be suppressed.

In the energy recovery device according to a second aspect of the present invention, in the first aspect, the control unit is provided in the first cylinder and the second cylinder, and the first piston or the second piston corresponds to the first cylinder. Alternatively, a pair of position detectors for detecting that the vicinity of the other end of the second cylinder has been reached is provided, and the first flow path switching mechanism and the second flow path switching are performed based on detection signals of the pair of position detectors. The mechanism is controlled.
That is, in this energy recovery device, since the first flow path switching mechanism and the second flow path switching mechanism are controlled based on the detection signal of the position detector, the position of the first piston or the second piston can be accurately detected, The first flow path switching mechanism and the second flow path switching mechanism can be controlled according to the position of the first piston or the second piston.

According to a third aspect of the present invention, there is provided the energy recovery apparatus according to the second aspect, wherein the first flow path switching mechanism and the second flow path switching mechanism include a drive cylinder device that drives the switching cylinder device, The control unit supplies pressure oil to the drive cylinder device of the first flow path switching mechanism via a first hydraulic pipe, and supplies the drive cylinder device of the second flow path switching mechanism to the drive cylinder apparatus via a second hydraulic pipe. A hydraulic pressure source for supplying pressure oil, a first switching valve connected to the first hydraulic piping, a second switching valve connected to the second hydraulic piping, the first switching valve and the second switching valve; And a pressure oil adjusting mechanism for adjusting the pressure oil flow rate in the drive cylinder device, and the control body is configured to control the first switching valve and the second switching valve based on the detection signal. Operate the drive cylinder device by controlling the valve And wherein the door.
That is, in this energy recovery device, the control unit includes a pressure oil adjusting mechanism that adjusts the pressure oil flow rate in the drive cylinder device, and the control unit main body includes the first switching valve and the second switching valve based on the detection signal. Since the driving cylinder device is operated under control, the moving speed of the piston of the driving cylinder device can be reduced by adjusting the pressure oil flow rate in the driving cylinder device switched by the switching valve by the pressure oil adjusting mechanism. .

According to a fourth aspect of the present invention, there is provided the energy recovery device according to the third aspect, wherein the first hydraulic piping and the second hydraulic piping are switched through the first switching valve or the second switching valve to which the first hydraulic piping and the second hydraulic piping are connected. A supply-side piston that is branched into a first inflow / outflow pipe and a second inflow / outflow pipe that are reciprocated integrally with the drainage-side piston in the switching cylinder; The drain side piston is provided, the supply side piston is provided in an intermediate portion, and the other end is provided with a switching piston rod projecting outside from the other end of the switching cylinder. A hydraulic cylinder having a first pressure oil outlet / inlet connected to the first inlet / outlet pipe and a second pressure oil outlet / inlet connected to the second inlet / outlet pipe; and a hydraulic pressure reciprocating within the hydraulic cylinder. Piston and middle And a hydraulic piston rod having one end connected to the other end of the switching piston rod, and the hydraulic cylinder has a first hydraulic chamber on the other end side of the hydraulic piston. And having a second hydraulic chamber on one end side, a first protruding portion protruding into the first hydraulic chamber, and a second protruding portion protruding into the second hydraulic chamber, wherein the hydraulic piston rod is A first shaft protrusion that closes the first hydraulic chamber on the other end side of the first protrusion when the reciprocating movement is on the other end side of the hydraulic piston and faces the first protrusion. A second shaft projection that closes the second hydraulic chamber on the one end side of the second projection when the reciprocating movement is located on the one end side of the hydraulic piston; The pressure oil adjusting mechanism is provided in the first hydraulic chamber. A pair of first hydraulic pipes, one end of which is connected across one protrusion, a pair of second hydraulic pipes, one end of which is connected to the second hydraulic chamber with the second protrusion interposed therebetween, and the pair of first hydraulic pipes A first check valve and a first flow rate adjustment valve connected in parallel to the other end side of the one hydraulic pipe and communicating the pair of first hydraulic pipes, and in parallel to the other end side of the pair of second hydraulic pipes A second check valve and a second flow rate adjustment valve connected to the pair of second hydraulic pipes, the switching cylinder being connected to the drain pipe and provided at one end side; An inflow port connected to the concentrated water pipe and provided in an intermediate portion; and an inflow / outflow port connected to the first cylinder device or the second cylinder device and provided between the outflow port and the inflow port. When the drain side piston closes the inflow / outflow port, The first projecting portion and the first shaft projecting portion are set at positions facing each other, and the second projecting portion and the second shaft projecting portion are set at positions facing each other, and the first check The valve can flow only in the direction from the first hydraulic pipe on the other end side of the first protrusion to the first hydraulic pipe on the one end side, and the second check valve can be connected to the second protrusion. It is possible to flow only in the direction from the second hydraulic pipe on one end side to the second hydraulic pipe on the other end side.
That is, in this energy recovery apparatus, the pressure oil adjustment mechanism includes a pair of first hydraulic pipes, a pair of second hydraulic pipes, a first check valve and a first flow rate adjustment valve, a second check valve, and a second check valve. Since the second flow rate adjusting valve is provided, when the first projecting portion and the first shaft projecting portion start to face each other, the second projecting portion and the second shaft projecting portion start to face each other. The pressure oil cannot flow into the first hydraulic chamber or the second hydraulic chamber, and a part flows from the pair of hydraulic pipes to the hydraulic chamber via the flow rate adjusting valve. Therefore, the hydraulic chamber in a state where the first protrusion and the first shaft protrusion are in a position not facing each other, and in a state where the second protrusion and the second shaft protrusion are not facing each other. The moving speed of the hydraulic piston is reduced by setting the pressure oil flow rate of the flow rate adjusting valve so as to be less than the pressure oil flow rate.

According to a fifth aspect of the present invention, there is provided the energy recovery apparatus according to the fourth aspect, wherein the switching piston rod is formed with a communication hole that connects one end side and the other end side in the switching cylinder. And
That is, in this energy recovery device, the switching piston rod is formed with a communication hole that connects the switching piston rod to the one end side and the other end side in the switching cylinder. It becomes unnecessary, and the cylinder length can be shortened accordingly. Also, piping associated with the adjustment port is not necessary, and the flow path switching device can be made compact.

An energy recovery device according to a sixth aspect of the present invention is characterized in that, in the fourth or fifth aspect, the hydraulic piston and the hydraulic piston rod are integrally formed.
That is, in this energy recovery device, the hydraulic piston and the hydraulic piston rod are integrally formed, so that the number of parts can be reduced and the device can be easily manufactured. In particular, when the outer diameter of the hydraulic piston is small, it becomes easy to integrally form the hydraulic piston and the hydraulic piston rod by machining.

An energy recovery device according to a seventh invention is the energy recovery device according to the fourth or fifth invention, wherein a first male thread groove is formed on the outer peripheral surface on the other end side of the hydraulic piston rod and the first outer peripheral surface on the one end side. 2 male screw grooves are formed, the first shaft protrusion is an annular member, the first shaft protrusion is fitted in the first male screw groove, and the first shaft protrusion is formed in the first male screw groove. It is fixed by a screwed nut to restrict rotation around the axis and movement in the axial direction, the second shaft projection is an annular member, and the second shaft projection is formed in the second male screw groove. The second shaft protrusion is fixed by a nut screwed into the second male screw groove and is restricted from rotating around the axis and moving in the axial direction. .
That is, in this energy recovery device, the first shaft protrusion of the annular member is fixed by a nut screwed into the first male screw groove, and the second shaft protrusion of the ring member is fixed to the second male screw groove. Since it is fixed by a screwed nut, the arrangement positions of the first shaft projection and the second shaft projection can be easily changed, and the hydraulic piston moves in the deceleration start position or the hydraulic piston in the deceleration state. The distance can be easily changed.

The present invention has the following effects.
That is, according to the energy recovery device of the present invention, the movement speed of the drain side piston of the switching cylinder device is reduced before the communication between the outflow port and the outflow port is interrupted at the end of the filling process. A sudden stop of a stable continuous flow is suppressed, and it is possible to prevent an impact sound from being generated by a water hammer. Also, at the start of the filling process, the moving speed of the drain side piston of the switching cylinder device is reduced before the communication between the outflow port and the outflow port is started, so that the residual pressure in the cylinder device is gradually released. Thus, the generation of impact sound can be prevented.

It is a mimetic diagram showing a 1st embodiment of an energy recovery device concerning the present invention. In 1st Embodiment, it is sectional drawing which shows the cylinder apparatus for switching, and a drive cylinder apparatus. In 1st Embodiment, it is a figure which shows the schematic cross section and piping for demonstrating the state at the time of the piston of a switching cylinder apparatus and a drive cylinder apparatus moving to one end side. In 1st Embodiment, it is a figure which shows the schematic cross section and piping for demonstrating the state at the time of the piston of a switching cylinder apparatus and a drive cylinder apparatus moving to the other end side. In 1st Embodiment, it is sectional drawing which shows operation | movement of the cylinder apparatus for switching, and a drive cylinder apparatus in order. In 1st Embodiment, it is sectional drawing which shows operation | movement of the cylinder apparatus for switching, and a drive cylinder apparatus in order. It is sectional drawing which shows the cylinder apparatus for switching and the drive cylinder apparatus in 2nd Embodiment of the energy recovery apparatus which concerns on this invention. In 3rd Embodiment of the energy recovery apparatus which concerns on this invention, it is a front view which shows a hydraulic piston and a hydraulic cylinder rod.

  Hereinafter, a first embodiment of an energy recovery apparatus according to the present invention will be described with reference to FIGS. 1 to 6.

  As shown in FIG. 1, the energy recovery device 1 in the present embodiment is connected to a high-pressure seawater supply pipe 2 a, separates high-pressure seawater into fresh water and concentrated seawater using a reverse osmosis membrane, and discharges freshwater to the freshwater pipe 3. This is an energy recovery device connected to a membrane separation device 5 that discharges high-pressure concentrated seawater to the concentrated water pipe 4.

  This energy recovery device 1 has one end connected to the concentrated water pipe 4 and drained via a first flow path switching mechanism 6A that performs communication with and shuts off the concentrated water pipe 4 and also connects and disconnects the concentrated seawater drain pipe 19. The first cylinder device 9A having a first piston 8A, which is connected to the pipe 19 and reciprocatingly moves in the first cylinder 7A, communicates with the concentrated water pipe 4 and shuts off and communicates with the drain pipe 19. A second cylinder device 9B having a second piston 8B, one end of which is connected to the concentrated water pipe 4 and the drain pipe 19 via the second flow path switching mechanism 6B for reciprocally moving in the second cylinder 7B; By controlling the first flow path switching mechanism 6A and the second flow path switching mechanism 6B, the connection of the first cylinder device 9A and the second cylinder device 9B to the concentrated water pipe 4 and the drain pipe 19 is switched, and the high-pressure concentrated seawater is changed to the first. 1 cylinder device 9A and the first A control unit C having a control function for alternately flowing into the cylinder device 9B and a control function for alternately discharging concentrated seawater from the first cylinder device 9A and the second cylinder device 9B; and the other end of the first cylinder device 9A; Connected to the other end of the second cylinder device 9B, seawater is alternately supplied to the first cylinder device 9A and the second cylinder device 9B, and alternately from the first cylinder device 9A and the second cylinder device 9B at high pressure. And a flow path direction regulating mechanism 11 for returning seawater pushed out to the membrane separation device 5 through the pressure increasing means 10.

A pressure pump 33 is connected to the proximal end side of the supply pipe 2a, and a water intake pump 12 is connected to the proximal end side of the water supply pipe 2b.
The concentrated water pipe 4 is branched in the middle and connected to the first flow path switching mechanism 6A and the second flow path switching mechanism 6B.
The first flow path switching mechanism 6A and the second flow path switching mechanism 6B are configured to supply and stop the concentrated seawater to the first cylinder device 9A or the second cylinder device 9B and to stop the first seawater device 9A or the second cylinder device 9B. Is provided with a switching cylinder device 13 for switching between discharging the concentrated seawater from the water and stopping it.

The switching cylinder device 13 is moved back and forth within the switching cylinder 20 and the switching cylinder 20 connected to one end of the first cylinder device 9A or the second cylinder device 9B, the drain pipe 19 and the concentrated water pipe 4. One end of the first cylinder device 9A or the second cylinder device 9B and a drain side piston 21a capable of communicating with and blocking the drain pipe 19 and the concentrated water pipe 4 are provided.
The control unit C controls the first flow path switching mechanism 6A so that when the one end of the first cylinder device 9A and the drain pipe 19 are communicated with each other, the moving speed of the drain side piston 21a is reduced so as to communicate gently. At the same time, when the communication between the one end of the first cylinder device 9A and the drain pipe 19 is cut off, the moving speed of the drain side piston 21a is reduced to cut off the communication gently, and the second flow path switching mechanism 6B is further turned off. When the one end of the second cylinder device 9B and the drain pipe 19 are communicated with each other, the moving speed of the drain side piston 21a is reduced to start the communication gently, and the one end of the second cylinder device 9B and the drain pipe are started. 19 has a function of slowing the communication by slowing down the moving speed of the drain-side piston 21a when the communication with the engine 19 is interrupted.

  The control unit C is provided near the other ends of the first cylinder 7A and the second cylinder 7B, and the first piston 8A or the second piston 8B reaches the vicinity of the other end of the corresponding first cylinder 7A or the second cylinder 7B. A pair of first position detectors S1 for detecting this is provided. Further, the control unit C has a function of controlling the first flow path switching mechanism 6A and the second flow path switching mechanism 6B based on the detection signals of the pair of first position detectors S1.

As shown in FIG. 2, the first flow path switching mechanism 6 </ b> A and the second flow path switching mechanism 6 </ b> B include a drive cylinder device 14 that drives the switching cylinder device 13.
Further, the control unit C supplies pressure oil to the drive cylinder device 14 of the first flow path switching mechanism 6A via the first hydraulic pipe 15A and the second to the drive cylinder apparatus 14 of the second flow path switching mechanism 6B. A hydraulic pump (hydraulic source) 16 that supplies pressure oil via the hydraulic pipe 15B, a first switching valve 17A connected to the first hydraulic pipe 15A, and a second switching valve 17B connected to the second hydraulic pipe 15B And a control part main body C1 for controlling the first switching valve 17A and the second switching valve 17B, and a pressure oil adjusting mechanism 18 for adjusting the pressure oil flow rate in the drive cylinder device 14.

The control unit main body C1 has a function of operating the drive cylinder device 14 by controlling the first switching valve 17A and the second switching valve 17B, which are electromagnetic valves, based on the detection signal.
The switching cylinder device 13 includes a supply-side piston 21b that reciprocates integrally with the drain-side piston 21a in the switching cylinder 20, a drain-side piston 21a at one end, and a supply-side piston 21b at an intermediate portion. The switching piston rod 22 is provided with the other end protruding outside from the other end of the switching cylinder 20.

  The switching cylinder 20 is connected to a drain pipe 19 for concentrated seawater and has an outflow port 13a provided at one end, an inflow port 13b connected to the concentrated water pipe 4 and provided in an intermediate portion, and the first cylinder device 9A or It has an inflow / outflow port 13c connected between the second cylinder device 9B and provided between the outflow port 13a and the inflow port 13b, and an adjustment port 13d provided on the other end side of the inflow port 13b.

The drive cylinder device 14 has a hydraulic cylinder 23 having a first pressure oil inlet / outlet 23a connected to the first inlet / outlet pipe 15a and a second pressure oil outlet / inlet 23d connected to the second inlet / outlet pipe 15b. A hydraulic piston 24 that reciprocates in the hydraulic cylinder 23, and a hydraulic piston rod 25 that is provided with an intermediate portion of the hydraulic piston 24 and one end of which is connected to the other end of the switching piston rod 22. . The hydraulic cylinder 23 has a first hydraulic chamber 26a on the other end side than the hydraulic piston 24, a second hydraulic chamber 26b on one end side, and a first protrusion 27a protruding into the first hydraulic chamber 26a. And a second protrusion 27b protruding into the second hydraulic chamber 26b.
The first protrusion 27a and the second protrusion 27b are formed as annular protrusions protruding inward in the radial direction.

The hydraulic piston rod 25 is located on the other end side of the hydraulic piston 24 and closes the first hydraulic chamber 26a on the other end side with respect to the first projection portion 27a when facing the first projection portion 27a during reciprocation. A first shaft projection 25a and a second shaft that is on one end side of the hydraulic piston 24 and closes the second hydraulic chamber 26b on the one end side of the second projection portion 27b when facing the second projection portion 27b during reciprocation. And a protrusion 25b.
The first shaft protrusion 25a and the second shaft protrusion 25b are formed as annular protrusions that protrude outward in the radial direction in accordance with the corresponding first protrusion 27a or second protrusion 27b. .

The pressure oil adjusting mechanism 18 includes a pair of first hydraulic pipes 29a having one end connected to the first hydraulic chamber 26a with the first protrusion 27a interposed therebetween, and a second protrusion 27b interposed to the second hydraulic chamber 26b. A pair of second hydraulic pipes 29b connected at one end, and a first check valve 30a and a first check valve 30a connected in parallel to the other end side of the pair of first hydraulic pipes 29a and communicating with the pair of first hydraulic pipes 29a. A flow rate adjusting valve 31a, and a second check valve 30b and a second flow rate adjusting valve 31b connected in parallel to each other on the other end side of the pair of second hydraulic pipes 29b and connecting the pair of second hydraulic pipes 29b are provided. Yes.
That is, one end of each of the first check valve 30a and the first flow rate adjusting valve 31a is connected to one of the pair of first hydraulic pipes 29a, and the other end of each of the first check valve 30a and the first flow rate adjusting valve 31a is paired with the pair of first hydraulic pipes 29a. Is connected to the other of the two. One end of each of the second check valve 30b and the second flow rate adjustment valve 31b is connected to one of the pair of second hydraulic pipes 29b, and the other end of each of the second check valve 30b and the second flow rate adjusting valve 31b is a pair of second hydraulic pipes 29b. Is connected to the other of the two.

Further, when the drain side piston 21a closes the inflow / outflow port 13c, the first protrusion 27a and the first shaft protrusion 25a are set at positions facing each other, and the second protrusion 27b and the second shaft protrusion are set. The portion 25b is set at a position facing each other.
Further, the first check valve 30a can flow only in the direction from the first hydraulic pipe 29a on the other end side of the first protrusion 27a to the first hydraulic pipe 29a on the one end side, and the second check valve 30b can flow only in the direction from the second hydraulic pipe 29b on one end side of the second protrusion 27b to the second hydraulic pipe 29b on the other end side.

The other end of each of the first cylinder device 9A and the second cylinder device 9B is communicated with the water intake pump 12 and the pressure increasing means 10 via a flow path direction regulating mechanism 11 composed of four check valves 11a. . The pressure increasing means 10 is, for example, a pressure increasing pump.
One end of the first cylinder device 9A communicates with the inflow / outflow port 13c of the switching cylinder device 13 in the first flow path switching mechanism 6A, and one end of the second cylinder device 9B is for switching in the second flow path switching mechanism 6B. The cylinder device 13 communicates with an inflow / outflow port 13c.

The flow path direction regulating mechanism 11 has an annular pipe 11c connected to the water supply pipe 2b via a connecting pipe 11b, and the other ends of the first cylinder device 9A and the second cylinder device 9B are connected to the annular pipe 11c. Are connected via a cylinder connecting pipe 11d. In the annular pipe 11c, a pair of check valves 11a are provided on both sides of the connecting portion of the cylinder connecting pipe 11d. Further, between the connecting portions of the two cylinder connecting pipes 11d in the annular pipe 11c and the supply pipe 2a are connected by a connecting pipe 11e via the pressure increasing means 10.
Note that a high-pressure pump 33 is connected between a connection portion between the water supply pipe 2b and the flow path direction regulating mechanism 11 and a connection portion between the supply pipe 2a and the connection pipe 11e.

  The inflow port 13 b of the switching cylinder device 13 is communicated with the concentrated water pipe 4. Furthermore, an outlet port 13 a is provided at one end of the switching cylinder device 13. The drain side piston 21 a and the supply side piston 21 b disposed in the switching cylinder 20 are connected to the switching piston rod 22. One end of the switching piston rod 22 is connected to the drive cylinder device 14 and reciprocates in the switching cylinder 20 in conjunction with the drive cylinder device 14.

The adjustment port 13d is a discharge / inlet for a fluid necessary for the reciprocating motion of the drain side piston 21a and the supply side piston 21b, and is provided at the end of the first switching cylinder 20.
A first position detector S1 and a second position detector S2 are disposed on the outer peripheral wall of the first cylinder device 9A and the second cylinder device 9B on the flow path direction regulating mechanism 11 side. In addition, the first position detector S1 and the second position detector S2 are arranged with an appropriate interval set in the moving direction of the corresponding first piston 8A or second piston 8B.

Next, the configuration of the drive cylinder device 14 will be described in more detail with reference to FIG.
In the hydraulic cylinder 23 of the drive cylinder device 14, a hydraulic piston chamber 26c is formed at the center in the axial direction, and a first hydraulic chamber 26a is formed at the other end side of the hydraulic piston chamber 26c. 13a side) is formed with a second hydraulic chamber 26b. A hydraulic piston 24 is disposed in the hydraulic piston chamber 26c. One end of the first hydraulic piston rod 25A is joined to the first hydraulic chamber 26a side of the hydraulic piston 24 with a bolt (not shown), and a second hydraulic pressure is provided. One end of the second hydraulic piston rod 25B is joined to the chamber 26b side by a bolt (not shown), and the hydraulic piston rod 25 is configured as a whole.

  As the hydraulic piston 24 reciprocates, the first hydraulic piston rod 25A reciprocates in the first hydraulic chamber 26a, and the second hydraulic piston rod 25B reciprocates in the second hydraulic chamber 26b. The hydraulic piston chamber 26c, the first hydraulic chamber 26a, and the second hydraulic chamber 26b have a circular cross section orthogonal to the axial direction, and are directed inward to the inner walls of the first hydraulic chamber 26a and the second hydraulic chamber 26b. An annular first projecting portion 27a and a second projecting portion 27b projecting from each other are provided, and the inner diameters of the first hydraulic chamber 26a and the second hydraulic chamber 26b are narrowed.

The first hydraulic piston rod 25A and the second hydraulic piston rod 25B are provided with the first axial protrusion 25a and the second axial protrusion 25b, respectively. The outer diameter of the first shaft protrusion 25a is slightly smaller than the inner diameter of the first protrusion 27a, and the outer diameter of the second shaft protrusion 25b is slightly smaller than the inner diameter of the second protrusion 27b. Furthermore, it is set equal to the distance _{L 2} between the distance _{L 1} between the first protrusion 27a and the first shaft protrusion 25a and the second protrusion 27b and the second shaft protruding portion 25b.

A first pressure oil outlet / inlet 23a is provided at the end of the side wall on the other axial end side of the first hydraulic chamber 26a, and is connected to the first inlet / outlet pipe 15a of the first hydraulic pipe 15A or the second hydraulic pipe 15B. Is done. In addition, a third pressure oil outlet 23b and a fourth pressure oil outlet 23c are provided on the side wall of the first hydraulic chamber 26a with the first protrusion 27a interposed therebetween. One end of the pair of first hydraulic pipes 29a is connected to the third pressure oil outflow inlet 23b, and the other end of the pair of first hydraulic pipes 29a is connected to the fourth pressure oil outflow inlet 23c. The pair of first hydraulic pipes 29a is branched at the other end into two, one of the branched branches communicates with the pair of first hydraulic pipes 29a via the first check valve 30a, and the other is the first flow rate adjustment. A pair of first hydraulic pipes 29a communicate with each other through the valve 31a.
Although the flow of the pressure oil from the third pressure oil outlet 23b to the fourth pressure oil outlet 23c is not restricted by the first check valve 30a, the flow from the fourth pressure oil outlet 23c to the third pressure oil outlet 23b is not restricted. Flow is regulated.

A second pressure oil outflow inlet 23d is provided at the end of the side wall on the one axial end side of the second hydraulic chamber 26b, and is connected to the second inflow / outflow pipe 15b of the first hydraulic pipe 15A or the second hydraulic pipe 15B. ing.
Further, a fifth pressure oil outflow inlet 23e and a sixth pressure oil outflow inlet 23f are provided on the side wall of the second hydraulic chamber 26b with the second protrusion 27b interposed therebetween. One end of the pair of second hydraulic pipes 29b is connected to the fifth pressure oil outflow inlet 23e, and the other end of the pair of second hydraulic pipes 29b is connected to the sixth pressure oil outflow inlet 23f. The other end of each of the pair of second hydraulic pipes 29b is branched into two. One of the branched branches communicates with the pair of second hydraulic pipes 29b via the second check valve 30b, and the other is the second flow rate adjustment. A pair of second hydraulic pipes 29b communicate with each other through the valve 31b.
Although the flow from the sixth pressure oil outlet 23f to the fifth pressure oil outlet 23e is not restricted by the second check valve 30b, the pressure oil from the fifth pressure oil outlet 23e to the sixth pressure oil outlet 23f Flow is regulated.

One end of the second hydraulic piston rod 25B projects through the side wall of the second hydraulic chamber 26b and is connected to one end of the switching piston rod 22 by a shaft coupling 34. The switching piston rod 22 is driven by the drive cylinder device 14. .
The switching cylinder device 13 is provided with an outflow port 13a, an inflow / outflow port 13c, an inflow port 13b, and an adjustment port 13d in the switching cylinder 20, and the inflow / outflow port 13c is one end of the first cylinder device 9A or the second cylinder device 9B. Communicated with.

  A drain side piston 21 a and a supply side piston 21 b are connected to the switching piston rod 22, and reciprocate in the switching cylinder 20 together with the switching piston rod 22. The drain side piston 21a is located between the outflow port 13a and the outflow / inflow port 13c to block communication between the outflow port 13a and the outflow / inflow port 13c, and is positioned between the outflow / inflow port 13c and the inflow port 13b. As a result, the switching cylinder 20 reciprocates so as to block communication between the inflow / outflow port 13c and the inflow port 13b.

  The supply-side piston 21b is disposed so as to be positioned closer to the adjustment port 13d than the inflow port 13b in a state where the drain-side piston 21a is positioned between the outflow port 13a and the outflow / inflow port 13c. That is, the supply-side piston 21b is disposed at a position where any of the outflow port 13a, the outflow / inflow port 13c, and the inflow port 13b is not communicated or blocked by reciprocation.

Next, operation | movement of the energy recovery apparatus 1 of this embodiment is demonstrated with reference to drawings.
First, as shown in FIG. 1, when the first piston 8A of the first cylinder device 9A in the pressure feeding process moves in the direction of the solid line arrow (from right to left on the paper surface) and reaches the position of the first position detector S1. The detection signal is transmitted from the first position detector S1 to the control unit main body C1 of the control unit C. When the control body C1 receives this detection signal, a switching signal is transmitted from the control body C1 to the second switching valve 17B that switches the hydraulic flow path of the drive cylinder device 14 of the second flow path switching mechanism 6B.

  In response to the switching signal, the second switching valve 17B switches the hydraulic flow path from the hydraulic pump 16, drives the hydraulic piston 24 of the drive cylinder device 14 in the second flow path switching mechanism 6B, and the second flow path switching mechanism. The drain side piston 21a and the supply side piston 21b of the switching cylinder device 13 in 6B start moving to one end side (the lower side on the paper surface) at a predetermined constant speed. At this time, when the movement starts, the inflow / outflow port 13c of the switching cylinder device 13 of the second flow path switching mechanism 6B is fully opened, and the concentrated seawater is discharged from the second cylinder device 9B to the drain pipe 19 at a constant flow rate.

  As shown in FIG. 3, when the supply-side piston 21b moves in the arrow direction (downward on the paper surface) at a constant speed and reaches a predetermined position Pb before completely closing the opening of the inflow / outflow port 13c. The flow rate of the hydraulic oil that drives the hydraulic piston 24 of the drive cylinder device 14 is reduced to reduce the drive speed of the hydraulic piston 24, and at the same time, the supply-side piston 21b of the switching cylinder device 13 in the second flow path switching mechanism 6B. The movement speed of is reduced.

  After the supply-side piston 21b reaches the position Pb, the inflow / outflow port 13c of the switching cylinder device 13 in the second flow path switching mechanism 6B is completely closed, and the inflow / outflow port 13c and the outflow port 13a of the switching cylinder device 13 are closed. Until the communication with is interrupted, the outflow rate of the concentrated seawater to the drain pipe 19 is gradually stopped while gradually decreasing. Since the outflow flow rate gradually decreases in this way, the stable continuous flow in the drain pipe 19 does not stop abruptly, so that cavitation does not occur and the generation of impact sound at the end of the filling process can be prevented. .

When this switching is completed, the inflow port 13b and the inflow / outflow port 13c of the switching cylinder device 13 in the second flow path switching mechanism 6B are connected to supply high-pressure concentrated seawater from the membrane separation device 5 to the second cylinder device 9B. At the same time, the communication between the outflow / inflow port 13c and the outflow port 13a is blocked, and the pressure feeding process of the second cylinder device 9B is started.
At this time, when the first piston 8A of the first cylinder device 9A still in the pumping process moves further in the direction of the solid arrow and reaches the position of the second position detector S2, the second position detector S2 A detection signal is transmitted to the control unit main body C1.

  When the control unit body C1 receives this detection signal, a switching signal is transmitted from the control unit body C1 to the first switching valve 17A that switches the hydraulic passage of the drive cylinder device 14 in the first passage switching mechanism 6A. Upon receiving the switching signal, the first switching valve 17A switches the hydraulic flow path from the hydraulic pump 16 (hydraulic power source) and drives the hydraulic piston 24 of the drive cylinder device 14 in the first flow path switching mechanism 6A to generate the first flow. The drain-side piston 21a and the supply-side piston 21b in the path switching mechanism 6A start moving from the lower end position to the other end side (above the paper surface).

  As shown in FIG. 4, when the movement starts, the inflow / outflow port 13c of the switching cylinder device 13 in the first flow path switching mechanism 6A is fully open, and the high-pressure concentrated seawater from the membrane separation device 5 is the first at a constant flow rate. It flows into the cylinder device 9A. When the drain-side piston 21a moves to the other end side (above the paper surface) at a predetermined constant speed, and the inflow / outflow port 13c reaches the predetermined position Q1a before the communication with the outflow port 13a starts, the first flow The drive speed of the hydraulic piston 24 is reduced by reducing the flow rate of the hydraulic pressure that drives the hydraulic piston 24 of the drive cylinder device 14 in the path switching mechanism 6A.

  As the hydraulic piston 24 decelerates, the moving speed of the supply-side piston 21b of the switching cylinder device 13 in the first flow path switching mechanism 6A is decelerated, the inflow / outflow port 13c is gently opened, and the outflow / ingress port 13c and the outflow port Communication with 13a begins, and the filling process of the first cylinder device 9A is started. Until the drain side piston 21a reaches the position Q2a from the predetermined position Q1a, the hydraulic piston 24 moves in a decelerated state, so that the outflow / inflow port 13c and the outflow port 13a are gently communicated to each other. The high residual pressure held in the cylinder device 9A is gradually released. Therefore, the impact sound at the start of the filling process can be prevented without the concentrated seawater blowing out at a stretch.

  When the drain-side piston 21a reaches the predetermined position Q2a, the hydraulic flow rate for driving the hydraulic piston 24 of the drive cylinder device 14 returns to the original predetermined flow rate, and the driving speed of the hydraulic piston 24 increases to the speed before deceleration. Speeded. As the hydraulic piston 24 increases in speed, the moving speed of the drain side piston 21a of the switching cylinder device 13 in the first flow path switching mechanism 6A is also increased to the speed before deceleration, and the inflow / outlet port 13c is fully opened, and the concentrated seawater Is discharged to the drain pipe 19 at a constant flow rate.

  When the second piston 8B of the second cylinder device 9B in the pressure feeding process moves in the direction of the arrow indicated by the broken line (on the switching cylinder device 13 side) and reaches the position of the first position detector S1, the first position detection is performed. A detection signal is transmitted from the controller S1 to the control unit main body C1. When the control unit main body C1 receives the detection signal, a switching signal is transmitted from the control unit main body C1 to the first switching valve 17A that switches the hydraulic flow path of the drive cylinder device 14 of the first flow path switching mechanism 6A. The 17A hydraulic flow path is switched.

When the hydraulic flow path of the first switching valve 17A is switched, the hydraulic piston 24 of the drive cylinder device 14 is driven, and the drain side piston 21a supply side piston 21b of the switching cylinder device 13 of the first flow path switching mechanism 6A is one end. Start moving to the side (downward on the page) at a predetermined constant speed.
At the start of movement, the inflow / outflow port 13c of the switching cylinder device 13 in the first flow path switching mechanism 6A is fully opened, and the concentrated seawater is discharged from the first cylinder device 9A to the drain pipe 19 at a constant flow rate. When the drain-side piston 21a moves to one end side (downward in the drawing) at a constant speed and reaches a predetermined position Pa before completely closing the opening of the inflow / outflow port 13c, as shown in FIG. By reducing the flow rate of the hydraulic pressure that drives the hydraulic piston 24 of the cylinder device 14, the drive speed of the hydraulic piston 24 is reduced.

  As the hydraulic piston 24 decelerates, the moving speed of the drain side piston 21a of the switching cylinder device 13 in the first flow path switching mechanism 6A is decelerated, and the inflow / outflow port 13c is gradually closed. Therefore, until the drainage side piston 21a reaches the position Pa and the inflow / outflow port 13c is completely blocked and the communication between the outflow / ingress port 13c and the outflow port 13a is blocked, the concentrated seawater is supplied to the drainage pipe 19. The outflow rate gradually stops while gradually decreasing. When this switching is completed, the inflow port 13b and the inflow / outflow port 13c of the switching cylinder device 13 in the first flow path switching mechanism 6A are connected to supply high-pressure concentrated seawater from the membrane separation device 5 to the first cylinder device 9A. At the same time, the communication between the outflow / inflow port 13c and the outflow port 13a is blocked, and the pressure feeding process of the first cylinder device 9A is started.

  At this time, when the second piston 8B of the second cylinder device 9B still in the pumping process moves further to the other end side (in the direction of the broken arrow) and reaches the position of the second position detector S2, the second A detection signal is transmitted from the position detector S2 to the control unit main body C1. When the control unit main body C1 receives this detection signal, a switching signal is transmitted from the control unit main body C1 to the second switching valve 17B that switches the hydraulic flow path of the drive cylinder device 14 in the second flow path switching mechanism 6B. The hydraulic flow path of the valve 17B is switched.

  When the hydraulic flow path of the second switching valve 17B is switched, the drive cylinder device 14 in the second flow path switching mechanism 6B is driven and the drain side piston 21a and the supply side piston 21b of the switching cylinder device 13 are on the other end side ( The movement starts on the upper side of the drawing. At the start of movement, the inflow / outflow port 13c of the switching cylinder device 13 in the second flow path switching mechanism 6B is fully open, and high-pressure concentrated seawater flows from the membrane separation device 5 into the second cylinder device 9B at a constant flow rate. ing. When the drain side piston 21a moves to the other end side (above the paper surface) at a predetermined constant speed and reaches a predetermined position Q1b before the communication between the outflow port 13c and the outflow port 13a starts, the second flow path The driving speed of the hydraulic piston 24 is reduced by reducing the flow rate of the hydraulic pressure that drives the hydraulic piston 24 of the drive cylinder device 14 in the switching mechanism 6B.

As the hydraulic piston 24 decelerates, the moving speed of the drain side piston 21a of the switching cylinder device 13 in the second flow path switching mechanism 6B is decelerated, the inflow / outflow port 13c is gently opened, and the outflow / ingress port 13c and the outflow port 13a. And the filling process of the second cylinder device 9B is started.
As shown in FIG. 4, until the drain side piston 21a reaches the position Q2b from the predetermined position Q1b, the hydraulic piston 24 moves in a decelerated state, so that the outflow / inflow port 13c and the outflow port 13a are The high pressure residual pressure that is gently communicated and held in the second cylinder device 9B is gradually released. Therefore, the concentrated seawater does not blow out at a stretch, and the impact sound at the start of the filling process can be prevented.

  When the drain side piston 21a reaches the predetermined position Q2b, the hydraulic flow rate for driving the hydraulic piston 24 of the drive cylinder device 14 returns to the flow rate before deceleration, and the drive speed of the hydraulic piston 24 is increased to the predetermined speed. The As the hydraulic piston 24 increases in speed, the drain side piston 21a of the switching cylinder device 13 in the second flow path switching mechanism 6B is also increased to the speed before deceleration, the inflow / outlet port 13c is fully opened, and the concentrated seawater has a constant flow rate. Is discharged to the drain pipe 19.

  Next, operations of the drive cylinder device 14 and the switching cylinder device 13 will be described with reference to FIGS. 5 and 6.

  FIG. 5A shows a state when the first cylinder device 9A or the second cylinder device 9B is in the filling process, and the concentrated seawater is discharged with the inflow / outflow port 13c fully opened. FIG. 5 (b) shows a state immediately before the filling process is completed when the inflow / outflow port 13c of the first cylinder device 9A or the second cylinder device 9B approaches full closure. 5 (c), the filling process of the first cylinder device 9A or the second cylinder device 9B is completed, the communication between the outflow port 13a and the outflow / inflow port 13c is blocked, and the outflow / inflow port 13c and the inflow port 13b is in communication with the first cylinder device 9A or the second cylinder device 9B when the pressure feeding process is started. FIG. 5D shows a state in which the first cylinder device 9A or the second cylinder device 9B is in the pressure feeding process, and the inflow / outlet port 13c is fully open and the concentrated seawater is inflowing.

  FIG. 6 (e) shows a state immediately before the pumping process is completed when the inflow / outflow port 13c of the first cylinder device 9A or the second cylinder device 9B approaches full closure. 6 (f), the pumping process of the first cylinder device 9A or the second cylinder device 9B is completed, the outflow port 13a and the outflow / inflow port 13c are communicated, and the outflow / inflow port 13c and the inflow port 13b Is cut off and the filling process of the first cylinder device 9A or the second cylinder device 9B is started. 6 (g) returns to the state of FIG. 5 (a), the first cylinder device 9A or the second cylinder device 9B is in the filling process, and the inflow / outflow port 13c is fully opened to discharge the concentrated seawater. It is the state when it is being performed.

  First, as shown in FIG. 5A, the hydraulic piston 24 is moved to the other end side (right end portion of the paper) of the hydraulic piston chamber 26c by the pressure oil flowing in from the second pressure oil outlet 23d of the drive cylinder device 14. Moved and stopped. At this time, the drain side piston 21a of the switching cylinder device 13 is located between the inflow / outflow port 13c and the inflow port 13b, and the inflow / outflow port 13c is fully opened, and the first cylinder device 9A or the second Concentrated seawater is discharged from the cylinder device 9B.

  From this state, when a flow path switching signal (detection signal) is transmitted to the first switching valve 17A or the second switching valve 17B, the hydraulic flow path is switched, and the pressure oil is discharged from the first pressure oil outlet 23a of the drive cylinder device 14. The hydraulic piston 24 is pressed by the pressure oil and starts moving in the hydraulic piston chamber 26c to one end side (leftward in the drawing). At the same time, the drain side piston 21a and the supply side piston 21b of the switching cylinder device 13 are also turned on. Start moving to one end (left side of the page).

  Due to the movement of the hydraulic piston 24 toward one end (leftward in the drawing), the pressure oil in the hydraulic piston chamber 26c and the second hydraulic chamber 26b flows out from the second pressure oil outlet 23d to the outside. The movement speed of the hydraulic piston 24 is appropriately adjusted according to the flow rate of the pressure oil, and moves at a constant speed according to the flow rate of the pressure oil. As shown in FIGS. 3 and 4, the pressure oil flow rate for adjusting the moving speed of the hydraulic piston 24 toward one end side (leftward in the drawing) is the first hydraulic pipe 15A connected to the second pressure oil outlet 23d or This is performed by a pipe flow rate adjusting valve 35 provided in the second hydraulic pipe 15B.

  Next, as shown in FIG. 5B, the hydraulic piston 24 moves to one end side (leftward in the drawing) at a constant speed, and the first projecting portion 27a and the first shaft projecting portion 25a and the second When reaching the position where the protrusion 27b and the second shaft protrusion 25b start to face each other, the pressure oil can no longer flow in the first hydraulic chamber 26a, and thus the pair of first pressures from the third pressure oil outlet 23b. The hydraulic pipe 29a, the first check valve 30a, and a part thereof again flow into the first hydraulic chamber 26a from the fourth pressure oil outlet / inlet 23c through the first flow rate adjusting valve 31a and press the hydraulic piston 24.

  On the other hand, since the pressure oil in the hydraulic piston chamber 26c and the second hydraulic chamber 26b on the second hydraulic chamber 26b side cannot flow in the second hydraulic chamber 26b, the pressure oil from the fifth pressure oil outlet 23e. The second hydraulic pipe 29b enters the second hydraulic chamber 26b through the pipe line provided with the second flow rate adjustment valve 31b and the pair of second hydraulic pipes 29b, and enters the second hydraulic oil outlet 26d to the outside. To leak. The second flow rate adjusting valve 31b is set so that the flow rate of the hydraulic piston 24 can be reduced so as to be smaller than the pressure oil flow rate when the second projecting portion 27b and the second shaft projecting portion 25b are not opposed to each other. An appropriate pressure oil flow rate is set.

  When the second projecting portion 27b and the second shaft projecting portion 25b of the drive cylinder device 14 reach a position where they face each other, the first cylinder device 9A or the second cylinder device 9B is immediately before the end of the filling process, and the switching cylinder A part of the inflow / outflow port 13c of the device 13 is opened to discharge concentrated seawater. From this point of time, the moving speed of the hydraulic piston 24 is decelerated, and at the same time, the moving speed of the drain side piston 21a is decelerated, and the flow rate of the concentrated seawater flowing out from the inflow / outflow port 13c gradually decreases.

  Next, as shown in FIG. 5C, the hydraulic piston 24 is decelerated and further moved to one end side (left direction in the drawing), and the opposing of the second projecting portion 27b and the second shaft projecting portion 25b is released. Then, the pressure oil in the hydraulic piston chamber 26c and the second hydraulic chamber 26b flows through the second hydraulic chamber 26b to the outside from the second pressure oil outlet 23d, and the pressure oil flow rate Is restored to the initial flow rate, and the moving speed of the hydraulic piston 24 returns to the speed before deceleration. At this time, the inflow / outflow port 13c and the inflow port 13b are connected, and the high-pressure concentrated seawater flows into the first cylinder device 9A or the second cylinder device 9B.

  Next, as shown in FIG. 5 (d), the hydraulic piston 24 is moved to one end portion (the left end portion in the drawing) of the hydraulic piston chamber 26c by the pressure oil flowing in from the first pressure oil outflow inlet 23a of the drive cylinder device 14. Moved and stopped. At this time, the drain side piston 21a of the switching cylinder device 13 is located between the outflow / inflow port 13c and the outflow port 13a, and the outflow / inflow port 13c is fully opened, and the first cylinder device 9A or the second Concentrated seawater of high-pressure concentrated seawater flows into the cylinder device 9B.

  In this state, when a flow path switching signal (detection signal) is transmitted to the first switching valve 17A or the second switching valve 17B, the hydraulic flow path is switched, and the pressure oil is discharged from the second pressure oil inlet / outlet 23d of the drive cylinder device 14. The hydraulic piston 24 is pressed by the pressure oil and starts moving in the hydraulic piston chamber 26c to the other end side (to the right in the drawing). At the same time, the drain side piston 21a and the supply side piston 21b of the switching cylinder device 13 are used. Also starts moving to the other end side (to the right in the drawing).

  Due to the movement of the hydraulic piston 24 to the other end side (the right direction in the drawing), the pressure oil in the hydraulic piston chamber 26c and the first hydraulic chamber 26a flows out from the first pressure oil outflow inlet 23a. The moving speed of the hydraulic piston 24 is appropriately adjusted according to the flow rate of the pressure oil, and moves at a constant speed according to the flow rate of the pressure oil. The pressure oil flow rate for adjusting the moving speed of the hydraulic piston 24 to the other end side (the right direction in the drawing) is provided in the first hydraulic pipe 15A or the second hydraulic pipe 15B connected to the first pressure oil outflow inlet 23a. This is performed by the pipe flow rate adjustment valve 35.

  Next, as shown in FIG. 6E, the hydraulic piston 24 moves to the other end side (to the right in the drawing) at a constant speed, and the first projecting portion 27a and the first shaft projecting portion 25a When the two projecting portions 27b and the second shaft projecting portion 25b reach positions where they face each other, the pressure oil can no longer flow through the second hydraulic chamber 26b. The pipe 29b, the second check valve 30b, and a part thereof again flow into the second hydraulic chamber 26b from the fifth pressure oil outlet 23e through the second flow rate adjusting valve 31b, and press the hydraulic piston 24.

  On the other hand, since the pressure oil in the hydraulic piston chamber 26c and the first hydraulic chamber 26a on the first hydraulic chamber 26a side cannot flow in the first hydraulic chamber 26a, the pressure oil from the fourth pressure oil outflow inlet 23c. The first hydraulic pipe 29a enters the first hydraulic chamber 26a through the first hydraulic pipe 29a through the pipe line provided with the first flow rate adjusting valve 31a and the first hydraulic oil outlet 29a to the outside. leak. The first flow rate adjusting valve 31a is set so that the flow rate of the hydraulic piston 24 can be reduced so as to be smaller than the pressure oil flow rate when the first projecting portion 27a and the second shaft projecting portion 25b are not opposed to each other. An appropriate pressure oil flow rate is set.

  When the first projecting portion 27a and the first shaft projecting portion 25a of the drive cylinder device 14 reach a position where they face each other, the first cylinder device 9A or the second cylinder device 9B is immediately before the end of the pressure feeding process, and the switching cylinder A part of the inflow / outflow port 13c of the apparatus 13 is opened, and high-pressure concentrated seawater flows in. From this point of time, the moving speed of the hydraulic piston 24 is decelerated, and at the same time, the moving speed of the drain side piston 21a is decelerated to shift from a gentle blockage of the inflow / outflow port 13c to a gentle opening.

Next, as shown in FIG. 6 (f), the hydraulic piston 24 is decelerated and further moved to the other end side (to the right in the drawing), so that the first protrusion 27a and the first shaft protrusion 25a face each other. When released, the pressure oil in the hydraulic piston chamber 26c and the first hydraulic chamber 26a passes through the first hydraulic chamber 26a and flows out from the first pressure oil outlet 23a to the outside. The flow rate is restored to the initial flow rate, and the moving speed of the hydraulic piston 24 returns to the speed before deceleration. At this time, the inflow / outflow port 13c and the outflow port 13a communicate with each other, and the concentrated seawater is discharged from the first cylinder device 9A or the second cylinder device 9B.
Next, as shown in FIG. 6G, the hydraulic piston 24 is moved to the other end of the hydraulic piston chamber 26c by the pressure oil flowing in from the second pressure oil inflow / outflow port 23d of the drive cylinder device 14 (the right end of the drawing). To stop and return to the state of FIG.

  In the above-described operation, the disposition position and the axial length of the first protrusion 27a and the first axial protrusion 25a, and the disposition position and the axial length of the second protrusion 27b and the second axial protrusion 25b. By changing the length, the deceleration start position of the hydraulic piston 24 and the movement distance of the hydraulic piston 24 in the decelerated state can be changed. Moreover, the moving speed of the hydraulic piston 24 can be arbitrarily set by adjusting the flow rates of the first flow rate adjusting valve 31a and the second flow rate adjusting valve 31b. That is, the deceleration speed, deceleration start position, and deceleration release position of the drain side piston 21a of the switching cylinder device 13 can be set as appropriate.

Accordingly, since the communication between the inflow / outflow port 13c and the outflow port 13a at the start of the filling process can be performed gently, the residual pressure in the first cylinder device 9A and the second cylinder device 9B can be gradually released. Moreover, since the inflow / outflow port 13c and the outflow port 13a can be gently shut off at the end of the filling process, the discharge of the concentrated seawater can be stopped while gradually decreasing.
In the present embodiment, the distance _{L 1} between the first protrusion 27a and the first shaft protrusion 25a, while the distance _{L 2} between the second protrusion 27b and the second shaft protruding portion 25b are equal, _{L 1} and it is also possible to L ₂ and sets the position of the differently projections.

  As described above, in the energy recovery device 1 of the present embodiment, the control unit C decelerates the moving speed of the drain side piston 21a when the one end of the first cylinder device 9A or the second cylinder device 9B and the drain pipe 19 are communicated. Thus, the communication is started gently, and when the communication between the one end of the first cylinder device 9A or the second cylinder device 9B and the drain pipe 19 is interrupted, the moving speed of the drain side piston 21a is reduced to make the communication gently. Since it is cut off, the residual pressure in the cylinder device is gently released when communicating with the drain pipe 19 and the discharge flow rate from the cylinder device is gently reduced when shutting off, so that the impact sound from the water hammer is generated. Can be prevented.

  Further, the control unit C includes a pressure oil adjusting mechanism 18 that adjusts the flow rate of pressure oil in the drive cylinder device 14, and the control unit main body C1 controls the first switching valve 17A and the second switching valve 17B based on the detection signal. Since the driving cylinder device 14 is operated under control, the pressure oil flow rate in the driving cylinder device 14 that is switched by the switching valve is adjusted by the pressure oil adjusting mechanism 18 to reduce the moving speed of the piston of the driving cylinder device 14. Can be made.

  Further, the pressure oil adjusting mechanism 18 includes a pair of first hydraulic pipes 29a, a pair of second hydraulic pipes 29b, a first check valve 30a and a first flow rate adjusting valve 31a, a second check valve 30b and a second check valve. 2 Since the flow rate adjusting valve 31b is provided, when the first projecting portion 27a and the first shaft projecting portion 25a reach a position where they face each other, the second projecting portion 27b and the second shaft projecting portion 25b When reaching a position where they start to face each other, the pressure oil can no longer flow into the first hydraulic chamber 26a or the second hydraulic chamber 26b, and a part thereof passes through the first flow rate adjustment valve 31a or the second flow rate adjustment valve 31b. A pair of first hydraulic pipe 29a or second hydraulic pipe 29b flows into the hydraulic chamber. Therefore, the state in which the first protrusion 27a and the first shaft protrusion 25a are not opposed to each other, and the state in which the second protrusion 27b and the second shaft protrusion 25b are not opposite to each other. By setting the pressure oil flow rate of the first flow rate adjustment valve 31a or the second flow rate adjustment valve 31b so as to be smaller than the pressure oil flow rate in the hydraulic chamber, the moving speed of the hydraulic piston is reduced.

  Next, 2nd and 3rd embodiment of the energy recovery apparatus in this invention is described based on FIG.7 and FIG.8. In the following description of each embodiment, the same constituent elements described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the adjustment port 13d of the switching cylinder 20 is formed, whereas in the energy recovery device of the second embodiment, FIG. As shown in FIG. 3, the switching piston rod 122 has a communication hole 122a between the one end of the drain side piston 21a and the other end of the supply side piston 21b. The first cylinder chamber 223a on one end side is in communication with the second cylinder chamber 223b on the other end side.

  In the first embodiment, the hydraulic piston 24, the first hydraulic piston rod 25A, and the second hydraulic piston rod 25B, which are separate members, are joined by bolts, whereas in the energy recovery device of the second embodiment, The hydraulic piston 24 is different from the first hydraulic piston rod 25 </ b> A and the second hydraulic piston rod 25 </ b> B in that the hydraulic piston 24 is integrally formed as a hydraulic piston rod 125.

In the switching cylinder, the other end side from the supply side piston 221b is a first cylinder chamber 223a, and the one end side from the drain side piston 221a is a second cylinder chamber 223b.
The communication hole 122a has one end opened to the end surface of the drain side piston 21a and the other end opened to the outer surface of the switching piston rod 122 inside the supply side piston 221b. The supply-side piston 221b is formed in a cylindrical shape whose one end is closed in order to secure a space for opening the communication hole 122a.

  In the second embodiment, when the first cylinder device 9A is in the filling process and the inflow / outflow port 13c is fully open and the concentrated seawater is being discharged, the hydraulic piston 24 moves to one end side (leftward in the drawing). The drain side piston 21a and the supply side piston 221b of the switching cylinder device 13 also move to one end side (leftward in the drawing). At this time, the second cylinder chamber 223b is reduced, and the same amount of concentrated seawater as the reduced capacity is generated. Since the two cylinder chambers 223b flow into the first cylinder chamber 223a through the communication hole 122a, the movement of the drain side piston 21a and the supply side piston 221b is not hindered.

On the other hand, when the drain side piston 21a and the supply side piston 221b move to the other end side (to the right in the drawing), the first cylinder chamber 223a is reduced, and the same amount of concentrated seawater as the reduced capacity is stored in the first cylinder. Since the chamber 223a is discharged to the second cylinder chamber 223b through the communication hole 122a, the movement of the drain side piston 21a and the supply side piston 221b is not hindered.
That is, the communication hole 122a can perform the same function as the adjustment port of the first embodiment.

  Thus, in the energy recovery device of the second embodiment, the switching piston rod 122, the switching piston rod, the one end side (second cylinder chamber 223b) of the drain side piston 21a and the other end side of the supply side piston 221b. Since the communication hole 122a communicated with the (first cylinder chamber 223a) is formed, the installation space for the adjustment port becomes unnecessary, and the cylinder length can be shortened accordingly. Also, piping associated with the adjustment port is not necessary, and the flow path switching mechanism can be made compact.

  Furthermore, since the hydraulic piston 24, the first hydraulic piston rod 25A and the second hydraulic piston rod 25B are integrally formed, the number of parts can be reduced and the device can be easily manufactured. In particular, when the outer diameter of the hydraulic piston 24 is small, it becomes easy to integrally form the hydraulic piston 24, the first hydraulic piston rod 25A, and the second hydraulic piston rod 25B by machining.

  Next, the difference between the third embodiment and the first embodiment is that, in the first embodiment, the first shaft projection portion 25a and the second shaft projection portion 25b are the first hydraulic piston rod 25A and the second hydraulic piston rod. On the other hand, in the energy recovery device of the third embodiment, the first shaft protrusion 325a and the second shaft protrusion 325b are installed so as to be movable in the axial direction as shown in FIG. It is a point.

  That is, in the third embodiment, the first male screw groove 301a is formed on the outer peripheral surface on the other end side of the first hydraulic piston rod 325A, and the second male screw groove 301b is formed on the outer peripheral surface on one end side of the second hydraulic piston rod 325B. Is formed. The first shaft projection 325a is an annular member, the first shaft projection 325a is fitted into the first male screw groove 301a, the second shaft projection 325b is an annular member, and the second male screw The second shaft protrusion 325b is fitted in the groove 301b.

A first step portion 325c is provided near the center of the first hydraulic piston rod 325A, and a first male thread groove portion 301a is formed from the first step portion 325c to the tip portion. The first nut 326a is screwed into the first hydraulic piston rod 325A up to the first stepped portion 325c to restrict the movement of the first nut 326a toward the hydraulic piston 24, and the first shaft protrusion member 325a is also moved to the first nut 326a. It is inserted to the position where it contacts.
The first shaft protrusion member 325a is cylindrical and has an outer diameter larger than the maximum outer diameter of the first nut 326a. The first shaft protrusion member 325a is restricted from rotating around the axis and moving in the axial direction by the first nut 326a and the second nut 327a. The arrangement position of the first shaft projection member 325a can be easily set to a desired position by moving the first nut 326a and the second nut 327a to the other end side of the first hydraulic piston rod 325A.

A second step 325d is provided near the center of the second hydraulic piston rod 325B, and a second male screw groove 301b is provided from the second step 325d toward the tip. The vicinity of the tip of the second hydraulic piston rod 325B is formed with a smaller diameter than the portion where the second male thread groove 301b is provided, and a thread groove is formed for connection to the switching piston rod 22 of the switching cylinder device 13 (not shown). Has been.
In the second hydraulic piston rod 325B, a third nut 326b is screwed to the second stepped portion 325d to restrict the movement of the third nut 326b toward the hydraulic piston 24, and the second shaft projection member 325b is third. It is inserted to the position where it abuts on the nut 326b.
The second shaft projection member 325b is cylindrical and has an outer diameter larger than the maximum outer diameter of the third nut 326b. The second shaft protrusion member 325b is restricted from rotating around the axis and moving in the axial direction by the third nut 326b and the fourth nut 327b. The disposition position of the second shaft projection member 325b can be set to a desired position by moving the third nut 326b and the fourth nut 327b to the tip side of the second hydraulic piston rod 325B.

As described above, in the energy recovery device according to the third embodiment, the first shaft protrusion 325a is an annular member and is fitted in the first male screw groove 301a, and the first nut 326a and the second nut 327a The rotation around the axis of the one-axis protrusion 325a and the movement in the axial direction are restricted, the second axis protrusion 325b is an annular member, and is fitted into the second male screw groove 301b, and the third nut 326b. And the fourth nut 327b restrict the rotation of the second shaft projection 325b around the axis and the movement in the axial direction, so that the arrangement positions of the first shaft projection 325a and the second shaft projection 325b are It can be easily changed, and the deceleration start position of the hydraulic piston 24 and the movement distance of the hydraulic piston 24 in the decelerated state can be easily changed.
In the third embodiment, the first shaft protrusion and the second shaft protrusion are each formed by an annular member, and these annular members are fitted into the male thread groove portion of the hydraulic piston rod, and the shafts are respectively connected by two nuts. Although it is configured to restrict rotation and movement in the axial direction, an annular member with an internal thread groove formed inside is screwed into the external thread groove of the hydraulic piston rod and further to a position where it comes into contact with the annular member A nut can be screwed in to restrict rotation around the axis and movement in the axial direction.

  In addition, this invention is not limited to said each embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  DESCRIPTION OF SYMBOLS 1 ... Energy recovery apparatus, 2a ... Supply pipe, 2b ... Water supply pipe, 3 ... Fresh water pipe, 4 ... Concentrated water pipe, 5 ... Membrane separator, 6A ... 1st flow-path switching mechanism, 6B ... 2nd flow-path switching mechanism, 7A ... 1st cylinder, 7B ... 2nd cylinder, 9A ... 1st cylinder device, 9B ... 2nd cylinder device, 10 ... Pressure-intensifying means, 11 ... Flow path direction control mechanism, 13, 213 ... Switching cylinder device, 13a ... Outlet port, 13b ... Inlet port, 13c ... Outlet / inlet port, 13d ... Adjustment port, 14 ... Drive cylinder device, 15A ... First hydraulic pipe, 15B ... Second hydraulic pipe, 16 ... Hydraulic pump (hydraulic power source), 17A DESCRIPTION OF SYMBOLS 1st switching valve, 17B ... 2nd switching valve, 18 ... Pressure oil adjustment mechanism, 19 ... Concentrated seawater drain pipe, 20 ... Switching cylinder, 21a ... Drain side piston, 21b, 221b ... Supply side piston, 22, 122 ... for switching Stone rod, 23 ... hydraulic cylinder, 23a ... first pressure oil outflow inlet, 23d ... second pressure oil outflow inlet, 24 ... hydraulic piston, 25,125 ... hydraulic piston rod, 25A ... first hydraulic piston rod, 25B ... first 2 hydraulic piston rods, 25a, 325a ... 1st shaft projection, 25b, 325b ... 2nd shaft projection, 26a ... 1st hydraulic chamber, 26b ... 2nd hydraulic chamber, 27a ... 1st projection, 27b ... 2nd Projection, 29a ... first hydraulic pipe, 29b ... second hydraulic pipe, 30a ... first check valve, 30b ... second check valve, 31a ... first flow rate adjustment valve, 31b ... second flow rate adjustment valve, 122a ... Communication hole, 301a ... first male screw groove, 301b ... second male screw groove, 326a ... first nut, 327a ... second nut, 326b ... third nut, 327b ... fourth nut, C ... control unit, C1 ... control Body, 1 ... the first position detector, S2 ... second position detector

Claims (7)

An energy recovery device connected to a membrane separator for separating high-pressure seawater into fresh water and concentrated seawater with a reverse osmosis membrane and discharging the fresh water into a fresh water pipe and discharging the high-pressure concentrated seawater into the concentrated water pipe,
One end is connected to the concentrated water pipe and the drain pipe through a first flow path switching mechanism that performs communication with and shuts off the concentrated water pipe and communicates with and shuts off the concentrated sea water drain pipe. A first cylinder device having a first piston that reciprocates in one cylinder;
One end is connected to the concentrated water pipe and the drain pipe through a second flow path switching mechanism that communicates with and shuts off the concentrated water pipe and communicates with and shuts off the drain pipe. A second cylinder device having a second piston that reciprocates;
The first flow path switching mechanism and the second flow path switching mechanism are controlled to switch the connection between the first cylinder device and the second cylinder device to the concentrated water pipe and the drain pipe, and the high-pressure concentrated seawater is supplied. A control unit having a control function of alternately flowing into the first cylinder device and the second cylinder device and a control function of alternately discharging the concentrated seawater from the first cylinder device and the second cylinder device;
The other end of the first cylinder device and the other end of the second cylinder device are connected to supply seawater alternately to the first cylinder device and the second cylinder device, and the first cylinder device and the A flow path direction regulating mechanism for returning the seawater alternately pushed out from the second cylinder device at a high pressure to the membrane separation device via a pressure increasing means,
The first flow path switching mechanism and the second flow path switching mechanism are configured to supply and stop the concentrated seawater to the first cylinder apparatus or the second cylinder apparatus, and to stop the first cylinder apparatus or the second cylinder apparatus. A switching cylinder device for switching between discharging and stopping the concentrated seawater from
The switching cylinder device is reciprocally moved in the switching cylinder, the switching cylinder connected to one end of the first cylinder device or the second cylinder device, the drain pipe, and the concentrated water pipe, and the first cylinder apparatus. One end of a cylinder device or the second cylinder device and a drain side piston capable of communicating with and blocking the drain pipe and the concentrated water pipe, and the control unit controls the first flow path switching mechanism. When the one end of the first cylinder device and the drain pipe communicate with each other, the moving speed of the drain side piston is reduced to start communication gently, and the one end of the first cylinder device and the drain pipe are connected to each other. When the communication is cut off, the moving speed of the drain side piston is reduced to gently cut off the communication, and the second flow path switching mechanism is controlled so that one end of the second cylinder device and the drainage are controlled. When the communication is established, the movement speed of the drain-side piston is reduced to slowly start communication, and when the communication between one end of the second cylinder device and the drain pipe is interrupted, the movement of the drain-side piston An energy recovery device characterized in that the communication is gently cut off by reducing the speed. The energy recovery device according to claim 1,
The control unit is provided in the first cylinder and the second cylinder and detects that the first piston or the second piston has reached the vicinity of the other end of the corresponding first cylinder or the second cylinder. With a position detector
An energy recovery apparatus that controls the first flow path switching mechanism and the second flow path switching mechanism based on detection signals of the pair of position detectors. The energy recovery device according to claim 2,
The first flow path switching mechanism and the second flow path switching mechanism include a drive cylinder device that drives the switching cylinder device;
The controller supplies pressure oil to the drive cylinder device of the first flow path switching mechanism via a first hydraulic pipe, and also supplies the drive cylinder device of the second flow path switching mechanism to the drive cylinder apparatus via a second hydraulic pipe. A hydraulic pressure source for supplying pressure oil, a first switching valve connected to the first hydraulic piping, a second switching valve connected to the second hydraulic piping, the first switching valve and the second switching valve. A control unit main body for controlling the valve, and a pressure oil adjusting mechanism for adjusting a pressure oil flow rate in the drive cylinder device,
The energy recovery device, wherein the control unit body controls the first switching valve and the second switching valve based on the detection signal to operate the drive cylinder device. The energy recovery device according to claim 3,
The first hydraulic pipe and the second hydraulic pipe are connected to the first inflow / outflow pipe and the second inflow / outflow pipe which are switched through the connected first switching valve or the second switching valve. Branched,
The switching cylinder device includes a supply-side piston that reciprocates integrally with the drainage-side piston in the switching cylinder, the drainage-side piston at one end, and the supply-side piston at an intermediate portion. A switching piston rod having the other end protruding outside from the other end of the switching cylinder,
The drive cylinder device includes a hydraulic cylinder having a first pressure oil outlet / inlet connected to the first inlet / outlet pipe and a second pressure oil outlet / inlet connected to the second inlet / outlet pipe; A hydraulic piston that reciprocates in a cylinder, and a hydraulic piston rod that is provided with an intermediate portion and has one end connected to the other end of the switching piston rod.
The hydraulic cylinder has a first hydraulic chamber on the other end side with respect to the hydraulic piston, a second hydraulic chamber on one end side, and a first protrusion protruding into the first hydraulic chamber, and the second A second protrusion protruding into the hydraulic chamber,
The hydraulic piston rod is located on the other end side of the hydraulic piston, and closes the first hydraulic chamber on the other end side from the first projection portion when facing the first projection portion during reciprocation. A shaft protrusion and a second shaft protrusion that is located on one end side of the hydraulic piston and closes the second hydraulic chamber on the one end side of the second protrusion when facing the second protrusion during reciprocation. And
The pressure oil adjusting mechanism includes a pair of first hydraulic pipes having one end connected to the first hydraulic chamber with the first protrusion interposed therebetween, and one end sandwiching the second protrusion from the second hydraulic chamber. A pair of connected second hydraulic pipes, a first check valve and a first flow rate adjusting valve connected in parallel to each other at the other end of the pair of first hydraulic pipes and communicating the pair of first hydraulic pipes; A second check valve and a second flow rate adjustment valve connected in parallel to each other on the other end side of the pair of second hydraulic pipes and communicating with the pair of second hydraulic pipes,
The switching cylinder is connected to the drain pipe and provided at one end, an inflow port connected to the concentrated water pipe and provided in an intermediate portion, and the first cylinder device or the second cylinder device. An inflow / outflow port connected and provided between the outflow port and the inflow port;
When the drain side piston closes the inflow / outflow port, the first protrusion and the first shaft protrusion are set at positions facing each other, and the second protrusion and the second shaft protrusion. Are set at positions facing each other,
The first check valve can flow only in the direction from the first hydraulic pipe on the other end side of the first protrusion to the first hydraulic pipe on one end side, and the second check valve An energy recovery device characterized in that it can flow only in the direction from the second hydraulic pipe on one end side of the second protrusion to the second hydraulic pipe on the other end side. The energy recovery device according to claim 4,
An energy recovery device, wherein the switching piston rod is formed with a communication hole that communicates one end side and the other end side in the switching cylinder. In the energy recovery device according to claim 4 or 5,
The energy recovery apparatus, wherein the hydraulic piston and the hydraulic piston rod are integrally formed. In the energy recovery device according to any one of claims 4 to 6,
A first male thread groove is formed on the outer peripheral surface on the other end side of the hydraulic piston rod, and a second male thread groove is formed on the outer peripheral surface on the one end side,
The first shaft protrusion is an annular member, and the first shaft protrusion is fitted into the first male screw groove and fixed with a nut screwed into the first male screw groove. The rotation around the axis and the movement in the axial direction are restricted,
The second shaft projecting portion is an annular member, and the second shaft projecting portion is fitted into the second male thread groove portion, and the second shaft projecting portion is fixed with a nut threaded into the second male thread groove portion. The energy recovery device is characterized in that the rotation around the axis and the movement in the axial direction are restricted.

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