JP2012096151A - Seawater desalination system and energy exchange chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seawater desalination system, capable of reducing mixing of condensed seawater with seawater in an energy exchange chamber while solving the problem of abrasion of a slide member by constituting the energy exchange chamber in a piston-free form.SOLUTION: The seawater desalination system for producing fresh water from seawater by passing seawater pressurized by a pump to a reverse osmosis membrane separation device 4 to separate the seawater into fresh water and condensed seawater includes the energy exchange chamber 20 wherein the pressure energy of the condensed seawater discharged from the reverse osmosis membrane separation device 4 is used as energy for pressurizing part of the seawater. The energy exchange chamber 20 includes a condensed seawater port P1 letting the condensed seawater in and out, a seawater port P2 letting the seawater in and out, and a plurality of sectioned channels R provided inside the chamber to communicate the condensed seawater port P1 with the seawater port P2. The plurality of sectioned channels R have the same sectional area and the same shape, and no fluid flows in other parts than the channels.

Description

  The present invention relates to a seawater desalination system for desalinating seawater by removing salt from seawater, and an energy exchange chamber suitably used in the seawater desalination system (seawater desalination plant).

  Conventionally, as a system for desalinating seawater, a seawater desalination system is known in which seawater is passed through a reverse osmosis membrane separator and desalted. In this seawater desalination system, the collected seawater is adjusted to a constant water quality condition by a pretreatment device, and then pressurized by a high-pressure pump and pumped to a reverse osmosis membrane separation device. A part of the high-pressure seawater is taken out as fresh water from which the salt content has been removed by overcoming the reverse osmosis pressure and passing through the reverse osmosis membrane. The other seawater is discharged as reject (concentrated seawater) from the reverse osmosis membrane separation device in a state where the salinity is increased and concentrated. Here, the maximum operating cost (electric power cost) in the seawater desalination system greatly depends on the energy for raising the pretreated seawater to a pressure that can overcome the osmotic pressure, that is, the reverse osmotic pressure, that is, the pressurized energy by the high-pressure pump. To do.

  That is, more than half of the power cost, which is the maximum operating cost in a seawater desalination plant, is often spent on pressurization by a high-pressure pump. Therefore, the pressure energy possessed by the high salinity and high pressure reject (concentrated seawater) discharged from the reverse osmosis membrane separator is used as energy for boosting a part of the seawater. Then, as a means for using the pressure energy of the concentrated seawater discharged from the reverse osmosis membrane separation device as energy for boosting a part of the seawater, the inside of the cylinder is circulated by a piston movably fitted in the cylinder. An energy exchange chamber is used, which is divided into two volume chambers and provided with a concentrated seawater port for entering and exiting concentrated seawater in one of the two separated spaces, and a seawater port for entering and exiting seawater on the other. ing.

  FIG. 22 is a schematic diagram showing a configuration example of a conventional seawater desalination system. As shown in FIG. 22, seawater taken by a water intake pump (not shown) is pretreated by a pretreatment device and adjusted to a predetermined water quality condition, and then a motor M is directly connected via a seawater supply line 1. Supplied to the high-pressure pump 2. Seawater pressurized by the high-pressure pump 2 is supplied to the reverse osmosis membrane separation device 4 via the discharge line 3. The reverse osmosis membrane separation device 4 obtains fresh water from seawater by separating seawater into concentrated seawater having a high salinity concentration and fresh water having a low salinity concentration. At this time, concentrated seawater with a high salinity is discharged from the reverse osmosis membrane separation device 4, but this concentrated seawater still has a high pressure. A concentrated seawater line 5 for discharging concentrated seawater from the reverse osmosis membrane separation device 4 is connected to a concentrated seawater port P1 of the energy exchange chamber 10 via a direction switching valve 6. A seawater supply line 1 for supplying pre-processed low-pressure seawater branches upstream of the high-pressure pump 2 and is connected to a seawater port P2 of the energy exchange chamber 10 via a valve 7. The energy exchange chamber 10 includes a piston 12 therein, and the piston 12 is fitted so as to be movable while separating the inside of the energy exchange chamber 10 into two volume chambers.

  The seawater pressurized using the pressure of the concentrated seawater in the energy exchange chamber 10 is supplied to the booster pump 8. Then, the booster pump 8 further increases the pressure of the seawater so that the pressure becomes the same level as the discharge line 3 of the high-pressure pump 2, and the pressurized seawater merges with the discharge line 3 of the high-pressure pump 2 via the valve 9 and reverses. The osmotic membrane separation device 4 is supplied.

  This type of seawater desalination system and energy exchange chamber are described in, for example, US Pat. No. 5,306,428, US Patent Publication No. 2006-0151033, and US Pat. No. 7,168,927.

  In the energy exchange chamber 10, in order to suck in the seawater from the seawater port P2, the direction switching valve 6 switches to the side of draining the concentrated seawater, the seawater flows into the energy exchange chamber 10 from the seawater port P2, and the piston 12 is concentrated seawater. Move to the port P1 side. In this state, the energy exchange chamber 10 is almost filled with seawater. And if the direction switching valve 6 switches to the side which supplies high pressure concentrated seawater to the energy exchange chamber 10, the piston 12 will move to the seawater port P2 side so that the seawater which flowed in the energy exchange chamber 10 may be pushed out, and seawater A valve 7 on the port P2 side supplies seawater to the booster pump 8 side.

  The valve 7 on the seawater port P2 side is composed of known fluid devices such as a check valve and a direction switching valve so that high pressure fluid flows to the booster pump 8 side and low pressure fluid flows to the energy exchange chamber 10.

  The booster pump 8 boosts the seawater boosted by the energy exchange chamber 10 to the same pressure as the high-pressure pump 2, and can therefore be driven with a small amount of energy. That is, the flow rate of seawater supplied to the reverse osmosis membrane separation device 4 is a flow rate obtained by adding the flow rates of seawater from the high-pressure pump 2 and the energy exchange chamber 10, and a large processing flow rate of the entire system can be obtained. Since the seawater from is pressurized using the energy of high-pressure concentrated seawater, the input energy of the entire system can be reduced. In other words, a system capable of reducing the capacity and driving energy of the high-pressure pump in order to obtain the same processing flow rate can be constructed.

  The conventional energy exchange chamber described above is appropriately selected in size and number depending on the volume (flow rate) to be processed in the seawater desalination system, but generally has a large diameter and long cylindrical shape. The piston is movably fitted while being separated into two volume chambers.

  FIG. 23 is a cross-sectional view showing a configuration example of a conventional energy exchange chamber 10. As shown in FIG. 23, the energy exchange chamber 10 includes a cylindrical cylinder 11, a piston 12 that reciprocates within the cylinder 11, and a flange 13 that closes both open ends of the cylinder 11. The flange 13 is fixed to the flange portion 11 f of the cylinder 11 with bolts 14 and nuts 15. The concentrated seawater port P <b> 1 is formed on one flange 13, and the seawater port P <b> 2 is formed on the other flange 13.

  Here, for the purpose of improving the slidability of the piston 12 with the cylinder inner wall, a sliding ring 16 is fitted on the cylindrical surface of the cylindrical piston 12. The sliding ring 16 is made of a material having low friction and excellent wear resistance. For example, an engineering plastic is selected. Since the piston 12 flows seawater into the chamber and pushes it out with the concentrated seawater, the piston 12 always reciprocates in the chamber. For this reason, even if the piston 12 is made of a material having excellent wear resistance, it will eventually wear out and need to be replaced. Further, since the piston 12 reciprocates in the chamber, it is difficult to grasp the wear state. When the sliding seal 16 is worn, the metal part of the piston 12 comes into direct contact with the metal part of the cylinder 11 and damages each member. In some cases, the chamber itself must be replaced.

  In addition, the inner diameter of the energy exchange chamber needs to be a uniform cylinder in accordance with the outer diameter of the piston (sliding seal outer diameter). Therefore, when the chamber is several meters long, it is difficult to process the inner diameter, and the chamber itself becomes a very expensive product.

US Pat. No. 5,306,428 US Patent Publication No. 2006-0151033 US Pat. No. 7,168,927

As described above, the conventional energy exchange chamber requires the piston to reciprocate in the chamber for suction and discharge of seawater, and the position of the piston in the chamber is between the concentrated seawater port side and the seawater port side. It was reciprocating.
For this reason, the piston in the conventional energy exchange chamber slides with the inner wall of the cylinder, and the sliding member of the piston wears, so that periodic replacement is necessary. In addition, the inner diameter of the long chamber needs to be accurately processed according to the outer shape of the piston, and the processing cost is very expensive.

The present inventors examined applying an energy exchange chamber without a piston to a seawater desalination system. In this energy exchange chamber, the interface between concentrated seawater and seawater moves in the chamber due to the pressure balance between the concentrated seawater and seawater.
The problem with this method is that the salinity of the intake seawater increases in the chamber due to the mixing of the concentrated seawater and seawater at the interface. As a result, when the so-called pressurized seawater pressurized in the chamber and seawater discharged from the high-pressure pump merge and are introduced into the reverse osmosis membrane separator, the salinity of the pressurized seawater increases. In addition to lowering the desalination rate of the reverse osmosis membrane, there are problems such as reducing the life of the reverse osmosis membrane and shortening the replacement cycle of the reverse osmosis membrane itself.

  The present invention has been made in view of the above circumstances, and an energy exchange chamber that pressurizes a part of seawater by pressure energy of concentrated seawater discharged from a reverse osmosis membrane separation device of a seawater desalination system has a form without a piston. This eliminates the problem of sliding member wear, does not require excessive machining accuracy in the chamber, and does not require long machining. It is an object of the present invention to provide an energy exchange chamber capable of suppressing mixing of concentrated seawater and seawater and a seawater desalination system including the energy exchange chamber.

  In order to achieve the above-mentioned object, the seawater desalination system of the present invention is a seawater desalination system in which seawater pressurized by a pump is passed through a reverse osmosis membrane separation device and separated into freshwater and concentrated seawater to produce freshwater from seawater. The energy exchange chamber includes an energy exchange chamber that uses the pressure energy of the concentrated seawater discharged from the reverse osmosis membrane separator as energy for boosting a part of the seawater, and the energy exchange chamber allows the concentrated seawater to enter and exit. A concentrated seawater port to perform, a seawater port to enter and exit the seawater, and a plurality of partitioned flow paths that are provided in a chamber and communicate with the concentrated seawater port and the seawater port. The flow paths have the same cross-sectional area and the same shape, and other portions are configured so that fluid does not flow. To.

According to the seawater desalination system of the present invention, the concentrated seawater that has flowed into the chamber from the concentrated seawater port and the seawater that has flowed into the chamber from the seawater port flow into a plurality of partitioned flow paths. Concentrated seawater and seawater come into contact with each other, but the vortex generated in the channel having a small channel cross-sectional area becomes a small vortex in the pipe, so that the interface between the concentrated seawater and the seawater is not disturbed without large diffusion. Since a plurality of channels with a small channel cross-sectional area gather together to form a large chamber, the interface between concentrated seawater and seawater is maintained in each channel, and the interface between concentrated seawater and seawater as a whole. In other words, the seawater can be pressurized and discharged by the concentrated seawater while the mixing of the concentrated seawater and the seawater is suppressed. In addition, since both are mixed at the boundary where the concentrated seawater and seawater are in contact with each other, the interface here is a boundary portion between the concentrated seawater and seawater and a region where the concentrated seawater and seawater are mixed at a predetermined ratio ( This region is a region having a predetermined volume.
According to the seawater desalination system of the present invention, the piston in the chamber is unnecessary, maintenance is not required, and the reliability of the system can be improved. In addition, since processing of the cylinder in the chamber becomes easy, the manufacture of the chamber becomes easy and inexpensive.

  According to the seawater desalination system of the present invention, a plurality of partitioned flow paths are formed in the chamber so as to have the same shape and the same cross-sectional area by tubes, honeycombs, lattices, etc. It does not flow. By comprising in this way, the flow resistance in all the division flow paths in a chamber can be made uniform, and the behavior of an interface can be made uniform.

In a preferred aspect of the present invention, a pipe holding the plurality of partitioned flow paths is provided, and the pipe is fitted into the energy exchange chamber.
According to the present invention, a pipe holding a plurality of divided flow paths can be attached to and detached from the chamber as a pipe having substantially the same diameter as the inner diameter of the chamber. Can be done. In addition, when mounting a flow path consisting of tubes, honeycombs, etc. in the chamber, the pipe mounted with the flow path is fitted into the chamber as a separate piece without applying processing, welding, or bonding to the chamber that is a pressure vessel. The configuration is simple and the assembly is easy.

In a preferred aspect of the present invention, the pipe is divided into a plurality of parts in the longitudinal direction.
According to the present invention, by dividing a pipe holding a plurality of partitioned flow paths into a plurality, it is possible to adopt a configuration in which the flow path in the pipe is also divided into a plurality of parts in the longitudinal direction. This makes it easier to manufacture tubes and honeycombs.

In a preferred aspect of the present invention, the pipe extends in a space without the plurality of partitioned flow paths in the energy exchange chamber.
According to the present invention, it is possible to install a rectifier or the like in the extended pipe by extending the pipe to a space without a plurality of partitioned flow paths.

In a preferred aspect of the present invention, the pipe is provided with a hole communicating the inner diameter side and the outer shape side.
According to the present invention, since the hole communicating the inner diameter side and the outer diameter side of the pipe functions as a pressure balance hole, even if a high internal pressure is applied to the pipe, the internal pressure of the pipe is released by releasing the internal pressure from the pressure balance hole. Can be made the same pressure, and the force acting on the pipe can be offset.

A preferred embodiment of the present invention includes at least one switching valve that includes a plurality of the energy exchange chambers and switches between supply of concentrated seawater to the concentrated seawater port and discharge of concentrated seawater from the concentrated seawater port in the plurality of energy exchange chambers. It is provided with.
According to the present invention, by providing at least two energy exchange chambers, the following operation modes can be taken.
1) High-pressure concentrated seawater is introduced into the first energy exchange chamber through a switching valve, and the seawater in the first energy exchange chamber is pressurized using the pressure of the concentrated seawater, and the pressurized seawater is converted into the first energy. Can be discharged from the exchange chamber. In parallel with this, seawater is introduced into the second energy exchange chamber, and at the same time, the concentrated seawater in the second energy exchange chamber is discharged through the switching valve.
2) High-pressure concentrated seawater is introduced into the second energy exchange chamber through the switching valve, and the seawater in the second energy exchange chamber is boosted using the pressure of the concentrated seawater, and the pressurized seawater is second energy. Can be discharged from the exchange chamber. In parallel with this, seawater is introduced into the first energy exchange chamber, and at the same time, the concentrated seawater in the first energy exchange chamber is discharged through the direction switching valve.
Therefore, according to the present invention, pressurized seawater can be discharged at all times, the discharge flow rate from the energy exchange chamber can be stabilized, and the supply of fresh water from the reverse osmosis membrane separation device can be stably performed. be able to.

In a preferred aspect of the present invention, the plurality of partitioned flow paths have the same cross-sectional area and the same shape, and the other portions are filled so that fluid does not enter.
According to the present invention, the filling process so that the fluid does not enter can be performed by an optical modeling method using a photocurable resin.

According to a preferred aspect of the present invention, the plurality of divided flow paths are divided into a plurality of parts in the longitudinal direction of the chamber, and the fluid is buried so that the fluid does not enter at each connection portion of the plurality of flow paths divided in the longitudinal direction. It is characterized in that positioning means is provided at the location. The positioning means includes, for example, a positioning pin and a positioning hole.
Even if the plurality of divided flow paths are divided into a plurality in the longitudinal direction of the chamber in this way, by providing positioning means, the flow paths can be formed without uneven flow cross-sectional areas and shapes on the divided surfaces. Can be configured. Thus, when a plurality of partitioned flow paths are put into the chamber, workability can be improved by inserting the divided flow paths into the chamber without inserting a member having the same length as the entire length of the chamber. Moreover, the flow path itself can be easily manufactured by dividing the flow path.

  The energy exchange chamber of the present invention is a seawater desalination system in which seawater pressurized by a pump is passed through a reverse osmosis membrane separator and separated into fresh water and concentrated seawater to produce fresh water from the seawater. An energy exchange chamber that uses the pressure energy of the discharged concentrated seawater as energy for boosting the seawater, the energy exchange chamber comprising a concentrated seawater port through which the concentrated seawater enters and exits, and seawater through which the seawater enters and exits And a plurality of partitioned flow paths that are provided in the chamber and communicate with the concentrated seawater port and the seawater port, and the plurality of partitioned flow paths have the same cross-sectional area and the same shape. And other portions are configured such that fluid does not flow.

According to the energy exchange chamber of the present invention, the concentrated seawater that has flowed into the chamber from the concentrated seawater port and the seawater that has flowed into the chamber from the seawater port flow into a plurality of partitioned flow paths. However, the vortex generated in the channel having a small channel cross-sectional area becomes a small vortex in the pipe, so that the interface between the concentrated seawater and the seawater is not disturbed without being largely diffused. Since a plurality of channels with a small channel cross-sectional area gather together to form a large chamber, the interface between concentrated seawater and seawater is maintained in each channel, and the interface between concentrated seawater and seawater as a whole. In other words, the seawater can be pressurized and discharged by the concentrated seawater while the mixing of the concentrated seawater and the seawater is suppressed.
According to the energy exchange chamber of the present invention, the piston in the chamber is not required, and maintenance is not required, so that the reliability of the system can be improved. In addition, since processing of the cylinder in the chamber becomes easy, the manufacture of the chamber becomes easy and inexpensive.

  According to the energy exchange chamber of the present invention, a plurality of partitioned flow paths having the same shape and the same cross-sectional area are formed in the chamber by tubes, honeycombs, lattices, and the like, and fluid flows in other portions. It is supposed not to. By comprising in this way, the flow resistance in all the division flow paths in a chamber can be made uniform, and the behavior of an interface can be made uniform.

In a preferred aspect of the energy exchange chamber of the present invention, the energy exchange chamber includes a pipe holding the plurality of partitioned flow paths, and the pipe is fitted into the energy exchange chamber.
According to the present invention, a pipe holding a plurality of divided flow paths can be attached to and detached from the chamber as a pipe having substantially the same diameter as the inner diameter of the chamber. Can be done. In addition, when mounting a flow path consisting of tubes, honeycombs, etc., the pipe mounted with the flow path is simply fitted into the chamber as a separate piece without processing, welding, or bonding to the pressure vessel. Well, the configuration is simple and the assembly is easy.

In a preferred aspect of the energy exchange chamber of the present invention, the pipe is divided into a plurality of parts in the longitudinal direction.
According to the present invention, by dividing a pipe holding a plurality of partitioned flow paths into a plurality of parts, it is possible to adopt a configuration in which the flow path in the pipe is also divided into a plurality of parts in the longitudinal direction. Becomes easy.

In a preferred aspect of the energy exchange chamber according to the present invention, the pipe extends in a space without the plurality of partitioned flow paths in the energy exchange chamber.
According to the present invention, it is possible to install a rectifier or the like in the extended pipe by extending the pipe to a space without a plurality of partitioned flow paths.

In a preferred aspect of the energy exchange chamber of the present invention, the pipe is provided with a hole communicating the inner diameter side and the outer shape side.
According to the present invention, since the hole communicating the inner diameter side and the outer diameter side of the pipe functions as a pressure balance hole, even if a high internal pressure is applied to the pipe, the internal pressure of the pipe is released by releasing the internal pressure from the pressure balance hole. Can be made the same pressure, and the force acting on the pipe can be offset.

In a preferred aspect of the energy exchange chamber of the present invention, a rectifying means is provided between the concentrated seawater port and the plurality of partitioned flow paths.
According to the present invention, the concentrated seawater flowing into the chamber can be made to flow uniformly in the partitioned flow path, so that the interface between the concentrated seawater and seawater can be made uniform.
In a preferred aspect of the energy exchange chamber of the present invention, a rectifying means is provided between the seawater port and the plurality of partitioned flow paths.
According to the present invention, since the seawater flowing into the chamber can be made to flow uniformly in the partitioned flow path, the interface between the concentrated seawater and the seawater can be made uniform.

In a preferred aspect of the energy exchange chamber according to the present invention, the plurality of partitioned flow paths have the same cross-sectional area and the same shape, and the other portions are buried so that no fluid enters. Features.
According to the present invention, the process of filling so that no fluid enters can be performed by rapid prototyping.

In a preferred aspect of the energy exchange chamber according to the present invention, the plurality of divided flow paths are divided into a plurality of the longitudinal directions of the chamber, and the fluid does not enter at each connection portion of the plurality of flow paths divided in the longitudinal direction. Thus, a positioning means is provided in the buried portion. The positioning means includes, for example, a positioning pin and a positioning hole.
Even if the plurality of divided flow paths are divided into a plurality in the longitudinal direction of the chamber in this way, by providing positioning means, the flow paths can be formed without uneven flow cross-sectional areas and shapes on the divided surfaces. Can be configured. Thus, when a plurality of partitioned flow paths are put into the chamber, workability can be improved by inserting the divided flow paths into the chamber without inserting a member having the same length as the entire length of the chamber. Moreover, the flow path itself can be easily manufactured by dividing the flow path.

The present invention has the following effects.
1) Since there is no piston in the chamber, the problem of wear of the sliding member is solved, and no excessive machining accuracy is required for the chamber and long machining is not required. Therefore, the manufacturing cost of the chamber can be reduced.
2) Regardless of the form in which there is no piston in the chamber, mixing of concentrated seawater and seawater in the chamber is suppressed, and seawater can be pressurized with concentrated seawater while maintaining the interface between the concentrated seawater and seawater.
3) Mixing of concentrated seawater and seawater due to turbulent diffusion in the chamber can be suppressed, and high-concentration seawater is not sent to the reverse osmosis membrane separation device, so the performance of the reverse osmosis membrane separation device is fully demonstrated And the exchange cycle of the reverse osmosis membrane itself can be lengthened.
4) Since the plurality of partitioned flow paths in the chamber have the same cross-sectional area and the same shape, and fluid is not allowed to flow in other portions, in all the partitioned flow paths in the chamber The flow resistance can be made uniform and the interface behavior can be made uniform.
5) A pipe holding a plurality of divided flow paths can be attached to and detached from the chamber as a pipe having substantially the same diameter as the inner diameter of the chamber, so that the flow paths themselves made of tubes, honeycombs, etc. can be easily exchanged. it can. In addition, when mounting a flow path consisting of tubes, honeycombs, etc. in the chamber, the pipe mounted with the flow path is fitted into the chamber as a separate piece without applying processing, welding, or bonding to the chamber that is a pressure vessel. The configuration is simple and the assembly is easy.

FIG. 1 is a schematic diagram showing a configuration example of a seawater desalination system according to the present invention. FIG. 2 is a cross-sectional view showing a configuration example of the energy exchange chamber of the present invention. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a schematic cross-sectional view showing the state of the interface between concentrated seawater and seawater with and without a plurality of flow paths partitioned in the chamber. FIG. 5 is a diagram illustrating an example in which the cross-sectional area and the shape of the circular cross-section tube, the honeycomb-shaped flow path, and the lattice-shaped flow path are uniform. FIG. 6 is a perspective view showing a case where the flow path R shown in FIG. 5B is divided into a plurality in the longitudinal direction. FIG. 7 is a cross-sectional view showing an embodiment in which rectifying means is provided in the energy exchange chamber shown in FIG. FIG. 8 is a cross-sectional view showing an embodiment in which another rectifying means is provided in the energy exchange chamber. FIG. 9 is a perspective view of the rectifying means shown in FIG. FIG. 10 is a cross-sectional view showing an embodiment in which another rectifying means is provided in the energy exchange chamber. FIG. 11 is a plan view of the rectifying means shown in FIG. FIG. 12 is a schematic cross-sectional view showing a state of an interface between concentrated seawater and seawater in the embodiment shown in FIG. FIG. 13 is a schematic cross-sectional view showing an embodiment in which a concentrated seawater drain port is provided in an energy exchange chamber provided with four flow straightening means composed of a large number of flow paths and perforated plates formed of tubes shown in FIG. is there. FIG. 14 is a view showing a specific example when the rectifying means and the tube are installed in the cylinder in the energy exchange chamber of the present invention, and is a cross-sectional view of the energy exchange chamber. FIG. 15 is a view showing a specific example when the rectifying means and the tube are installed in the cylinder in the energy exchange chamber of the present invention, and is a perspective view showing the inside of the cylinder by removing substantially half of the cylinder. FIG. 16 is an enlarged view of a main part of FIG. FIG. 17 is an enlarged cross-sectional view of the portion XVII in FIG. FIG. 18 illustrates a directional control valve that switches between introduction of concentrated seawater into the energy exchange chamber and discharge of the concentrated seawater from the energy exchange chamber, and supply of intake seawater to the energy exchange chamber and discharge of intake seawater from the energy exchange chamber. It is the circuit diagram which showed the structure of the valve concretely. FIG. 19 is a schematic diagram showing a configuration example of a seawater desalination system including two energy exchange chambers of the present invention. 20 (a) and 20 (b) are schematic cross-sectional views showing the relationship between the direction switching valve and the two energy exchange chambers in the seawater desalination system shown in FIG. FIG. 21 is a schematic diagram showing a configuration example of a seawater desalination system including three energy exchange chambers of the present invention. FIG. 22 is a schematic diagram showing a configuration example of a conventional seawater desalination system. FIG. 23 is a cross-sectional view showing a configuration example of a conventional energy exchange chamber.

Hereinafter, an embodiment of a seawater desalination system according to the present invention will be described with reference to FIGS. 1 to 21. In FIG. 1 to FIG. 21, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a schematic diagram showing a configuration example of a seawater desalination system according to the present invention. As shown in FIG. 1, seawater taken by a water intake pump (not shown) is pretreated by a pretreatment device and adjusted to a predetermined water quality condition, and then a motor M is directly connected via a seawater supply line 1. Supplied to the high-pressure pump 2. Seawater pressurized by the high-pressure pump 2 is supplied to the reverse osmosis membrane separation device 4 via the discharge line 3. The reverse osmosis membrane separation device 4 obtains fresh water from seawater by separating seawater into concentrated seawater having a high salinity concentration and fresh water having a low salinity concentration. At this time, concentrated seawater with a high salinity is discharged from the reverse osmosis membrane separation device 4, but this concentrated seawater still has a high pressure. A concentrated seawater line 5 for discharging concentrated seawater from the reverse osmosis membrane separation device 4 is connected to a concentrated seawater port P1 of the energy exchange chamber 20 via a direction switching valve 6. A seawater supply line 1 for supplying pre-processed low-pressure seawater branches upstream of the high-pressure pump 2 and is connected to a seawater port P2 of the energy exchange chamber 20 via a valve 7. The energy exchange chamber 20 has a flow path defined between the concentrated seawater port P1 and the seawater port P2 in the chamber, and transmits energy while separating two fluids at the interface between the concentrated seawater and seawater. is there.

  Seawater that has been pressurized using the pressure of concentrated seawater in the energy exchange chamber 20 is supplied to the booster pump 8. Then, the booster pump 8 further increases the pressure of the seawater so that the pressure becomes the same level as the discharge line 3 of the high-pressure pump 2, and the pressurized seawater merges with the discharge line 3 of the high-pressure pump 2 via the valve 9 and reverses. The osmotic membrane separation device 4 is supplied. On the other hand, the concentrated seawater that has lost its energy by boosting the seawater is discharged from the energy exchange chamber 20 to the concentrated seawater discharge line 17 via the direction switching valve 6.

  FIG. 2 is a cross-sectional view showing a configuration example of the energy exchange chamber 20 of the present invention. As shown in FIG. 2, the energy exchange chamber 20 includes a long cylindrical cylinder 21 and a flange 23 that closes both open ends of the cylinder 21. The flange 23 is fixed to the flange portion 21 f of the cylinder 21 with bolts 14 and nuts 15. The concentrated seawater port P <b> 1 is formed on one flange 23, and the seawater port P <b> 2 is formed on the other flange 23. A large number of partitioned flow paths R extending in the longitudinal direction of the chamber formed in the cylinder 21 are formed in the cylinder 21. And the concentrated seawater port P1 and the seawater port P2 are connected by these flow paths R.

  3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 3, a plurality of small-diameter tubes 25 are disposed in a chamber formed in the cylinder 21. And the flow path R into which concentrated seawater and seawater flow in in each tube 25 is formed. Since each tube 25 consists of a small diameter tube, the flow-path cross-sectional area in a tube is set small. A method for forming the multiple flow paths R shown in FIG. 3 will be described later.

  Here, when there is no divided flow path, the concentrated seawater that has flowed from the concentrated seawater port P1 diffuses into the seawater sucked from the seawater port P2 and is mixed. In the case of sucking seawater from the seawater port P2, the seawater is similarly diffused in the concentrated seawater. This is because when each fluid flows in the chamber, it creates a vortex and diffuses greatly.

  According to the energy exchange chamber 20 of the present invention, the fluid sucked into the chamber flows into the channel R having a small channel cross-sectional area. At this time, the concentrated seawater and seawater come into contact with each other, but the vortex generated in the channel R having a small channel cross-sectional area becomes a small vortex in the pipe, so that the interface between the concentrated seawater and the seawater is not disturbed without large diffusion. . In this way, since a plurality of channels R having a small channel cross-sectional area are gathered to form a large chamber, the interface between the concentrated seawater and seawater is maintained in each channel R, and the interface between the concentrated seawater and seawater as a whole is maintained. While maintaining, that is, while suppressing the mixing of the concentrated seawater and seawater, the seawater can be pressurized and discharged by the concentrated seawater.

4 (a) and 4 (b) are diagrams showing a state of mixing when concentrated seawater flows into the chamber filled with seawater from the concentrated seawater port, and a plurality of compartments partitioned in the chamber It is typical sectional drawing which shows the state of the interface of the concentrated seawater and seawater with and without a flow path. FIG. 4 (a) shows the state of the interface between concentrated seawater and seawater when there is only a single flow path without a plurality of flow paths partitioned in the chamber, and FIG. 4 (b) shows the partition in the chamber. The state of the interface between concentrated seawater and seawater in the case where there are a plurality of flow paths R is shown.
4 (a) and 4 (b), the area indicated by A10 is an area of concentrated seawater 100% to 90%, and each area (A9 to A2) as it goes from the concentrated seawater port P1 to the seawater port P2. The concentration is 10% lower, and the area indicated by A1 is the area of 10% to 0% concentrated seawater. Also in the area indicated by A1, the concentration seawater is 10% in the vicinity of the boundary with the area A2 and the area A2, but in the area close to the seawater port P2, the concentration seawater is 0%, that is, the seawater is 100%. is there.

As shown in FIG. 4 (a), when there are no plural flow paths partitioned in the chamber, the concentrated seawater flowing from the concentrated seawater port P1 diffuses into the seawater sucked from the seawater port P2 and is mixed over a wide range. It will fit. In the case of sucking seawater from the seawater port P2, the seawater is similarly diffused in the concentrated seawater. This is because, as each fluid flows in the chamber, a vortex is created and diffused greatly as shown by the areas indicated by A9 to A2.
On the other hand, as shown in FIG. 4B, when there are a plurality of flow paths R partitioned in the chamber, each flow having a small flow path cross-sectional area in which the concentrated seawater is partitioned from the concentrated seawater port P1. The water flows into the path R, and the seawater flows into the flow paths R from the seawater port P2. At this time, the concentrated seawater and seawater come into contact with each other in each flow path R, but the vortex generated in the flow path R having a small flow path cross-sectional area becomes a small vortex in the pipe. The seawater interface I (area indicated by A9 to A2) is not disturbed.
That is, the area indicated by A10 in FIG. 4B is an area of concentrated seawater 100% to 90%, and the concentration decreases by 10% for each area from the concentrated seawater port P1 toward the seawater port P2. The indicated area is an area of 10% to 0% concentrated seawater. When viewed from the concentrated seawater port P1 toward the seawater port P2, the ratio of the concentrated seawater is 10% from the area A9 where the concentrated seawater adjacent to the area A10 is 90% to 80%, and the interface between the concentrated seawater and the seawater is This is a set of eight narrow belt-like regions ranging from a region A9 where the concentrated seawater is 90% to 80% to a region A2 where the concentrated seawater is 20% to 10%.
In this way, since a plurality of channels R having a small channel cross-sectional area are gathered to form a large chamber, the interface I between the concentrated seawater and seawater is maintained in each channel R, and the interface between the concentrated seawater and seawater is maintained as a whole. Thus, seawater can be pressurized and discharged by the concentrated seawater while suppressing mixing of the concentrated seawater and seawater.

  According to the present invention, as shown in FIG. 4 (b), even if the piston in the chamber is eliminated, the concentrated seawater and the seawater are almost bisected by providing a plurality of flow paths R partitioned in the chamber. Can exchange energy.

In such a configuration, the interface reciprocates through a plurality of divided flow paths, but it prevents the concentrated seawater from leaking into the seawater by mistake, and the input and discharge of seawater and concentrated seawater. In order to improve the controllability of the switching timing, it is desirable that the behavior of the interface is the same in all the flow paths.
The present applicant has previously proposed an energy exchange chamber 20 in which a number of tubes 25 having a circular cross section are arranged in the chamber in the cylinder 21 in the embodiment of FIG. 3 in Japanese Patent Application No. 2010-112803. In the form, the cross-sectional areas of the divided flow paths are greatly different in the space between the tubes 25 and the portion where the tube 25 cannot maintain a circular cross section at the outer diameter portion in the chamber. In addition, in the embodiment of FIG. 5 of the same application, a configuration in which a honeycomb-like channel or a lattice-like channel is formed in the chamber in the cylinder 21 is proposed, but this configuration is also disconnected at the outer diameter portion in the chamber. Compartmental channels with greatly different areas and shapes are created.
As described above, in the divided flow paths having greatly different cross-sectional areas and shapes, the flow resistance is different from the other divided flow paths, and the interface behavior may be different. If the behavior of the interface does not coincide with other flow paths, the controllability is reduced, and there is a possibility that the concentrated seawater is mixed into the seawater supplied to the reverse osmosis membrane (RO).

In the embodiment shown in FIG. 5, the cross-sectional areas and shapes of the circular cross-section tube, honeycomb-shaped flow path, and lattice-shaped flow path shown in FIG. 3 and FIG. It eliminates the drawbacks.
In the example shown in FIG. 5A, a plurality of small diameter tubes 25 are arranged in a chamber formed in the cylinder 21. A flow path R into which the concentrated seawater and seawater flow is formed in each tube 25. And the part (shaded part) where the tube cannot maintain a circular cross section at the outer diameter part in the chamber is formed solid by filling the resin or the like so that fluid cannot flow in.
In the example shown in FIG. 5B, a plurality of honeycomb-shaped flow paths R are formed by providing partitions 26 in a chamber formed in the cylinder 21. And the part (shaded part) where the honeycomb cannot maintain the hexagonal cross section in the outer diameter part in the chamber is formed solid by filling the resin or the like so that the fluid cannot flow in.
In the example shown in FIG. 5C, a partition 26 is provided in a chamber formed in the cylinder 21 to form a plurality of lattice-shaped flow paths R. And the part (hatched part) where the lattice part cannot maintain the square cross section at the outer diameter part in the chamber is formed solid by filling the resin or the like so that the fluid cannot flow in.

As shown in FIGS. 5A, 5B, and 5C, a plurality of partitioned flow paths R are formed in the chamber so as to have the same shape and the same cross-sectional area by tubes, honeycombs, lattices, and the like. The other parts are buried so that the fluid does not flow. By comprising in this way, the flow resistance of all the division flow paths R in a chamber can be made uniform, and the behavior of an interface can be made uniform.
Further, by forming a large number of flow paths R, the vortex generated in each flow path R becomes a small vortex in the pipe, so that the interface between the concentrated seawater and the seawater is not disturbed without greatly diffusing. In this way, since a plurality of channels R having a small channel cross-sectional area are gathered to form a large chamber, the interface between the concentrated seawater and seawater is maintained in each channel R, and the interface between the concentrated seawater and seawater as a whole is maintained. While maintaining, that is, while suppressing the mixing of the concentrated seawater and seawater, the seawater can be pressurized and discharged by the concentrated seawater. 5 (a), (b), and (c), the diameter of the tube and the distance between two opposing sides of the honeycomb or lattice are preferably about 5 to 10 mm.
Forms as shown in FIGS. 5A, 5B, and 5C can be manufactured by rapid prototyping such as stereolithography and powder method. The optical modeling method is a modeling method in which a photo-curing resin that is cured when exposed to light is used and light is selectively applied to the photo-curing resin and selectively cured. The powder method is a method in which powdery materials are spread in layers and irradiated with a laser, and the portions irradiated with the laser are selectively sintered and bonded.
It is also possible to manufacture an actual product by molding using a member formed by rapid prototyping as a mold. Since an actual product uses seawater, a resin material is desirable, and epoxy, silicon, ABS, PEEK, and the like are appropriately selected.

FIG. 6 shows that a plurality of honeycomb-shaped flow paths R are formed in the chamber shown in FIG. 5 (b), a portion where the honeycomb cannot maintain a hexagonal shape is filled with resin at the outer diameter portion in the chamber, and the length of the chamber is further increased. It is a perspective view which shows the case where the flow path R is divided | segmented into plurality in the direction.
As shown in FIG. 6, when the flow path R is divided in the longitudinal direction of the chamber and accommodated in the chamber, the hexagonal honeycombs on both end faces cannot be maintained so that the divided flow path does not shift over the entire length of the chamber. A positioning hole 61 is formed in the outer diameter portion. When the divided flow paths are accommodated in the chamber, the positioning pins 60 are inserted into the positioning holes 61 and assembled so that the pins 60 enter the holes 61, so that the partitioned flow paths are not displaced. Fits over the entire length.
Even when the plurality of divided flow paths R are divided in the longitudinal direction of the chamber in this way, the flow path cross-sectional area and shape are reduced on the divided surfaces by providing the positioning pins 60 and the positioning holes 61. The flow path can be configured without becoming non-uniform. Thus, when a plurality of partitioned flow paths are put into the chamber, workability can be improved by inserting the divided flow paths into the chamber without inserting a member having the same length as the entire length of the chamber. Moreover, the flow path itself can be easily manufactured by dividing the flow path.

  FIG. 7 is a cross-sectional view showing an embodiment in which rectifying means is provided in the energy exchange chamber 20 shown in FIG. As shown in FIG. 7, spaces S1 and S2 are provided between the concentrated seawater port P1 and the seawater port P2 and the flow path R, and rectifying means 27 and 27 for rectifying the fluid when flowing into the spaces S1 and S2 are provided. Provided. The rectifying means 27 is formed of a conical rectifying plate that expands in a trumpet shape from a small-diameter port toward a large-diameter chamber cylindrical portion.

FIG. 8 is a cross-sectional view showing an embodiment in which another rectifying means is provided in the energy exchange chamber 20. In addition, the energy exchange chamber 20 shown in FIG. 8 has a larger inner diameter of the chamber than the diameter of the concentrated seawater port P1 and the seawater port P2 as compared to the energy exchange chamber 20 in FIG.
In the embodiment shown in FIG. 8, rectifying means 28 and 28 having a shape in which a conical shape that expands from the inflow side and further contracts at the bottom surface are provided at the center of the spaces S1 and S2 in the chamber. The fluid supplied to the central part of the chamber by the rectifying means 28 once spreads outward and then shrinks inward again, so that the flow from the small-diameter port can be made to flow uniformly to each partitioned flow path in the chamber. .
The conical rectifying plate expanding in a trumpet shape from the small-diameter port described in FIG. 7 toward the large-diameter chamber inner cylindrical portion has a relatively small ratio between the port inner diameter and the chamber inner diameter, that is, from the port to the chamber. Although effective when the expansion width is small, as shown in FIG. 8, when the ratio of the port inner diameter to the chamber inner diameter is large, that is, when the expansion width from the port to the chamber is large, the rectifying means 28 of this embodiment is It is valid.

  FIG. 9 is a perspective view of the rectifying means 28 shown in FIG. As shown in FIG. 9, the rectifying means 28 has a shape in which a cone 28a that expands from the left side to the right side and a cone 28b that contracts from the left side to the right side are combined on the bottom surface. . In order to hold the rectifying means 28 in the center of the chamber, a plurality of support plates 28c are attached to the conical member, and these support plates 28c are fixed to the inner wall of the chamber.

  As shown in FIGS. 7 to 9, the interface between the concentrated seawater and the seawater bisects one space in the chamber by rectifying the flow flowing into the chamber so as to flow evenly into each flow path R. Can do. The direction of flow is changed by the direction switching valve or the valve, and the interface between the concentrated seawater and the seawater reciprocates between the concentrated seawater port P1 and the seawater port P2.

  FIG. 10 is a cross-sectional view showing a configuration of an energy exchange chamber 20 in still another embodiment of the present invention. In the embodiment shown in FIG. 10, another rectifying means is provided. Spaces S1 and S2 are provided between the concentrated seawater port P1 and the flow path R and between the seawater port P2 and the flow path R, and rectifiers 29a, 29b, and 29c that rectify the fluid when flowing into the spaces S1 and S2. , 29d.

FIG. 11 is a plan view of the rectifying means shown in FIG. As shown in FIG. 11, the rectifying means 29a (29b, 29c, 29d) is composed of a porous plate in which a large number of holes 29h are formed in a disk-shaped member. The perforated plates are spaced apart from the ports P1 and P2 by a predetermined distance, and the adjacent perforated plates are spaced apart from each other by a predetermined distance. The perforated plate is disposed so as to be separated from the end of the partitioned flow path by a predetermined distance.
This embodiment shown in FIG. 10 is also effective when the ratio of the chamber inner diameter to the inflow port inner diameter is large. As described above, by arranging the perforated plate, the flow flowing in from the small-diameter ports P1 and P2 can be uniformly dispersed in the large-diameter chamber so as to flow uniformly in a plurality of partitioned flow paths.

The perforated plate shown in FIG. 11 uses a punching plate in which a large number of holes 29h are formed in a disk-shaped member. The punching plate can calculate the porosity with respect to the total area of the plate according to the hole diameter and the pitch between holes. The porosity is selected so that the porous plate does not cause a large pressure loss and has a good rectifying action.
Further, the rectifying means 29a, 29b (or 29c, 29d) using two perforated plates provided on one port side may have different hole diameters and porosity.

  FIG. 12 is a view showing a state of mixing when the concentrated seawater flows from the concentrated seawater port P1 into the energy exchange chamber 20 filled with seawater in the embodiment shown in FIG. 10, and the interface between the concentrated seawater and seawater. It is a typical sectional view showing the state. In FIG. 12, the area indicated by A10 is an area of 100% to 90% concentrated seawater, the concentration decreases by 10% for each area from the concentrated seawater port P1 toward the seawater port P2, and the area indicated by A1 is It is a region of 10% to 0% concentrated seawater. When viewed from the concentrated seawater port P1 toward the seawater port P2, the ratio of the concentrated seawater is 10% from the area A9 where the concentrated seawater adjacent to the area A10 is 90% to 80%, and the interface between the concentrated seawater and the seawater is This is a set of eight narrow belt-like regions ranging from region A9 in which the concentrated seawater is 90% to 80% to region A2 in which the concentrated seawater is 20% to 10%.

  By using the perforated plate as the rectifying means 29a, 29b, 29c, 29d, even if the flow path expands from the small-diameter port to the large-diameter chamber, the interface I between the concentrated seawater and seawater has two ports in the chamber. It can be seen that the fluid is divided into two regions A10 and A1 between P1 and P2. When the concentrated seawater is further introduced from the concentrated seawater port P1, the interface I moves to the seawater port P2 side, and the seawater pressurized to the same pressure as the concentrated seawater is discharged from the seawater port P2. Next, seawater is sucked in from the seawater port P2, and the concentrated seawater is drained from the concentrated seawater port P1. At this time, the seawater rectified so as to uniformly flow into the chamber by the rectifying means 29c and 29d by the two perforated plates on the seawater port P2 side is similarly dispersed and flows into the plurality of partitioned flow paths R. The turbulent diffusion is suppressed by the flow path R, and the concentrated seawater is discharged while the mixing of the two fluids is minimized by the interface I.

FIG. 13 shows an embodiment in which a concentrated seawater drainage port is provided in an energy exchange chamber provided with four flow straightening means comprising a number of flow paths formed of tubes shown in FIG. 3 and a perforated plate shown in FIG. It is typical sectional drawing. In FIG. 13, the concentrated seawater drain port P3 is provided on the wall surface of the cylinder 21 between the narrow pipe on the concentrated seawater port P1 side and the rectifying means 29b by the perforated plate.
When the chamber sucks seawater, the concentrated seawater is drained from the concentrated seawater drainage port P3, and the fluid in the mixed area of the concentrated seawater and seawater is discharged from the concentrated seawater drainage port P3 before the rectifying means 29b. ing. That is, after the fluid in the mixed region is discharged before the rectifying means 29b, the concentrated seawater is supplied from the concentrated seawater supply port P1 when the seawater is pushed out again by the concentrated seawater. In this manner, a new interface is always formed by discharging the fluid in the mixing region from the chamber, and the mixing of the concentrated seawater and the seawater can be prevented from expanding due to the reciprocation of the interface.
It should be noted that, depending on the control, the time of the suction process may be increased once every several times of the suction / discharge cycle, and the fluid in the mixed region may be discharged from the concentrated seawater drain port P3.

FIG. 14 and FIG. 15 are diagrams showing specific examples when the rectifying means 29a, 29b, 29c, 29d and the tube 25 are installed in the cylinder 21 in the energy exchange chamber 20 of the present invention, and FIG. 15 is a cross-sectional view of the chamber 20, and FIG. 15 is a perspective view showing the inside of the cylinder 21 with substantially half of the cylinder 21 removed.
As shown in FIGS. 14 and 15, in the cylinder 21 of the energy exchange chamber 20, pipe PA, pipe PB, pipe PC, pipe PD, pipe PE, from the concentrated seawater port P1 side to the seawater port P2 side, The pipe PF, the pipe PE, the pipe PD, the pipe PC, the pipe PB, and the pipe PA are arranged in this order. These pipes PA to PF are used as members for fixing the rectifying means 29a to 29d and the tube 25 to the chamber. The pipe PA, the pipe PB, the pipe PC, the pipe PD, and the pipe PE are arranged symmetrically about the pipe PF. The rectifying means 29a is sandwiched between the pipe PB and the pipe PC, and the rectifying means 29b is sandwiched between the pipe PC and the pipe PD. The rectifying means 29c is sandwiched between the pipe PC and the pipe PD, and the rectifying means 29d is sandwiched between the pipe PB and the pipe PC.

FIG. 16 is an enlarged view of a main part of FIG. As shown in FIG. 16, the pipe PA, pipe PB, pipe PC, pipe PD, pipe PE, and pipe PF each have an uneven shape at the outer end portion in the axial direction. Mated and connected.
Here, the rectifying means 29a, 29b (29c, 29d) are installed so as to be sandwiched between the gaps of the uneven portion 55 between the pipe PB and the pipe PC and between the pipe PC and the pipe PD, and are fixed in the axial direction.

Moreover, as shown in FIG. 14, the flow path R formed of a tube is installed in the pipe PF and the two pipes PE.
In the example shown in FIG. 14, the flow path R formed of a tube is divided into three in the axial direction and installed in the chamber. The number of divisions of the flow path R, the length of each pipe in the axial direction, and the inner and outer diameters of each pipe are appropriately set according to the use conditions, and are not limited to the form shown in FIG. 14 (three divisions).
In addition, each pipe PA-PF is provided with the pressure balance hole 56 in one place or multiple places on the outer peripheral surface. The diameter of the pressure balance hole 56 and the number of the pressure balance hole 56 in the axial direction and the circumferential direction are appropriately set.

FIG. 17 is an enlarged cross-sectional view of the portion XVII in FIG. As shown in FIG. 17, a fixed washer 57 is provided at the end of the pipe PA. The fixed washer 57 has a shaft portion 57a, and the shaft portion 57a is fitted in a hole h formed at an end portion of the pipe PA. An O-ring 58 is installed between the fixed washer 57 and the end surface of the pipe PA.
The shaft portion 57a of the fixed washer 57 is movable in the axial direction within the hole h, and the depth of the hole h and the length of the shaft portion 57a are such that the fixed washer 57 can move by a desired distance in the axial direction. Is set to The fixed washer 57 is also installed in another pipe PA that is symmetrical to the pipe PA shown in FIG. 17 (see FIG. 14).
As shown in FIGS. 14 and 17, a fixed washer 57 that is movable in the axial direction by elastic deformation of the O-ring 58 is installed at the end of the pipe PA, and the fixed washer 57 is pressed by the flange 23, whereby the pipe PA ~ PF can be fixed axially in the chamber.

  FIG. 18 shows a directional control valve 6 for switching the introduction of concentrated seawater into the energy exchange chamber 20 and the discharge of the concentrated seawater from the energy exchange chamber 20, the supply of intake seawater to the energy exchange chamber 20, and the It is the circuit diagram which showed concretely the structure of the valve | bulb 7 for discharge | emission of intake water seawater. The direction switching valve 6 is a three-way valve having a supply port, a control port, and a return port, and is a control valve that can arbitrarily adjust the valve opening degree according to an external signal. The valve 7 is a check valve module including two check valves.

FIG. 19 is a schematic diagram showing a configuration example of a seawater desalination system including two energy exchange chambers of the present invention. Similar to the seawater desalination system shown in FIG. 1, high-pressure concentrated seawater from the reverse osmosis membrane separation device 4 is supplied to the direction switching valve 6. In the present embodiment, the direction switching valve 6 is a four-way valve having two output ports, supplying concentrated seawater to one of the two energy exchange chambers 20 and simultaneously concentrating from the other energy exchange chamber 20. Operates to drain seawater. The valve 7 provided in the seawater port P2 is the same as that described in FIGS.
In the present embodiment, by adopting a four-way valve as the direction switching valve 6, the concentrated seawater is alternately supplied to the two energy exchange chambers 20, and the seawater that has been alternately pressurized is discharged from the two energy exchange chambers 20. Therefore, the flow rate of fresh water obtained from the reverse osmosis membrane separation device 4 can be kept stable.

20 (a) and 20 (b) are schematic cross-sectional views showing the relationship between the direction switching valve and the two energy exchange chambers in the seawater desalination system shown in FIG. In FIG. 20A and FIG. 20B, in order to distinguish and explain the two energy exchange chambers, one chamber is indicated by 20A and the other chamber is indicated by 20B. As shown in FIGS. 20A and 20B, the direction switching valve 6 includes a housing 101, a spool 102, and a drive unit 103. The spool 102 is fitted into the housing 101, and the spool 102 is moved. Thus, the flow path is switched.
The direction switching valve 6 has one supply port P, two control ports A and B, and two return ports Q. In the direction switching valve 6 according to the present invention, the supply port P communicates with the concentrated seawater line 5, the two control ports A and B communicate with the energy exchange chambers 20 A and 20 B, respectively, and the return port Q communicates with the concentrated seawater discharge line 17. Communicating with

The function of this directional switching valve 6 is to introduce energy by alternately introducing high-pressure concentrated seawater from the reverse osmosis membrane separation device 4 supplied to the directional switching valve 6 into the energy exchange chambers 20A and 20B by the operation of the spool 102. The seawater in the exchange chambers 20A and 20B is discharged.
In the example of the direction switching valve 6 according to the embodiment shown in FIGS. 20A and 20B, the spool 102 has three lands, but the direction switching valve has one or more supply ports P, two control ports A. , B, two or more return ports Q are formed, and the supply port P communicates with one of the control ports A (or B) by the operation of the spool (switching of the flow path in the control valve). As long as the other control port B (or A) and the return port Q communicate with each other, the invention is not limited to the structure / form example of the drawing such as a rotary spool type.

Next, an example of direction switching by the operation of the spool 102 of the direction switching valve 6 will be described.
(A) FIG. 20A shows a case where the spool 102 operates in a direction in which the supply port P of the direction switching valve 6 and the control port A communicate with each other.
High-pressure concentrated seawater is introduced into the energy exchange chamber 20A (upper part in FIG. 20A) through the direction switching valve 6 (P port → A port).
The interface (interface between concentrated seawater and seawater) I in the energy exchange chamber 20A (upper in FIG. 20A) moves to the right in the figure.
Seawater introduced into the energy exchange chamber 20A through the valve 7 (see FIG. 19) is pressurized by the movement of the interface I, and the pressurized seawater is supplied to the booster pump 8 (see FIG. 19) through the valve 7.
At the same time, the control port B and the return port Q of the direction switching valve 6 communicate with each other, and the concentrated seawater that has lost the energy in the energy exchange chamber 20B and has become low pressure is discharged to the concentrated seawater discharge line 17 and the seawater supply. Seawater is introduced from the line 1 through the valve 7 into the energy exchange chamber 20B (below in FIG. 20A).

(B) FIG. 20B shows a case where the spool 102 operates in a direction in which the supply port P of the direction switching valve 6 and the control port B communicate with each other.
High-pressure concentrated seawater is introduced into the energy exchange chamber 20B (lower in FIG. 20B) through the direction switching valve 6 (P port → B port).
The interface I in the energy exchange chamber 20B (lower in FIG. 20B) moves to the right in the figure.
Seawater introduced into the energy exchange chamber 20B through the valve 7 (see FIG. 19) is pressurized by the movement of the interface I, and the pressurized seawater is supplied to the booster pump 8 (see FIG. 19) through the valve 7.
At the same time, the control port A and the return port Q of the direction switching valve 6 communicate with each other, and the concentrated seawater that has lost the energy in the energy exchange chamber 20A and has become low pressure is discharged to the concentrated seawater discharge line 17 and the seawater supply. Seawater is introduced from the line 1 through the valve 7 into the energy exchange chamber 20A (upper part in FIG. 20B).

  FIG. 21 is a schematic diagram showing a configuration example of a seawater desalination system including three energy exchange chambers of the present invention. In the present embodiment, the concentrated seawater port of each of the three energy exchange chambers 20, 20, 20 is provided with a direction switching valve 6, and the seawater port is provided with a valve 7. Shift the timing of entering and exiting the concentrated seawater and seawater in the three energy exchange chambers so that high-pressure seawater is discharged simultaneously from the two energy exchange chambers, and at the same time, the seawater is sucked into one energy exchange chamber. The direction switching valve 6 is controlled. In the case of the embodiment shown in FIG. 19 and FIG. 20 with two energy exchange chambers, the discharge flow rate for one chamber is obtained with two chambers in order to discharge seawater alternately from the two chambers. In contrast, in the present embodiment, by providing three energy exchange chambers, discharge flow rates for two chambers can be obtained.

  As shown in FIGS. 19 to 21, it is possible to configure a seawater desalination system by arranging a plurality of energy exchange chambers 20 according to the present invention, and to exchange energy according to the scale of the amount of water produced by the seawater desalination system. By increasing or decreasing the number of chambers 20, it is possible to cope with any amount of fresh water.

  In FIG. 21, the direction switching valve 6 installed in the concentrated seawater port of the energy exchange chamber 20 and the valve 7 installed in the seawater port of the energy exchange chamber 20 are not connected by piping, but are connected to the flange of the chamber. It is configured to be attached directly to. In this way, it is easy to increase the number of chambers, and it is possible to minimize loss due to the pipeline.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and needless to say, may be implemented in various forms within the scope of the technical idea. The form and the like of the energy exchange chamber are not limited to the illustrated examples described above, and it goes without saying that various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Seawater supply line 2 High pressure pump 3 Discharge line 4 Reverse osmosis membrane separator 5 Concentrated seawater line 6 Directional switching valve 7 Valve 8 Booster pump 9 Valve 10 Energy exchange chamber 11 Cylinder 11f Flange part 12 Piston 13 Flange 14 Bolt 15 Nut 16 Sliding Moving ring 17 Concentrated seawater discharge line 20 Energy exchange chamber 20A, 20B Energy exchange chamber 21 Cylinder 21f Flange 23 Flange 25 Tube 26 Partition 27, 28 Rectifying means 28a, 28b Conical 28c Support plates 29a, 29b, 29c, 29d Rectifying means 29h Hole in perforated plate 55 Concave portion 56 Pressure balance hole 57 Fixed washer 57a Shaft portion 58 O-ring 60 Positioning pin 61 Positioning hole 101 Housing 102 Sp 103 Drive unit A Control port B Control port I Interface P Supply port Q Return port R Channel A10 Area of concentrated seawater 100% to 90% A1 Area of concentrated seawater 10% to 0% A9 to A2 Concentrated seawater and seawater Region (interface)
P1 Concentrated seawater port P2 Seawater port P3 Concentrated seawater drainage port S1, S2 space

Claims (17)

In a seawater desalination system that generates fresh water from seawater by passing seawater pressurized by a pump through a reverse osmosis membrane separator and separating it into freshwater and concentrated seawater.
An energy exchange chamber that utilizes the pressure energy of the concentrated seawater discharged from the reverse osmosis membrane separator as energy for boosting a part of the seawater;
The energy exchange chamber is provided with a concentrated seawater port through which the concentrated seawater enters and exits, a seawater port through which the seawater enters and exits, and a plurality of compartments that are provided in the chamber and communicate with the concentrated seawater port and the seawater port. With a flow path,
The seawater desalination system, wherein the plurality of partitioned flow paths have the same cross-sectional area and the same shape, and fluid does not flow in other portions.   The seawater desalination system according to claim 1, further comprising a pipe that holds the plurality of partitioned flow paths, and the pipe is fitted in the energy exchange chamber.   The seawater desalination system according to claim 2, wherein the pipe is divided into a plurality of parts in the longitudinal direction.   4. The seawater desalination system according to claim 2, wherein the pipe extends in a space without the plurality of partitioned flow paths in the energy exchange chamber.   The seawater desalination system according to any one of claims 2 to 4, wherein the pipe is provided with a hole communicating the inner diameter side and the outer shape side.   A plurality of the energy exchange chambers, and at least one switching valve for switching between supply of concentrated seawater to the concentrated seawater port and discharge of concentrated seawater from the concentrated seawater port in the plurality of energy exchange chambers, The seawater desalination system according to any one of claims 1 to 5.   2. The seawater desalination according to claim 1, wherein the plurality of divided flow paths have the same cross-sectional area and the same shape, and the other portions are buried so that fluid does not enter. system.   The plurality of partitioned flow paths are divided into a plurality in the longitudinal direction of the chamber, and positioning means is provided at a place where the fluid is not filled in at each connection portion of the plurality of flow paths divided in the longitudinal direction. The seawater desalination system according to claim 7, wherein: Pressure energy of concentrated seawater discharged from the reverse osmosis membrane separator in a seawater desalination system that generates fresh water from seawater by passing seawater pressurized by a pump through the reverse osmosis membrane separator. An energy exchange chamber for using the seawater as energy for pressurization,
The energy exchange chamber is provided with a concentrated seawater port through which the concentrated seawater enters and exits, a seawater port through which the seawater enters and exits, and a plurality of compartments that are provided in the chamber and communicate with the concentrated seawater port and the seawater port. With a flow path,
The plurality of partitioned flow paths have the same cross-sectional area and the same shape, and fluid is not allowed to flow in other portions.   The energy exchange chamber according to claim 9, further comprising a pipe holding the plurality of partitioned flow paths, wherein the pipe is fitted in the energy exchange chamber.   The energy exchange chamber according to claim 10, wherein the pipe is divided into a plurality of parts in the longitudinal direction.   12. The energy exchange chamber according to claim 10 or 11, wherein the pipe is also extended in a space without the plurality of partitioned flow paths in the energy exchange chamber.   The energy exchange chamber according to any one of claims 10 to 12, wherein the pipe is provided with a hole communicating the inner diameter side and the outer shape side.   The energy exchange chamber according to claim 9, further comprising a rectification unit between the concentrated seawater port and the plurality of partitioned flow paths.   The energy exchange chamber according to claim 9, further comprising a rectification unit between the seawater port and the plurality of partitioned flow paths.   10. The energy exchange chamber according to claim 9, wherein the plurality of partitioned flow paths have the same cross-sectional area and the same shape, and the other portions are filled so as not to enter a fluid. .   The plurality of partitioned flow paths are divided into a plurality in the longitudinal direction of the chamber, and positioning means is provided at a place where the fluid is not filled in at each connection portion of the plurality of flow paths divided in the longitudinal direction. The energy exchange chamber according to claim 16.

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