WO2012086478A1

WO2012086478A1 - Reverse osmosis processing device

Info

Publication number: WO2012086478A1
Application number: PCT/JP2011/078859
Authority: WO
Inventors: 光太郎北村; 真人大西; 一隆鈴木
Original assignee: 株式会社日立プラントテクノロジー
Priority date: 2010-12-20
Filing date: 2011-12-14
Publication date: 2012-06-28
Also published as: CN103328077A; JP2012130839A

Abstract

This reverse osmosis processing device (10) is provided with: a pressurized vessel (24); an inlet tube (56) that supplies water to be processed to one end of the pressurized vessel (24); a concentrated water discharging tube (62) that discharges concentrated water to the other end of the pressurized vessel (24); a plurality of reverse osmosis membrane elements (22) disposed within the pressurized vessel (24) and provided with a reverse osmosis membrane; a water collecting piping (34) that connects the plurality of reverse osmosis membrane elements (22) in series within the pressurized vessel (24) and through which permeated water that has passed through the reverse osmosis membrane flows; a first discharge tube (58) that discharges the permeated water on the concentrated water discharging tube (62) side of the pressurized vessel (24); and a resistance piping (90) on the inlet tube (56) side within the water collection piping (34).

Description

Reverse osmosis processing equipment

The present invention relates to a reverse osmosis treatment apparatus, and more particularly to a reverse osmosis treatment apparatus that eliminates unevenness in the amount of permeated water between an element on the supply water side and an element on the concentrate side.

In a desalination treatment apparatus using a reverse osmosis membrane (hereinafter referred to as RO (Reverse Osmosis) membrane), a reverse osmosis pressure is utilized. Therefore, as shown in FIG. The RO membrane elements 222 are arranged in series, and each RO membrane element 222 is connected by a water collecting pipe 234 at the center of the RO membrane element 222. Supply water is supplied from one of the desalination treatment devices by a high-pressure pump, and the inside of the pressurized container 224 is pressurized by the opening degree of a valve installed on the concentrated water side. When the pressurized pressure exceeds the osmotic pressure of the supplied water, it passes through the RO membrane, and desalinated water (permeated water) flows into the central water collecting pipe 234.

The supply water supplied into the pressurized container 224 has a salt concentration that increases from the supply water side to the concentrated water side, so that the pressure in the pressurized container 224 finally becomes the final stage salt concentration and the amount of permeated water. The pressure to be pressurized is determined by the supply water flow velocity on the membrane surface. Accordingly, since the pressure on the supply water side in the pressurized container 224 is more than necessary, the amount of permeated water increases. For example, FIG. 14 shows the relationship between the position of the RO membrane element and the relative flux (relative flux) when seven RO membrane elements 222 are arranged in series. The element position in FIG. 14 is the number from the supply water side. As shown in FIG. 14, it can be seen that the amount of permeated water on the supply water side is large, and the amount of permeated water decreases as it goes to the concentrated water side. This is because the salt concentration of the treated water increases as it goes to the concentrated water side, so a high pressure is required on the concentrated water side, but the same pressure is also applied on the supply water side. This is because more permeated water is generated. In this way, as shown in FIG. 14, the amount of permeated water in the pressurized container 224 is non-uniform, so that necessary power increases and contamination of the RO membrane element on the supply water side proceeds.

In order to solve such a problem, for example, in Patent Document 1 below, a plurality of separation membrane elements are connected in series, and the collection membrane elements provided in the separation membrane elements from the raw water side toward the permeate water side. A membrane separation system is described in which the inner diameter of the water tube is increased. By increasing the inner diameter of the water collecting pipe, the pressure loss in the water collecting pipe can be easily set so that the permeation flux in the separation membrane element becomes equal. Thereby, the operating conditions of all the separation membrane elements can be made uniform regardless of the positions of the separation membrane elements.

JP 2000-167358 A

However, in the membrane separation system described in Patent Document 1, the inner diameter of the water collection pipe is set for each separation membrane element, and further fine adjustment has not been possible.

The present invention has been made in view of such circumstances, and by adjusting the inner diameter of the water collecting pipe in the pressure vessel at an arbitrary position, the non-uniformity in the amount of permeated water of each reverse osmosis membrane element is eliminated. An object of the present invention is to provide a reverse osmosis treatment apparatus capable of obtaining a desired amount of permeated water with less power.

In order to achieve the above object, the first aspect of the present invention is a reverse osmosis treatment apparatus, comprising a pressure vessel, an introduction pipe for supplying water to be treated to one end of the pressure vessel, and the pressure A concentrated water discharge pipe for discharging concentrated water to the other end of the container; and a plurality of reverse osmosis membrane elements provided in the pressure vessel and including a reverse osmosis membrane, wherein the reverse osmosis membrane element further includes A drainage pipe through which the permeated water that has passed through the reverse osmosis membrane flows, the drainage pipe connecting the plurality of reverse osmosis membrane elements in series within the pressure vessel, and discharging the concentrated water from the pressure vessel Provided is a reverse osmosis treatment device comprising: a first discharge pipe for discharging the permeated water on a pipe side; and a resistance pipe on the introduction pipe side in the water collection pipe.

The reverse osmosis treatment apparatus according to the first aspect includes a resistance pipe on the introduction pipe side for supplying the treated water in the water collection pipe of the reverse osmosis membrane element including the reverse osmosis membrane. By providing the resistance pipe, it is possible to reduce the inner diameter of the water collection pipe, so that the amount of permeated water on the introduction pipe side where the resistance pipe is provided can be reduced. Thereby, since the to-be-processed water by the side of concentrated water can increase a flow volume and can make salt concentration low, the amount of permeated water by the side of concentrated water can be increased. Thereby, the non-uniformity of the permeated water amount of the reverse osmosis membrane element can be suppressed compared to the conventional case, and the permeated water amount can be increased as a whole. Therefore, even if the pressure is lowered, the amount of permeated water can be increased, power saving can be achieved, the generation of extremely osmotic reverse osmosis membrane elements can be prevented, and long-term use can be achieved.

According to the second aspect, in the reverse osmosis treatment device according to the first aspect, the reverse osmosis membrane in which the opening ratio of the opening provided on the side surface of the resistance pipe is provided on the side surface of the water collection pipe. It is smaller than the aperture ratio of the through-hole through which the permeated water that has passed through.

In the reverse osmosis treatment apparatus according to the second aspect, since the opening ratio of the opening provided in the resistance pipe is made smaller than the opening ratio of the through hole provided in the water collecting pipe, the flow rate of the permeated water is suppressed. And non-uniformity in the amount of permeated water can be eliminated.

According to the third aspect, in the reverse osmosis treatment device according to the second aspect, the resistance pipe opens from the inlet pipe side of the water collection pipe to the first discharge pipe side, and the opening of the opening portion opens. The rate increases.

In the reverse osmosis treatment apparatus according to the third aspect, according to the third aspect, the opening ratio of the opening of the resistance pipe is increased as the water to be treated is moved from the introduction pipe side to the first discharge pipe side. . Therefore, even in the portion where the resistance pipe is provided, the amount of permeate on the introduction pipe side in the water collection pipe can be reduced and the amount of permeate on the first discharge pipe side can be increased. Can be eliminated.

According to the fourth aspect, in the reverse osmosis treatment device according to any one of the first to third aspects, the resistance pipe goes from the introduction pipe side of the water collection pipe to the first discharge pipe side. As the thickness of the resistance pipe decreases.

In the reverse osmosis treatment apparatus according to the fourth aspect, the thickness of the resistance pipe is reduced, that is, the inner diameter of the water collection pipe is increased from the treated water introduction pipe side to the first discharge pipe side. ing. Therefore, even in the portion where the resistance pipe is provided, the amount of permeated water on the inlet pipe side in the water collecting pipe can be reduced and the amount of permeated water on the first discharge pipe side can be increased. Unevenness can be eliminated.

According to the fifth aspect, in the reverse osmosis treatment device according to any one of the first to fourth aspects, the resistance pipe is formed by connecting a plurality of pipes.

In the reverse osmosis treatment apparatus according to the fifth aspect, since the resistance pipe is formed by connecting a plurality of pipes, it is possible to easily form a desired resistance pipe such as the opening ratio of the opening and the thickness of the pipe. it can.

According to the sixth aspect, the reverse osmosis treatment device according to any of the first to fifth aspects includes a front stage that is a supply side of the treated water and a discharge side of the concentrated water in the water collection pipe. In the latter stage, there are further provided a resistor for separating the permeated water, and a second discharge pipe for discharging the previous stage permeated water on the introduction pipe side.

In the reverse osmosis treatment device according to the sixth aspect, a resistor is provided in the water collecting pipe, and the permeate in the subsequent stage is discharged from both sides of the resistor through the first discharge pipe, and the front stage is discharged through the second discharge pipe. The permeated water is discharged. Therefore, since the permeated water can be generated at different flow rates between the front and rear stages of the resistor, the amount of permeated water can be reduced by suppressing the flow rate on the supply side of the water to be treated. Therefore, since the salt concentration on the concentrated water side can be lowered, the amount of permeated water can be increased, and unevenness in the amount of permeated water of the reverse osmosis membrane element can be suppressed.

According to a seventh aspect, in the reverse osmosis treatment device according to the sixth aspect, the resistor is provided at an end of the resistance pipe on the first discharge pipe side.

In the reverse osmosis treatment device according to the seventh aspect, by providing the resistor at the end of the resistance pipe on the first discharge pipe side, the resistance pipe can effectively exhibit the effect of reducing the flow rate of the permeated water. it can.

According to the eighth aspect, in the reverse osmosis treatment device according to the sixth or seventh aspect, the resistor is impermeable to water.

In the reverse osmosis treatment apparatus according to the eighth aspect, the water collecting pipe can be divided by the resistor, so that the pressure in the water collecting pipe can be controlled with the resistor as a boundary. Therefore, the amount of permeated water can be easily adjusted.

According to the ninth aspect, in the reverse osmosis treatment device according to the sixth or seventh aspect, the resistor is water permeable.

According to the tenth aspect, in the reverse osmosis treatment device according to the ninth aspect, the resistor is made of a porous material.

According to the eleventh aspect, in the reverse osmosis treatment device according to any of the sixth to tenth aspects, the resistor is formed with a slit through which permeated water passes.

In the reverse osmosis treatment device according to any of the ninth to eleventh aspects, by allowing the resistor to be water permeable, or providing a slit in the resistor, the permeated water can pass through the resistor, Since resistance can be given in the water collecting pipe, the amount of permeated water can be made equal.

According to the twelfth aspect, in the reverse osmosis treatment device according to any of the ninth to eleventh aspects, a plurality of the resistors are provided in the water collecting pipe.

In the reverse osmosis treatment device according to the twelfth aspect, by providing a plurality of resistors in the water collection pipe, the pressure in the water collection pipe can be adjusted more finely, so the non-uniformity in the amount of permeate is eliminated. be able to.

According to the present invention, the resistance pipe is used to reduce the inner diameter of the water collection pipe of the reverse osmosis membrane element or to close some of the through holes provided in the side surface of the water collection pipe, thereby Water resistance can be increased. Thereby, since the flow volume of the permeated water on the supply water side can be reduced, the salt concentration on the concentrated water side can be lowered, and the overall pressure of the reverse osmosis membrane element can be lowered. Therefore, since pressure can be effectively applied to the reverse osmosis membrane element to generate permeated water, labor can be saved and cost can be reduced.

It is a block diagram of the desalination processing system in which the reverse osmosis processing apparatus of embodiment was installed. It is the perspective view which showed the structure of the element of the reverse osmosis processing apparatus of embodiment. It is the front view of the element which showed the state before RO membrane of the element shown in FIG. 2 was wound. FIG. 3 is a front view of the element shown in FIG. 2. It is sectional drawing which shows schematic structure of the reverse osmosis processing apparatus of embodiment. It is the graph which showed the relationship between the position of RO membrane element of the reverse osmosis processing apparatus of embodiment, and the relative flux of permeated water. It is sectional drawing (longitudinal direction sectional drawing) which shows resistance piping in water collection piping. It is sectional drawing (radial direction sectional drawing) which shows resistance piping in water collection piping. It is sectional drawing which shows the example of the other resistance piping in water collection piping. It is sectional drawing which shows the example of other resistance piping in water collection piping. It is sectional drawing which shows schematic structure of the reverse osmosis processing apparatus of other embodiment. It is sectional drawing (the 1) which shows the resistor in water collection piping. It is sectional drawing (the 2) which shows the resistor in water collection piping. It is a front view which shows the resistor in water collection piping (the 1). It is a front view (the 2) which shows a resistor in water collection piping. It is a front view (the 3) showing a resistor in water collection piping. It is a front view (the 4) showing a resistor in water collection piping. It is sectional drawing which shows schematic structure of the conventional reverse osmosis processing apparatus. It is the graph which showed the relationship between the position of RO membrane element of the conventional reverse osmosis processing apparatus, and the relative flux of permeate.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described with reference to the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment can be utilized. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims.

FIG. 1 is a block diagram of a desalination treatment system 20 in which the reverse osmosis treatment apparatus 10 of the embodiment is incorporated. In addition, the desalination processing system in this invention can be used for the system which carries out reverse osmosis processing of to-be-processed water, such as drainage reuse, pure water manufacture, brine water desalination, seawater desalination, etc., for example.

The desalination treatment system 20 shown in the figure is composed of a tank 12 in which treated water is stored, a high-pressure pump 14, and a reverse osmosis treatment device 10. The water to be treated in the tank 12 is supplied to the reverse osmosis treatment device 10 by the high pressure pump 14 at a high pressure, and is subjected to reverse osmosis treatment (desalting treatment) by each RO membrane (treatment membrane) of the reverse osmosis treatment device 10. The water is separated into desalted permeated water (separated water) 16 and concentrated water (treated water) 18 in which the salt content is concentrated. The permeated water 16 thus obtained is discharged to the outside of the reverse osmosis treatment device 10 through a discharge pipe, and the concentrated water 18 is similarly discharged through a discharge pipe different from the discharge pipe for discharging the permeated water. It is discharged outside the reverse osmosis treatment apparatus 10. In addition, although the desalination processing system 20 of embodiment supplies the to-be-processed water to the reverse osmosis processing apparatus 10 with the high voltage | pressure pump 14 at high pressure, a valve is provided in the concentrated water outlet side of the reverse osmosis processing apparatus 10, The pressure in the reverse osmosis treatment apparatus 10 is set according to the opening of the valve.

As the water to be treated in the tank 12, raw water may be used as it is, but it is preferable to use water to be treated from which turbid components and the like contained in the raw water are removed by pretreatment. Pretreatment includes use of a filter and treatment such as introducing raw water into a sedimentation basin and adding a sterilizing agent such as chlorine to precipitate and remove particles in the raw water and sterilize microorganisms. In addition, water to be treated may be used by adding a flocculant such as iron chloride to raw water to agglomerate turbid components and filtering them off.

A plurality of elements 22 shown in FIG. 2 are connected in series, filled in the cylindrical vessel 24 shown in FIG. 5 to form a module 26, and this module 26 is connected singly or in parallel, thereby reverse osmosis. The processing device 10 is configured.

As shown in FIG. 2, the element 22 is configured by arranging a membrane unit 32 including an RO membrane 28 and a discharge pipe 30 around a water collection pipe 34. As shown in FIG. 3, the membrane unit 32 has four bag-

like RO membranes

28, 28... Radially connected to the outer periphery of the water collecting pipe 34. These RO membranes 28, 28. It is configured by winding in a spiral around the water collection pipe 34. One end of the bag-like RO membrane 28 is opened, and the RO membrane 28 is bonded to the water collection pipe 34 so that the opening communicates with the through hole 36 of the water collection pipe 34 shown in FIG. The water to be treated flows on the outer surface of the RO membrane 28 and passes through the RO membrane 28 to be desalted. Then, the desalted water that has passed through the RO membrane 28 is collected from the inside of the RO membrane 28 into the water collection pipe 34 through the opening of the RO membrane 28 and the through holes 36 of the water collection pipe 34. The water is discharged from the element 22 from the water collecting pipe 34 through the discharge pipe 30. 3 is a mesh spacer disposed inside the RO membrane 28. The spacer 38 holds the RO membrane 28 so that the inner space of the RO membrane 28 is not crushed even when the RO membrane 28 is wound in a spiral shape. Reference numeral 40 denotes a mesh spacer disposed between the

adjacent RO membranes

28 and 28. The spacers 40 are also radially bonded to the outer periphery of the water collecting pipe 34 in the same manner as the RO membrane 28.

FIG. 5 is a cross-sectional view of the reverse osmosis treatment apparatus 10 of the embodiment. Both ends of the vessel 24 are opened so that water to be treated is introduced and discharged. A predetermined operating pressure is applied by the high-pressure pump 14 at the opening on the introduction side. 5 shows a module 26 in which five

elements

22, 22... Are connected in series, the number of elements 22 is not limited to five. Further, the vessel 24 can be constituted by FRP (Fiber Reinforced Plastic) or the like so as to withstand high pressure (5 MPa or more).

As shown in FIG. 5, the vessel 24 includes an introduction pipe 56 that introduces the water to be treated into the vessel 24, and a concentrated water discharge pipe that discharges the concentrated water that has not been permeated to the water collection pipe 34. 62. A concentrated water discharge valve 64 that adjusts the pressure in the vessel 24 is provided at the outlet of the concentrated water discharge pipe 62. The permeated water collected in the water collection pipe 34 through the RO membrane 28 is discharged from the element 22 through the first discharge pipe 58 provided on the concentrated water discharge pipe 62 side. A meter 66 is provided at the outlet of the first discharge pipe 58.

According to the vessel 24, the water to be treated supplied from the tank 12 of FIG. 1 via the introduction pipe 56 is guided to the element 22 through the flow path 57, and the water to be treated passes through the RO membrane 28 of the element 22. After passing sequentially, water is collected in the water collection pipe 34. In the present embodiment, by providing the resistance pipe 90 in the water collecting pipe 34, the through hole 36 provided in the water collecting pipe 34 through which the permeated water from the RO membrane 28 passes can be closed. Alternatively, the resistance pipe 90 can narrow the inner diameter of the water collection pipe 34. Thereby, the amount of permeated water collected in the water collection pipe 34 can be reduced. As shown in FIG. 5, by providing the resistance pipe 90 on the introduction pipe 56 side, the amount of treated water that permeates the RO membrane 28 on the supply water side can be reduced. By reducing the amount of permeated water on the supply water side, the amount of treated water on the concentrated water side can be increased, and the salt concentration can be lowered, so the flow rate of permeated water from the final stage of the element 22 can be increased, The amount of permeated water can be increased as a whole apparatus. Therefore, by making the amount of permeated water of each element 22 more uniform, the flow rate of permeated water can be increased at a low pressure as a whole, and the cost can be reduced.

FIG. 6 is a diagram showing the relationship between the position of the RO membrane element and the relative flux of the permeated water in the reverse osmosis treatment apparatus of the embodiment. In the data of the present invention, the opening ratio of the opening 92a is 50% and the outer diameter is slightly smaller than the inner diameter of the water collecting pipe 34 (the size that can be inserted) in the first and second elements from the supply side. The resistance pipe 90a is installed, and the number of elements is seven. As shown in FIG. 6, conventionally, a large amount of permeated water is generated from the supply water side, and the amount of permeate decreases as it goes to the concentrated water side. In contrast, in the present invention, the resistance pipe 90 is provided to reduce the flow rate of the permeated water on the supply water side, so that the salt concentration on the concentrated water side can be reduced as compared with the prior art, and the flow rate of the permeated water. Can be increased. Therefore, the nonuniformity of the permeated water amount of each RO membrane element can be eliminated. The pressure in the water collection pipe 34 can be adjusted by adjusting the opening of the concentrated water discharge valve 64 based on the numerical value measured by the measuring instrument 66. Moreover, by making the amount of permeated water uniform, contamination of the RO membrane on the supply water side can be suppressed, and long-term use can be enabled.

Next, the operation of the resistance pipe 90 will be described. 7A and 7B are cross-sectional views showing a resistance pipe 90a in the water collection pipe 34, FIG. 7A is a cross-sectional view of a side surface (when the water collection pipe is cut in the longitudinal direction), and FIG. It is sectional drawing of the case where a water collection piping is cut | disconnected in radial direction. The resistance pipe 90a is a pipe having an opening 92a on the wall surface. The opening ratio of the opening 92 a of the resistance pipe 90 a is set to be smaller than the opening ratio of the through hole 36 provided in the water collecting pipe 34. By reducing the opening ratio of the resistance pipe 90a, the through hole 36 can be closed by the resistance pipe 90a, so that the amount of permeated water passing through the RO membrane 28 can be reduced. The opening ratio can be reduced by reducing the number of openings 92a, and the opening ratio can be reduced by making the openings 92a smaller than the through holes 36 of the water collecting pipe 34.

FIG. 8 is a side sectional view showing a resistance pipe according to another embodiment. The resistance pipe 90b shown in FIG. 8 is different from the embodiment shown in FIGS. 7A and 7B in that the number of openings 92b increases from the supply water side indicated by the arrow in the figure to the concentrated water side. Yes. By adopting such a configuration, the amount of permeated water flowing into the water collecting pipe 34 on the supply water side can be reduced, and the amount of permeated water can be increased toward the concentrated water side, so that the amount of permeated water can be made uniform. Can do.

FIG. 9 is a side sectional view showing a resistance pipe of still another embodiment. The resistance pipe 90c shown in FIG. 9 is formed in a tapered shape in which the thickness of the resistance pipe 90c decreases as it goes from the supply water side to the concentrated water side indicated by an arrow in the drawing. By setting it as such a structure, the internal diameter of the resistance piping 90c by the side of water supply can be made small, and the internal diameter of the resistance piping 90c can be enlarged as it goes to the concentrated water side. By setting it as such a structure, as it goes to the concentrated water side from the supply water side, the amount of permeate can be increased and the amount of permeate can be made uniform. In FIG. 9, the inner diameter is increased as the taper shape increases from the supply water side toward the concentrated water side. However, the present invention is not limited to this, and the stepped shape increases from the supply water side toward the concentrated water side. It is also possible to adopt a configuration in which the inner diameter increases.

The resistance pipe 90 can be installed by inserting a single pipe into the water collection pipe 34, or can be a resistance pipe 90 by inserting a plurality of pipes. By using a plurality of pipes, it is possible to use a pipe having a different opening ratio and provide a resistance pipe 90b that increases the opening ratio as it goes from the supply water side to the concentrated water side as shown in FIG. Alternatively, a plurality of resistance pipes having different thicknesses may be used, and the inner diameter of the water collection pipe 34 may be increased stepwise as it goes from the supply water side to the concentrated water side. In addition, the length of the resistance pipe installed in the water collecting pipe 34 can be easily set depending on the number of the resistance pipes to be used. Various types of resistance pipes can be installed by installing them in the water collection pipes using a plurality of resistance pipes. The location where the resistance pipe 90 is provided is not an element 22 unit, but each element in the vessel 24 is considered as one long element, and can be determined at an arbitrary position in the water collecting pipe. The position of the resistance pipe 90 can be adjusted by inserting the resistance pipe 90 from the end of the element 22 and adjusting the length using a plurality of pipes.

The length of the resistance pipe 90 needs to be set as appropriate depending on the temperature and the salt concentration of the supply water, but is within a range of 10% to 90% from the end on the supply water side with respect to the total length of the water collection pipe 34. It is preferable to provide it.

Non-uniformity in the amount of permeated water at the element position was (1) water temperature, (2) feed salt concentration, (3) water permeability and salt rejection of the RO membrane itself, (4) averaged over all membranes in the vessel. It is determined by the amount of permeated water around the membrane area, (5) recovery rate, and (6) pressure. Among these, (3), (4), and (5) are determined at the time of design. (1) and (2) change due to environmental changes, and (6) changes when the film is contaminated by operation. By adjusting the opening degree of the concentrated water discharge valve 64 and the position of the resistance pipe 90 in accordance with the changes in (1), (2) and (6), it is possible to ensure a stable permeated water amount as a whole. Can do. In particular, (1) since the water temperature varies depending on the season, it is necessary to appropriately adjust the water temperature.

FIG. 10 is a cross-sectional view of the reverse osmosis treatment apparatus 110 according to another embodiment. The reverse osmosis treatment apparatus 110 includes a resistor 80 in the water collecting pipe 34 and a second discharge pipe 68, a measuring instrument 72, and a second valve 70 on the supply water side of the vessel 24. 5 is different from the reverse osmosis treatment apparatus 10 shown in FIG.

According to the reverse osmosis treatment device 110, the water to be treated supplied through the introduction pipe 56 is guided to the element 22 through the flow path 57, and the water to be treated passes through the RO membrane 28 of the element 22 in sequence, Water is collected in the water collection pipe 34. In the present embodiment, the reverse osmosis treatment device 110 includes a resistor 80 in the water collection pipe 34, and the permeate collected on the concentrated water side with the resistor 80 as a boundary is the first discharge pipe 58. To the outside of the vessel 24. Further, the permeated water collected on the supply water side is discharged from the second discharge pipe 68 to the outside of the vessel 24. The concentrated water that has not passed through the RO membrane 28 is discharged to the outside of the vessel 24 through the concentrated water discharge pipe 62.

As in this embodiment, by providing the resistor 80 in the water collecting pipe 34, the permeated water can be separated into the supply water side and the concentrated water side. By adjusting the amount of permeated water on the supply water side with the opening of the second valve 70, the pressure in the water collection pipe 34 on the supply water side can be adjusted. Furthermore, since the resistance pipe 90 is provided in the water collection pipe 34 from the supply water side of the water collection pipe 34 to the resistor 80, the pressure can be further suppressed, so that the water collection pipe 34 on the supply water side is collected. The amount of permeated water to be watered can be adjusted. By adjusting the amount of permeated water collected in the water collecting pipe 34 on the supply water side, the salt concentration on the concentrated water side can be lowered, so that the permeated water can be collected at a low pressure. Therefore, since the same permeated water as in the past can be collected at a low pressure, the cost can be reduced.

Also in this embodiment, (1) water temperature, (2) supply salt concentration, (3) water permeability and salt rejection of the RO membrane itself, (4) around the membrane area averaged over all membranes in the vessel The permeated water amount, (5) recovery rate, and (6) non-uniform permeated water amount are determined by pressure. Therefore, by adjusting the opening of the concentrated water discharge valve 64 and the second valve 70, and the positions of the resistor 80 and the resistance pipe 90, it is possible to ensure a stable permeated water amount as a whole.

The position of the resistor 80 is not provided at the element unit, that is, at the connection portion of the element, but each element in the vessel is considered as one long element, and the position of the resistor 80 of the water collecting pipe is arbitrarily determined. can do. The position of the resistor 80 can be adjusted by pushing it out from either one of the elements 22 with something like a long bar.

Further, the amount of permeated water can be adjusted by determining the opening degree of the concentrated water discharge valve 64 and the second valve 70 by the measuring

devices

66 and 72 provided in the first discharge pipe 58 and the second discharge pipe 68. It can also be done. As the measuring

instruments

66 and 72, a flow meter and a pressure gauge can be used.

Next, the resistor 80 will be described. As the resistor 80, as shown in FIG. 11A, the entire resistor 80 is an elastic body 82, or as shown in FIG. 11B, an inelastic body 84 is provided with an O-ring shaped elastic body 82. Is preferred. The resistor 80 is installed by bringing the elastic body 82 into close contact with the inner wall of the water collecting pipe 34. As described above, since the position adjustment of the resistor 80 is adjusted by pushing out from the end of the water collecting pipe 34, the contact portion with the inner wall is preferably formed of an elastic body 82. However, it is preferable to have a resistance with the inner wall of the water collection pipe 34 so that the position does not change due to the flow of permeated water. As such an elastic body, for example, EPDM (ethylene propylene diene rubber), silicon or the like can be used.

The resistor 80 can be made non-permeable as shown in FIG. 12A and can be completely closed by the resistor 80a so that the permeate cannot move through the water collection pipe 34. Moreover, as shown to FIG. 12B, it is also possible to make it water-permeable using a porous material as the resistor 80b. Moreover, as shown to FIG. 12C and 12D, a slit can be provided between the

resistors

80c and 80d and the inner wall of the water collection piping 34, and movement of permeated water can also be enabled. By allowing the permeated water to move between the resistors 80, resistance can be provided on both sides of the water collecting pipe 34 sandwiching the resistor 80, so that the amount of permeated water can be made equal. Further, when the resistor 80 has water permeability, the number of the resistors 80 is not limited, and a plurality of resistors 80 may be installed. By installing a plurality, the pressure in the water collecting pipe 34 can be adjusted more finely, so that the non-uniformity of the permeated water amount of each RO membrane can be eliminated. Similarly, a resistor 80 that does not have water permeability can be used as the main resistor 80, and a resistor having water permeability can also be installed in order to adjust the amount of permeated water.

DESCRIPTION OF SYMBOLS 10,110 ... Reverse osmosis processing apparatus, 12 ... Tank, 14 ... High pressure pump, 16 ... Permeate, 18 ... Concentrated water, 20 ... Desalination system, 22 ... Element, 24 ... Vessel, 26 ... Module, 28 ... RO Membrane, 30 ... discharge pipe, 32 ... membrane unit, 34 ... water collection pipe, 36 ... through hole, 38, 40 ... spacer, 56 ... introduction pipe, 57 ... flow path, 58 ... first discharge pipe, 62 ... concentration Water discharge pipe, 64 ... first valve, 66, 72 ... measuring instrument, 68 ... second discharge pipe, 70 ... second valve, 80 ... resistor, 82 ... elastic body, 84 ... inelastic body, 90 ... resistance piping, 92 ... opening

Claims

A reverse osmosis treatment device,
A pressure vessel;
An introduction pipe for supplying water to be treated to one end of the pressure vessel;
A concentrated water discharge pipe for discharging concentrated water to the other end of the pressure vessel;
A plurality of reverse osmosis membrane elements provided in the pressure vessel and provided with a reverse osmosis membrane, wherein the reverse osmosis membrane element is a water collecting pipe through which the permeated water that has passed through the reverse osmosis membrane flows. A water collecting pipe for connecting the plurality of reverse osmosis membrane elements in series in the pressure vessel,
A first discharge pipe for discharging the permeate to the concentrated water discharge pipe side of the pressure vessel;
A resistance pipe on the inlet pipe side in the water collection pipe;
A reverse osmosis treatment apparatus.
The opening rate of the opening part provided in the side surface of the said resistance piping is smaller than the opening rate of the through-hole through which the permeate which permeate | transmitted the said reverse osmosis membrane provided in the side surface of the said water collection piping flows. Reverse osmosis treatment equipment.
The reverse osmosis treatment device according to claim 2, wherein the opening ratio of the opening increases as the resistance pipe moves from the inlet pipe side to the first discharge pipe side of the water collecting pipe.
The reverse osmosis according to any one of claims 1 to 3, wherein a thickness of the resistance pipe decreases as the resistance pipe moves from the inlet pipe side to the first discharge pipe side of the water collection pipe. Processing equipment.
The reverse osmosis treatment apparatus according to any one of claims 1 to 4, wherein the resistance pipe is formed by connecting a plurality of pipes.
A resistor that separates the permeated water into a front stage that is a supply side of the treated water and a rear stage that is a discharge side of the concentrated water in the water collecting pipe;
A second discharge pipe for discharging the permeated water of the previous stage on the introduction pipe side;
The reverse osmosis processing apparatus of any one of Claim 1 to 5.
The reverse osmosis treatment apparatus according to claim 6, wherein the resistor is provided at an end of the resistance pipe on the first discharge pipe side.
The reverse osmosis treatment apparatus according to claim 6 or 7, wherein the resistor is impermeable to water.
The reverse osmosis treatment device according to claim 6 or 7, wherein the resistor is water permeable.
The reverse osmosis treatment device according to claim 9, wherein the resistor is made of a porous material.
The reverse osmosis treatment apparatus according to any one of claims 6 to 10, wherein a slit through which permeated water passes is formed in the resistor.
The reverse osmosis treatment device according to any one of claims 9 to 11, wherein a plurality of the resistors are provided in the water collecting pipe.