Forward osmosis membrane element

Abstract

To provide a forward osmosis membrane element which does not block a flow passage or does not cause a single flow in water flow in the flow passage.SOLUTION: A forward osmosis membrane element 1-1 includes: an outer frame 10; a pair of forward osmosis membranes 20, 30 fitted, oppositely to each other, onto both surfaces of an outer frame 10; flow passage walls 40-1 to 3 installed to form a flow passage R in an area S surrounded by the outer frame 10 and the pair of forward osmosis membranes 20, 30; and straightening walls 50-1 to 11 which are installed at positions dividing the flow passage R formed of the flow passage walls 40-1 to 3 and provided with water passing holes 51. While first fluid introduced through a flow passage port 11-1 provided in one end side of the flow passage R is guided through a flow passage port 11-2 provided in the other end side of the flow passage R, the forward osmosis membrane element 1-1 is impregnated to move water by osmotic pressure difference between the first fluid and the second fluid caused to contact outer surfaces of the pair of forward osmosis membranes 20, 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a forward osmosis membrane element that uses an osmotic pressure difference as a driving force to concentrate or dilute a solution. [Background technology]

[0002] 2. Description of the Related Art Membrane separation methods have been known as one of the methods for concentrating organic and inorganic matter in wastewater generated in sewage treatment plants and sewage treatment plants, diluting high-salt wastewater generated in seawater desalination facilities and the food industry, and diluting fertilizer in plant factories and the agricultural field.

[0003] Among these, a treatment method that combines biological treatment technology and membrane separation technology to treat organic wastewater containing organic matter, and a treatment method using a forward osmosis membrane to dilute concentrated seawater concentrated during seawater desalination are known.

[0004] For example, in the past, when the water to be treated was introduced into a reaction tank and aerated, if the solute concentration of the water in the reaction tank was increased, the size of the air bubbles supplied during the aeration process could be reduced, and the efficiency of oxygen dissolution into the water in the tank could be increased. It is known, however, to use a forward osmosis membrane to concentrate the water in the tank (see, for example, Patent Document 1 below).

[0005] In forward osmosis treatment, a feed solution (hereinafter referred to as "FS") and a draw solution (hereinafter referred to as "DS"), which has a higher osmotic pressure than the FS, are passed through the membrane, and the osmotic pressure difference is used as a driving force to draw water to the DS side.

[0006] The materials for the active layer of the forward osmosis membrane used in this treatment include cellulose triacetate, polyamides, etc. The supporting layer of the forward osmosis membrane includes organic materials such as polyketones and inorganic materials such as ceramics.

[0007] The forward osmosis membrane may be in the form of a flat membrane, a hollow fiber membrane, or a tubular membrane, and the forward osmosis membrane element may be in the form of a flat membrane, a casing membrane, a spiral membrane, or the like.

[0008] Patent Document 1 discloses a water treatment method having a step of introducing water to be treated into a reaction tank and aerating it, and a step of increasing the solute concentration of the water in the reaction tank, in which the solute concentration of the water in the reaction tank is increased using a forward osmosis membrane device, thereby reducing the size of the air bubbles supplied during the aeration treatment and increasing the efficiency of oxygen dissolution into the water in the tank.

[0009] Patent Document 2 discloses a spiral-type forward osmosis membrane element, which discloses a method of once diverting the inflowing water to the outside in order to reduce pressure loss caused by the inflowing water in the water collection pipe.

[0010] Patent Document 3 discloses an element in which a hollow fiber forward osmosis membrane is housed in a cylindrical case, in which water is drawn from a first region to which a low osmotic pressure solution is supplied to a second region to which a high osmotic pressure solution is supplied, where it is concentrated, and the increased amount of water on the high osmotic pressure solution side drives a water flow generator to generate electricity.

[0011] Patent Document 4 discloses an operating method for a filtration module in which a forward osmosis membrane is tubular and surrounded by a case, in which an FS is passed through the tubular membrane and a DS is passed through the case, thereby enabling efficient forward osmosis treatment.

[0012] Patent Document 5 discloses a flat membrane type separation membrane element in which a flow path material is provided on the inside and separation membranes are arranged on both sides of the flow path material so as to face each other. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2014-65008 A [Patent Document 2] JP 2014-023986 A [Patent Document 3] International Publication No. 2016 / 024573 [Patent Document 4] Patent Publication No. 2021-062320 [Patent Document 5] International Publication No. 2017 / 150531 Summary of the Invention [Problem to be solved by the invention]

[0014] However, in all of the above Patent Documents 1 to 5, raw water containing solids is passed through the gaps in the membrane, so when the raw water is passed through, there is a risk that the solids will clog the flow path, resulting in a significant decrease in filtration efficiency.

[0015] Furthermore, there is a risk that the water flow in the flow passage may cause a one-sided flow, resulting in stagnant portions in the flow passage where water does not flow.

[0016] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a forward osmosis membrane element that can prevent a flow path from becoming clogged when water is passing through it, and can prevent one-sided water flow within the flow path. [Means for solving the problem]

[0017] The present invention provides a forward osmosis membrane element comprising a pair of forward osmosis membranes attached to both sides of an outer frame so as to face each other, a flow path wall installed to form a flow path within an area surrounded by the outer frame and the pair of forward osmosis membranes, and a straightening wall installed at a position separating the flow path formed by the flow path walls and having a water passage hole, wherein a first fluid is introduced from a flow path opening provided on one end side of the flow path and is discharged from a flow path opening provided on the other end side of the flow path, while water is transferred between the first fluid and a second fluid brought into contact with the outer surfaces of the pair of forward osmosis membranes due to an osmotic pressure difference. According to the present invention, the flow of the first fluid is restricted to a predetermined direction (one direction) by providing a flow path wall, and a jet flow is generated by a water passage hole provided in the flow straightening wall, creating a strong flow in the flow path and preventing areas in the flow path where no fluid flows, i.e., one-way flow, so that the forward osmosis action by the forward osmosis membrane can be performed efficiently. Furthermore, according to the invention, for example, by using seawater containing no solids as the first fluid flowing through the flow path, and water to be treated containing solids as the second fluid flowing on the outer side of both forward osmosis membranes, blockage (clogging) due to solids in the flow path can be prevented, and good filtration efficiency can be maintained.

[0018] In addition to the above features, the present invention is characterized in that the pair of forward osmosis membranes are attached to all of the outer frame, the flow path wall, and the flow straightening wall. This makes it possible to easily and reliably form a flow path for the first fluid to flow.

[0019] In addition to the above-mentioned features, the present invention is characterized in that the flow straightening wall has a plurality of water passage holes. It is desirable to provide a large number of water holes at equal intervals. According to the present invention, since the water is jetted from a plurality of water passage holes, one-sided flow can be more reliably prevented, and forward osmosis can be performed more effectively and efficiently.

[0020] In addition to the above-mentioned features, the present invention is characterized in that there are a plurality of flow path walls, each of which is disposed at a position that divides the region at equal intervals. The multiple flow path walls are preferably installed so that the flow path in the forward osmosis membrane element has a meandering shape. According to the present invention, the flow path length of the first fluid flowing through the forward osmosis membrane element can be made long by the multiple flow path walls, and at the same time, the flow path can be made uniform in width by the flow path walls that divide the element at equal intervals, so that the flow rate of the first fluid can be made constant. This increases the chance of the first fluid and the second fluid coming into contact with each other across the forward osmosis membrane, and the forward osmosis action can be exerted evenly across the entire forward osmosis membrane, resulting in efficient forward osmosis.

[0021] In addition to the above features, the present invention is characterized in that the flow path wall is installed with its longitudinal direction facing the up-down direction. According to the present invention, since the flow path is oriented in the vertical direction, the air generated within the forward osmosis membrane element can be collected upward, and the air can be easily discharged.

[0022] In addition to the above-mentioned features, the present invention is characterized in that an air vent means is provided at an upper end of the flow path formed by the flow path wall, for venting air generated when a first fluid is caused to flow through the flow path. According to the present invention, air that has collected in the upper part of the forward osmosis membrane element can be easily and reliably discharged through the air vent hole, allowing the forward osmosis membrane to function more effectively.

[0023] In addition to the above-mentioned features, the present invention is also characterized in that the interval between each of the plurality of flow path walls or the interval between each of the plurality of flow straightening walls in the forward osmosis membrane element is preferably 50 to 500 mm.

[0024] In addition to the above-mentioned features, in the present invention, it is preferable that the intervals between the plurality of water-passing holes provided in the flow straightening wall are 5 to 50 mm, and the diameters of the plurality of water-passing holes are 2 to 40 mm.

[0025] In addition to the above characteristics, in the present invention, the forward osmosis membrane element preferably has a thickness of 5 to 50 mm and a side length of 100 to 2000 mm. Effect of the Invention

[0026] According to the present invention, clogging of the flow path can be prevented, and one-sided water flow within the flow path can be prevented, allowing the forward osmosis action by the forward osmosis membrane to be carried out efficiently. [Brief description of the drawings]

[0027] [Figure 1] 1(b) is a side view; FIG. 1(c) is a front view showing the forward osmosis membrane element 1-1 shown in FIG. 1(a) with a pair of forward osmosis membranes 20, 30 removed; and FIG. 1(d) is an enlarged view of the AA cross section of FIG. 1(c). [Diagram 2] 2(a) is a front view, FIG. 2(b) is a side view, and FIG. 2(c) is a front view showing the forward osmosis membrane element 1-2 shown in FIG. 2(a) with a pair of forward osmosis membranes 20, 30 removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a forward osmosis membrane element 1-1 according to a first embodiment of the present invention, where FIG. 1(a) is a front view, FIG. 1(b) is a side view, FIG. 1(c) is a front view showing the forward osmosis membrane element 1-1 shown in FIG. 1(a) with a pair of forward osmosis membranes 20, 30 removed, and FIG. 1(d) is an enlarged view of the AA cross section of FIG. 1(c).

[0029] As shown in these figures, the forward osmosis membrane element 1-1 is configured to include an outer frame 10 formed by assembling four frame bodies 10-1 to 4 into a rectangular shape, a pair of forward osmosis membranes 20, 30 attached to both sides of the outer frame 10 so as to face each other, flow path walls 40 (40-1 to 40-3) installed to form a meandering flow path R within an area S surrounded by the outer frame 10 and the pair of forward osmosis membranes 20, 30, and straightening walls 50 (50-1 to 50-11) installed at positions that divide the flow path R formed by the flow path walls 40 at predetermined intervals.

[0030] The outer frame 10 is configured by assembling four frame members 10-1, 10-2, 10-3, and 10-4 into a rectangular frame shape. The frame members 10-1 to 10-4 have a predetermined thickness for forming an area S described below. The material for the outer frame 10 may be polypropylene resin, polyvinyl chloride resin, polyvinylidene fluoride resin, or the like, but among these, it is preferable to use polyvinyl chloride resin in consideration of processability and durability.

[0031] The thickness of the outer frame 10 (the thickness dimension in the direction toward the front and rear of the paper surface in FIG. 1(a)) is preferably in the range of 5 to 50 mm, and the length of one side of the outer frame 10 is preferably in the range of 100 to 2000 mm. If the thickness or length of the outer frame 10 is greater than the above ranges, in a membrane module constituted by arranging a plurality of the forward osmosis membrane elements 1-1 and installing them in a reaction tank (in which a second fluid described below flows), the number of forward osmosis membrane elements 1-1 that can be installed will be reduced, and the total membrane area will be reduced.

[0032] The width of the outer frame 10 (the width dimension in the plane of the paper in FIG. 1(a)) is preferably in the range of 5 to 50 mm. If the width of the outer frame 10 is less than 5 mm, the adhesion area of ​​the forward osmosis membranes 20, 30 cannot be secured. If the width of the outer frame 10 exceeds 50 mm, the adhesion area of ​​the forward osmosis membranes 20, 30 increases, reducing the total membrane area of ​​the forward osmosis membrane element 1-1. The width of the outer frame 10 is more preferably in the range of 10 to 30 mm.

[0033] Flow path openings 11-1 and 11-2 that penetrate vertically are provided on both the left and right sides of a frame body 10-1 that constitutes the upper side of the outer frame 10. The flow path openings 11-1 and 11-2 are located at the start (or end in some cases) and end or start of a flow path R described below, respectively.

[0034] The forward osmosis membranes 20, 30 are identical flat thin films formed to have the same external dimensions as the external dimensions of the outer frame 10, and are configured by providing an active layer on the surface of a support layer. The active layer is made of a material such as cellulose triacetate or a polyamide. The support layer is made of an organic material such as polyketone or an inorganic material such as ceramic.

[0035] The two forward osmosis membranes 20, 30 are attached by adhesive to both sides of the outer frame 10 that face the forward osmosis membranes 20, 30. The two forward osmosis membranes 20, 30 attached to the outer frame 10 are attached so that the surfaces of their active layers face each other or the surfaces of their support layers face each other, thereby making the permeation conditions of both forward osmosis membranes 20, 30 the same.

[0036] The flow path walls 40-1 to 40-3 are installed in the outer frame 10 in parallel with each other in the vertical direction, with their longitudinal directions facing the up-down direction. The flow path walls 40-1 to 40-3 have the same thickness as the outer frame 10. A straightening wall 50-6 is formed in the vicinity of the upper end of the central flow path wall 40-2, connecting the upper end of the flow path wall 40-2 and the outer frame 10. Straightening walls 50-3 and 50-9 are also formed in the vicinity of the lower ends of the left and right flow path walls 40-1 and 40-3, respectively, connecting the lower ends of the flow path walls 40-1 and 40-3 and the outer frame 10. By installing the flow path walls 40-1 to 40-3 as described above, a flow path R that meanders in the vertical direction is formed in the outer frame 10, as indicated by the dotted arrow.

[0037] The material of the flow path walls 40-1 to 40-3 may be the same as that of the outer frame 10. The interval between the flow path walls 40-1 to 40-3 is preferably in the range of 50 to 500 mm. If the interval between the flow path walls 40-1 to 40-3 is less than 50 mm, the number of detouring in the flow path R increases, so that the pressure loss from one flow path opening 11-1 or 11-2 to the other flow path opening 11-2 or 11-1 increases, and the number of flow path walls 40 increases, so that the membrane area for forward osmosis decreases accordingly. If the interval between the flow path walls 40-1 to 40-3 exceeds 500 mm, the flow distribution occurs in the flow path R, and there is a risk that a portion where the fluid stagnates in the flow path R is formed. Both sides of the flow path walls 40-1 to 40-3 facing the forward osmosis membranes 20 and 30 are attached to the pair of forward osmosis membranes 20 and 30 by adhesive.

[0038] The straightening walls 50-1 to 50-11 are disposed at right angles toward the flow path R and at approximately equal intervals so as to separate the flow path R formed by the flow path wall 40. The straightening walls 50-1 to 50-11 have the same thickness dimension as the outer frame 10. As shown in FIG. 1(d), each of the straightening walls 50-1 to 50-11 is provided with a plurality of water passage holes 51 (seven in this example) that penetrate between the upper and lower surfaces of the straightening walls 50-1 to 50-11 at equal intervals in a row in the longitudinal direction. The opening ratio of the water passage holes 51 in each of the straightening walls 50-1 to 50-11 is preferably in the range of 1% to 20%. In addition, the interval between the plurality of water passage holes 51 provided in each of the straightening walls 50-1 to 50-11 is preferably 5 to 50 mm, and the diameter of the water passage hole 51 is preferably 2 to 40 mm.

[0039] The interval between the straightening walls 50-1 to 50-11 is preferably 50 to 500 mm. If the interval between the straightening walls 50-1 to 50-11 is less than 50 mm, the pressure loss from one flow passage port 11-1 or 11-2 to the other flow passage port 11-2 or 11-1 becomes large, and the number of the straightening walls 50 increases, so that the membrane area for forward osmosis becomes smaller. If the interval between the straightening walls 50-1 to 50-11 exceeds 500 mm, the effect of the straightening walls 50-1 to 50-11 described below may not be fully exhibited. Both sides of the straightening walls 50-1 to 50-11 facing the forward osmosis membranes 20 and 30 are attached to the pair of forward osmosis membranes 20 and 30 by adhesive.

[0040] An example of the operation of the forward osmosis membrane element 1-1 configured as above will be described. First, one or more of the forward osmosis membrane elements 1-1 are immersed and installed in a reaction tank filled with a second fluid (not shown) so that it can flow through. Here, the second fluid is, for example, FS, wastewater containing solids (organic and inorganic matter) generated in a sewage treatment plant or a sewage treatment plant. On the other hand, the first fluid is, for example, DS, seawater with a high salt concentration that does not contain solids.

[0041] A first fluid is introduced from one of the flow path openings 11-1 provided in the forward osmosis membrane element 1-1, and is discharged from the other flow path opening 11-2 in a state in which the entire flow path R is filled with the first fluid. Meanwhile, the second fluid filled in the reaction tank is also caused to flow over the surfaces of the forward osmosis membranes 20 and 30 of the forward osmosis membrane element 1-1.

[0042] As a result, the first fluid and the second fluid face each other through the forward osmosis membranes 20, 30, and with the osmotic pressure difference as the driving force, in this example, water is drawn from the second fluid, which is low in concentration and has a low osmotic pressure, to the first fluid, which has a high concentration and a high osmotic pressure. As a result, the second fluid is concentrated and the first fluid is diluted.

[0043] In order to effectively perform the forward osmosis action, it is necessary to constantly replace the first fluid that contacts the forward osmosis membrane and prevent one-sided flow that generates areas where water does not flow. In this embodiment, as described above, the flow path walls 40-1 to 40-3 are installed to form a flow path R within the region S surrounded by the outer frame 10 and the pair of forward osmosis membranes 20 and 30, so that the flow of the first fluid can be restricted to a predetermined direction (one direction, in this embodiment, one direction that meanders up and down), and the first fluid that contacts the forward osmosis membranes 20 and 30 can be smoothly flowed while constantly being replaced.

[0044] At the same time, the straightening walls 50-1 to 50-11 with the water passage holes 51 are provided at positions dividing the flow path R formed by the flow path walls 40-1 to 40-3, so that when the first fluid passes through the water passage holes 51, the flow speed is temporarily increased to generate a jet flow, which creates a strong flow in the flow path R, thereby reducing the portion (dead space) in the flow path R where the fluid does not flow, that is, preventing one-way flow. As a result, the forward osmosis action by the forward osmosis membranes 20 and 30 can be performed effectively and efficiently.

[0045] Furthermore, according to this embodiment, seawater containing no solids is used as the first fluid flowing through the flow path R of the forward osmosis membrane element 1-1, while water to be treated containing solids is flowed as the second fluid supplied to the outside of the forward osmosis membrane element 1-1 (i.e., flowing on the outer surface sides of both forward osmosis membranes 20, 30), thereby preventing blockage of the flow path R by solids and maintaining good filtration efficiency.

[0046] In addition, in the above embodiment, the number of water passage holes 51 provided in the flow-straightening walls 50-1 to 50-11 is multiple, so that the jet flow is jetted from the multiple water passage holes 51, which makes it possible to more reliably prevent one-way flow and to perform the forward osmosis action more effectively and efficiently.

[0047] As described above, the flow path walls 40-1 to 40-3 are provided at positions that divide the region S, so that the flow path length of the first fluid flowing through the forward osmosis membrane elements 20, 30 can be made long. At the same time, the flow path R can be made uniform in width by the flow path walls 40-1 to 40-3 that divide the region S at equal intervals, so that the flow rate of the first fluid can be made constant. As a result, the first fluid and the second fluid can come into contact with each other across the forward osmosis membranes 20, 30 more frequently. Furthermore, the forward osmosis action can be exerted evenly across the entire forward osmosis membrane, so that the forward osmosis action can be performed efficiently.

[0048] In addition, since the flow path walls 40-1 to 40-3 are installed so that their longitudinal directions face the vertical direction, the flow path R faces the vertical direction. Therefore, the air that accumulates in the forward osmosis membrane element 1-1 can be collected upward, and the air can be easily discharged.

[0049] 2 shows a forward osmosis membrane element 1-2 according to a second embodiment of the present invention, with Fig. 2(a) being a front view, Fig. 2(b) being a side view, and Fig. 2(c) being a front view showing the forward osmosis membrane element 1-2 shown in Fig. 2(a) with a pair of forward osmosis membranes 20, 30 removed. In the forward osmosis membrane element 1-2 shown in the figure, parts that are the same as or correspond to the forward osmosis membrane element 1-1 according to the embodiment shown in Fig. 1 are given the same reference numerals. Note that matters other than those described below are the same as those in the embodiment shown in Fig. 1.

[0050] The forward osmosis membrane element 1-2 differs from the forward osmosis membrane element 1-1 only in that an air vent means 60 for venting air is provided at the upper end of the vertically meandering flow path R formed by the flow path walls 40-1 to 40-3.

[0051] The air vent means 60 are attached to the outer frame 10 at two upper end portions of the flow path R which meanders in the vertical direction by the flow path walls 40-1 to 40-3, where the flow path R does not have the flow path openings 11-1, 11-2. In this example, the air vent means 60 is configured by connecting a pipe to an air vent hole which is provided in the frame body 10-1 and penetrates vertically.

[0052] If air (air bubbles) remain inside the forward osmosis membrane element 1-2, the pressure will rise, causing damage to the forward osmosis membranes 20, 30, reducing the flow rate of the first fluid passing through the inside, and reducing the effective membrane area due to air adhering to the forward osmosis membranes 20, 30, which may result in a decrease in the efficiency of the forward osmosis action. By providing an air venting means 60, however, the air trapped inside the forward osmosis membrane element 1-2 can be vented, solving the above problem and allowing the forward osmosis membrane to function more effectively.

[0053] In particular, in this embodiment, a flow path R that meanders in the vertical direction is formed, and an air venting means 60 is connected to the upper end of the meandering flow path R, so that air that accumulates near the upper end can be efficiently, easily, and reliably removed. Since this forward osmosis membrane element 1-2 uses an osmotic pressure difference for filtration, the first fluid is not pressurized, and the air is discharged to the outlet side flow path port 11-2 only by a naturally occurring water flow, so the air venting means 60 is open to the atmosphere.

[0054] The reason why the air venting means 60 is not provided at the positions of the flow path openings 11-1 and 11-2 is that these flow path openings 11-1 and 11-2 also serve as the air venting means.

[0055] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. Any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical ideas of the present invention as long as it provides the functions and effects of the present invention. For example, in the above embodiment, the flow path port 11-1 is an inlet for the first fluid, and the flow path port 11-2 is an outlet for the first fluid, but the inlet and outlet may be reversed.

[0056] In the above embodiment, the pair of forward osmosis membranes 20, 30 are attached by adhesive to both sides of the outer frame 10, the flow path walls 40-1 to 40-3, and the flow straightening walls 50-1 to 50-11, respectively. However, they may be attached by various joining means other than adhesive, such as mechanical joining or fixing.

[0057] Needless to say, the number of flow path walls 40-1 to 40-3 and flow straightening walls 50-1 to 50-11 and the number of water passage holes 51 can be changed in various ways.

[0058] In the above embodiment, seawater was used as the first fluid and wastewater from a sewage treatment plant or a human waste treatment plant was used as the second fluid, but other fluids (e.g., wastewater from a pickle factory with a high salt concentration instead of seawater) may be used. Furthermore, in the above embodiment, the first fluid is DS and the second fluid is FS, but these may be reversed.

[0059] In the above embodiment, the flow path walls 40-1 to 40-3 are arranged so that their longitudinal directions are oriented in the vertical direction, but they may be arranged so that they are oriented in a direction other than the vertical direction.

[0060] In the above embodiment, the air vent means 60 has a structure in which a pipe is connected to an air vent hole that penetrates vertically through the frame body 10-1. However, various other structures of means for venting air, such as the installation of an opening / closing valve, may also be used.

[0061] In addition, the embodiments described above and shown in each drawing can be combined with each other as long as there is no contradiction in the purpose, configuration, etc. In addition, even a part of the description in the above description and the description in each drawing can be an independent embodiment, and the embodiment of the present invention is not limited to one embodiment that combines the description in the above description and each drawing. [Explanation of symbols]

[0062] 1-1,1-2 Forward osmosis membrane element 10 Outer Frame 11-1,11-2 Channel mouth 20,30 Forward osmosis membrane S area R flow path 40-1~40-3 Channel wall 50-1~50-11 Rectification wall 51 Water Vent 60 Air bleed means

Claims

1. A pair of forward osmosis membranes attached to both sides of the outer frame so as to face each other; A flow path wall is disposed so as to form a flow path within a region surrounded by the outer frame and the pair of forward osmosis membranes; a straightening wall disposed at a position dividing the flow path formed by the flow path wall and having a water passage hole; Equipped with A forward osmosis membrane element characterized in that a first fluid is introduced through a flow path port provided at one end of the flow path and discharged from a flow path port provided at the other end of the flow path, while water is moved between the first fluid and a second fluid brought into contact with the outer surfaces of the pair of forward osmosis membranes due to an osmotic pressure difference.

2. The forward osmosis membrane element according to claim 1, The forward osmosis membrane element is characterized in that the pair of forward osmosis membranes are attached to all of the outer frame, the flow path wall, and the flow straightening wall.

3. The forward osmosis membrane element according to claim 1 or 2, A forward osmosis membrane element, wherein the flow straightening wall has a plurality of water passage holes.

4. The forward osmosis membrane element according to claim 1 or 2, The forward osmosis membrane element is characterized in that there are a plurality of flow path walls, each of which is disposed at a position that divides the region at equal intervals.

5. The forward osmosis membrane element according to claim 1 or 2, The forward osmosis membrane element is characterized in that the flow path walls are installed with their longitudinal directions facing up and down.

6. The forward osmosis membrane element according to claim 5, A forward osmosis membrane element, comprising: an air vent means provided at an upper end of a flow path formed by the flow path walls, for venting air generated when a first fluid is caused to flow through the flow path.

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