Hollow fiber membrane module

Abstract

To provide a hollow fiber membrane module capable of suppressing the hindrance of the inflow of a fluid into a case.SOLUTION: In a hollow fiber membrane module,: a plurality of projections 122 having arc-shaped parts extending along the periphery of an inflow port 121a, being projected toward an outflow port 131 side and regulating intrusion to an inflow port 121a side at the bent part of a hollow fiber membrane bundle 200 are arranged at intervals in a case 100; and the total sum of a flow passage area at a part passing a fluid between the plurality of arc-shaped parts is equal to or larger than the flow passage area of the inflow port 121a in a state that the bent part of the hollow fiber membrane bundle 200 is in contact with the plurality of arc-shaped parts.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hollow fiber membrane module. [Background technology]

[0002] A hollow fiber membrane module used in a water purifier or the like includes a case and a hollow fiber membrane bundle housed in the case. A known technique for such a hollow fiber membrane module involves bundling a plurality of hollow fiber membranes into a U-shape and housing the bundle in the case with the folded portion facing an inlet provided at one end of the case. In this case, the folded portion of the hollow fiber membrane bundle may block the inlet. Therefore, the applicant of the present application has already proposed a technique for preventing the inlet from being blocked by the folded portion of the hollow fiber membrane bundle (see Patent Document 1).

[0003] According to this technology, by providing an annular protrusion around the inlet and multiple radial protrusions extending radially outward from the annular protrusion, it is possible to prevent the folded portion of the hollow fiber membrane bundle from blocking the inlet. However, even with this technology, depending on the dimensions and shape of each part, there is a risk that the inflow of fluid from the inlet may be obstructed in the areas between the multiple radial protrusions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2016-198712 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a hollow fiber membrane module that can suppress obstruction of the inflow of fluid into the case. [Means for solving the problem]

[0006] The present invention employs the following means to solve the above problems.

[0007] That is, the hollow fiber membrane module of the present invention has the following features: a case having an inlet at one end and an outlet at the other end; a hollow fiber membrane bundle housed in the case in a state where both ends are bent toward the outlet; a sealing and fixing portion that fixes both ends of the hollow fiber membrane bundle to the case on the outlet side of the case while leaving the hollow interior of each hollow fiber membrane open; A hollow fiber membrane module comprising: In the case, Opens toward the outlet side a plurality of projections are provided at intervals, each having an arc-shaped portion extending along the periphery of the inlet and projecting toward the outlet, for restricting the intrusion of the folded portion of the hollow fiber membrane bundle into the inlet; The folded portion of the hollow fiber membrane bundle is All of the projections The present invention is characterized in that, when in contact with the arc-shaped portions, the sum of the flow path areas of the portions through which the fluid passes between the plurality of arc-shaped portions is equal to or greater than the flow path area of ​​the inlet.

[0008] According to the present invention, the provision of multiple protrusions prevents the inlet from being blocked by the folded portions of the hollow fiber membrane bundle, and also prevents the fluid flowing in from the inlet from being impeded when passing between the multiple arc-shaped portions.

[0009] The case has a cylindrical portion, and the plurality of protrusions are arranged at equal intervals, When the folded portions of the hollow fiber membrane bundle are arc-shaped and the outermost portions are in contact with the inner circumferential surface of the cylindrical portion and are in contact with the plurality of arc-shaped portions, and when the portion through which the fluid passes between the adjacent arc-shaped portions is viewed from the central axis of the cylindrical portion in a direction perpendicular to the central axis, a flow path is formed in the rectangular portion excluding the portion where the arc-shaped folded portions of the hollow fiber membrane bundle are inserted, and When the inner diameter of the cylindrical portion is A, the length and width of the rectangular portion are h and B, respectively, the central angle of the arc of the shortest portion from one contact position of the adjacent arc-shaped portions in the hollow fiber membrane bundle to the other contact position is θ, the number of the protrusions is N, and the flow path area of ​​the inlet is S, S≦N(hB-(θA2 / 8-(AB / 4)cos(θ / 2))) The present invention is characterized in that:

[0010] By setting it in this manner, when the folded portion of the hollow fiber membrane bundle is in contact with the multiple arc-shaped portions, the sum of the flow path areas of the portions where the fluid passes between the multiple arc-shaped portions can be made to be equal to or greater than the flow path area of ​​the inlet. [Effects of the Invention]

[0011] As described above, according to the present invention, it is possible to provide a hollow fiber membrane module that can prevent the flow of fluid into the case from being obstructed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view of a hollow fiber membrane module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view of the inlet forming member according to the embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing the dimensional relationship of each part of a hollow fiber membrane module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following detailed description of the present invention will be given by way of example with reference to the accompanying drawings, although the dimensions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0014] (Example) A hollow fiber membrane module according to an embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a schematic cross-sectional view of a hollow fiber membrane module according to an embodiment of the present invention. Note that Figure 1 simply shows a cross-section of the hollow fiber membrane module taken along a plane including the central axis of the hollow fiber membrane module. Figure 2 is a rear view of an inlet-forming member according to an embodiment of the present invention. Note that the cross-sectional view of the inlet-forming member in Figure 1 corresponds to the PP cross-sectional view in Figure 2. Figure 3 is a schematic view showing the dimensional relationship of each part of a hollow fiber membrane module according to an embodiment of the present invention.

[0015] The hollow fiber membrane module 10 according to this embodiment is used in a water purifier for removing foreign matter (impurities) from a liquid such as tap water. More specifically, the hollow fiber membrane module 10 is configured to be detachable from the water purifier body. This allows the hollow fiber membrane module 10 to be easily replaced with a new hollow fiber membrane module 10 when the membrane separation function of the hollow fiber membrane module 10 deteriorates and reaches the end of its life. However, the hollow fiber membrane module 10 according to this embodiment is not limited to this application and can also be used for other applications.

[0016] <Hollow fiber membrane module> In particular, the configuration of the hollow fiber membrane module according to this embodiment will be described with reference to FIG. The hollow fiber membrane module 10 according to this embodiment comprises a case 100, a hollow fiber membrane bundle 200 housed in the case 100, and sealing fixing parts 300 that fix both ends of the hollow fiber membrane bundle 200 to the case 100.

[0017] The case 100 includes a cylindrical case body 110 as a cylindrical portion, an inlet forming member 120 fixed to one end of the case body 110, and an outlet forming member 130 fixed to the other end of the case body 110. An inlet 121a is provided in the center of the inlet forming member 120, and an outlet 131 is provided in the center of the outlet forming member 130.

[0018] A hollow fiber membrane bundle 200 made up of a plurality of hollow fiber membranes is stored in the case 100 in a state where both ends are bent so as to face the outlet 131. More specifically, the hollow fiber membrane bundle 200 made up of a plurality of hollow fiber membranes is stored in the case 100 in a state where the vicinity of the center thereof is bent in a curved shape (approximately a U-shape).

[0019] The sealing and fixing parts 300 are configured to fix both ends of the hollow fiber membrane bundle 200 to the case 100 on the outlet 131 side of the case 100 while leaving the hollow interior of each hollow fiber membrane constituting the hollow fiber membrane bundle 200 open. More specifically, the hollow fiber membrane bundle 200 is fixed to the case main body 110 with the hollow interior of each hollow fiber membrane open and the opening of the case main body 110 sealed by the sealing and fixing parts 300. The sealing and fixing parts 300 are made of a sealing material (potting material) such as hardened epoxy resin.

[0020] The hollow fiber membrane module 10 configured as described above is placed, for example, inside a water purifier main body (not shown). At this time, the case 100 is placed with the outlet-forming member 130 side facing vertically downward. Foreign matter contained in a liquid (such as tap water) that flows in through an inlet 121a provided in the inlet-forming member 120 of the case 100 is removed by membrane separation processing using the hollow fiber membranes. The liquid that has been subjected to membrane separation processing using the hollow fiber membranes flows out from an outlet 131 provided in the outlet-forming member 130.

[0021] <Inlet forming member> The inlet-forming member 120, which is a component of the case 100, will now be described in more detail. The inlet-forming member 120 has an inlet 121a with a circular opening at its center. A cylindrical protrusion 121 that protrudes toward the outlet-forming member 130 is provided along the periphery of the inlet 121a. In other words, the inner peripheral surface of the cylindrical protrusion 121 corresponds to the inlet 121a.

[0022] The inlet-forming member 120 is provided with a plurality of projections 122 spaced apart from one another around the cylindrical projection 121, projecting toward the outlet 131. Each projection 122 has an arc-shaped portion 122a extending along the periphery of the inlet 121a. The projection 122 according to this embodiment includes the arc-shaped portion 122a, a pair of radial portions 122b extending radially outward from both ends of the arc-shaped portion 122a, and an arc-shaped connecting portion 122c connecting the radially outer ends of the pair of radial portions 122b. In this embodiment, the opening shape of the inlet 121a is circular, so the arc-shaped portion 122a is arc-shaped. The pair of radial portions 122b and the connecting portion 122c are configured to project to a degree that minimizes contact with the hollow fiber membrane bundle 200. For example, the projection amounts of the pair of radial portions 122b and the connecting portion 122c may be set to be equal to those of the arc-shaped portion 122a. This creates a sufficient space between the pair of radiating portions 122b and connecting portion 122c and the hollow fiber membrane bundle 200, so that the flow of fluid flowing into the case 100 through the gaps between adjacent protrusions 122 is not obstructed.

[0023] These multiple protrusions 122 serve to restrict the intrusion of the bent portion of the hollow fiber membrane bundle 200 into the inlet 121a side. However, in order to fully fulfill this role, it is desirable to provide three or more, and more preferably four or more.

[0024] In this embodiment, when the folded portion of the hollow fiber membrane bundle 200 is in contact with the multiple arc-shaped portions 122a, the sum of the flow path areas of the portions where the fluid passes between the multiple arc-shaped portions 122a is set to be equal to or greater than the flow path area of ​​the inlet 121a. This setting will be explained below with particular reference to Figure 3. Figure 3 schematically shows the vicinity of the portion where the fluid passes between the multiple arc-shaped portions 122a when the hollow fiber membrane bundle 200 is housed in the case 100 and the folded portion of the hollow fiber membrane bundle 200 is in contact with the multiple arc-shaped portions 122a. The pair of protrusions 122 in Figure 3 corresponds to the case where adjacent protrusions 122 are viewed in the direction of arrow V in Figure 2.

[0025] When the hollow fiber membrane bundle 200 is filled in the case 100 in a curved state, the folded portion of the hollow fiber membrane bundle 200 is roughly arc-shaped, and the outermost portion is in contact with the multiple arc-shaped portions 122a while contacting the inner circumferential surface of the case body 110. In this state, the outer shape of the arc-shaped portion is approximately semicircular. FIG. 3 schematically shows the portion where fluid passes between adjacent arc-shaped portions 122a in this state, viewed from the central axis of the case body 110 in a direction perpendicular to the central axis. As can be seen from this figure, the portion where fluid passes between adjacent arc-shaped portions 122a forms a flow path such that the rectangular portion excludes the portion where the arc-shaped folded portion of the hollow fiber membrane bundle 200 enters. Note that FIG. 3 also schematically shows the outer shape of the protrusion 122 and the arc-shaped portion 200X of the hollow fiber membrane bundle 200 that is in contact with the arc-shaped portion 122a.

[0026] As shown in the figure, the inner diameter of the case body 110, which is a cylindrical portion, is defined as A. The length and width of the rectangle are defined as h and B, respectively. In this embodiment, the amount of protrusion of the arc-shaped portion 122a from the tip of the cylindrical protrusion 121 corresponds to h. The interval (linear distance) between adjacent arc-shaped portions 122a corresponds to B. The central angle of the arc of the shortest portion from one contact position P of adjacent arc-shaped portions 122a in the hollow fiber membrane bundle 200 (arcuate portion 200X) to the other contact position Q is defined as θ. The protrusions 122 are provided at equal intervals, and the number of these protrusions 122 is defined as N. Furthermore, the flow path area of ​​the inlet 121a is defined as S. In this embodiment, the opening shape of the inlet 121a is circular, and if its inner diameter is C, then S=(1 / 4)πC 2 This becomes:

[0027] The area of ​​the portion through which the fluid passes between adjacent arc-shaped portions 122a is the area of ​​the rectangle (the portion surrounded by the thick dotted line) in Figure 3 minus the area of ​​the portion where the fan-shaped portion (the portion surrounded by the thick line) and the rectangular portion overlap.

[0028] The area of ​​the rectangular part is hB. The area of ​​the sector part is π(A / 2) 2 (θ / 2π)=θA 2 / 8, and the area of ​​the triangular part of the sector that does not overlap with the rectangular part is (B / 2)((A / 2)cos(θ / 2))=(AB / 4)cos(θ / 2). Therefore, the area of ​​the overlapping part of the sector and the rectangular part is the area of ​​the sector minus the area of ​​the triangular part, so (θA 2 / 8-(AB / 4)cos(θ / 2)).

[0029] From the above, the area of ​​the portion through which the fluid passes between the adjacent arc-shaped portions 122a is (hB - (θA 2 Therefore, the total flow path area of ​​the portion where the fluid passes between the plurality of arc-shaped portions 122a is N(hB-(θA 2 / 8-(AB / 4)cos(θ / 2))).

[0030] Therefore, S(=(1 / 4)πC 2 )≦N(hB-(θA2 / 8-(AB / 4)cos( θ / 2))) is satisfied, the total flow path area of ​​the portions where the fluid passes between the plurality of arc-shaped portions 122a can be made equal to or larger than the flow path area of ​​the inlet 121a.

[0031] <Advantages of the hollow fiber membrane module according to this embodiment> According to the hollow fiber membrane module 10 of this embodiment, the provision of multiple protrusions 122 prevents the inlet 121a from being blocked by the bent portions of the hollow fiber membrane bundle 200. In addition, the fluid that flows in from the inlet 121a is not hindered from passing between the multiple arc-shaped portions 122a.

[0032] The experiment was carried out on the hollow fiber membrane module 10, which was set to the following dimensions: the inner diameter C of the inlet 121a was set to 6 mm. In this case, the flow path area S of the inlet 121a was set to 28.3 mm. 2The inner diameter A of the case body 110 (substantially equal to the outer diameter of the hollow fiber membrane bundle 200 to be filled) is set to 28 mm, h = 2.2 mm, B = 3.7 mm, θ = 15°, and N = 4. From the above formula, the total flow path area of ​​the portion where the fluid passes between the multiple arc-shaped portions 122a is 30.00 mm 2 According to the hollow fiber membrane module 10 configured as above, the flow of the fluid flowing in from the inlet 121a was not obstructed near the inlet 121a, and no decrease in flow rate (increase in pressure loss) was observed. [Explanation of symbols]

[0033] 10 Hollow fiber membrane module 100 cases 110 Case body 120 Inlet forming member 121 Cylindrical protrusion 121a Inlet 122 Protrusion 122a Arc-shaped part 122b Radiating part 122c connection part 130 Outlet forming member 131 Outlet 200 Hollow fiber membrane bundle 300 Sealing fixing part

Claims

1. a case having an inlet at one end and an outlet at the other end; a hollow fiber membrane bundle housed in the case in a state where both ends are bent toward the outlet; a sealing and fixing portion that fixes both ends of the hollow fiber membrane bundle to the case on the outlet side of the case while leaving the hollow interior of each hollow fiber membrane open; A hollow fiber membrane module comprising: The case has an arc-shaped portion extending along the periphery of the inlet opening toward the outlet side, and a plurality of projections are provided at intervals, protruding toward the outlet side and restricting the bent portion of the hollow fiber membrane bundle from entering the inlet side; a hollow fiber membrane module characterized in that, when the bent portion of the hollow fiber membrane bundle is in contact with all of the arc-shaped portions of the plurality of protrusions, the sum of the flow path areas of the portions through which the fluid passes between the plurality of arc-shaped portions is equal to or greater than the flow path area of ​​the inlet.

2. the case has a cylindrical portion, and the plurality of protrusions are arranged at equal intervals; When the folded portions of the hollow fiber membrane bundle are arc-shaped and the outermost portions are in contact with the inner circumferential surface of the cylindrical portion and are in contact with the plurality of arc-shaped portions, and when the portion through which the fluid passes between the adjacent arc-shaped portions is viewed from the central axis of the cylindrical portion in a direction perpendicular to the central axis, a flow path is formed in the rectangular portion excluding the portion where the arc-shaped folded portions of the hollow fiber membrane bundle are inserted, and Let A be the inner diameter of the cylindrical portion, h and B be the length and width of the rectangular portion, θ be the central angle of the arc of the shortest portion from one contact position of the adjacent arc-shaped portions in the hollow fiber membrane bundle to the other contact position, N be the number of the protrusions, and S be the flow path area of ​​the inlet. S≦N(hB-(θA ２ / 8-(1B / 4)cos (θ / 2))) 2. The hollow fiber membrane module according to claim 1, wherein the following is satisfied:

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