JP2020062598A - Membrane element, membrane separation equipment and membrane element manufacturing method - Google Patents

Abstract

To provide a membrane element which can easily perform sealing of an end edge part.SOLUTION: There is provided a membrane element 12 in which a filtration membrane 22 and a passage material 21 are joined and which has plural end edge parts 12a, 12b. The passage material 21 comprises a knitted fabric in which threads are knitted in a three-dimensional structure and has a gap 32 in which a permeate flows therein. The threads constituting the passage material 21 have plural low melting point threads 37 and plural high melting point threads 38 of which softening points are different. The plural melting point threads 37, which have been heated at a heating temperature, which is a softening point of the low melting point thread 37 or more, are molten, whereby the end edge parts 12a, 12b of the passage material 21 are deposited and sealed.SELECTED DRAWING: Figure 8

Description

  INDUSTRIAL APPLICABILITY The present invention relates to a membrane element used for separating sludge from treated water in a field called, for example, a membrane separation activated sludge method (MBR), a submerged membrane separation apparatus including the membrane element, and production of the membrane element. It is about the method.

  Conventionally, as this type of membrane element, as shown in, for example, FIG. 15 and FIG. 16, a first filtration membrane 111, a second filtration membrane 112, and a drainage liquid provided between both filtration membranes 111 and 112. Membrane element having woven cloth 113, adhesive net 114 for adhering first filtration membrane 111 and drainage woven cloth 113, and adhesive net 115 for adhering second filtration membrane 112 and drainage woven cloth 113 There is 116. The drainage cloth 113 is a spacer cloth having a three-dimensional structure knitted so as to form a loop.

  The drainage woven fabric 113 and the adhesive nets 114 and 115 are laminated between the first filtration membrane 111 and the second filtration membrane 112, and the adhesive nets 114 and 115 are temporarily rolled by rolling with a heating roll. And the first filtering membrane 111 and the drainage woven cloth 113 are bonded to each other via the first adhesive net 114, and the second filtering membrane 112 and the drainage woven cloth are bonded to each other via the second adhesive net 115. 113 is adhered to complete the membrane element 116.

  The membrane element as described above is described, for example, in Patent Document 1 below.

Special table 2011-519716

  However, in the above conventional type, as shown in FIG. 15, when sealing the edge 117 of the membrane element 116, an adhesive is applied to the edge 117 or the edge 117 is machined with a thread. The edge 117 is sewn to seal it. For this reason, there is a problem that it takes time to seal the edge 117 of the membrane element 116.

  It is an object of the present invention to provide a membrane element, a membrane separation device, and a method of manufacturing a membrane element, which can easily perform a sealing process on an edge portion.

In order to achieve the above object, the first aspect of the present invention is a membrane element in which a filtration membrane and a flow path member are joined, and which has a plurality of edge portions,
The flow path material is made of a knitted fabric in which threads are knitted into a three-dimensional structure, and has a void inside which the permeated liquid that has permeated the filtration membrane flows,
The yarn constituting the flow path member has a plurality of low melting point yarns and a plurality of high melting point yarns having different softening points,
By melting a plurality of low-melting-point yarns heated at a heating temperature equal to or higher than the softening point of the low-melting-point yarns, at least one edge portion of the channel material is welded and sealed.

  According to this, by heating the edge portion of the membrane element at a heating temperature equal to or higher than the softening point of the low melting point yarn of the channel material, the low melting point yarn of the edge portion of the channel material melts, and the edge of the membrane element ends. The edge portion is welded and closed with the resin of the low melting point thread of the flow path material to be sealed. Thereby, the sealing process of the edge portion of the membrane element can be easily performed.

In the membrane element according to the second aspect of the present invention, the flow path member has a plurality of face yarns that form a joint surface with the filtration membrane, and a plurality of pile yarns that are bonded to the face yarns.
Voids that allow permeate to flow are formed between multiple pile threads,
The pile yarn has a low melting point yarn and a high melting point yarn.

  According to this, by heating the edge portion of the membrane element at a heating temperature equal to or higher than the softening point of the low melting point yarn of the channel material, the low melting point yarn of the pile yarn at the edge portion of the channel material melts, The edge portion of the element is welded and closed with the resin of the low melting point thread of the flow path material to be sealed.

  In addition, since the high melting point yarn of the pile yarn is less likely to be softened than the low melting point yarn, when the filtration membrane is joined to the channel material by hot rolling, the channel material is crushed and the permeated liquid in the channel material flows. Does not disappear. As a result, the flow of the permeated liquid inside the flow path member is not hindered.

  In the membrane element according to the third aspect of the present invention, the pile yarn is a multifilament yarn in which a low melting point yarn and a high melting point yarn are twisted together.

In the membrane element according to the fourth aspect of the present invention, at least a part of the low melting point yarn is formed of a core material and a sheath material covering the core material,
The sheath material has a softening point lower than that of the high melting point yarn,
The core material has a softening point higher than that of the sheath material.

  According to this, by heating the edge portion of the membrane element at a heating temperature equal to or higher than the softening point of the sheath material of the low melting point yarn of the channel material, the sheath material of the low melting point yarn at the edge portion of the channel material melts. Then, the edge portion of the membrane element is welded with the resin of the sheath material in which the low melting point yarn of the flow path material is melted, and is closed and sealed.

  Further, since the core material of the low melting point yarn has lower flexibility (or higher repulsive force or higher elasticity) than the sheath material, the low melting point yarn becomes stronger.

  In the membrane element according to the fifth aspect of the present invention, the material of the low melting point yarn is a polyolefin resin.

  In the membrane element according to the sixth aspect of the present invention, the sheath material is a polyolefin resin.

  In the membrane element according to the seventh aspect of the present invention, the material of the high melting point yarn is polyester resin.

In the membrane element according to the eighth aspect of the present invention, the filtration membrane has a porous membrane sheet,
The membrane sheet has a softening point higher than that of the low melting point yarn of the channel material.

  According to this, by heating the edge portion of the membrane element at a heating temperature equal to or higher than the softening point of the low melting point yarn of the channel material and lower than the softening point of the membrane sheet, the low melting point of the edge portion of the channel material is obtained. The yarn is melted, and the edge portion of the membrane element is welded and blocked by the melted low melting point resin of the flow path material to be sealed.

  Moreover, since the heating temperature is lower than the softening point of the membrane sheet as described above, it is possible to prevent the membrane sheet from softening and expanding the fine pores of the membrane sheet.

A ninth invention of the present invention is a membrane separation device comprising the membrane element according to any one of the first invention to the eighth invention,
A support member supporting a plurality of membrane elements,
The support member has a water collecting space inside,
The unsealed edge of each membrane element is inserted into the water collection space,
The permeated liquid that has passed through the filtration membrane flows into the water collecting space of the support member from the unsealed edge portion of the membrane element through the void in the flow channel material.

  According to this, in a state in which the membrane separation device is immersed in the liquid to be treated, by performing the filtration operation, the liquid to be treated is filtered by passing through the filtration membrane of the membrane element from the primary side to the secondary side, After that, the permeated liquid flows into the void inside the channel material, passes through the void inside the channel material, and flows out from the unsealed edge portion of the membrane element to the water collecting space of the support member.

A tenth invention of the present invention is the method for producing a membrane element according to any one of the first invention to the eighth invention,
A filtration membrane is joined to a long channel material to form a long membrane element,
By sandwiching the long membrane element with a pair of heated cutting members, the long membrane element is heated to a predetermined length while the flow path material at the cutting point is heated at a heating temperature equal to or higher than the softening point of the low melting point yarn. It is to cut into.

  According to this, when the long membrane element is cut into a predetermined length, the flow path material at the cut portion is heated at a heating temperature which is equal to or higher than the softening point of the low melting point yarn and lower than the softening point of the high melting point yarn. Therefore, the low melting point thread of the flow path material at the cutting point melts, and the cutting point of the membrane element (corresponding to the edge of the membrane element after cutting) is welded and blocked by the melted low melting point thread resin of the flow path material. It peels off and is sealed. This makes it possible to easily perform the sealing treatment of the edge portion of the membrane element, and thus the cutting of the membrane element and the sealing treatment of the edge portion can be performed at the same time, so that the productivity of the membrane element is improved.

  As described above, according to the present invention, it is possible to easily perform the sealing treatment of the edge portion of the membrane element.

It is a front view of a membrane separation device using a plurality of membrane separation devices in a 1st embodiment of the present invention. FIG. 3 is a perspective view of the membrane separation device. FIG. 3 is a sectional view of the membrane separation device. FIG. 3 is a partially cutaway perspective view showing a configuration of a membrane element of the membrane separation device. FIG. 3B is an enlarged schematic view of the cross section of the membrane element, showing an unsealed edge portion. FIG. 3 is an enlarged schematic view of the cross section of the channel material of the membrane element. It is a XX arrow line view in FIG. 6, and is the schematic diagram which expanded the face of the flow path material. FIG. 3B is an enlarged schematic view of the cross section of the membrane element, showing the sealed edge portion. FIG. 3 is a side view showing the same method for manufacturing a membrane element. It is a XX arrow line view in FIG. FIG. 3 is a side view showing the same method for manufacturing a membrane element. FIG. 3 is a side view showing the same method for manufacturing a membrane element. It is the schematic diagram which expanded the cross section of the low melting point yarn of the pile yarn of the flow path material of the membrane element in the 2nd Embodiment of this invention. It is the schematic diagram which expanded the cross section of the membrane element in the 3rd Embodiment of this invention, and shows the edge part currently sealed. It is a perspective view of the conventional membrane element. FIG. 3 is a partially cutaway perspective view showing the structure of the membrane element.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
In the first embodiment, as shown in FIG. 1, reference numeral 1 is an immersion type membrane separation device for performing membrane filtration, which is immersed in a liquid to be treated 2 such as organic waste water and installed in a treatment tank 3. Has been done. The membrane separation device 1 has a plurality of membrane separation devices 5 (also referred to as a membrane filtration module) that are vertically stacked, and an air diffuser 6 provided at the lowest stage.

  As shown in FIGS. 2 and 3, the membrane separation device 5 includes a pair of left and right water collecting cases 11 (an example of a supporting member), and a plurality of membrane elements 12 supported between the both water collecting cases 11. It has a pair of front and rear connecting plates 13. The water collection case 11 is a hollow member having a water collection space 15 inside. The connecting plate 13 is provided between the front end portions and the rear end portions of the water collecting cases 11, respectively.

  The water collection space 15 in the water collection case 11 of the lower membrane separation device 5 and the water collection space 15 in the water collection case 11 of the higher membrane separation device 5 communicate with each other through a communication port 16.

  The membrane element 12 is a rectangular sheet-shaped member having a predetermined length A and a predetermined width B, and has an upper edge 12a, a lower edge 12b, a left edge 12c, and a right edge 12d. There is. The upper edge 12a and the lower edge 12b are sealed (sealed), and the left edge 12c and the right edge 12d are not sealed.

  A plurality of vertically elongated through holes are formed in the inner wall 17 of the water collection case 11, and the left and right end edges 12c and 12d (the unsealed edge portions) of each membrane element 12 are formed in the through holes. It is inserted and plunges into the water collection space 15.

  As shown in FIGS. 4 to 8, the membrane element 12 has a flow channel member 21 and a filtration membrane 22 bonded to both front and back surfaces of the flow channel member 21.

  The flow path member 21 is a spacer fabric made of a knitted yarn having a three-dimensional structure, and has a pair of front and back faces 25 and a large number of pile yarns 27 connecting the pair of faces 25. The face 25 is a knitted fabric having a large number of face yarns 29 crossing each other in the vertical and horizontal directions, and the pile yarns 27 are bonded to the face yarns 29.

  Between the pile yarns 27 inside the flow path member 21, minute voids 32 in which the permeated liquid 33 that has permeated the filtration membrane 22 flows are formed.

  The pile yarn 27 has a low melting point yarn 37 (indicated by a solid line) and a high melting point yarn 38 (indicated by a two-dot chain line) having different softening points. The ratio of the low melting point yarn 37 and the high melting point yarn 38 is 50% each. As the low melting point yarn 37, a yarn made of polyethylene (PE) having a softening point T1 of about 80 ° C. to 120 ° C. is used. As the high melting point yarn 38, a yarn made of polyethylene terephthalate (PET) having a softening point T2 of about 240 ° C. to 280 ° C. is used.

  Further, as the face yarn 29, a yarn made of polyethylene terephthalate (PET) having a softening point T3 of about 240 ° C. to 280 ° C. is used.

In addition, as the thread usage of the flow path member 21 made of the spacer fabric as described above, for example, the face thread 29 is "84T24", the low melting point thread 37 of the pile thread 27 is "56T24", and the high melting point thread 38 of the pile thread 27 is, for example. Is "56T1", and the density of the pile yarn 27 is about 379 filaments / cm ² . Further, the thickness C of the flow path member 21 alone before manufacturing the membrane element 12 is, for example, about 2 mm to 5 mm.

  The "84T24" means that the twisted yarn has a thickness of 84 dtex and the number of twisted yarns is 24, and "56T24" means that the twisted yarn has a thickness of 56 dtex and the number of twisted yarns. "56T1" means that the yarn thickness is 56 dtex and the number of twisted yarns is 1 (that is, monofilament yarn).

  As shown in FIG. 5, the filtration membrane 22 has a porous membrane sheet 34 having a large number of fine pores on the outer surface side, and has a nonwoven fabric 35 supporting the membrane sheet 34 on the inner surface side. The membrane sheet 34 and the non-woven fabric 35 are laminated.

The nonwoven fabric 35 has a basis weight of 20 to 500 g / m ² . Further, the non-woven fabric 35 is a mixture of low melting point yarn made of polyethylene (PE) and high melting point yarn made of polyethylene terephthalate (PET).

  As the material of the film sheet 34, polytetrafluoroethylene (ePTFE) having a softening point T4 of about 330 ° C. to 350 ° C. is used. The softening point T4 of the film sheet 34 is higher than any of the softening point T1 of the low melting point yarn 37 of the pile yarn 27, the softening point T2 of the high melting point yarn 38, and the softening point T3 of the face yarn 29. That is, the softening points have a relationship of T1 <T2 and T3 <T4.

  As shown in FIG. 8, the upper edge portion 12a and the lower edge portion 12b of the membrane element 12 are fused and sealed by melting the low melting point yarn 37 of the pile yarn 27.

  A method for manufacturing the membrane element 12 will be described below.

  As shown in FIGS. 9 and 10, a long filtration membrane 22 is bonded to both front and back surfaces of a long flow path member 21 to have a predetermined width B and a length longer than a predetermined length A. The membrane element 40 is formed.

  At this time, the long channel material 21 and the filtration membrane 22 are sandwiched between a pair of heating rollers and rolled (hot rolling) while being heated to form the long membrane element 40 as described above. However, by setting the heating temperature at this time to a temperature equal to or higher than the softening point of the low melting point yarn of the nonwoven fabric 35 of the filtration membrane 22 and lower than the softening point of the high melting point yarn 38 of the pile yarn 27 of the flow path member 21, The low melting point yarn of the non-woven fabric 35 is softened and the resin of the low melting point yarn is entangled with the face yarn 29 of the flow channel member 21, so that the filtration membrane 22 is bonded to the flow channel member 21. At the heating temperature as described above, the high melting point yarn 38 of the pile yarn 27 is not softened, so that the flow path member 21 is not crushed and the minute voids 32 in the flow path member 21 are not lost. As a result, the flow of the permeated liquid inside the flow path member 21 is not hindered.

  After the long membrane element 40 is formed in this manner, as shown in FIG. 11, the long membrane element 40 is cut into the membrane element 12 having a predetermined length A by using the cutting device 42.

  The cutting device 42 has a pair of upper and lower cutting blades 43 and 44 (an example of a cutting member) that can be opened and closed, and a heating device (not shown) that heats the cutting blades 43 and 44.

  When the long membrane element 40 is cut using the cutting device 42, the pair of heated cutting blades 43 and 44 are closed and the long membrane element 40 is sandwiched by both cutting blades 43 and 44, and the flow path at the cutting location The material 21 is heated at a heating temperature (for example, 120 to 240 ° C.) equal to or higher than the softening point T1 of the low melting point yarn 37 for a predetermined time (for example, 1 to 10 seconds), and in this state, the long membrane element 40 is set to a predetermined temperature. Cut to length A.

  After the predetermined time has elapsed, both cutting blades 43 and 44 are opened as shown in FIG. Thereby, the membrane element 12 cut into the predetermined length A is obtained. Immediately after opening both cutting blades 43 and 44 as described above, a gas such as air may be blown to the cut portion of the membrane element 12 to forcibly cool the cut portion.

  According to the above-mentioned manufacturing method, when the long membrane element 40 is cut into the predetermined length A, the flow path material 21 at the cut portion is heated at a heating temperature equal to or higher than the softening point T1 of the low melting point yarn 37. Therefore, the low melting point yarn 37 of the pile yarn 27 of the flow path material 21 at the cut portion is melted, and as shown in FIG. 8, the cut portion of the long membrane element 40 (the upper end edge portion 12a of the cut membrane element 12 is cut off). (Corresponding to the lower edge portion 12b) is welded and closed by the resin of the melted low melting point yarn 37 of the flow path member 21 to be sealed. As a result, it is possible to easily perform the sealing treatment of the upper edge 12a and the lower edge 12b of the membrane element 12 after cutting, and thus the cutting of the membrane element 12 and the sealing treatment of the edge can be performed at the same time. Therefore, the productivity of the membrane element 12 is improved.

  Further, since the high melting point yarn 38 of the pile yarn 27 has a larger repulsive force (or higher elasticity) than the low melting point yarn 37, the cut portion of the flow path member 21 (the upper edge 12a and the lower end of the membrane element 12 after cutting). In portions other than the edge portion 12b), the gap 32 through which the permeated liquid 33 flows is secured between the pile yarns 27 without being blocked. As a result, the flow of the permeated liquid 33 inside the flow path member 21 is not hindered.

  The membrane separation device 5 is manufactured using the membrane element 12 manufactured by the above manufacturing method, and the membrane separation device 1 is assembled using the membrane separation device 5. As shown in FIG. 1, by performing the filtration operation in a state where the membrane separation device 1 is immersed in the liquid to be treated 2, the liquid to be treated 2 becomes the filtration membrane 22 of the membrane element 12 of each membrane separation device 5. Filtered from the primary side to the secondary side, and then flows into the void 32 inside the flow path member 21 as the permeate 33, passes through the void 32, and the left and right edge portions 12c, 12d of the membrane element 12 are filtered. (That is, the unsealed edge portion) flows out into the water collecting space 15 of the water collecting case 11, passes through the communication hole 16, and from the inside of the water collecting case 11 of the uppermost membrane separation device 5 to the treatment tank 3 It is taken out.

  In the first embodiment, polyethylene is used as the material of the low melting point yarn 37 of the pile yarn 27, but the material is not limited to this, and a polyolefin resin other than polyethylene may be used. Further, polyethylene terephthalate is used as the material of the high melting point yarn 38 of the pile yarn 27 and the material of the face yarn 29, but the material is not limited to this, and a polyester resin other than polyethylene terephthalate may be used. Good.

  In the first embodiment, the low melting point yarn 37 is formed by twisting a plurality of twisted yarns, but all the twisted yarns may be low melting point yarns, or a part of the twisted yarns may have a high melting point. A melting point thread may be included.

In the above-described first embodiment, the flow path member 21 at the cut portion is heated at a heating temperature equal to or higher than the softening point T1 of the low melting point yarn 37, and in this state, the long membrane element 40 has a predetermined length. Although cut into A, the heating may be performed at a heating temperature which is equal to or higher than the softening point T1 of the low melting point yarn 37 and lower than the softening point T2 of the high melting point yarn 38.
(Second embodiment)
In the second embodiment, as shown in FIG. 13, the low melting point yarn 37 of the pile yarn 27 is formed of a core material 51 and a sheath material 52 that covers the core material 51. The sheath material 52 has a softening point T1 lower than the softening point T2 of the high melting point yarn 38. As the sheath material 52, a sheath material made of polyethylene (PE) having a softening point T1 of about 80 ° C. to 120 ° C. is used.

  Further, the core material 51 has a softening point T2 higher than the softening point T1 of the sheath material 52. As the core material 51, a core material made of polyethylene terephthalate (PET) having a softening point T2 of about 240 ° C. to 280 ° C. is used.

  According to this, in the method of manufacturing the membrane element 12, when the long membrane element 40 is cut using the cutting device 42, the pair of heated cutting blades 43, 44 is closed and the long cutting blades 43, 44 are used. Sandwiching the membrane element 40, the channel material 21 at the cut point is heated at a heating temperature (for example, 120 to 240 ° C.) equal to or higher than the softening point T1 of the sheath material 52 for a predetermined time (for example, 1 to 10 seconds), and in this state Then, the long membrane element 40 is cut into a predetermined length A.

  When the long membrane element 40 is cut by the manufacturing method of the membrane element 12, the flow path material 21 at the cut portion is heated at a heating temperature equal to or higher than the softening point T1 of the sheath material 52 of the low melting point yarn 37. Therefore, the sheath material 52 of the low melting point yarn 37 of the pile yarn 27 of the flow path member 21 at the cut portion is melted, and the cut portion of the long membrane element 40 is welded with the resin of the melted sheath material 52 of the flow path member 21. Is closed and sealed. As a result, the sealing treatment of the upper edge 12a and the lower edge 12b of the membrane element 12 after cutting can be easily performed.

  Further, since the core material 51 of the low melting point yarn 37 has the softening point T2 higher than the softening point T1 of the sheath material 52, it is possible to prevent the core material 51 from being softened. Thus, by configuring the core material 51 using a resin having lower flexibility (or higher repulsion force or higher elasticity) than the sheath material 52, the low melting point yarn 37 has low flexibility (or repulsion). When the filter membrane 22 is joined to the channel material 21 by hot rolling, the channel material 21 is crushed and the minute voids 32 in the channel material 21 disappear. Absent.

  In the second embodiment, polyethylene is used as the material of the sheath material 52, but the material is not limited to this, and a polyolefin resin other than polyethylene may be used. Further, although polyethylene terephthalate is used as the material of the core material 51, the material is not limited to this, and a polyester resin other than polyethylene terephthalate may be used.

  In the second embodiment, all the low melting point yarns 37 of the pile yarn 27 may be core-sheath structure yarns having a core material 51 and a sheath material 52, or one of the low melting point yarns 37. A core-sheath structure thread may be used for the part and a polyethylene thread may be used for the rest.

In the second embodiment described above, the flow path member 21 at the cut position is heated at a heating temperature equal to or higher than the softening point T1 of the sheath material 52, and in this state, the long membrane element 40 is heated to a predetermined length A. Although cut into pieces, heating may be performed at a heating temperature that is equal to or higher than the softening point T1 of the sheath material 52 and lower than the softening point T2 of the high melting point yarn 38.
(Third Embodiment)
In the third embodiment, as shown in FIG. 14, the pile yarn 27 is a multifilament yarn in which a plurality of low melting point yarns and high melting point yarns are twisted together. For example, when using the "56T24" yarn as the pile yarn 27, out of the 24 twisted yarns twisted together, 12 yarns are low melting point yarns and the remaining 12 yarns are high melting point yarns.

  According to this, when the long membrane element 40 is cut into the predetermined length A, the flow path member 21 at the cut portion is heated at a heating temperature equal to or higher than the softening point T1 of the low melting point yarn of the pile yarn 27. Therefore, the low melting point yarn of the pile yarn 27 of the flow path material 21 at the cut portion is melted, and the cut portion of the long membrane element 40 (corresponding to the upper end edge 12a and the lower end edge 12b of the membrane element 12 after cutting). ) Is welded and blocked by the resin of the low melting point thread of the flow path member 21 to be sealed.

  In each of the above-described embodiments, as shown in FIG. 4, the filtration membranes 22 are bonded to both front and back surfaces of the flow path member 21, but the filtration membrane 22 is bonded to either one of the front and back surfaces of the flow path material 21, The other side may be watertight.

  In each of the above embodiments, as shown in FIG. 5, the filtration membrane 22 is formed by laminating the membrane sheet 34 and the non-woven fabric 35. However, the non-woven fabric 35 is not provided and only the membrane sheet 34 is provided. Good.

  In each of the above-mentioned embodiments, as shown in FIG. 3, the membrane element 12 is formed in a quadrangle, but it may be a polygon other than the quadrangle. Further, two of the four sides of the membrane element 12 (that is, the upper edge 12a and the lower edge 12b) are sealed, but a membrane element in which only one side or three or more sides are sealed is also possible. Good.

  In each of the above embodiments, the softening points T1 to T4 are used as indices, but the melting points may be used as indices instead of the softening points T1 to T4. Even when the melting point is used as an index, the same temperature relationship as that of the softening points T1 to T4 is established.

  Further, the materials and numerical values of polyethylene, polyethylene terephthalate, polytetrafluoroethylene, etc. shown in each of the above embodiments are merely examples, and the present invention is not limited to these.

5 Membrane separation device 11 Water collection case (support member)
12 Membrane Element 12a Upper Edge 12b Lower Edge 12c Left Edge (Unsealed Edge)
12d Right edge (edge not sealed)
15 Water collecting space 21 Channel material 22 Filtration membrane 27 Pile thread 29 Face thread 32 Gap 33 Permeate 34 Membrane sheet 37 Low melting point thread 38 High melting point thread 40 Long membrane element 43, 44 Cutting blade (cutting member)
51 core material 52 sheath material A predetermined length T1 softening point of low melting point yarn, softening point of sheath material T2 softening point of high melting point yarn, softening point of core material T4 softening point of membrane sheet

Claims (10)

A membrane element in which a filtration membrane and a flow path member are joined, and which has a plurality of edge portions,
The flow path material is made of a knitted fabric in which threads are knitted into a three-dimensional structure, and has a void inside which the permeated liquid that has permeated the filtration membrane flows,
The yarn constituting the flow path member has a plurality of low melting point yarns and a plurality of high melting point yarns having different softening points,
A film characterized in that at least one edge portion of a channel material is welded and sealed by melting a plurality of low-melting threads heated at a heating temperature equal to or higher than the softening point of the low-melting thread. element. The flow path member has a plurality of face threads forming a joint surface with the filtration membrane, and a plurality of pile threads bonded to the face threads,
Voids that allow permeate to flow are formed between multiple pile threads,
The membrane element according to claim 1, wherein the pile yarn has a low melting point yarn and a high melting point yarn. The membrane element according to claim 2, wherein the pile yarn is a multifilament yarn in which a low melting point yarn and a high melting point yarn are twisted together. At least a part of the low melting point yarn is formed of a core material and a sheath material that covers the core material,
The sheath material has a softening point lower than that of the high melting point yarn,
The membrane element according to any one of claims 1 to 3, wherein the core material has a softening point higher than that of the sheath material. The membrane element according to any one of claims 1 to 3, wherein the material of the low melting point yarn is a polyolefin resin. The membrane element according to claim 4, wherein the sheath material is a polyolefin resin. The membrane element according to any one of claims 1 to 6, wherein the material of the high melting point yarn is a polyester resin. The filtration membrane has a porous membrane sheet,
The membrane element according to any one of claims 1 to 7, wherein the membrane sheet has a softening point higher than that of the low melting point yarn of the channel material. A membrane separation device comprising the membrane element according to claim 1.
A support member supporting a plurality of membrane elements,
The support member has a water collecting space inside,
The unsealed edge of each membrane element is inserted into the water collection space,
A membrane separation device, wherein the permeated liquid that has permeated through the filtration membrane flows into the water collecting space of the support member from the unsealed edge portion of the membrane element through the void in the flow channel material. The method for producing a membrane element according to any one of claims 1 to 8,
A filtration membrane is joined to a long channel material to form a long membrane element,
By sandwiching the long membrane element with a pair of heated cutting members, the long membrane element is heated to a predetermined length while the flow path material at the cutting point is heated at a heating temperature equal to or higher than the softening point of the low melting point yarn. A method for producing a membrane element, which comprises cutting into pieces.

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