Roll-type membrane central tube and roll-type membrane element comprising roll-type membrane central tube

Abstract

The utility model provides a spiral-wound membrane central tube and a spiral-wound membrane element including the same, the spiral-wound membrane central tube comprises a tube body, a first water collecting hole and a second water collecting hole, the outer wall of the tube body comprises a first area and a second area, the first area is close to the center of the axial direction of the tube body, and the second area is close to at least one end of the tube body. The first water collecting holes are formed in the first area, the second water collecting holes are formed in the second area, and the hole diameter of the first water collecting holes is larger than that of the second water collecting holes. The spiral-wound membrane element comprises the spiral-wound membrane central tube. Due to the fact that the water flow of the outer wall of the pipe body is small at two ends and large in the middle, the area with large flow in the middle of the pipe body can be matched with large apertures, and the areas with small flow at two ends of the pipe body can be matched with small apertures. By reasonably designing the positions and sizes of the water collecting holes, the water collecting efficiency of the central pipe can be directly improved, the flow limiting problem is reduced, and the effect on a large-flow membrane element is more remarkable.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of water purifier, especially relates to a spiral wound membrane center tube and spiral wound membrane element containing it. BACKGROUND

[0002] The spiral wound membrane usually has a center tube structure, and the filter membrane is wound on the outer wall of the center tube. One of the main applications is to collect the purified water filtered by the membrane and output it to the outside of the structure. The existing center tube has a small number of surface water collection holes and uneven distribution. Generally, there are only two rows of water collection holes, and the water collection holes are not evenly distributed on the whole center tube, but are generally concentrated in the upper 2 / 3. This is mainly because it meets the demand of adapting the length of the center tube to multiple types of membrane elements. However, due to the different water flow rates at different positions on the surface of the center tube, the water flow rate is greater near the axial middle region of the center tube. Therefore, setting water collection holes only at the upper 2 / 3 of the center tube will result in uneven water collection efficiency of the center tube. Especially for large-flux membrane elements, this often leads to flow limitation. SUMMARY

[0003] The technical problem to be solved by the utility model is to overcome the defects of flow limitation caused by low water collection efficiency in the prior art, and to provide a spiral wound membrane center tube and a spiral wound membrane element containing the same.

[0004] The utility model solves the above technical problems by the following technical scheme:

[0005] The utility model provides a spiral wound membrane center tube, which comprises a tube body, a first water collection hole and a second water collection hole. The outer wall of the tube body comprises a first region and a second region. The first region is close to the center of the axial direction of the tube body, and the second region is close to at least one end of the tube body. The first water collection hole is arranged in the first region, and the second water collection hole is arranged in the second region. The aperture of the first water collection hole is larger than that of the second water collection hole.

[0006] In this scheme, due to the characteristics of the water flow rate of the outer wall of the tube body being small at both ends and large in the middle, the outer wall of the tube body comprises a first region and a second region. The first region is close to the axial center of the tube body, i.e. in the middle region of the axial direction of the tube body, and the second region is close to one end of the tube body, i.e. one of the two regions away from the middle region of the tube body. Different first water collection holes and second water collection holes are arranged in the first region and the second region, respectively, and the aperture of the first water collection hole is larger than that of the second water collection hole. Such a structure can match a larger aperture in the region of the tube body where the flow rate is large in the middle, and match a smaller aperture in the region of the tube body where the flow rate is small at both ends. By reasonably designing the position and size of the water collection hole, the water collection efficiency of the center tube can be directly improved, and the flow limitation problem can be reduced. The effect is more significant on large-flux membrane elements.

[0007] Preferably, the length of the first region in the axial direction of the tube body is at least 1 / 2 of the axial length of the tube body.

[0008] In this solution, the length of the first region in the axial direction of the tube body is not less than 1 / 2, which can expand the distribution range of the water collecting holes in the first region, meet the water collecting needs of the large flow area in the middle of the tube body, and effectively avoid flow restriction in water collecting.

[0009] Preferably, the outer wall of the tube body is provided with a first groove, and the first region is arranged on the wall surface of the first groove; and / or, the outer wall of the tube body is provided with a second groove, and the second region is arranged on the wall surface of the second groove.

[0010] In this solution, the first water collecting hole or the second water collecting hole is designed to sink and arranged in the first groove or the second groove, respectively, which can form a cavity between the water collecting hole and the flow guide structure such as the flow guide cloth. Compared with the flow guide cloth closely adhering to the water collecting hole to guide the water flow into the water collecting hole, the above structure can improve the flow guiding efficiency by guiding the water flow into the cavity through the flow guide cloth. For a large flow membrane element, in order to put more filter membrane pieces as much as possible, the flow guide cloth and other flow guide structures will use as thin material as possible. Thin flow guide cloth means that its flow guide channel is limited, especially when the flow guide cloth is closely adhered to the water collecting hole. At this time, if the flowable area of the water collecting is increased, the water collecting efficiency will be greatly improved.

[0011] Preferably, the outer wall of the tube body is provided with a welding region, and the welding region is provided with a welding bump for connecting with the flow guide cloth; wherein the welding region does not coincide with the first region in the radial and / or axial direction of the tube body; and / or, the welding region does not coincide with the second region in the radial and / or axial direction of the tube body.

[0012] In this solution, since the first region and the second region do not coincide with the welding region, the use of such a structure can avoid the overlap between the welding point and the water collecting hole during welding, so as to block the water collecting hole and affect the water collecting efficiency. Reserving the welding bump on the welding region to connect with the flow guide cloth and other flow guide structures can improve the welding strength of the flow guide cloth and other flow guide structures and the central tube. The larger the flow of the membrane element is, the more filter membrane pieces are needed, and the tension of the membrane element will also increase. Through the above structure, the firmness of the tube body and the flow guide cloth and other structures can be directly improved, so as to realize the improvement of the degree of tension that the membrane element can withstand.

[0013] Preferably, one end of the tube body connected to the water outlet pipe is provided with a third groove, the third groove is annularly arranged along the outer wall of the tube body, and the third groove is used for sealing connection between the sealing ring, the tube body and the water outlet pipe.

[0014] In the scheme, the annular sealing ring can be installed in the annular third groove, so as to ensure the sealing performance of the pipe body and the external water outlet pipe, avoid the leakage of the filtered liquid and the pollution of the filtered liquid.

[0015] Preferably, at least one end of the pipe body is provided with a fourth groove, the fourth groove is annularly arranged along the outer wall of the pipe body, and the fourth groove is used for sealing connection of the sealing strip and the membrane.

[0016] In the scheme, compared with the conventional point glue connection of the filtering membrane and the pipe body, the above structure can prevent the problem of sealing failure between the membrane and the pipe body caused by excessive tension of the membrane, the sealing strip can be installed in the fourth groove, the multi-layer membrane can be pressed into the groove by the sealing strip, and the sealing strength of the membrane can be effectively improved. Especially, the needs of the membrane element with large flow can be met.

[0017] Preferably, the roll type membrane center pipe further comprises an extension part, one end of the extension part is detachably connected to one end of the pipe body, and the other end of the extension part is connected to a power source.

[0018] In the scheme, compared with the conventional point glue connection of the filtering membrane and the pipe body, the above structure can prevent the problem of sealing failure between the membrane and the pipe body caused by excessive tension of the membrane, the sealing strip can be installed in the fourth groove, the multi-layer membrane can be pressed into the groove by the sealing strip, and the sealing strength of the membrane can be effectively improved. Especially, the needs of the membrane element with large flow can be met.

[0019] Preferably, the extension part and the pipe body are provided with a protrusion part at one end of the extension part and a recess part at the other end, and the protrusion part is matched with the recess part.

[0020] In the scheme, the extension part and the pipe body are connected through the splicing design of the protrusion part and the recess part, so as to meet the strength requirement and realize the positioning effect on the basis of detachable connection, facilitate the installation and disassembly of the extension part.

[0021] Preferably, one end of the extension part connected to the power source is a polyhedron, and the output end of the power source is matched with the shape of the polyhedron.

[0022] In the scheme, compared with the structure that one end of the extension part connected to the power source is a polygonal cylinder, the above structure adopts a polyhedral structure, so that the output end of the power source is a polygonal cylinder, which can prevent the power end of the extension part from being cracked due to excessive stress. Because the output end of the power source is usually made of metal material and has high hardness, the polygonal cylinder made of harder material can drive the power end of the extension part made of softer material to be stressed without slipping, cracking or being stuck.

[0023] A roll type membrane element comprises the roll type membrane center pipe as described above.

[0024] The positive progress effect of the utility model lies in that:

[0025] The roll type membrane center pipe and the roll type membrane element comprising the same of the utility model have the characteristics that the water flow of the outer wall of the pipe body is small at both ends and large in the middle, the outer wall of the pipe body is divided into a first region and a second region, the first region is close to the axial center of the pipe body, that is, in the middle region of the axial direction of the pipe body, the second region is close to both ends of the pipe body, that is, the region on both sides away from the middle region of the pipe body, the first water collecting hole and the second water collecting hole with different hole diameters are arranged in the first region and the second region respectively, and the first water collecting hole is larger than the second water collecting hole. Such a structure can realize the matching of a larger hole diameter in the region with a large flow in the middle of the pipe body and the matching of a smaller hole diameter in the region with a small flow at both ends of the pipe body. The water collecting efficiency of the center pipe can be directly improved, the flow limiting problem can be reduced, and the effect is more significant on the membrane element with large flow. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a perspective view of the roll type membrane center pipe of the utility model embodiment

[0027] Figure 2 It is a structural schematic view of one end of the roll type membrane center pipe connected with the water outlet pipe of the utility model embodiment

[0028] Figure 3 It is a structural schematic view of the other end of the roll type membrane center pipe away from the water outlet pipe of the utility model embodiment

[0029] Figure 4 It is a structural schematic view of the extension part of the utility model embodiment

[0030] BRIEF DESCRIPTION OF DRAWINGS:

[0031] The roll type membrane center pipe 100

[0032] The pipe body 1

[0033] The first water collecting hole 2

[0034] The second water collecting hole 3

[0035] The first region 4

[0036] The second region 5

[0037] The water collecting hole setting region 6

[0038] The first groove 7

[0039] The second groove 8

[0040] The welding region 9

[0041] The third groove 10

[0042] The fourth groove 11

[0043] extension part 12

[0044] first connecting part 13

[0045] second connecting part 14

[0046] protrusion part 15

[0047] recess part 16

[0048] reinforcing rib 17 DETAILED DESCRIPTION

[0049] The utility model will be described below in a preferred embodiment and in conjunction with the drawings.

[0050] As Figures 1-4 shown, the embodiment provides a roll type membrane center pipe 100, which comprises a pipe body 1, a first water collecting hole 2 and a second water collecting hole 3, the outer wall of the pipe body 1 comprises a first area 4 and a second area 5, the first area 4 is close to the axial center of the pipe body 1, the second area 5 is close to at least one end of the pipe body 1, the first water collecting hole 2 is arranged in the first area 4, the second water collecting hole 3 is arranged in the second area 5, and the aperture of the first water collecting hole 2 is greater than the aperture of the second water collecting hole 3.

[0051] Therefore, due to the characteristic that the water flow of the outer wall of the pipe body 1 is large in the middle and small at both ends, the outer wall of the pipe body 1 comprises the first area 4 and the second area 5, the first area 4 is close to the axial center of the pipe body 1, i.e. in the middle area of the axial direction of the pipe body 1, the second area 5 is close to one of the two side areas of the pipe body 1 away from the middle area of the pipe body 1, the first water collecting hole 2 and the second water collecting hole 3 with different apertures are arranged in the first area 4 and the second area 5 respectively, and the first water collecting hole 2 is greater than the second water collecting hole 3. Such a structure can realize that the area with large flow in the middle of the pipe body 1 matches a larger aperture, and the area with small flow at both ends of the pipe body 1 matches a smaller aperture. By reasonably designing the position and size of the water collecting hole, the water collecting efficiency of the center pipe can be directly improved, the flow limiting problem can be reduced, and the effect is more significant on the membrane element with large flow.

[0052] In the embodiment, as Figure 1 shown, a plurality of water collecting hole arrangement areas 6 are arranged along the axial direction of the pipe body 1, each water collecting hole arrangement area 6 is sequentially connected by the second area 5, the first area 4 and the second area 5 from one end to the other end of the axial direction of the pipe body 1. The plurality of water collecting hole arrangement areas 6 are arranged along the radial direction of the pipe body 1. The first water collecting hole 2 in the first area 4 is a plurality of holes, and the second water collecting hole 3 in the second area 5 is also a plurality of holes. The aperture of the first water collecting hole 2 is greater than the aperture of the second water collecting hole 3. Among them, the first water collecting hole 2 can be an elliptical hole, and the second water collecting hole 3 is a circular hole, the major axis of the elliptical hole is twice the diameter of the circular hole. As Figure 1For example, the embodiment takes the water collecting hole setting area 6 as an example of 4 groups for illustrative expression. In other embodiments, the number of water collecting hole setting areas 6 can be adjusted according to actual needs, and the specific number of water collecting hole setting areas 6 is not limited herein. In other embodiments, each group of water collecting hole setting areas 6 can also be arranged along the radial direction of the pipe body 1, and multiple groups of water collecting holes are arranged along the axial direction of the pipe body 1.

[0053] Specifically, the length of the first area 4 in the axial direction of the pipe body 1 is at least 1 / 2 of the axial length of the pipe body 1.

[0054] In this way, the length of the first area 4 in the axial direction of the pipe body 1 is not less than 1 / 2, which can expand the distribution range of the water collecting holes in the first area 4, meet the water collecting needs of the large flow area in the middle of the pipe body 1, and effectively avoid flow restriction in water collecting.

[0055] In the embodiment, as shown in Figure 1 the center of the first area 4 coincides with the center of the pipe body 1 in the axial direction, and occupies 1 / 2 of the length of the pipe body 1. The first area 4 is connected to the second area 5 at both ends, and each second area 5 occupies 1 / 4 of the axial direction of the pipe body 1. In other embodiments, a person skilled in the art can adjust the proportion range.

[0056] Specifically, the outer wall of the pipe body 1 is provided with a first groove 7, and the first area 4 is arranged on the wall surface of the first groove 7; and / or, the outer wall of the pipe body 1 is provided with a second groove 8, and the second area 5 is arranged on the wall surface of the second groove 8.

[0057] In this way, the first water collecting hole 2 or the second water collecting hole 3 is designed to sink, and is arranged in the first groove 7 or the second groove 8, respectively, to form a cavity between the water collecting hole and the flow guide structure such as the flow guide cloth. Compared with the flow guide cloth tightly adhering to the water collecting hole to guide the water flow into the water collecting hole, the above structure can improve the flow guide efficiency by guiding the water flow into the cavity through the flow guide cloth. For a large flow membrane element, in order to reduce the diameter of the rolled membrane as much as possible and place more filter membrane pieces, the flow guide structure such as the flow guide cloth will use as thin material as possible. Thin flow guide cloth means that its flow guide channel is limited, especially when the flow guide cloth is tightly adhered to the water collecting hole. At this time, increasing the flowable area of the water collecting hole will greatly improve the water collecting efficiency.

[0058] In the embodiment, as shown in Figure 1As shown, the first groove 7 and the second groove 8 can be arranged axially along the pipe body 1 or radially. The first groove 7 can coincide with the first area 4, and the second groove 8 can coincide with the second area 5, that is, the first groove 7 is arranged in the middle area of the pipe body 1, and the second groove 8 is arranged in the end area of the pipe body 1. The first groove 7 and the second groove 8 can also be connected to form a whole, and the whole groove can coincide with the water collecting hole arrangement area 6. The first water collecting hole 2 and the second water collecting hole 3 can be arranged on the bottom wall of the first groove 7 and the second groove 8, respectively, or on the side wall.

[0059] Specifically, the outer wall of the pipe body 1 is provided with a welding area 9, and the welding area 9 is provided with a welding bump for connecting with the flow guide cloth. The welding area is not coincident with the second area 5 in the radial and / or axial direction of the pipe body 1.

[0060] Therefore, since the first area 4 and the second area 5 do not coincide with the welding area, the welding area can avoid overlapping between the welding point and the water collecting hole during welding, thereby blocking the water collecting hole and affecting the water collecting efficiency. The welding bump reserved on the welding area 9 is connected with the flow guide cloth and other flow guide structures, which can improve the welding strength between the flow guide cloth and the center pipe. The greater the flow capacity of the membrane element is, the more the number of filter membranes required will be, and the tension of the membrane element will also increase. The above structure can directly improve the firmness of the pipe body 1 and the flow guide cloth and other structures, thereby improving the tension that the membrane element can withstand.

[0061] In the embodiment, as shown, Figure 1 The welding area is arranged between two adjacent groups of water collecting hole arrangement areas 6, and the length of the welding area can be the same as that of the water collecting hole arrangement area 6. Preferably, the welding bump is a plurality of welding bumps uniformly arranged in the welding area.

[0062] Specifically, the pipe body 1 is provided with a third groove 10 at one end of the water outlet pipe, and the third groove 10 is arranged annularly along the outer wall of the pipe body 1. The third groove 10 is used for sealing connection between the pipe body 1 and the water outlet pipe.

[0063] Therefore, the annular sealing ring can be installed in the annular third groove 10, so as to ensure the sealing performance of the pipe body 1 and the external water outlet pipe, and avoid the escape of filtered liquid and the pollution of filtered liquid.

[0064] In the embodiment, the pipe body 1 is inserted into the external water outlet pipe, and the sealing ring is arranged in the third groove 10. The sealing ring protrudes from the outer wall of the pipe body 1 to fill the gap between the pipe body 1 and the water outlet pipe, thereby achieving the sealing effect. The third groove 10 is a plurality of grooves, as shown in Figure 2As shown, the embodiment is schematically expressed by taking the number of the third grooves 10 as 2, and in other embodiments, the number of the third grooves 10 can be adjusted according to actual needs, and the specific number of the third grooves 10 is not limited herein.

[0065] Specifically, at least one end of the tube body 1 is provided with a fourth groove 11, and the fourth groove 11 is annularly arranged along the outer wall of the tube body 1, and the fourth groove 11 is used for sealing strip sealing connection of the membrane and the tube body 1.

[0066] In this way, compared with the conventional glue connection of the filtering membrane and the tube body 1, the above structure can prevent the problem of sealing failure between the membrane and the tube body 1 caused by excessive tension of the membrane, the sealing strip can be installed in the fourth groove 11, and the sealing strip can be used to press the multi-layer membrane into the groove, which can effectively improve the sealing strength of the membrane, and especially can meet the needs of the membrane element with large flow.

[0067] In the embodiment, as shown, Figure 1 Preferably, the fourth groove 11 is opened at both ends of the tube body 1, and glue sealing can be assisted on the basis of the sealing strip. The fourth groove 11 opened at the end close to the water outlet pipe of the tube body 1 is arranged between the third groove 10 and the water collecting hole, and the fourth groove 11 opened at the end away from the water outlet pipe of the tube body 1 extends into the inner cavity of the central pipe and blocks the inner cavity, so as to realize the water outlet at one end of the central pipe and the sealing at the other end. Among them, the fourth groove 11 is a plurality of strips, as shown, Figure 2 and Figure 3 As shown, the embodiment is schematically expressed by taking the number of the fourth grooves 11 as 4, and two are arranged at each end of the tube body 1. In other embodiments, the number of the fourth grooves 11 can be adjusted according to actual needs, and the specific number of the fourth grooves 11 is not limited herein.

[0068] Specifically, the roll type membrane central pipe 100 further comprises an extension part 12, one end of the extension part 12 is detachably connected to one end of the tube body 1, and the other end of the extension part 12 is connected to a power source.

[0069] In this way, compared with the power end integrally formed in the past, which needs to be cut off after the roll membrane is completed, the extension part 12 in the above structure provides torque as the power end when the central pipe rolls the membrane, and is detachably installed at one end of the tube body 1, which is convenient to remove after the roll membrane operation is completed, can reduce the operation steps of cutting the pipe and reduce the waste of raw materials.

[0070] In the embodiment, the extension part 12 can be connected to one end of the pipe body 1 connected to the water outlet pipe, or can be connected to one end of the pipe body 1 away from the water outlet pipe. Preferably, the extension part 12 is connected to one end away from the water outlet pipe. This is because the inside of one end away from the water outlet pipe is blocked, which can provide higher strength for the rotation of the extension part 12. In addition, the extension part 12 can be detachably connected to the pipe body 1 in the form of a screw bolt or the like. The material of the extension part can be the same as that of the pipe body 1, and can be rolled together with the pipe body 1; or can be a metal material, and can be rolled separately from the pipe body 1 and connected to the power source device; the connection mode can be adjusted according to the actual situation of the film rolling workshop.

[0071] Specifically, the extension part 12 and the pipe body 1 are provided with a protrusion 15 at one end of the extension part 12 and a recess 16 at the other end, and the protrusion 15 matches the recess 16.

[0072] In this way, the connection between the extension part 12 and the pipe body 1 is designed by splicing the protrusion 15 and the recess 16, which can achieve the positioning effect while meeting the strength requirement on the basis of detachable connection, facilitating the installation and disassembly of the extension part 12.

[0073] In the embodiment, as shown in Figure 4 the extension part 12 is provided with a first connecting part 13 at one end connected to the pipe body 1, and the first connecting part 13 is a column with a diameter smaller than that of the pipe body 1. The first connecting part 13 can extend into the pipe body 1 by a depth of 20-25 mm. A plurality of protrusions 15 are arranged on the side wall of the first connecting part 13, and the protrusions 15 protrude from the surface of the side wall of the first connecting part 13. The pipe body 1 is provided with a U-shaped recess 16 at one end connected to the extension part 12, and the protrusions 15 match the recess 16.

[0074] Specifically, one end of the extension part 12 connected to the power source is a polyhedron, and the output end of the power source matches the shape of the polyhedron.

[0075] In this way, compared with the structure in which the one end of the extension part 12 connected to the power source is a polygonal cylinder, the above structure adopts a polyhedral structure, so that the output end of the power source is a polygonal cylinder, which can ensure that the power end of the extension part 12 will not crack due to excessive force. This is because the output end of the power source is usually made of metal material and has high hardness. For the extension part 12 with relatively low hardness, the polygonal cylinder made of relatively hard material can drive the power end of the extension part 12 made of relatively soft material to be subjected to force without slipping, cracking or being stuck.

[0076] In the embodiment, as shown in Figure 4As shown, the second connecting part 14 is a solid polyhedron, preferably a hexagonal prism. The output end of the power source is an internal hexagonal cylinder, and the output end of the internal hexagonal cylinder is nested on the second connecting part 14 of the hexagonal prism. The length of the second connecting part 14 can be adjusted according to the needs of the membrane element, which is not limited in the embodiment. In other embodiments, those skilled in the art can also use other shapes of the second connecting part 14.

[0077] Specifically, in order to further meet the needs of large flux and high strength central pipe, the diameter and wall thickness of the central pipe can also be increased. According to the calculation of the pipe body 1 diameter D = 2√(flow Q / π·V), if a membrane element with a flow of 2000G, i.e. 5.25L / min, is needed, the inner diameter of the pipe body 1 needs to be ≥φ20mm, and in order to ensure the strength of the pipe body 1, the wall thickness of the pipe body 1 needs to be 3-4mm, i.e. the outer diameter of the pipe body 1 is φ26-33mm, and the length of the pipe body 1 can be selected according to the actual needs of the membrane element. Such a spiral membrane central pipe 100 is sufficient to meet the flux demand of about 2000G in terms of strength and size, and will not become a flow limiting reason.

[0078] Specifically, as shown in Figure 1 and Figure 3 The pipe body 1 is provided with a reinforcing rib 17 away from the connecting water outlet pipe, which can improve the strength and meet the demand of large-diameter membrane with large tension.

[0079] The embodiment also provides a spiral membrane element, which comprises the spiral membrane central pipe 100 as above.

[0080] Therefore, due to the characteristics of the water flow of the outer wall of the pipe body 1 being small at both ends and large in the middle, the outer wall of the pipe body 1 is divided into a first area 4 and a second area 5, the first area 4 is close to the axial center of the pipe body 1, i.e. in the middle area of the pipe body 1, the second area 5 is close to both ends of the pipe body 1, i.e. the two side areas away from the middle area of the pipe body 1, the first water collecting hole 2 and the second water collecting hole 3 with different hole diameters are arranged in the first area 4 and the second area 5 respectively, and the first water collecting hole 2 is larger than the second water collecting hole 3. Such a structure can realize the matching of larger hole diameter in the middle area of the pipe body 1 with large flow, and the matching of smaller hole diameter in the two end areas of the pipe body 1 with small flow. By reasonably designing the position and size of the water collecting hole, the water collecting efficiency of the central pipe can be directly improved, and the flow limiting problem can be reduced, which is more significant in a large flow membrane element.

[0081] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, but these changes and modifications all fall within the protection scope of the present application.

Claims

1. A spiral wound center tube, characterized by, The pipe body includes a first area close to the center of the axial direction of the pipe body and a second area close to at least one end of the pipe body, the first water collecting hole is arranged in the first area, and the second water collecting hole is arranged in the second area.

2. The spiral-wound central tube of claim 1 wherein, The length of the first area along the axial direction of the pipe body accounts for at least 1 / 2 of the axial length of the pipe body.

3. The spiral-wound central tube of claim 1 wherein, The outer wall of the pipe body is provided with a first groove, and the first area is arranged on the wall surface of the first groove. The outer wall of the pipe body is provided with a second groove, and the second area is arranged on the wall surface of the second groove.

4. The spiral-wound central tube of claim 1 wherein, The outer wall of the pipe body is provided with a welding area, and the welding area is provided with a welding bump for connecting with a flow guide cloth. The welding area does not overlap with the first area in the radial and / or axial direction of the pipe body. The welding area does not overlap with the second area in the radial and / or axial direction of the pipe body.

5. The spiral-wound central tube of claim 1 wherein, One end of the pipe body connected to the water outlet pipe is provided with a third groove arranged annularly along the outer wall of the pipe body, and the third groove is used for sealing connection of the pipe body and the water outlet pipe by a sealing ring.

6. The spiral-wound central tube of claim 1 wherein, At least one end of the pipe body is provided with a fourth groove arranged annularly along the outer wall of the pipe body, and the fourth groove is used for sealing connection of the diaphragm and the pipe body by a sealing strip.

7. The spiral-wound central tube of claim 1 wherein, The pipe body further includes an extension part, one end of the extension part is detachably connected to one end of the pipe body, and the other end of the extension part is connected to a power source.

8. The spiral wound center pipe as claimed in claim 7, wherein, The extension part and the pipe body are provided with a protruding part at the end towards the extension part and a recessed part at the other end, and the protruding part matches the recessed part.

9. The spiral wound center pipe as claimed in claim 7, wherein, One end of the extension part connected to the power source is a polyhedron, and the output end of the power source matches the shape of the polyhedron.

10. A spiral-wound membrane element characterized by, The pipe body further includes the roll type membrane center pipe according to any one of claims 1-9.

Images