Composite spiral-wound membrane element

Abstract

The utility model relates to the technical field of membrane separation, in particular to a composite spiral-wound membrane element. The membrane element comprises a central water collecting pipe, a water purification membrane assembly and an appearance protection membrane, the water purification membrane component is wound on the central water collecting pipe by taking one end of the water purification membrane component in the length direction as a starting point; the water purification membrane assembly comprises a first fresh water flow guide net, a composite dechlorination water purification membrane layer, a staggered folding membrane, a concentrated water separation net and a second fresh water flow guide net; the appearance protection film is wound on the water purification film assembly and is used for setting the water purification film assembly on the central water collecting pipe. According to the utility model, the composite spiral-wound membrane element with high removal rate of residual chlorine in produced water and low bacterial content can be prepared.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of membrane separation technology, specifically relates to a composite roll type membrane element. BACKGROUND

[0002] The traditional roll type membrane element adopts the following rolling method: a membrane sheet (such as a reverse osmosis membrane sheet) is folded into an n shape along the length direction, and a concentrated water separation net is placed in the middle of the n shape; a fresh water separation net is placed on the folded membrane sheet, and a resin sealing agent is coated on the three opening connecting edges of the membrane sheet to adhere the fresh water separation net to the membrane sheet; the membrane sheet is wound on a central water collecting pipe in a spiral manner to form a roll type membrane element. When the roll type membrane element is applied, the pure water filtered by the membrane sheet is directly connected to the fresh water separation net and gathered on the central water collecting pipe, and the pure water is collected and produced by the central water collecting pipe. However, the pure water produced by the roll type membrane element has the problems of low residual chlorine removal rate and high bacterial content.

[0003] In summary, it is necessary to develop a composite roll type membrane element to solve the problems of low residual chlorine removal rate and high bacterial content of the pure water produced by the existing roll type membrane element. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a composite roll type membrane element, and the specific technical scheme is as follows:

[0005] A composite roll type membrane element, comprising a central water collecting pipe, a pure water membrane assembly and an appearance protection film;

[0006] The pure water membrane assembly is wound on the central water collecting pipe with one end in the length direction as a starting point;

[0007] The pure water membrane assembly comprises a first fresh water guide net, a composite chlorine removal pure water membrane layer, a staggered folded membrane sheet, a concentrated water separation net and a second fresh water guide net;

[0008] The starting point is arranged on one end in the length direction of the first fresh water guide net; the composite chlorine removal pure water membrane layer is adhered and arranged on the first fresh water guide net, and the distance from the starting point is more than one time of the circumference of the central water collecting pipe; the length of the composite chlorine removal pure water membrane layer can be wound on the central water collecting pipe for at least one turn;

[0009] The staggered folded membrane sheet comprises integrally connected long membrane sheet pages and short membrane sheet pages; the concentrated water separation net is arranged in the middle of the staggered folded membrane sheet; a plurality of staggered folded membrane sheets containing the concentrated water separation net are sequentially and staggeredly arranged on the first fresh water guide net, and the second fresh water guide net is adhered and arranged between every two adjacent staggered folded membrane sheets; the staggered folded membrane sheet in contact with the first fresh water guide net is adhered and arranged on the first fresh water guide net;

[0010] When the staggered layers are stacked, the connecting ends of each staggered folded membrane are sequentially moved away from the composite dechlorination and water purification membrane layer, and the short membrane sheets in each staggered folded membrane sheet are closer to the first freshwater guide net than the long membrane sheets.

[0011] The protective film is wound around the water purification membrane assembly to shape and install the water purification membrane assembly on the central water collection pipe; wherein, an inlet and an outlet are reserved on the protective film.

[0012] Optionally, the composite dechlorination and water purification membrane layer includes a carbon fiber membrane layer and an antibacterial membrane layer stacked together, or it includes a carbon fiber membrane layer and an antibacterial membrane layer spaced apart along the length direction of the first freshwater guide net.

[0013] When the carbon fiber membrane layer and the antibacterial membrane layer are spaced apart along the length of the first freshwater guide net, the lengths of both the carbon fiber membrane layer and the antibacterial membrane layer can be wound around the central water collection pipe at least once.

[0014] Optionally, a first sealing adhesive line is applied to the first freshwater guiding net; there are two first sealing adhesive lines, which are arranged parallel to each other at both ends along the wide side of the first freshwater guiding net; the composite dechlorination water purification membrane layer is bonded to the first freshwater guiding net through the first sealing adhesive line.

[0015] Alternatively, a first sealing adhesive line is applied to the composite dechlorination water purification membrane layer; there are two first sealing adhesive lines, which are arranged parallel to each other at both ends along the wide side of the composite dechlorination water purification membrane layer; the first freshwater guide net is bonded to the composite dechlorination water purification membrane layer through the first sealing adhesive lines.

[0016] The length of the first sealing adhesive line is equal to the length of the composite dechlorination and water purification membrane layer.

[0017] Optionally, the shortest distance between the first sealing glue line and the end of the first freshwater guide net in the wide side direction is 10-25mm; the width of the first sealing glue line is 4-8mm.

[0018] Optionally, a second sealing adhesive line is applied to the outer surface of each of the three open ends of the staggered folded diaphragm; each of the second sealing adhesive lines forms a U-shaped structure.

[0019] Optionally, both the first and second sealing lines may use polyurethane adhesive as the sealant.

[0020] Optionally, multiple water collection holes are spaced apart on the pipe wall along the length of the central water collection pipe, and all of them are covered by the composite dechlorination and water purification membrane layer wound around the central water collection pipe.

[0021] Optionally, the length of the first freshwater guide net is greater than the length of the second freshwater guide net.

[0022] Optionally, the length of the second freshwater guide net is greater than or equal to the length of the long membrane sheet page in the staggered folding membrane sheet.

[0023] Optionally, the composite type spiral membrane element comprises any one of a reverse osmosis spiral membrane element, a nanofiltration spiral membrane element and an ultrafiltration spiral membrane element.

[0024] The technical scheme of the utility model has at least the following beneficial effects:

[0025] The composite type spiral membrane element provided by the utility model can produce a composite type spiral membrane element with high residual chlorine removal rate and low bacterial content.

[0026] In addition to the purposes, features and advantages described above, the utility model has other purposes, features and advantages. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which form a part of the present application, are used to provide a further understanding of the present application, and the illustrative embodiments of the present application and their description are used to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0028] Figure 1 is a structural schematic view of the composite chlorine removal and water purification membrane layer being adhesively arranged on the first freshwater guide net and before being wound in example 1;

[0029] Figure 2is the structural schematic view of sequentially arranging each staggered folding membrane piece on the first fresh water guide net and before rolling in example 1 (the arrow direction in the figure represents the winding direction);

[0030] Wherein, 1, the first fresh water guide net, 2, the central water collecting pipe, 3, the composite chlorine removal water purification membrane layer, 4, the staggered folding membrane piece, 5, the concentrated water separation net, 6, the second fresh water guide net, 7, the first sealing glue line, 8, the second sealing glue line. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art belong to the protection scope of the utility model.

[0032] Example 1:

[0033] Referring to Figures 1-2 A composite type roll type membrane element, comprising a central water collecting pipe 2 (the diameter is 17mm, and the length is 298mm), a water purification membrane assembly and an appearance protection film;

[0034] The water purification membrane assembly is wound and arranged on the central water collecting pipe 2 with one end in the length direction as a starting point;

[0035] The water purification membrane assembly comprises a first fresh water guide net 1 (the material is polyethylene terephthalate), a composite chlorine removal water purification membrane layer 3, a staggered folding membrane piece 4, a concentrated water separation net 5 and a second fresh water guide net 6;

[0036] The starting point is arranged on one end in the length direction of the first fresh water guide net 1; the composite chlorine removal water purification membrane layer 3 is adhesively arranged on the first fresh water guide net 1, and the distance from the starting point is more than one time of the circumference of the central water collecting pipe 2, so that the first fresh water guide net 1 can be wound on the central water collecting pipe 2 at least one time, which increases the water purification contact area of the composite chlorine removal water purification membrane layer 3 wound on the central water collecting pipe 2 subsequently, and effectively improves the water flow permeability; the length of the composite chlorine removal water purification membrane layer 3 can be wound and arranged on the central water collecting pipe 2 at least one time, so as to ensure that all water bodies can be purified by the composite chlorine removal water purification membrane layer 3;

[0037] The dislocation folded membrane sheet 4 comprises long and short membrane sheet pages connected integrally; the concentrated water separation net 5 (made of polypropylene) is arranged in the middle of the dislocation folded membrane sheet 4; a plurality of (such as 1-20, and 2 are selected in particular) dislocation folded membrane sheets 4 containing the concentrated water separation net 5 are sequentially and dislocationally stacked on the first fresh water guide net 1, and the second fresh water guide net 6 (made of polyethylene terephthalate) is arranged between each adjacent two dislocation folded membrane sheets 4; the dislocation folded membrane sheet 4 in contact with the first fresh water guide net 1 is arranged on the first fresh water guide net 1;

[0038] When being stacked in dislocation, the connecting end of each dislocation folded membrane sheet 4 is sequentially away from the composite chlorine-removing and purifying membrane layer 3, and the short membrane sheet page in each dislocation folded membrane sheet 4 is closer to the first fresh water guide net 1 than the long membrane sheet page;

[0039] The dislocation folded membrane sheet 4 and the sequential and dislocationally stacked dislocation folded membrane sheets 4 are used to improve the effective membrane area of the dislocation folded membrane sheet 4 after being rolled;

[0040] The appearance protection film (made of biaxially oriented polypropylene film; not shown in the figure) is wound on the purifying membrane assembly, used to press and fix the purifying membrane assembly on the central water collecting pipe 2, and ensure the stability of the structure of the purifying membrane assembly during water purification; wherein, the water inlet and the water outlet are reserved on the appearance protection film.

[0041] The composite chlorine-removing and purifying membrane layer 3 comprises a carbon fiber membrane layer (specifically, an activated carbon fiber felt) and a bacteriostatic membrane layer (specifically, a bacteriostatic membrane made of quaternary ammonium salt) stacked, or comprises a carbon fiber membrane layer and a bacteriostatic membrane layer arranged along the length direction of the first fresh water guide net 1. When the carbon fiber membrane layer and the bacteriostatic membrane layer are stacked, the carbon fiber membrane layer is closer to the first fresh water guide net 1 than the bacteriostatic membrane layer, or the bacteriostatic membrane layer is closer to the first fresh water guide net 1 than the carbon fiber membrane layer; in this embodiment, the carbon fiber membrane layer is closer to the first fresh water guide net 1 than the bacteriostatic membrane layer. When the carbon fiber membrane layer and the bacteriostatic membrane layer are arranged along the length direction of the first fresh water guide net 1, the carbon fiber membrane layer is closer to the central water collecting pipe 2 than the bacteriostatic membrane layer, or the bacteriostatic membrane layer is closer to the central water collecting pipe 2 than the carbon fiber membrane layer, and the carbon fiber membrane layer and the bacteriostatic membrane layer are wound on the central water collecting pipe 2 with the first fresh water guide net 1 at least one turn, so as to ensure that all water bodies can be purified by the composite chlorine-removing and purifying membrane layer 3.

[0042] A first sealant line 7 is coated on the first freshwater guide net 1; the first sealant line 7 is two parallel lines arranged along the two ends of the first freshwater guide net 1 in the width direction; the composite chlorine-removing water purification membrane layer 3 is adhered to the first freshwater guide net 1 through the first sealant line 7;

[0043] Alternatively, a first sealant line 7 is coated on the composite chlorine-removing water purification membrane layer 3; the first sealant line 7 is two parallel lines arranged on the two ends of the composite chlorine-removing water purification membrane layer 3 in the width direction; the first freshwater guide net 1 is adhered to the composite chlorine-removing water purification membrane layer 3 through the first sealant line 7;

[0044] The length of the first sealant line 7 is equal to the length of the composite chlorine-removing water purification membrane layer 3, which ensures that the composite chlorine-removing water purification membrane layer 3 is effectively sealed at both ends in the width direction, so as to be fully adsorbed and purified in the subsequent water body.

[0045] The shortest distance between the first sealant line 7 and the end of the first freshwater guide net 1 in the width direction is 10-25 mm (specifically 20 mm), which ensures the maximum effective membrane area; the width of the first sealant line 7 is 4-8 mm (specifically 6 mm), which ensures that the composite chlorine-removing water purification membrane layer 3 and the first freshwater guide net 1 are firmly adhered to each other, achieving a sealing effect, and ensuring that the water purified by the combination of the composite chlorine-removing water purification membrane layer 3 and the first freshwater guide net 1 is collected in the sealed area surrounded by the first sealant line 7 and then discharged into the central water collecting pipe 2.

[0046] A second sealant line 8 is coated on the outer surface of each of the three open ends of the staggered folded membrane 4; each of the second sealant lines 8 forms a U-shaped structure, which ensures that the water preliminarily purified by the staggered folded membrane 4 flows into the U-shaped structure, and the water is directed to the sealed area formed by the first freshwater guide net 1, the first sealant line 7 and the composite chlorine-removing water purification membrane layer 3 through the sealing effect of the edge of the U-shaped structure, and is fully adsorbed and purified.

[0047] The sealant used in the first sealant line 7 and the second sealant line 8 is polyurethane glue (i.e. polyurethane resin), which not only has good penetration rate for the staggered folded membrane 4, the first freshwater guide net 1, the second freshwater guide net 6 and the composite chlorine-removing water purification membrane layer 3, ensuring firm adhesion, but also has certain fluidity to reduce the winding difficulty.

[0048] A plurality of (specifically eleven) water collecting holes are arranged on the pipe wall in the length direction of the central water collecting pipe 2, and are covered by the composite chlorine-removing water purification membrane layer 3, ensuring that all the water can be purified by the composite chlorine-removing water purification membrane layer 3.

[0049] The length of the first freshwater guide net 1 is greater than the length of the second freshwater guide net 6, ensuring the successful completion of the rolling operation.

[0050] The length of the second freshwater guide net 6 is greater than or equal to the length of the long membrane sheet page in the staggered folded membrane sheet 4, ensuring that the staggered folded membrane sheet 4 can be completely covered by the second freshwater guide net 6 when the second freshwater guide net 6 is stacked with the staggered folded membrane sheet 4, facilitating effective purification of the water body.

[0051] The composite type rolling membrane element includes any one of a reverse osmosis rolling membrane element, a nanofiltration rolling membrane element, and an ultrafiltration rolling membrane element. When the membrane sheet is a reverse osmosis membrane, the composite type rolling membrane element is a reverse osmosis rolling membrane element. When the membrane sheet is a nanofiltration membrane, the composite type rolling membrane element is a nanofiltration rolling membrane element. When the membrane sheet is an ultrafiltration membrane, the composite type rolling membrane element is an ultrafiltration rolling membrane element. In the present embodiment 1, the composite type rolling membrane element is a reverse osmosis rolling membrane element.

[0052] The operation principle of the composite type rolling membrane element prepared in the present embodiment 1 for purifying the water body is as follows: the staggered folded membrane sheet 4 containing the concentrated water separation net 5 is first used to complete the preliminary purification of the water body; and then the combination of the first freshwater guide net 1, the second freshwater guide net 6, and the composite chlorine removal water purification membrane layer 3 is used to complete the sufficient adsorption purification of the water body, so that the residual chlorine removal rate of the produced water is high and the bacterial content is low.

[0053] Comparative Example 1:

[0054] Unlike the present embodiment 1, the composite chlorine removal water purification membrane layer 3 is not provided.

[0055] Comparative Example 2:

[0056] Unlike the present embodiment 1, the composite chlorine removal water purification membrane layer 3 is replaced by a carbon fiber membrane layer, and the length of the carbon fiber membrane layer is insufficient for one turn around the central water collection pipe 2; in addition, a carbon fiber membrane layer is also provided in the staggered folded membrane sheet 4, which is stacked with the concentrated water separation net 5.

[0057] The composite type rolling membrane elements prepared in the present embodiment 1 and Comparative Examples 1-2 are respectively subjected to produced water performance and water quality tests. The test results are shown in Table 1. The produced water performance test method is as follows:

[0058] The pressure before the membrane was controlled at 60 Psi, and the composite type of the membrane element was washed with pure water for 20 min, and then the composite type of the membrane element was run with the test solution (i.e. the tap water of Zhuzhou Municipal) for 10 min to measure the initial flow rate and the initial desalination rate. Subsequently, the composite type of the membrane element was run with the test solution for 30 days, and then the initial flow rate after 30 days and the desalination rate after 30 days were measured. The model of each composite type of the membrane element was 1812 (the "18" represents 1.8 inches; the "12" represents 12 inches). The recovery rate of the composite type of the membrane element in Example 1 was 50% to 55%; the recovery rate of the composite type of the membrane element in Comparative Example 1 was 50% to 55%; the recovery rate of the composite type of the membrane element in Comparative Example 2 was 50% to 55%; the recovery rate = the water production quantity ÷ (the water production quantity + the waste water quantity) x 100%; the flow rate attenuation rate = (1 - the flow rate after 30 days / the initial flow rate) x 100%.

[0059] The water quality test included the water production bacteria test and the residual chlorine removal rate test.

[0060] The water production bacteria test method was completed according to the "GB / T 5750.12-2006 Standard Test Methods for Drinking Water Microbiological Indicators".

[0061] The residual chlorine removal rate test method was completed according to the "GB 11896-89 Water Quality Determination of Chlorides Silver Nitrate Titration Method". The residual chlorine removal rate = (1 - the chlorine ion content in the water production / the chlorine ion content in the test solution) x 100%.

[0062] Table 1 Water production performance and water quality test results

[0063]

[0064] As shown in Table 1, compared with Example 1, the composite type of the membrane element prepared in Comparative Example 1 and Comparative Example 2 both had the problem of unqualified water production bacteria after running. This is because no bacteriostatic membrane layer was provided in Comparative Example 1 and Comparative Example 2.

[0065] Compared with Example 1 and Comparative Example 1, the composite type of the membrane element prepared in Comparative Example 2 not only had the problem of significantly reduced initial flow rate after running, but also had the problem of reduced flow rate after 30 days. This is because the carbon fiber membrane layer was also provided in the staggered folding membrane sheet 4 and stacked with the concentrated water screen 5, which increased the water inlet resistance and reduced the water inlet quantity per unit time, so that the initial flow rate of Comparative Example 2 was significantly reduced. With the blocking effect of the carbon fiber membrane layer stacked with the concentrated water screen 5, the impurities in the water inlet water body were blocked at the water inlet end of the concentrated water screen 5, so that the flow rate of the composite type of the membrane element prepared in Comparative Example 2 was reduced again after running for 30 days.

[0066] Compared with Example 1, the composite type roll type membrane element prepared in Comparative Example 2 has a relatively low residual chlorine removal rate of produced water after operation. This is because the length of the carbon fiber membrane layer in Comparative Example 2 is less than one turn of the central water collecting pipe 2, so that the carbon fiber membrane layer cannot completely cover the central water collecting pipe 2, resulting in poor adsorption purification effect of the area of the central water collecting pipe 2 not covered by the carbon fiber membrane layer, and the residual chlorine in the water body cannot be fully adsorbed and removed by the carbon fiber membrane layer, resulting in a relatively low residual chlorine removal rate of produced water compared with Example 1.

[0067] The composite type roll type membrane elements prepared in Example 1 and Comparative Examples 1-2 were respectively subjected to water efficiency water test according to national standard GB 34914-2021 to determine the initial flow rate and initial desalination rate. The test results are shown in Table 2, and the residual chlorine removal rate test (the residual chlorine removal rate test refers to GB 11896-89 Water Quality Chloride Determination Silver Nitrate Titration Method) was also completed. Among them, the pre-membrane pressure was controlled at 100 Psi; the type of each composite type roll type membrane element was 4012 (“40” represents 4.0 inches; “12” represents 12 inches); the recovery rate of the composite type roll type membrane element in Example 1 was 70%-75%; the recovery rate of the composite type roll type membrane element in Comparative Example 1 was 70%-75%; the recovery rate of the composite type roll type membrane element in Comparative Example 2 was 70%-75%; the recovery rate was the percentage of the produced water amount to the water inlet amount.

[0068] Table 2: Water efficiency water test results and residual chlorine removal rate test results

[0069] Group Initial flow mL / min Initial desalination rate % Residual chlorine removal rate % Comparative Example 1 2174 93.2 87.4 Comparative Example 2 1851 92.8 98.6 Example 1 4972 93.3 99.2

[0070] As shown in Table 2, compared with Comparative Example 1, the composite type roll type membrane elements prepared in Example 1 and Comparative Example 2 have relatively high residual chlorine removal rates of produced water after operation. This is because carbon fiber membrane layers are used in both Example 1 and Comparative Example 2, which can fully adsorb and remove the residual chlorine in the water body.

[0071] Further, compared with Example 1, the composite type roll type membrane element prepared in Comparative Example 2 has a relatively low residual chlorine removal rate of produced water after operation. The reason is the same as the data analysis in Table 1.

[0072] Compared with Example 1 and Comparative Example 1, the initial flow rate of the composite type roll type membrane element prepared in Comparative Example 2 is significantly reduced after operation. The reason is the same as the data analysis in Table 1.

[0073] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A composite spiral-wound membrane element, characterized by, The water purification membrane assembly comprises a central water collecting pipe (2), a water purification membrane assembly and an appearance protection film. The water purification membrane assembly is wound on the central water collecting pipe (2) from one end of the length direction of the water purification membrane assembly. The water purification membrane assembly comprises a first fresh water guide net (1), a composite chlorine removal water purification membrane layer (3), a staggered folding membrane sheet (4), a concentrated water separation net (5) and a second fresh water guide net (6). The starting point is arranged on one end of the length direction of the first fresh water guide net (1); the composite chlorine removal water purification membrane layer (3) is arranged on the first fresh water guide net (1) and is spaced apart from the starting point by more than one circumference of the central water collecting pipe (2); and the length of the composite chlorine removal water purification membrane layer (3) can be wound on the central water collecting pipe (2) for at least one turn. The staggered folding membrane sheet (4) comprises long and short integral membrane sheet pages; the concentrated water separation net (5) is arranged in the middle of the staggered folding membrane sheet (4); a plurality of the staggered folding membrane sheets (4) containing the concentrated water separation net (5) are arranged in sequence on the first fresh water guide net (1) in a staggered and stacked manner, and the second fresh water guide net (6) is arranged between each two adjacent staggered folding membrane sheets (4); and the staggered folding membrane sheet (4) in contact with the first fresh water guide net (1) is arranged on the first fresh water guide net (1). In the staggered and stacked arrangement, the connecting ends of the staggered folding membrane sheets (4) are sequentially away from the composite chlorine removal water purification membrane layer (3), and the short membrane sheet pages in the staggered folding membrane sheets (4) are closer to the first fresh water guide net (1) than the long membrane sheet pages. The appearance protection film is wound on the water purification membrane assembly to shape the water purification membrane assembly on the central water collecting pipe (2); and the water inlet and the water outlet are reserved on the appearance protection film.

2. The composite spiral-wound membrane element of claim 1, wherein The composite chlorine removal water purification membrane layer (3) comprises a carbon fiber membrane layer and a bacteriostatic membrane layer arranged in a stacked manner, or comprises a carbon fiber membrane layer and a bacteriostatic membrane layer arranged along the length direction of the first fresh water guide net (1) at intervals. In the arrangement of the carbon fiber membrane layer and the bacteriostatic membrane layer along the length direction of the first fresh water guide net (1) at intervals, the length of the carbon fiber membrane layer and the length of the bacteriostatic membrane layer can be wound on the central water collecting pipe (2) for at least one turn.

3. The composite spiral-wound membrane element of claim 1, wherein A first sealant line (7) is coated on the first fresh water guide net (1); the first sealant line (7) is two parallel lines arranged along the two ends of the width direction of the first fresh water guide net (1); and the composite chlorine removal water purification membrane layer (3) is adhered to the first fresh water guide net (1) through the first sealant line (7). Alternatively, a first sealant line (7) is coated on the composite chlorine removal water purification membrane layer (3); the first sealant line (7) is two parallel lines arranged on the two ends of the width direction of the composite chlorine removal water purification membrane layer (3); and the first fresh water guide net (1) is adhered to the composite chlorine removal water purification membrane layer (3) through the first sealant line (7). The length of the first sealant line (7) is equal to the length of the composite chlorine-removing and water-purifying membrane layer (3).

4. The composite spiral-wound membrane element of claim 3, wherein The shortest distance between the first sealant line (7) and the end of the first freshwater guide net (1) in the width direction is 10-25 mm; and the width of the first sealant line (7) is 4-8 mm.

5. The composite spiral-wound membrane element of claim 3, wherein A second sealant line (8) is coated on the outer surface of each of the three open ends of each of the staggered folded membrane sheets (4); and each of the second sealant lines (8) forms a U-shaped structure.

6. The composite spiral-wound membrane element of claim 5, wherein The sealant used in the first sealant line (7) and the second sealant line (8) comprises polyurethane glue.

7. The composite spiral-wound membrane element of claim 1, wherein A plurality of water collecting holes are arranged on the pipe wall of the central water collecting pipe (2) in the length direction, and are covered by the composite chlorine-removing and water-purifying membrane layer (3) of the central water collecting pipe (2).

8. The composite spiral-wound membrane element of claim 1, wherein The length of the first freshwater guide net (1) is greater than the length of the second freshwater guide net (6).

9. The composite spiral-wound membrane element of claim 1, wherein The length of the second freshwater guide net (6) is greater than or equal to the length of the long membrane sheet page in the staggered folded membrane sheets (4).

10. The composite spiral-wound membrane element according to any one of claims 1 to 9, characterized in that The composite type of the rolled membrane element comprises any one of a reverse osmosis rolled membrane element, a nanofiltration rolled membrane element and an ultrafiltration rolled membrane element.

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