Membrane element end cap and membrane module comprising same

Abstract

The application provides an end cover, which comprises a supporting framework, a flow guide and a fastener. The flow guide is arranged on the supporting framework and is used for guiding fluid flowing through a membrane element. The fastener is arranged on the supporting framework and is used for strengthening the connection between the membrane element and the supporting framework. Through the design of the supporting framework and the fastener, the connection strength between the end cover and the membrane element is better, so that the membrane assembly can withstand high water pressure or high pressure difference after membrane fouling, and the service life of the membrane assembly is greatly prolonged. The application further discloses a membrane assembly, which comprises a membrane element and an end cover for the membrane element. The end cover for the membrane element is arranged at the end of the membrane element, and the fastener is sleeved on the membrane element and is in contact with the membrane element, so that the connection strength between the end cover and the membrane element is strengthened, the service life of the membrane assembly is prolonged, and the application value is great.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of membrane separation technology, in particular to an end cover for a membrane element and a membrane assembly comprising the same. BACKGROUND

[0002] Membrane filtration is a solid-liquid separation technology, which is to filter water through membrane pores and retain impurities in water without chemical changes, and is a simple treatment technology.

[0003] There are various types of membranes in the prior art. For a spiral membrane assembly, it is generally assembled by a membrane shell (epoxy glass steel shell), a membrane element, an end cover and other components. The function of the end cover of the spiral membrane element is mainly to support the entire membrane assembly and guide the water inlet of the membrane element. The connection strength of the end cover and the membrane element is the key to the stability of the membrane assembly.

[0004] The end cover in the prior art is composed of an inner ring, an outer ring and a guide plate connecting the inner ring and the outer ring. Some end covers are provided with a brim on the outer ring, but the end cover is not physically connected with the membrane element and needs to be fixed by the membrane shell. During use of the membrane product, due to the effect of high pressure of the water inlet or high pressure difference after the membrane is blocked, the end cover often separates from the membrane element, thereby damaging the membrane element and shortening the service life of the membrane assembly and increasing the use cost.

[0005] In summary, it is of great significance to design an end cover with a simple structure, convenient to use and capable of strengthening the connection strength of the membrane assembly, and a membrane assembly comprising the same. SUMMARY

[0006] The present application aims to provide an end cover for a membrane element with a simple structure, convenient to use and capable of strengthening the connection strength of the membrane assembly, and the specific technical solutions are as follows:

[0007] An end cover for a membrane element, comprising a support framework, a flow guide and a fastener;

[0008] The flow guide is arranged on the support framework and is used for guiding the fluid flowing through the membrane element;

[0009] The fastener is arranged on the support framework and is used for strengthening the connection between the membrane element and the support framework.

[0010] In the above scheme, preferably, the fastener is a sheet-shaped or ring-shaped structure extending from the support framework, and the fastener and the membrane element are arranged in the same length direction; the fastener and the support framework are in an integrated structure or a detachable structure; and the material of the fastener is resin, rubber or metal.

[0011] In the above scheme, preferably, the fastener comprises a curtain part, the curtain part comprising at least two curtain plates arranged side by side along the circumferential direction of the membrane element. The inner wall of the fastener in contact with the membrane element is a smooth plane or a non-smooth plane provided with convex points. The surface of the fastener in contact with the membrane shell is a non-smooth plane provided with convex points.

[0012] In the above scheme, preferably, the support framework comprises an inner ring framework and an outer ring framework, the flow guide comprises one flow guide plate or at least two flow guide plates, and the flow guide plate connects the inner ring framework and the outer ring framework; the plurality of flow guide plates are arranged uniformly along the central axis of the membrane element.

[0013] In the above scheme, preferably, the flow guide plate is one of a fan-shaped plate and a honeycomb plate; the outer ring framework is provided with a mounting groove for mounting a sealing element, and the mounting groove is provided with at least one exhaust hole; the exhaust hole is at least one of a circular hole, a square hole and a star-shaped hole.

[0014] The end cover of the application comprises a support framework, a flow guide and a fastener. The flow guide is arranged on the support framework and is used for guiding the fluid flowing through the membrane element. The fastener is arranged on the support framework and is used for strengthening the connection between the membrane element and the support framework. Through the design of the support framework combined with the design of the fastener, the connection strength between the end cover and the membrane element is better, so that the membrane assembly can withstand high water pressure or high pressure difference after membrane blockage, greatly prolonging the service life of the membrane assembly.

[0015] The application further discloses a membrane assembly comprising a membrane element and the end cover for the membrane element. The end cover for the membrane element is arranged at the end of the membrane element, and the fastener is sleeved on the membrane element and is in contact with the membrane element, thereby strengthening the connection strength between the end cover and the membrane element, prolonging the service life of the membrane assembly and having great application value.

[0016] In addition to the objects, features and advantages described above, the application has other objects, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings constituting a part of this application are used to provide further understanding of the application, and the schematic embodiments of the application and the description thereof are used to explain the application and do not constitute improper limitation on the application. In the drawings:

[0018] Figure 1 is a structural schematic view of a membrane assembly in preferred embodiment 1 of the application (without showing the membrane shell);

[0019] Figure 2 is Figure 1 is a three-dimensional structural schematic view of the end cover in the preferred embodiment 1 of the application;

[0020] Figure 3 is Figure 2 A view of

[0021] Figure 4 is Figure 3 the right view in

[0022] Figure 5 is Figure 2 a partial enlarged view of the fastener in

[0023] Figure 6 is a diagram showing the variation of desalination rate of Example 1 and prior art;

[0024] Wherein, 1, end cover, 1.1, support framework, 1.11, outer ring framework, 1.12, inner ring framework, 1.13, mounting groove, 1.2, flow guide, 1.3, fastener, 1.31, curtain part, B, curtain plate, 2, membrane element, 2.1, membrane roll, 2.2, center tube. DETAILED DESCRIPTION

[0025] The embodiments of the present application will be described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the claims.

[0026] Example 1:

[0027] A membrane assembly, as described in detail in Figure 1 , comprising a membrane shell (generally using an epoxy glass steel shell), an end cover 1 and a membrane element 2, specifically:

[0028] The membrane element 2 is composed of a center tube 2.2 and a membrane roll 2.1 arranged on the center tube 2.2, and the membrane roll is a seawater desalination membrane sheet roll.

[0029] The membrane element 2 is provided with an end cover 1 at each end, and the membrane shell sleeve is arranged on the membrane element and the end cover.

[0030] The material of the end cover 1 in this embodiment is ABS resin, and its structure is described in detail in Figures 2-4 , specifically:

[0031] The end cover 1 comprises a support framework 1.1, a flow guide 1.2 and a fastener 1.3, the flow guide 1.2 is arranged on the support framework 1.1 and is used for guiding the fluid flowing through the membrane element, and the fastener 1.3 is arranged on the support framework 1.1 and is used for strengthening the connection between the membrane element and the support framework 1.1, as follows:

[0032] The support framework 1.1 comprises an inner ring framework 1.11 and an outer ring framework 1.12, and the flow guide 1.2 comprises one flow guide piece or at least two flow guide pieces Figures 2-4The guide vanes are connected to the inner ring skeleton 1.11 and the outer ring skeleton 1.12, and are arranged along the central axis of the membrane element. The inner ring skeleton and the outer ring skeleton are both regular rings (e.g. circular rings) in this embodiment. The central tube 2.2 is inserted into the central hole of the inner ring skeleton 1.11.

[0033] The fastener 1.3 is a sheet or ring structure extending from the support skeleton 1.1, and is arranged along the length direction of the membrane element. The fastener 1.3 and the support skeleton 1.1 are in an integrated structure or a detachable structure, which can be selected according to actual needs. The length L of the fastener 1.3 is preferably 2-35 mm in this embodiment.

[0034] In addition, the fastener 1.3 includes a curtain part 1.31, which includes at least two curtain plates B (preferably 4-68 plates, as shown in the figure) arranged side by side along the circumferential direction of the membrane element, Figures 2-4 The distance d between adjacent two curtain plates is 0.5-10 mm, and the length L1 of the curtain plate along the length direction of the membrane element is 2-100 mm, as shown in the figure. Figure 5 The fastener can be appropriately stretched along the membrane element, which increases the friction at the contact part between the fastener and the membrane element, and enhances the connection strength between the end cover and the membrane element.

[0035] The inner wall of the fastener 1.3 in contact with the membrane element is a smooth plane in this embodiment.

[0036] The guide vanes in this embodiment are one of a fan plate and a honeycomb plate, and other structures can also be used as long as they can achieve the function of guiding flow. The outer ring skeleton 1.12 is also provided with a mounting groove 1.13 for mounting a sealing member (e.g. a ring-shaped sealing ring), as shown in the figure. Figure 2 At least one exhaust hole is arranged in the mounting groove 1.13 to enhance the sealing effect. The exhaust hole can be at least one of a circular hole, a square hole and a star-shaped hole.

[0037] The membrane assembly obtained in this embodiment and the membrane assembly in the prior art (using the end cover in the prior art) are subjected to long-time high-pressure operation test. The specific test method is as follows: 32000 mg / L NaCl solution is used as the feed water, the water temperature is 25℃±2℃, the operation pressure is 55 bar, the recovery rate is set to 15%, and a single membrane assembly is continuously operated. The parameters such as the conductivity and the flow rate of the produced water are tested regularly (see the prior art), the change of the desalination rate is calculated, and the effect is as follows: Figure 6 Figure 6 ​It can be seen that the membrane module in the prior art has a rapid decrease in desalination rate after 10 days of long-term operation under high pressure, indicating that the membrane module is damaged under high pressure and has poor structural strength. The membrane module prepared in this embodiment has no obvious change in desalination rate after 30 days of operation, indicating that the basic structure of the membrane module is not damaged under high pressure and the membrane module has good strength.

[0038] The tensile strength between the end cap and the membrane body of the membrane module in this embodiment is tested, and the results are shown in Table 1.

[0039] Example 2

[0040] The difference between this embodiment and Example 1 is that the inner wall of the fastener in contact with the membrane element is a non-smooth plane provided with protrusions (the shape of the protrusions is hemispherical or the like). The friction at the contact part of the fastener and the membrane element is increased, and the connection strength between the end cap and the membrane element is enhanced.

[0041] The tensile strength between the end cap and the membrane body of the membrane module in this embodiment is tested, and the results are shown in Table 1.

[0042] Example 3

[0043] The difference between this embodiment and Example 1 is that the inner wall of the fastener in contact with the membrane element is a non-smooth plane provided with protrusions (the shape of the protrusions is hemispherical or the like); and the surface of the fastener in contact with the epoxy glass steel shell is a non-smooth plane provided with protrusions. The friction at the contact part of the fastener and the epoxy glass steel shell and the friction at the contact part of the fastener and the membrane element are both increased, thereby enhancing the connection strength between the end cap and the membrane element.

[0044] The tensile strength between the end cap and the membrane body of the membrane module in this embodiment is tested, and the results are shown in Table 1.

[0045] Table 1 Tensile strength test results between the end cap and the membrane element of the prior art and Examples 1-3 of the present application

[0046]

[0047]

[0048] Note: The test results are the average values of 100 randomly selected samples for each sample.

[0049] As can be seen from Table 1, the tensile strength of the membrane module is greatly improved by using the end cap provided with the fastener (Examples 1-3) of the present application; and the tensile strength of the membrane module is further improved by additionally providing protrusions on the inner wall and / or the outer wall of the fastener to form a non-smooth plane.

[0050] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. An end cap for a membrane element, characterized by The end cover (1) comprises a support skeleton (1.1), a flow guide (1.2) and a fastener (1.3); The flow guide (1.2) is arranged on the support skeleton (1.1) and used for guiding the fluid flowing through the membrane element; The fastener (1.3) is arranged on the support skeleton (1.1) and used for strengthening the connection between the membrane element and the support skeleton (1.1); The inner wall of the fastener (1.3) in contact with the membrane element is a smooth plane or a non-smooth plane provided with convex points; The surface of the fastener (1.3) in contact with the membrane shell is a non-smooth plane provided with convex points; The fastener (1.3) comprises a curtain part (1.31), and the curtain part (1.31) comprises at least two curtain plates (B) arranged side by side in the circumferential direction of the membrane element, the distance d between the adjacent two curtain plates (B) is 0.5-10 mm, and the length L1 of the curtain plate (B) in the length direction of the membrane element is 2-100 mm.

2. The end cap for a membrane element of claim 1, wherein The fastener (1.3) is a sheet-shaped or ring-shaped structure extended from the support skeleton (1.1), and the fastener (1.3) and the membrane element are arranged in the same length direction.

3. The end cap for a membrane element of claim 1, wherein The fastener (1.3) and the support skeleton (1.1) are in an integrated structure or a detachable structure.

4. The end cap for a membrane element of claim 1, wherein The support skeleton (1.1) comprises an inner ring skeleton (1.11) and an outer ring skeleton (1.12), the flow guide (1.2) comprises one flow guide sheet or at least two flow guide sheets, the flow guide sheet connects the inner ring skeleton (1.11) and the outer ring skeleton (1.12), and the plurality of flow guide sheets are arranged uniformly along the central axis of the membrane element.

5. The end cap for a membrane element of claim 4, wherein The flow guide sheet is one of a fan leaf plate and a honeycomb hole plate, the outer ring skeleton (1.12) is provided with a mounting groove (1.13) for mounting a sealing element, at least one exhaust hole is arranged in the mounting groove (1.13), and the exhaust hole is at least one of a circular hole, a square hole and a star-shaped hole.

6. A membrane module characterized by, The membrane element (2) and the end cover for the membrane element according to any one of claims 1-5 are provided, the end cover for the membrane element is arranged at the end of the membrane element (2), and the fastener (1.3) is sleeved on the membrane element.

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