WO2023246740A1

WO2023246740A1 - Short flow channel membrane element and filter

Info

Publication number: WO2023246740A1
Application number: PCT/CN2023/101266
Authority: WO
Inventors: 王小侠
Original assignee: 杭州苏博瑞驰科技有限公司
Priority date: 2022-06-21
Filing date: 2023-06-20
Publication date: 2023-12-28

Abstract

A short flow channel membrane element, comprising a membrane bag (1). The membrane bag (1) has a first long edge (101) and a second long edge (102) opposite to each other, and a first short edge (103) and a second short edge (104) opposite to each other. The membrane bag (1) is rolled along the extension direction of the first long edge (101) to form a membrane element. The membrane bag (1) is formed by folding a thin base membrane (100) along the first long edge (101). The thickness of the thin base membrane (100) is 0.005-0.08 mm, and the softness is 2.0-10g, such that the thin base membrane (100) can eliminate wrinkles formed at the first long edge (100) during membrane rolling. During filtering, water flow enters a raw water side, pure water formed by passing through the thin base membrane (100) flows out from the first long edge (101) side along a pure water flow channel (02), and the remaining concentrated water on the raw water side is discharged from the first short edge (103) and/or the second short edge (104) along an original water flow channel (01). The pure water side flow channel in the membrane element is shortened, such that the pure water production efficiency is improved, and the service life is long.

Description

Short flow channel membrane elements and filter elements

Technical field

The present invention relates to the technical field of water purification, and more specifically, to a short flow channel membrane element and a filter element.

Background technique

As people pay more and more attention to health issues, the quality of drinking water has also received more and more attention, and water purifiers have gradually become a necessity for every household. For water purifiers, the filter element is an important part of water filtration. It generally includes a basic membrane that can be rolled into a filter element, a raw water channel and a pure water channel located on the opposite side of the basic membrane. When used, the raw water flows from the raw water channel The inlet flows into the raw water channel, and then passes through the membrane and becomes pure water and enters the pure water channel. The impurities are filtered through the reverse osmosis of the membrane, thereby discharging the pure water that people need.

The existing rolled reverse osmosis membrane elements use water inlet guide nets with exactly the same thickness and weaving density. Since part of the incoming water penetrates into the back of the reverse osmosis membrane to form pure water, the flow rate of the incoming water will become smaller and smaller. Since the flow rate of the raw water incoming water gradually decreases along the direction of the flow channel, this also leads to a decrease in the flow rate. Due to the decrease in flow rate The decrease causes a difference in water flow velocity between the inlet end and the concentrated water end of the reverse osmosis membrane element, which directly leads to concentration polarization. The concentration polarization phenomenon at the concentrated water end of the reverse osmosis membrane element is intensified, which will accelerate the pollution of the reverse osmosis membrane surface in this end area, resulting in a reduction in the desalination rate and water production, and shortening the life of the reverse osmosis membrane element.

Combined with Figure 1, in the filter element solution disclosed in patent CN201810506458.2, the thickness of the raw water diversion net and the produced water diversion net in the rolled membrane element is set to be gradient distributed along the direction from the raw water inlet end to the concentrated water discharge end. , increase the linear speed of drainage at the concentrated water drainage end, making the membrane element less likely to be blocked. This solution increases the water flow by reducing the thickness of the diversion net. However, in the actual production process, it is difficult to achieve a gradual thickness change in the water diversion net.

In the solution shown in Figure 2, which is a solution disclosed in the patent CN201120187959.2, the reverse osmosis membrane is folded to form three folds on the side of the central pipe, and the middle fold is deep into the inlet water channel to allow the inlet water to flow. The channel is divided into upper and lower forward water channels located on the side of the central pipe and a rear inlet channel located on the concentrated water outlet side. The water inlet diversion network is divided into a large water inlet diversion network and a small water inlet diversion network. The large water inlet diversion network is Placed in one of the forward water channels and rear inlet water channels, the small water inlet diversion net is only placed in the other forward water channel. This patent actually increases the water flow rate by increasing the thickness of the water inlet side, and then creates a thickness difference to increase the water flow velocity at the end of the raw water.

Although the above scheme has changed the flow rate of the raw water side, the pure water channel is long, and the pure water formed through the reverse osmosis membrane has a large pressure loss. If the flow channel is long, the flow rate of the stored water will be greatly reduced. It is difficult to increase the amount of purified water per unit time. To solve this problem, patent CN205095658U provides a membrane element with a short flow channel. The solution is to form a sealing portion on one long side, so that raw water can flow out from the end. This solution seems to be able to realize the short flow channel implementation of pure water, but in the actual rolled film, due to the radial difference between the inner and outer diaphragms at the sealing portion, a large number of wrinkles will appear at the end. Moreover, the entire rolled filter element will also exhibit a conical structure, which is simply impossible to implement in practice.

Contents of the invention

1. The technical problem to be solved by the invention

The purpose of the present invention is to overcome the shortcomings of reverse osmosis membrane elements in the prior art that are difficult to achieve short flow channels and large flow of pure water, and provide a short flow channel membrane element and a filter element. This solution enables the pure water prepared by the membrane element to flow out quickly from the end through the shorter flow channel, improving the water purification efficiency.

2.Technical solutions

In order to achieve the above objects, the technical solutions provided by the present invention are:

A short flow channel membrane element of the present invention includes a membrane bag. The membrane bag has opposite first long sides and second long sides, and opposite first short sides and second short sides. The membrane bag is along the first The long side extension direction is rolled to form a membrane element;

The membrane bag is formed by folding a thin base membrane sheet along the first long side. The opposite inner side of the membrane bag is the raw water side, and the outer side is the pure water side; during filtration, the water flow enters the raw water side and passes through the thin base membrane sheet to form The pure water flows out from the first long side along the pure water channel, and the remaining concentrated water on the raw water side is discharged from the concentrated water outlet along the raw water channel;

The thickness of the thin base film is 0.005-0.08mm, and the softness is 2.0-10g, so that it can eliminate wrinkles formed on the first long side when rolling the film.

Further, the stiffness of the thin base film is 2.0-4.2cm, and the surface of the rolled film bag is a flat curved surface.

Further, the thickness of the thin base film is 0.01-0.04mm.

Further, on the pure water side of the membrane bag, a seal is formed on at least the first short side, the second short side and the second long side, so that the pure water passing through the thin base membrane flows in the direction of the first long side, and the pure water It flows out from the end face where the first long side of the membrane element is located.

Further, a seal is formed at the second long side of the raw water side of the membrane bag, one side of the first short side or the second short side serves as the raw water inlet, and the other side serves as the concentrated water outlet.

Further, on the raw water side of the membrane bag, the second long side is partially sealed so that a raw water inlet is formed near the middle of the second long side, and the first short side and/or the second short side serve as the concentrated water outlet.

Further, on the raw water side of the membrane bag, one of the first short side or the second short side is the sealing side, and the other short side forms the concentrated water outlet; the second long side is partially sealed, so that the second short side is partially sealed. A raw water inlet is reserved at one end of the long side close to the sealing side.

Further, a raw water diversion net is provided on the raw water side of the film bag. The raw water diversion net is basically consistent with the size of the film bag in the width direction; in the length direction, the raw water diversion net is used to form a raw water channel.

Further, the membrane element is provided with a pure water guide cloth, which is arranged on the pure water side of the membrane bag to form a pure water flow channel.

Further, the length of the film bag along the first longitudinal direction is 1.0-4.6m.

A short-flow channel membrane element of the present invention is provided with at least two membrane bags. The membrane bags adopt the membrane bag structure in the aforementioned membrane element, and there is a pure water diversion cloth between adjacent membrane bags.

Further, at least two of the film bags have an integrated structure, which is formed by folding a thin base film sheet along the first long side and then folding it twice along the second short side; or:

At least two of the film bags have an integrated structure, which is formed by folding a thin base film sheet along the first long side and then folding it twice along the second long side to form an M-shaped structure.

A filter element of the present invention, the filter element includes the aforementioned membrane element.

Further, the filter element includes a central tube, which is parallel to the second short side of the membrane bag. The membrane element is wound on the central tube from the second short side, and the end where the first long side is located is the pure water outlet. end; the raw water enters the membrane bag along the raw water diversion net, and the filtered pure water flows out from the pure water outlet end along the pure water diversion cloth.

Further, a raw water inlet is provided on the side of the second long side close to the central pipe, and the first short side is the raw water outlet, so that one end of the filter element is the raw water inlet end and the other end is the pure water outlet end.

Further, the pure water diversion cloth is connected to the central tube, and the second short side of the membrane bag is in a non-contact state with the central tube; and the area between the second short side and the central tube is sealed at the pure water outlet end, Used to isolate raw water.

Furthermore, the central tube has a hollow structure and forms a water flow cavity, which is used as a water channel for raw water, pure water or concentrated water.

Further, the central tube protrudes from the first long side in the axial direction, and is provided with a guide hole at the protruding position, and is provided with a cavity at the pure water outlet end. The cavity is connected to the guide hole so that it can communicate with the outside. The connected pure water connector and raw water connector are located at the same end of the filter element.

Further, the outer shell of the filter element is formed with a secondary flow channel, and a cavity is provided at the pure water outlet end. One end of the secondary flow channel is connected to the cavity of the pure water outlet end, and the other end is connected to the pure water connector, so that The pure water connector and raw water connector connected to the outside are located at the same end of the filter element.

A filter element of the present invention includes a central tube and the aforementioned membrane element. The central tube is parallel to the short side of the membrane bag. At least one membrane element is wound on the central tube; during winding, the membrane bag is stretched by stretching. Tightly wound around the central tube, making the surface of the film bag a flat curved surface.

Further, the thickness of the thin base film is 0.01-0.03mm, the softness is 2.2-5.0g, and the stiffness is 2.5-4.0cm.

3. Beneficial effects

Compared with the existing technology, the technical solution provided by the present invention has the following beneficial effects:

In the short flow channel membrane element of the present invention, the membrane bag is formed by folding a thin base membrane sheet along the first long side, and winding it along the extending direction of the first long side to form a membrane element, thereby shortening the pure water side flow channel and improving the efficiency of the membrane element. improve the pure water production efficiency; in addition, the thin base membrane The thickness and softness are limited to a certain range, so that it can eliminate the wrinkles formed at the first long side when rolling the film, ensuring that the membrane element of this folding scheme can have a long service life.

Description of the drawings

Figure 1 is a schematic diagram of the pure water channel method in the prior art;

Figure 2 is a schematic diagram of the short side folding and winding method in the prior art;

Figure 3 is a schematic diagram of a folding method of the film bag of the present application;

Figure 4 is a schematic diagram of the unfolded structure of a film bag according to the present application;

Figure 5 is a schematic diagram of the deformation principle of the folded edge when the diaphragm is folded;

Figure 6 is a schematic diagram of the winding effect after folding the long side of the existing diaphragm;

Figure 7 is a schematic diagram of the winding effect after folding the long side of the diaphragm of this application;

Figure 8 is a schematic diagram of the unfolded structure of a membrane element of the present application;

Figure 9a is a schematic diagram of a sealing method on the pure water side of the membrane element;

Figure 9b is a schematic diagram of another sealing method on the pure water side of the membrane element;

Figure 10a is a schematic diagram of the water inlet and outlet method on the short side of the membrane element;

Figure 10b is a schematic diagram of another embodiment of the water inlet and outlet on the short side of the membrane element;

Figure 10c is a schematic diagram of an embodiment of water inlet and outlet at the middle position of the membrane element;

Figure 10d is a schematic diagram of an embodiment of water inlet at the end of the membrane element and water outlet at the short side;

Figure 10e is a schematic structural diagram of the membrane element in Figure 10d after winding;

Figure 11 is a schematic diagram of the membrane element structure in the form of double folding of the short side;

Figure 12 is a structural schematic diagram of a filter element that discharges pure water from the end;

Figure 13 is a structural schematic diagram of a filter element that conducts pure water diversion through a central tube.

Label description in the schematic diagram:

01. Raw water channel; 02. Pure water channel;

1. Membrane bag; 100, thin base diaphragm; 100a, A diaphragm; 100b, B diaphragm; 101, first long side; 102, second long side; 103, first short side; 104, second short side side;

110. Raw water diversion net; 120. Rubber strips; 121. Main rubber strips; 122. Side rubber strips;

2. Central tube;

3. Pure water diversion cloth.

Detailed ways

In order to further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings and embodiments.

The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to coordinate with the content disclosed in the specification and are for the understanding and reading of those familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented. Therefore, It has no technical substantive significance. Any structural modifications, changes in proportions or adjustments in size shall still fall within the scope of the technology disclosed in the present invention as long as it does not affect the effectiveness and purpose of the present invention. The content must be within the scope that can be covered. At the same time, terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for convenience of description and are not used to limit the scope of implementation. Changes or adjustments in relative relationships, provided there is no substantial change in the technical content, shall also be deemed to be within the scope of the present invention.

In response to the problem of long pure water channels in water purification filters, many solutions have been proposed in the industry, but their implementation is relatively complex, or the possibility of implementation is only theoretically possible. In this case, the short flow channel membrane element of the present application is proposed.

With reference to Figures 3 and 4, a short flow channel membrane element in this embodiment includes a film bag 1. The film bag 1 has an opposite first long side 101 and a second long side 102, and an opposite first short side. 103 and the second short side 104. The film bag 1 is rolled along the extending direction of the first long side 101 to form a membrane element. For example, a central tube is used and placed parallel to the second short side 104, which can extend along the first long side 101. Directional winding forms a membrane element with a central tube. In order to clearly illustrate the structure of the membrane element, this embodiment will be combined with the unfolded state or the rolled state of the membrane element to clearly show the structure of the membrane element. Therefore, it is not limited to the unfolded state or the rolled state of the membrane element. state, when used as part of the filter element, it is required to be in the coiled state.

The membrane bag 1 is formed by folding a thin base membrane sheet 100 along the first long side 101. The thin base membrane sheet 100 is divided into an A membrane sheet 100a and a B membrane sheet 100b. The opposite inner side of the membrane bag 1 is the raw water side, and the outer side is the raw water side. is the pure water side. That is, the opposite side of the A diaphragm 100a and the B diaphragm 100b is the raw water side, and the opposite outer side is the pure water side.

The rolled membrane element has a multi-layer winding structure, and a raw water channel 01 is formed on the raw water side, so that the raw water can flow around the circumference of the filter element from the inner layer to the outer layer or from the outer layer to the inner layer. On the pure water side, an axial pure water channel 02 will be formed. During filtration, the water flows into the raw water side, and the pure water formed by passing through the thin base membrane 100 flows out from the first long side 101 along the pure water channel 02. The remaining concentrated water on the raw water side is discharged from the concentrated water outlet along the raw water channel 01. , for example, discharged from the first short side 103 or the second short side 104 , or discharged from the first short side 103 and the second short side 104 at the same time.

It is worth noting that in this embodiment, the thickness of the thin base film 100 is 0.005~0.08mm, and the softness is 2.0~10g, so that it can eliminate the wrinkles formed at the first long side 101 when rolling the film, and can normally to perform filtering work.

Most of the existing diaphragms are thicker than 0.1mm, and their thickness is relatively large. If the long-side folding method of the present application is adopted, the radial size of the rolled membrane element at one end of the first long side will be larger, and the other end will be larger due to There are no folds, the radial size is small, and the overall tapered structure is present. When the short sides are folded, since the folded dimensions are accumulated in the axial direction, and multiple folded sides can be evenly distributed, membrane elements with relatively consistent radial dimensions can be formed.

Figure 5 shows a schematic diagram of the folding principle. It is a thin base film with a thickness of d. After folding, the inner and outer edges of the fold are equivalent to rotating nearly 180° around the fold line. Due to the existence of thickness d, when folding, the rotation circumferences of the inner and outer sides of the membrane are different. As shown in the figure, marked point C1, when rotating the same distance, the inner side is already close to rotating 180°, while the outer side of the membrane rotates tangentially. The angle may only be about 90°, then there will be greater deformation tension on the outside after folding, and there will be tension to resist compression on the inside. If the film is hard enough, an irremovable crease will be formed after folding, indicating its internal organization. be destroyed.

Not only that, if the conventional film is folded along the long side in the manner of this application, it must be wound along the long side through the central tube. During winding, the radial circumferences of the inner and outer sides of the film bag are different, and they also have displacement differences, which will cause After winding, more obvious wrinkles are formed. As shown in Figure 6, due to its own thickness, there will be more sharp corners. These folds and sharp corners will trap dirt and evil during filtration, and the service life of the filter element will be short, and it may even fail to meet standards.

In this application, in order to eliminate or reduce wrinkles caused by such thickness and hardness, the thickness of the thin base film 100 used is 0.005 to 0.08 mm. Within this thickness range, the softness is limited to 2.0 to 10g, so that the reverse osmosis membrane has better tensile deformation and compression deformation capabilities, so that the wrinkles formed at the first long side when rolling the membrane can be eliminated normally. Filtration works. Of course, as some other embodiments, the thickness can be further limited to 0.018-0.050mm, and the softness can be limited to 2.3-6.0g. The thin base membrane can be a reverse osmosis membrane with a corresponding thickness, or a microfiltration, ultrafiltration, or nanofiltration water treatment membrane, which can realize cross-flow filtration in this embodiment.

The softness detection method in the present invention is based on the standard EDANA WSP 90.3, and the test is performed by Thwing-Albert Instrument Company's Handle-O-Meter. The standard measurement range is 0-100g, and the weighted measurement range is 0-1000g. The unit g is the unit in the measuring range of the instrument. Softness in this application is the measured softness value. When measuring, it can be divided into transverse softness test and longitudinal softness, and the value is within the range of 2.0 to 10g limited by this application. Softness measured with other instruments can be converted based on the unit.

As a further limitation, in other embodiments, the stiffness of the thin base film 100 is 2.0-4.2 cm, and the surface of the rolled film bag 1 is a flat curved surface. The stiffness here can be determined by referring to the detection method of bending length in the national standard GB/T 18318-2001. The length of the film bag 1 along the direction of the first long side 101 can be greater than 1.0m, such as 2.0m, 3.2m, 4.5m, etc.

Softer membrane materials can reduce the impact of wrinkles, but because the material itself is soft and has insufficient support strength, it is easy to deform. Within a limited stiffness range, the surface of the rolled membrane element can be roughly flat and curved. Reduces wrinkles.

Figure 7 is a schematic diagram of the film rolling effect of a reverse osmosis membrane with a certain degree of softness and stiffness used in this application. The long sides of different layers are staggered so that the folded edges of different layers can be observed during rolling. There are still no obvious wrinkles at the end, and the sharp corners formed due to force transmission are eliminated.

As a further embodiment, the thickness of the thin base film 100 is 0.01-0.04mm, such as 0.020mm, 0.025mm, 0.032mm. The membrane may be a membrane formed of a polyolefin microporous membrane, or the like. For example, a reverse osmosis polyolefin microporous membrane can be formed by coating a thin base membrane with filter material. For details, please refer to the existing membrane material processing technology.

Figure 9 shows another embodiment of the membrane element. In this embodiment, a raw water diversion net 110 is provided on the raw water side of the membrane bag 1. The raw water diversion net 110 is basically in line with the membrane in the width direction and length direction. The bag 1 has the same size; in the length direction, the raw water diversion net 110 can at least be connected with the raw water inlet for guiding raw water into the membrane bag 1 .

In the membrane bag 1, on the first long side 101, due to the folding of the membrane, the raw water diversion net 110 can only be placed on the inside, and the width cannot be flush with the first long side 101. On the side of the second long side 102, the raw water diversion net 110 can be flush with the second long side 102. In addition, by controlling the width of the raw water diversion net 110, it is also possible to ensure that no tapered structure occurs when rolling the film.

The thickness of the raw water diversion net 110 can be 0.05-0.8mm, such as 0.08mm, 0.25mm, 0.50mm; it can be further limited to 0.015-0.500mm. In this embodiment, a relatively thin raw water diversion net 110 can be selected, which has a better cooperation effect with the thin base diaphragm 100 and can avoid large deformation of the thin base diaphragm 100 .

In the length direction, the raw water diversion net 110 can be equal to the length of the membrane bag 1, or can be longer than the length of the membrane bag 1 to facilitate water inlet.

Furthermore, preferably, the membrane element is provided with a pure water guide cloth 3, and the pure water guide cloth 3 is provided on the pure water side of the membrane bag 1 for forming a pure water flow channel. In one embodiment, the pure water diversion cloth 3 can be connected to the central tube 2, and the membrane bag 1 is connected to the central tube and rolled to form a membrane element. In another embodiment, the pure water diversion cloth 3 can be connected to the central tube 2, and there is a certain distance between the membrane bag 1 and the central tube to form a non-contact structure.

Based on the above embodiments, the membrane element water inlet and outlet structure of the present application can have various specific embodiments.

Figure 9a shows a sealing method on the pure water side. On the pure water side of the membrane bag 1, a seal is formed on at least the first short side 103, the second short side 104 and the second long side 102. The sealing is made by using a rubber strip. 120 is pasted on the pure water side of the membrane bag 1. After winding, the adhesive strip 120 and the pure water side surface of the membrane bag 1 form a closed area, which can be isolated from raw water and concentrated water. On the raw water side of membrane bag 1, raw water can flow circumferentially after entering. The specific water inlet and outlet methods can refer to the water inlet and outlet methods of existing membrane elements. When purifying water, after raw water enters, the pure water that passes through the thin base membrane 100 flows in the direction of the first long side 101, and the pure water flows out from the end surface where the first long side 101 of the membrane element is located.

Figure 9b shows another sealing method on the pure water side. Based on Figure 9a, more rubber strips 120 parallel to the short sides can be provided in this embodiment. As shown in the figure, two additional rubber strips divide the pure water channel into multiple zones, which have a certain flow diversion and stabilizing effect.

As for the way of raw water inflow, Figure 10a shows one way. The raw water enters from the central pipe 2 and flows out from the hole opened in the hollow central pipe to enter the raw water channel. In this embodiment, a seal is formed at the second long side 102 of the membrane bag 1 , the second short side 104 serves as the raw water inlet, and the side where the first short side 103 is located serves as the concentrated water outlet.

It is worth noting that in this embodiment, the pure water side is close to the main rubber strip 121 and the second short side 104 of the second short side 104. There is a certain distance, and the length of the distance can enable the raw water to be circumferentially isolated from the pure water side. In addition, the area between the main rubber strip 120 and the central tube 2 is sealed by the side rubber strip 122, which is close to the first long side 101, ensuring that the pure water and raw water at the end can also be sealed. Of course, as other sealing methods, sealing can be achieved by applying glue to the center ring at the end of the wound membrane element instead of the side rubber strips 122, or a combination of multiple sealing methods.

Correspondingly, the same method can be used to isolate pure water and concentrated water at the concentrated water outlet, which can be sealed by applying adhesive strips to the membrane bag and gluing the outer ring of the end.

Figure 10b shows another water inlet method, which is opposite to the direction of raw water inlet and concentrated water outlet in Figure 10a, that is, the side where the first short side 103 is located is the raw water inlet side, and the side where the second short side 104 is located is the concentrated water inlet side. On the water outlet side, the sealing method can refer to the aforementioned embodiment.

Figure 10c shows an embodiment of intermediate water inlet on the raw water side.

In the solution of Figure 10c, a water inlet is provided in the middle of the membrane bag 1. On the raw water side of the membrane bag 1, the second long side 102 is partially sealed so that a raw water inlet is formed near the middle of the second long side 102. The first short side 103 and/or the second short side 104 serve as the concentrated water outlet.

Since the raw water inlet is formed in the middle of the second long side 102, partial sealing is formed on both sides of the raw water inlet. The sealing can be in the form of adhesive strips, or the end face and the filter element end cover are sealed with glue. The focus of this embodiment is to illustrate the water inlet method. The sealing method can adopt existing technologies that can be implemented without specific limitations. The middle position of the second long side 102 does not need to be the geometric center position of the second long side 102 , and it can also be close to either the first short side 103 or the second short side 104 .

In the solution of Figure 10c, after the raw water enters from the water inlet at the middle position of the second long side 102, due to the existence of water pressure, the raw water will flow in the direction of the first short side 103 and the second short side 104 at the same time, and can pass through the flow. The channel is set up so that the filtered concentrated water flows from the central tube and the gap between the membrane element and the filter element housing to the external concentrated water discharge port.

Figure 10d shows an embodiment in which water is inlet from the end and water is discharged from one side.

In the embodiment of Figure 10d, on the raw water side of the film bag 1, the second short side 104 is the sealing side, which can be sealed by a rubber strip. The first short side 103 forms a concentrated water outlet; the second long side 102 is partially sealed so that an end of the second long side 102 close to the second short side 104 reserves a raw water inlet.

In this embodiment, the central pipe does not serve as a raw water channel, but forms a raw water inlet at the end opening, and the first short side 103 serves as a concentrated water outlet. In this membrane element, raw water enters at one end and pure water flows out at the other end. This is reflected in the rolled membrane element, as shown in Figure 10e.

Combined with the above embodiments, in this embodiment, the length of the film bag 1 along the first long side 101 is further limited, and can be 1.0 to 4.6 m. At present, conventional membrane elements are generally controlled within 0.8m due to the limitations of pure water channels to avoid the formation of long flow channels. In the solution of the present invention, due to the short flow channel structure, the pure water flow is not affected by the length of the membrane bag. ring. Longer membrane elements can be used to lengthen the raw water channel, which can increase the flow rate of the raw water side and avoid the formation of sedimentation.

Combining the corresponding structures of the membrane elements and membrane bags in the above embodiments, as another membrane element embodiment of the present invention, at least two membrane bags 1 may be provided in the membrane element, for example, 3 or 4 membrane bags may be used. There is a pure water diversion cloth 3 between adjacent film bags 1 .

Figure 11 shows another method of membrane elements. The two membrane bags 1 are an integrated structure. They are made of a thin base membrane sheet 100 that is folded along the first long side 101 and then folded twice along the second short side 104. form. When four membrane bags 1 are provided, two membrane bags 1 with an integrated structure are used as a group, and the four membrane bags can be divided into two groups to form one membrane element. When an odd number of film bags are used, one of the film bags can be a separate film bag structure.

In addition, as another integrated structure form, at least two of the film bags 1 are an integrated structure, which is formed by folding the thin base film 100 along the first long side 101 and then folding it twice along the second long side 101 to form M shape structure. At this time, the second long side 101 connected by the two film bags is the common long side.

The present invention also provides a filter element. As a specific embodiment thereof, the membrane element used is the membrane element in each of the above embodiments, or a membrane element that combines various parts in different embodiments.

As a specific explanation, as shown in Figure 12, the filter element includes a central tube 2, and the membrane element is wound around the central tube 2. The central tube 2 is parallel to the second short side 104 of the membrane bag 1. The membrane element is wound on the central tube 2 from the second short side 104. The end where the first long side 101 is located is the pure water outlet end; the raw water flows along the raw water The diversion net 110 enters the membrane bag 1, and the filtered pure water flows out from the pure water outlet along the pure water diversion cloth 3.

Further, in one embodiment, a raw water inlet is provided on the side of the second long side 102 close to the central pipe 2, and the first short side 103 is a concentrated water outlet, so that one end of the filter element is the raw water inlet end and the other end It is the outlet end of pure water. The water inlet end and the water outlet end referred to in the above embodiments are more relative to the membrane element, and are ultimately formed on the complete filter housing structure. Whether they are located at the same end or both ends, they can be passed through the central tube or the inside of the housing. Other waterways will be improved.

As an implementable method, the pure water diversion cloth 3 is connected to the central tube 2, and the second short side 104 of the membrane bag 1 is in a non-contact state with the central tube 2; The area between them is sealed at the pure water outlet end to isolate raw water.

In the above method, when the central pipe 2 is not used for water inlet or outlet, the central pipe 2 can only play a supporting role and does not have a waterway structure. As other embodiments, the central tube 2 may have a hollow structure to form a water flow cavity and be used as a water channel for raw water, pure water, or concentrated water.

Figure 13 shows an implementation using a central pipe as a pure water channel.

In the solution shown in Figure 13, the central tube 2 protrudes from the first long side 101 in the axial direction, and is provided with a guide hole at the protruding position, and is provided with a cavity at the pure water outlet end. The cavity and the guide hole are Connected so that the pure water connector and raw water are connected to the outside The connector is located on the same end of the filter element.

In this embodiment, the flow guide hole may be a central hole at the end of the central tube, or a through hole opened on the side wall of the central tube.

In other embodiments, a secondary flow channel can be formed on the outer shell of the filter element, and a cavity is provided at the pure water outlet end. One end of the secondary flow channel is connected to the cavity at the pure water outlet end, and the other end is connected to the pure water outlet end. The water connector is connected so that the pure water connector and raw water connector connected to the outside are located at the same end of the filter element.

In addition, the central tube can also be configured as a tube structure with concentric rings, that is, a central cavity and an outer ring cavity are formed on the central pipe. Both cavities are arranged axially, and the outer ring cavity can be used as a raw water inlet. The raw water is introduced into the cavity through the open-pore phase membrane element on the pipe wall, and the central cavity is used as a pure water channel. In this structural form, other water flow forms can also be used without specific restrictions.

As a filter element of the present invention, it includes a central tube 2 and a membrane element wound on the central tube. The central tube 2 is parallel to the short side of the membrane bag 1, and at least one membrane element is wound on the central tube 2; , the film bag 1 is wound around the central tube 2 by stretching and tensioning, so that the surface of the film bag 1 becomes a flat curved surface.

Specifically, the membrane bag 1 in the membrane element has opposite first long sides 101 and second long sides 102, and opposite first short sides 103 and second short sides 104. The membrane bag 1 extends along the first long side 101. Directional winding to form a membrane element. The membrane bag 1 is formed by folding a thin base membrane sheet 100 along the first long side 101. The opposite inner side of the membrane bag 1 is the raw water side, and the outer side is the pure water side; during filtration, the water flow enters the raw water side and passes through the thin base membrane. The pure water formed in the sheet 100 flows out from the first long side 101 along the pure water channel 02, and the remaining concentrated water on the raw water side is discharged from the first short side 103 or the second short side 104 along the raw water channel 01.

Further, the thickness of the thin base film 100 is 0.01-0.03mm, the softness is 2.2-3.5g, and the stiffness is 2.5-4.0cm. During winding, the film bag 1 is wound around the central tube 2 by stretching and tensioning, so that the surface of the film bag 1 becomes a flat curved surface.

Since the softness range in this embodiment is small, the surface will show more wrinkles in the natural state. In order to ensure the flatness after rolling the film, the tension provided to the film by stretching and tightening can make the surface appear as Flat state. During implementation, the tensioning force can be maintained by a tension roller for winding, or the film can be wound at one end and clamped by two flat or arc surfaces at the other end to maintain the tension of the diaphragm.

For traditional membrane elements, they are more folded and rolled on the short side.

The present invention and its embodiments are schematically described above. This description is not limiting. What is shown in the drawings is only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by the invention and without departing from the spirit of the invention, can devise structural methods and embodiments similar to the technical solution without inventiveness, they shall all fall within the protection scope of the invention. .

Claims

A short flow channel membrane element includes a membrane bag. The membrane bag (1) has an opposite first long side (101) and a second long side (102), and an opposite first short side (103) and a second The short side (104), the film bag (1) is rolled along the extension direction of the first long side (101) to form a film element; it is characterized by:

The membrane bag (1) is formed by folding a thin base membrane sheet (100) along the first long side (101). The opposite inner side of the membrane bag (1) is the raw water side, and the outer side is the pure water side; during filtration, The water flow enters the raw water side, and the pure water formed by passing through the thin base diaphragm (100) flows out from the first long side (101) along the pure water channel (02). The remaining concentrated water on the raw water side flows along the raw water channel (01) Discharge from the concentrated water outlet;

The thickness of the thin base film (100) is 0.005-0.08mm, and the softness is 2.0-10g, so that it can eliminate wrinkles formed on the first long side (101) when rolling the film.
A short flow channel membrane element according to claim 1, characterized in that: the stiffness of the thin base membrane (100) is 2.0-4.2cm, and the surface of the rolled membrane bag (1) is a flat curved surface .
A short flow channel membrane element according to claim 2, characterized in that: the thickness of the thin base diaphragm (100) is 0.01 to 0.04 mm.
A short flow channel membrane element according to claim 1, characterized in that: on the pure water side of the membrane bag (1), at least the first short side (103), the second short side (104) and the second The long side (102) forms a seal, so that the pure water passing through the thin base membrane (100) flows in the direction of the first long side (101), and the pure water flows out from the end surface where the first long side (101) of the membrane element is located.
A short flow channel membrane element according to claim 4, characterized in that a seal is formed at the second long side (102) of the raw water side of the membrane bag (1), and the first short side (103) or the third One side of the two short sides (104) serves as the raw water inlet, and the other side serves as the concentrated water outlet.
A short flow channel membrane element according to claim 4, characterized in that: on the raw water side of the membrane bag (1), the second long side (102) is partially sealed so as to be close to the middle position of the second long side (102) A raw water inlet is formed, and the first short side (103) and/or the second short side (104) serve as a concentrated water outlet.
A short flow channel membrane element according to claim 4, characterized in that: on the raw water side of the membrane bag (1), one of the first short side (103) or the second short side (104) is One side is the sealed side, and the other short side forms a concentrated water outlet; the second long side (102) is partially sealed, so that an end of the second long side (102) close to the sealed side reserves a raw water inlet.
A short flow channel membrane element according to claim 1, characterized in that: a raw water diversion net (110) is provided on the raw water side of the membrane bag (1), and the raw water diversion net (110) extends in the width direction Basically the same size as the membrane bag (1); in the length direction, the raw water diversion net (110) is used to form a raw water channel.
A short flow channel membrane element according to claim 8, characterized in that: the membrane element is provided with a pure water guide cloth (3), and the pure water guide cloth (3) is arranged on the membrane bag (1) The pure water side is used to form a pure water flow channel.
A short flow channel membrane element according to claim 8, characterized in that: the membrane bag (1) is along the first long side. The length in the (101) direction is 1.0~4.6m.
A short flow channel membrane element, characterized in that: at least two membrane bags (1) are provided, and the membrane bag (1) adopts the membrane bag (1) in the membrane element described in any one of claims 1-10. Structure, there is a pure water diversion cloth (3) between adjacent membrane bags (1).
A short flow channel membrane element according to claim 11, characterized in that at least two of the membrane bags (1) are of an integrated structure and are made of a thin base membrane (100) along the first long side (101). After folding, fold again along the second short side (104) to form; or:

At least two of the film bags (1) have an integrated structure, which is made of a thin base film (100) folded along the first long side (101) and then folded twice along the second long side (101) to form an M-shaped structure. .
A filter element, characterized in that: the filter element includes the membrane element according to any one of claims 1-12.
A filter element according to claim 13, characterized in that: the filter element includes a central tube (2), the central tube (2) is parallel to the second short side (104) of the membrane bag (1), and the membrane element is from The second short side (104) is wound around the central tube (2), and the end where the first long side (101) is located is the pure water outlet end; raw water enters the membrane bag (1) along the raw water diversion net (110) , the filtered pure water flows out from the pure water outlet end along the pure water guide cloth (3).
A filter element according to claim 14, characterized in that: a raw water inlet is provided on the side of the second long side (102) close to the central pipe (2), and the first short side (103) is a raw water outlet, so that One end of the filter element is the raw water inlet end, and the other end is the pure water outlet end.
A filter element according to claim 15, characterized in that: the pure water guide cloth (3) is connected to the central tube (2), and the second short side (104) of the membrane bag (1) is connected to the central tube (2). 2) In a non-contact state; and seal the area between the second short side (104) and the central tube (2) at the pure water outlet end to isolate raw water.
A filter element according to claim 15, characterized in that the central tube (2) is a hollow structure, forming a water flow cavity and used as a water channel for raw water, pure water or concentrated water.
A filter element according to claim 17, characterized in that: the central tube (2) protrudes from the first long side (101) in the axial direction, and is provided with a guide hole at the protruding position, and when the pure water is discharged, A cavity is provided at one end, and the cavity is connected with the guide hole, so that the pure water connector and the raw water connector connected to the outside are located at the same end of the filter element.
A filter element according to claim 15, characterized in that: the outer shell of the filter element is formed with a secondary flow channel, and a cavity is provided at the pure water outlet end, and one end of the secondary flow channel is connected to the cavity at the pure water outlet end. The other end is connected to the pure water connector, so that the pure water connector and raw water connector connected to the outside are located at the same end of the filter element.
A filter element, characterized in that it includes a central tube (2) and the membrane element according to any one of claims 1 to 12. The central tube (2) is parallel to the short side of the membrane bag (1), and at least one The membrane element is wound on the central tube (2); during winding, the membrane bag (1) is wound on the central tube (2) by stretching and tensioning, so that the surface of the membrane bag (1) is a flat curved surface.
A filter element according to claim 20, characterized in that: the thickness of the thin base membrane (100) is 0.01～0.03mm, softness 2.2～5.0g, stiffness 2.5～4.0cm.