Water inlet separation net, reverse osmosis membrane unit, reverse osmosis membrane element, filter element and filter system

Abstract

The invention relates to a water inlet separation net, a reverse osmosis membrane unit, a reverse osmosis membrane element, a filter element and a filter system in the technical field of reverse osmosis membranes. The reverse osmosis membrane unit comprises a water inlet separation net body and a reverse osmosis membrane attached to the reverse osmosis membrane element; the water inlet separation net body is provided with water blocking parts which are arranged at intervals and in a staggered mode in the extending direction of the water inlet separation net body, so that the water inlet separation net forms a water diversion flow channel which is continuously bent; and the distance between every two adjacent water blocking parts is reduced in sequence. The water diversion flow channel is designed to be bent, and the distance between every two adjacent water blocking parts is sequentially reduced, so that the flow speed of raw water is gradually increased, on the basis that the water diversion flow channel is designed to be relatively long, the flow speed of the raw water can be maintained to be gradually increased, the raw water spirally flows in the water diversion flow channel, and the flow area of the raw water is gradually reduced; the shear flow velocity of the concentrated water end is improved, and concentration polarization caused by poor water quality of the concentrated water end is weakened, so that the reverse osmosis membrane can more effectively resist pollution and blockage.

Description

Technical Field

[0001] The present invention relates to the technical field of reverse osmosis membranes, and in particular to a water inlet screen, a reverse osmosis membrane unit, a reverse osmosis membrane element, a filter element and a filtration system. Background Art

[0002] In the technology related to reverse osmosis elements, the current rolled reverse osmosis membrane elements are all made of an inlet mesh, a reverse osmosis membrane, and a pure water guide cloth wound on a central water production pipe and sealed and connected. In the water production process, raw water enters from one end of the reverse osmosis membrane element, and a part of the raw water passes through the back of the membrane under pressure to form pure water. The pure water flows out from one or both ends along the pure water guide cloth through the central pipe, and the other part of the raw water forms concentrated water and flows out from the other end of the membrane element along the inlet mesh. Under normal circumstances, the final discharge flow rate of the concentrated water end is generally 20% to 70% of the raw water inlet flow rate. As the flow rate of the raw water inlet gradually decreases along the flow channel direction, the flow rate on the membrane surface decreases, the process is short, the concentration polarization phenomenon on the concentrated water side of the reverse osmosis membrane is aggravated, and the life of the reverse osmosis membrane element is shortened. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the existing reverse osmosis membrane raw water inlet flow rate is low and the process is short, which leads to the aggravation of the concentration polarization phenomenon on the concentrated water side of the reverse osmosis membrane and the shortening of the life of the reverse osmosis membrane element. For this reason, an inlet spacer, a reverse osmosis membrane unit, a reverse osmosis membrane element, a filter element and a filtration system are proposed.

[0004] The present invention provides a water inlet spacer for a reverse osmosis membrane element, comprising:

[0005] A water inlet screen body, used for being attached to the reverse osmosis membrane in the reverse osmosis membrane element;

[0006] The water inlet screen body has water blocking parts that are spaced and staggered along the extension direction of the water inlet screen body, so that the water inlet screen forms a continuously curved water diversion channel;

[0007] The distance between two adjacent water blocking portions decreases successively.

[0008] In some embodiments, the water blocking portion is a rubber line that attaches the water inlet screen body to the reverse osmosis membrane.

[0009] In some embodiments, the water diversion channel includes a plurality of water diversion channels;

[0010] The plurality of water diversion diversion channels are designed such that: the incoming water has different flow directions in two adjacent water diversion diversion channels, and the plurality of water diversion diversion channels are sequentially connected along the incoming water flow direction;

[0011] The flow areas of the plurality of water diversion channels decrease sequentially along the water inlet flow direction.

[0012] In some embodiments, the plurality of water diversion channels can enable the incoming water to flow in an S-shape within the water inlet screen.

[0013] In some embodiments, a reverse osmosis membrane unit is provided, comprising:

[0014] A reverse osmosis membrane having a first side and a second side opposite to each other;

[0015] A water inlet spacer sandwiched between the first surfaces of the two layers of the reverse osmosis membranes to form a water diversion channel with the reverse osmosis membranes, wherein the water inlet spacer is the above-mentioned water inlet spacer;

[0016] A pure water guide cloth is arranged on the second surface of the reverse osmosis membrane.

[0017] In some embodiments, a reverse osmosis membrane element is provided, comprising:

[0018] Central tube;

[0019] The above reverse osmosis membrane unit;

[0020] Wherein, a plurality of the reverse osmosis membrane units are wound on the outside of the central tube in the order from close to the central tube to far from the central tube, the reverse osmosis membrane element has a first end and a second end opposite to each other in the axial direction, a circumferential seal is arranged on the outer circumferential surface of the first end and the outer circumferential surface of the second end, a first radial seal is arranged on the end surface of the first end, and a second radial seal is arranged on the end surface of the second end;

[0021] The portion of the end surface of the first end that does not cover the first radial seal forms a raw water inlet, and the portion of the end surface of the second end that does not cover the second radial seal forms a concentrated water outlet;

[0022] A pure water outlet is formed between the two circumferential seals.

[0023] In some embodiments, in the radial direction of the central tube, the length of the water inlet screen body is L, the length of the raw water inlet is L1, and the length of the concentrated water outlet is L2;

[0024] Among them, L / 15≤L2<L1≤L / 2.

[0025] In some embodiments, the plurality of water diversion channels in the water diversion channel include a first water diversion channel, a second water diversion channel, and a third water diversion channel, the first water diversion channel has a width of H1, the second water diversion channel has a width of H2, and the third water diversion channel has a width of H3;

[0026] Among them, L1≥H1>H2>H3≥L2.

[0027] In some embodiments, the end surface of the first end and the end surface of the second end are both configured as annular surfaces;

[0028] The first radial seal and the second radial seal are both configured as an annular sealing wall;

[0029] The pure water outlet is configured as a strip-shaped outlet extending axially along the central tube;

[0030] The annular diameters of the end faces of the first end and the second end are both R, the annular diameter of the first radial seal is r1, the annular diameter of the second radial seal is r2, and R-r1>R-r2.

[0031] In some embodiments, both end side walls and the peripheral side wall of the central tube are configured as closed wall surfaces.

[0032] In some embodiments, a filter element includes:

[0033] The above reverse osmosis membrane element.

[0034] In some embodiments, a filtration system is provided, comprising:

[0035] The above filter element.

[0036] The solution provided by the present invention has the following beneficial effects compared with the prior art:

[0037] By arranging a water blocking portion on the water inlet screen body, the water blocking portion adopts a rubber line, which can form a curved water diversion flow channel between the water inlet screen body and the reverse osmosis membrane, and can also play a role of fixing and bonding between the water inlet screen body and the reverse osmosis membrane. Under the premise of not adding additional components, the water blocking portions are staggered to form a curved water diversion flow channel. Raw water enters from the water inlet screen body and flows along the curved water diversion flow channel. The flow path of the raw water is extended, the flow time of the raw water in the water diversion flow channel is increased, and then the contact time between the raw water and the reverse osmosis membrane is increased, and the overall water filtration efficiency of the reverse osmosis membrane unit is improved. At the same time, under the condition of a certain raw water flow rate, the distance between two adjacent water blocking portions is As the spacing decreases successively, the flow rate of raw water will gradually increase. On the basis of the relatively long design of the water diversion channel, the flow rate of raw water can also be maintained to increase gradually. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrate end is improved, and the concentration polarization caused by the poor water quality at the concentrate end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane is slowed down, and the pollution of the surface of the reverse osmosis filter element is effectively alleviated, and the scaling rate is delayed. The water inlet spacer in this embodiment increases the surface flow rate of the reverse osmosis membrane by designing the water blocking part, so that the reverse osmosis membrane can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings:

[0039] Figure 1 is a cross-sectional view of a water inlet screen body shown in an embodiment of the present invention;

[0040] Figure 2 It is one of the structural schematic diagrams of the reverse osmosis membrane element shown in the embodiment of the present invention;

[0041] Figure 3 This is the second structural schematic diagram of the reverse osmosis membrane element shown in the embodiment of the present invention;

[0042] Figure 4 It is one of the structural side views of the reverse osmosis membrane element shown in the embodiment of the present invention;

[0043] Figure 5 This is the second structural side view of the reverse osmosis membrane element shown in the embodiment of the present invention;

[0044] Figure 6 This is a third structural side view of a reverse osmosis membrane element shown in an embodiment of the present invention;

[0045] Figure 7 1 is a top view of a reverse osmosis membrane element according to an embodiment of the present invention.

[0046] In the figure: 1-reverse osmosis membrane, 2-water inlet screen body, 201-water diversion channel, 2011-first water diversion channel, 2012-second water diversion channel, 2013-third water diversion channel, 202-raw water inlet, 203-concentrated water outlet, 3-pure water guide cloth, 4-water blocking part, 5-center tube, 6-rubber line, 7-pure water outlet, 8-first radial seal, 9-second radial seal, 10-circumferential seal.

[0047] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0048] In the description of the present invention, it should be noted that the terms "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "contacted", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] The existing reverse osmosis membrane raw water inlet flow rate is low and the process is short, which leads to the aggravation of the concentration polarization phenomenon on the concentrate side of the reverse osmosis membrane and the shortening of the life of the reverse osmosis membrane element.

[0051] Based on this, the following embodiments are proposed.

[0052] Embodiment 1

[0053] like Figure 1 , 2 As shown, this embodiment provides a water inlet screen applied to a reverse osmosis membrane element, comprising:

[0054] The water inlet screen body 2 is used to be attached to the reverse osmosis membrane 1 in the reverse osmosis membrane element;

[0055] The water inlet screen body 2 has water blocking parts 4 which are spaced and staggered along the extension direction of the water inlet screen body 2, so that the water inlet screen forms a continuously curved water diversion channel;

[0056] The distance between two adjacent water blocking portions 4 decreases successively.

[0057] Preferably, the water blocking portion 4 is a rubber line for attaching the water inlet screen body 2 to the reverse osmosis membrane 1 .

[0058] In the present embodiment, the extension direction of the water inlet screen body 2 means that when the water inlet screen body 2 and the central tube 5 in the reverse osmosis membrane element are assembled and used, the extension direction of the water inlet screen body 2 is consistent with the axial direction of the central tube 5, and the water blocking portion 4 adopts a rubber line, which can not only form a curved water diversion channel between the water inlet screen body 2 and the reverse osmosis membrane 1, but also play a role in fixing and bonding the water inlet screen body 2 and the reverse osmosis membrane 1. Without adding additional components, the water blocking portions 4 are staggered to form a curved water diversion channel. Raw water enters from the water inlet screen body 2 and flows along the curved water diversion channel. The flow path of the raw water is extended, which increases the flow time of the raw water in the water diversion channel, thereby increasing the contact time between the raw water and the reverse osmosis membrane 1, and improving the overall quality of the reverse osmosis membrane unit. The water filtration efficiency is improved. At the same time, under the condition of a certain raw water flow rate, the spacing between two adjacent water blocking parts 4 decreases successively, and the flow rate of raw water will gradually increase. On the basis of a relatively long water diversion channel design, the raw water flow rate can also be maintained to gradually increase. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrated water end is improved, and the concentration polarization caused by the poor water quality at the concentrated water end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down, and the surface pollution of the reverse osmosis filter element is effectively alleviated, and the scaling rate is delayed. The water inlet spacer in this embodiment increases the surface flow rate of the reverse osmosis membrane 1 by designing the water blocking part 4, so that the reverse osmosis membrane 1 can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole.

[0059] Optionally, in an implementation of this embodiment, as Figure 1 As shown,

[0060] The water diversion channel includes a plurality of water diversion diversion channels 201;

[0061] The multiple water diversion channels 201 are designed such that the incoming water has different flow directions in two adjacent water diversion channels 201, and the multiple water diversion channels 201 are connected in sequence along the incoming water flow direction;

[0062] The flow areas of the plurality of water diversion channels 201 decrease sequentially along the incoming water flow direction.

[0063] Preferably, the plurality of water diversion channels 201 can enable the incoming water to flow in an S-shape within the water inlet screen.

[0064] In this embodiment, raw water enters from the water inlet screen body 2 and flows along multiple water diversion channels 201. During the flow, the flow direction is constantly changed, thereby relatively extending the effective flow path length of the water diversion channel as a whole, increasing the flow time of raw water in the water diversion channel, and then increasing the contact time between raw water and the reverse osmosis membrane 1, thereby improving the overall water filtration efficiency of the reverse osmosis membrane unit. In combination with the design that the flow areas of multiple water diversion channels 201 decrease in sequence, the raw water enters the water diversion channel from the water inlet screen body 2 and flows in an S-shaped manner along the winding direction of the water inlet screen body 2. On this basis, the raw water flow rate V = Q / (l×T), where Q is the raw water flow rate, l is the width of the water diversion channel, T is the thickness of the water diversion channel, and l×T is the flow area of ​​the water diversion channel. Under the condition of a certain raw water flow rate, the flow areas of multiple water diversion channels 201 gradually decrease, and the flow rate of raw water will gradually increase. On the basis of the relatively long design of the water diversion channel, The raw water flow rate can be maintained to increase gradually at the same time, the raw water flows in a spiral in the water inlet channel and the flow area of ​​the raw water gradually decreases, the shear flow rate at the concentrate end is improved, the concentration polarization caused by the poor water quality at the concentrate end is weakened, and the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down to a certain extent, and the surface pollution of the reverse osmosis filter element membrane is effectively alleviated, and the scaling rate is delayed. The water inlet spacer increases the surface flow rate of the reverse osmosis membrane 1 by designing the water blocking part 4, so that the reverse osmosis membrane 1 can resist pollution and blockage more effectively, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole.

[0065] Embodiment 2

[0066] like Figure 2 As shown, a reverse osmosis membrane unit comprises:

[0067] The reverse osmosis membrane 1 has a first surface and a second surface opposite to each other;

[0068] A water inlet screen sandwiched between the first surfaces of the two layers of reverse osmosis membranes 1 to form a water diversion channel with the reverse osmosis membranes 1, the water inlet screen being the water inlet screen in the first embodiment;

[0069] The pure water guide cloth 3 is provided on the second surface of the reverse osmosis membrane 1 .

[0070] In this embodiment, the water inlet screen body 2 is sandwiched between the folded reverse osmosis membrane sheets 1, the water inlet screen body 2 is fixedly clamped by the folded reverse osmosis membrane sheets 1, and the folded reverse osmosis membrane sheets 1 are attached between the adjacent pure water guide fabrics 3, as shown in FIG. Figure 7 As shown, a glue line 6 is provided on the pure water guide cloth 3 to facilitate the bonding of the reverse osmosis membrane 1 and the pure water guide cloth 3 .

[0071] Raw water enters from the water inlet screen body 2 and flows along the curved water diversion channel. The flow path of the raw water is extended, the flow time of the raw water in the water diversion channel is increased, and the contact time between the raw water and the reverse osmosis membrane 1 is increased, thereby improving the overall water filtration efficiency of the reverse osmosis membrane unit. At the same time, under the condition of a certain raw water flow rate, the spacing between two adjacent water blocking parts 4 is reduced successively, and the flow rate of the raw water will gradually increase. On the basis of the relatively long design of the water diversion channel, the raw water flow rate can also be maintained to gradually increase. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrated water end is improved, and the concentration polarization caused by the poor water quality at the concentrated water end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down, and the surface pollution of the reverse osmosis filter element membrane is effectively alleviated, and the scaling rate is delayed. The water inlet screen in this embodiment increases the surface flow rate of the reverse osmosis membrane 1 by designing the water blocking part 4, so that the reverse osmosis membrane 1 can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole.

[0072] Embodiment 3

[0073] like Figure 2-6 As shown, this embodiment provides a reverse osmosis membrane element, comprising:

[0074] Central tube 5;

[0075] A plurality of reverse osmosis membrane units as claimed in claim 5;

[0076] Wherein, a plurality of the reverse osmosis membrane units are wound on the outside of the central tube 5 in the order from close to the central tube 5 to far away from the central tube 5, the reverse osmosis membrane element has a first end and a second end opposite to each other in the axial direction, a circumferential seal 10 is arranged on the outer circumferential surface of the first end and the outer circumferential surface of the second end, a first radial seal 8 is arranged on the end surface of the first end, and a second radial seal 9 is arranged on the end surface of the second end;

[0077] The portion of the end surface of the first end that does not cover the first radial seal 8 forms a raw water inlet 202, and the portion of the end surface of the second end that does not cover the second radial seal 9 forms a concentrated water outlet 203;

[0078] A pure water outlet 7 is formed between the two circumferential seals 10 .

[0079] In this embodiment, the reverse osmosis membrane element is a rolled reverse osmosis membrane element, and the central tube 5 plays a role in fixing and supporting a plurality of reverse osmosis membrane units composed of a reverse osmosis membrane sheet 1 , a water inlet screen body 2 and a pure water guide cloth 3 .

[0080] Raw water enters from the raw water inlet 202 and flows along multiple water diversion channels 201. During the flow, the flow direction is constantly changed, thereby relatively extending the effective flow path length of the entire water diversion channel, increasing the flow time of raw water in the water diversion channel, and then increasing the contact time between raw water and the reverse osmosis membrane 1, thereby improving the overall water filtration efficiency of the reverse osmosis membrane unit. Combined with the design of the flow area of ​​the multiple water diversion channels 201 gradually decreasing, under the condition of a certain raw water flow rate, the flow area of ​​the multiple water diversion channels 201 gradually decreases, and the flow rate of the raw water gradually increases. On the basis of the relatively long design of the water diversion channel, the raw water flow rate can also be maintained to gradually increase. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrate end is improved, and the concentration polarization caused by the poor water quality at the concentrate end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down, and the surface pollution of the reverse osmosis membrane 1 is effectively alleviated, and the scaling rate is slowed down, so that the reverse osmosis membrane element as a whole can more effectively resist pollution and blockage, thereby extending the overall service life of the reverse osmosis membrane element.

[0081] Raw water continuously enters from the raw water inlet 202 , and the pure water filtered by the reverse osmosis membrane 1 is guided by the pure water guide cloth 3 to the pure water outlet 7 for discharge, while the concentrated water is discharged through the concentrated water outlet 203 .

[0082] Optionally, in an implementation of this embodiment, as Figure 1 As shown,

[0083] In the radial direction of the central tube 5, the length of the water inlet screen body 2 is L, the length of the raw water inlet 202 is L1, and the length of the concentrated water outlet 203 is L2;

[0084] Among them, L / 15≤L2<L1≤L / 2.

[0085] In this embodiment, by limiting the relationship between the raw water inlet 202 and the concentrated water outlet 203 and the total length of the water inlet screen body 2, the raw water inlet flow rate is moderate, matching the circulation time of the raw water in the S-shaped water diversion channel, so that the raw water can be better filtered and efficient filtration can be achieved.

[0086] Optionally, in an implementation of this embodiment, as Figure 1 As shown,

[0087] The plurality of water diversion channels 201 in the water diversion channel include a first water diversion channel 2011, a second water diversion channel 2012 and a third water diversion channel 2013. The first water diversion channel 2011 has a width of H1, the second water diversion channel 2012 has a width of H2, and the third water diversion channel 2013 has a width of H3.

[0088] Among them, L1≥H1>H2>H3≥L2.

[0089] In this embodiment, the widths of the first water diversion channel 2011, the second water diversion channel 2012 and the third water diversion channel 2013 are gradually reduced, and the raw water flow rate V=Q / (l×T), where Q is the raw water flow rate, l is the width of the water diversion channel, T is the thickness of the water diversion channel, and l×T is the flow area of ​​the water diversion channel. Under the condition that the raw water flow rate and the thickness of the water diversion channel are constant, the widths of the first water diversion channel 2011, the second water diversion channel 2012 and the third water diversion channel 2013 are gradually reduced, and the raw water flow rate will gradually increase. On the basis of the relatively long overall design of the water diversion channel On the basis, the raw water flow rate can be maintained to increase gradually at the same time, the raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases, the shear flow rate at the concentrated water end is improved, the concentration polarization caused by the poor water quality at the concentrated water end is weakened, and the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down to a certain extent, effectively alleviating the surface pollution of the reverse osmosis filter element membrane, and delaying the scaling rate. The reverse osmosis membrane unit in this embodiment is designed to increase the surface flow rate of the reverse osmosis membrane 1 while optimizing the water inlet method and the water diversion channel, so that the reverse osmosis membrane 1 can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit as a whole. At the same time, the width of the first water diversion channel 2011, the second water diversion channel 2012 and the third water diversion channel 2013 is limited to be greater than the length L1 of the raw water inlet 202, and less than the length L2 of the concentrated water outlet 203, so that the reverse osmosis membrane element has a suitable water inlet, and the inlet water can be fully filtered by the reverse osmosis membrane 1 during the circulation of the water diversion channel.

[0090] Optionally, in an implementation of this embodiment, as Figure 5 , 6 As shown,

[0091] The end surface of the first end and the end surface of the second end are both configured as annular surfaces;

[0092] The first radial seal 8 and the second radial seal 9 are both constructed as annular sealing walls;

[0093] The pure water outlet 7 is configured as a strip-shaped outlet extending axially along the central tube 5;

[0094] The annular diameters of the end faces of the first end and the second end are both R, the annular diameter of the first radial seal 8 is r1, the annular diameter of the second radial seal 9 is r2, and R-r1>R-r2.

[0095] In this embodiment, in the reverse osmosis membrane element, the portion of the radial sealing surface on one side close to the central tube 5 is sealed to form a first radial seal 8, and only the portion away from the central tube 5 is reserved as a raw water inlet 202 for raw water to enter, and the portion of the radial sealing surface on the other side away from the central tube 5 is sealed to form a second radial seal 9, and only the portion close to the central tube 5 is reserved as a concentrated water outlet 203 for concentrated water to be discharged, thereby achieving separation of raw water entry and concentrated water discharge.

[0096] The pure water filtered by the reverse osmosis membrane 1 is discharged along the pure water outlet 7 on the circumferential surface of the pure water guide cloth 3 in the winding direction on the central tube 5. In order to facilitate the discharge of pure water, a shell can be provided on the outermost layer of the reverse osmosis membrane element, and the pure water outlet 7 is directly connected to the shell, thereby forming a pure water outlet 7 independent of the raw water inlet 202 and the concentrated water outlet 203, which is convenient for collecting pure water.

[0097] R-r1>R-r2, ensuring that the area of ​​the raw water inlet 202 is larger than the concentrate outlet 203, thereby increasing the concentrate outlet flow rate and further reducing concentration polarization.

[0098] Optionally, in an implementation of this embodiment, as Figure 2 As shown,

[0099] The side walls at both ends and the peripheral side wall of the central tube 5 are both constructed as closed wall surfaces.

[0100] In this embodiment, pure water filtered by the reverse osmosis membrane 1 is discharged from the pure water outlet 7 of the pure water guide cloth 3, instead of the original reverse osmosis membrane element in which pure water is discharged from the central tube. In this embodiment, pure water is directly discharged from the pure water guide cloth 3. Since the pure water flow rate in the area close to the central tube is higher, this discharge method can reduce the impact of the high back pressure in the area close to the central tube 5 on the reverse osmosis membrane 1, thereby greatly improving the water production efficiency of the reverse osmosis membrane unit.

[0101] At the same time, the pure water outlet 7 is designed to extend axially along the central tube 5 on the pure water guide cloth 3, so that the pure water outlet 7 can be discharged from the peripheral side wall of the pure water guide cloth 3, and the discharge area is relatively large, which further reduces the influence of the high back pressure in the area close to the central tube 5 on the reverse osmosis membrane 1, and improves the water filtration efficiency of the reverse osmosis membrane element.

[0102] Embodiment 4

[0103] This embodiment provides a filter element, including:

[0104] The reverse osmosis membrane element in Example 3.

[0105] The filter element provided in this embodiment also has the advantages possessed by the reverse osmosis membrane element in the third embodiment.

[0106] The reverse osmosis membrane 1 in the third embodiment can be replaced by a filter membrane structure such as a nanofiltration membrane or a microfiltration membrane as required to form filter elements for different purposes.

[0107] Embodiment 5

[0108] This embodiment provides a filtering system, including:

[0109] The filter element in embodiment 4.

[0110] Specifically, the filtration system also includes:

[0111] Raw water tank, concentrated water collection tank, pure water collection tank;

[0112] The raw water tank is connected to the raw water inlet 202 , the concentrated water collection tank is connected to the concentrated water outlet 203 , and the pure water collection tank is connected to the pure water outlet 7 .

[0113] In the filtration system, raw water enters from the water inlet screen body 2 and flows along the curved water diversion channel. The flow path of the raw water is extended, the flow time of the raw water in the water diversion channel is increased, and the contact time between the raw water and the reverse osmosis membrane 1 is increased, thereby improving the overall water filtration efficiency of the reverse osmosis membrane unit. At the same time, under the condition of a certain raw water flow rate, the spacing between two adjacent water blocking parts 4 is reduced successively, and the flow rate of the raw water will gradually increase. On the basis of the relatively long design of the water diversion channel, the raw water flow rate can also be maintained to gradually increase. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrated water end is increased, and the concentration polarization caused by the poor water quality at the concentrated water end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane 1 is slowed down, and the surface pollution of the reverse osmosis filter element membrane is effectively alleviated, and the scaling rate is delayed. The water inlet screen in this embodiment increases the surface flow rate of the reverse osmosis membrane 1 by designing the water blocking part 4, so that the reverse osmosis membrane 1 can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole.

[0114] In summary, the ingenious design of the water inlet screen and reverse osmosis membrane element is:

[0115] First, by arranging a water blocking portion on the water inlet screen body, the water blocking portion adopts a rubber line, which can not only form a curved water diversion channel between the water inlet screen body and the reverse osmosis membrane, but also play a role in fixing and bonding the water inlet screen body and the reverse osmosis membrane. Without adding additional components, the water blocking portions are staggered to form a curved water diversion channel. Raw water enters from the water inlet screen body and flows along the curved water diversion channel. The flow path of the raw water is extended, the flow time of the raw water in the water diversion channel is increased, and then the contact time between the raw water and the reverse osmosis membrane is increased, thereby improving the overall water filtration efficiency of the reverse osmosis membrane unit. At the same time, under the condition of a certain raw water flow rate, the gap between two adjacent water blocking portions is The spacing between the two decreases successively, and the flow rate of the raw water will gradually increase. On the basis of the relatively long design of the water diversion channel, the flow rate of the raw water can also be maintained to increase gradually. The raw water flows in a spiral in the water diversion channel and the flow area of ​​the raw water gradually decreases. The shear flow rate at the concentrate end is improved, and the concentration polarization caused by the poor water quality at the concentrate end is weakened. To a certain extent, the concentration polarization phenomenon on the surface of the reverse osmosis membrane is slowed down, and the pollution of the surface of the reverse osmosis filter element is effectively alleviated, and the scaling rate is delayed. The water inlet spacer in this embodiment increases the surface flow rate of the reverse osmosis membrane by designing the water blocking part, so that the reverse osmosis membrane can more effectively resist pollution and blockage, thereby extending the service life of the reverse osmosis membrane unit and the reverse osmosis membrane element as a whole.

[0116] Second, the side walls and the surrounding side walls of the central tube are designed to be closed walls. The pure water filtered by the reverse osmosis membrane is exported from the pure water outlet of the pure water guide cloth, replacing the original reverse osmosis membrane element in which the pure water is exported from the central tube. The pure water is directly exported from the pure water guide cloth. Since the pure water flow rate in the area close to the central tube is relatively high, this export method can reduce the impact of the high back pressure in the area close to the central tube on the reverse osmosis membrane 1, and improve the water production efficiency of the reverse osmosis membrane unit to a large extent. At the same time, the pure water outlet is designed to extend along the axial direction of the central tube on the pure water guide cloth, so that the pure water outlet can be discharged from the surrounding side walls of the pure water guide cloth, and the discharge area is relatively large, which further reduces the impact of the high back pressure in the area close to the central tube on the reverse osmosis membrane and improves the water filtration efficiency of the reverse osmosis membrane element.

[0117] It is further understood that in the present disclosure, "plurality" refers to two or more than two, and other quantifiers are similar thereto. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The singular forms "a", "the" and "the" are also intended to include plural forms, unless the context clearly indicates other meanings.

[0118] It is further understood that the terms "first", "second", etc. are used to describe various information, but such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other, and do not indicate a specific order or degree of importance. In fact, the expressions "first", "second", etc. can be used interchangeably. For example, without departing from the scope of the present disclosure, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

[0119] It is further understood that, although the operations are described in a specific order in the drawings in the embodiments of the present disclosure, it should not be understood as requiring the operations to be performed in the specific order shown or in a serial order, or requiring the execution of all the operations shown to obtain the desired results. In certain environments, multitasking and parallel processing may be advantageous.

[0120] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0121] It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the scope of the appended claims.

Claims

1. A water inlet screen for a reverse osmosis membrane element, characterized in that: include: A water inlet screen body (2) used for being attached to the reverse osmosis membrane sheet (1) in the reverse osmosis membrane element; The water inlet screen body (2) has water blocking portions (4) which are spaced apart and arranged in an interlaced manner along the extension direction of the water inlet screen body (2), so that the water inlet screen forms a continuously curved water diversion channel; The distance between two adjacent water blocking portions (4) decreases successively.

2. The water inlet screen according to claim 1, characterized in that: The water blocking portion (4) is a rubber strip that attaches the water inlet screen body (2) to the reverse osmosis membrane (1).

3. The water inlet screen according to claim 1, characterized in that: The water diversion channel comprises a plurality of water diversion diversion channels (201); The multiple water diversion diversion channels (201) are designed such that: the incoming water has different flow directions in two adjacent water diversion diversion channels (201), and the multiple water diversion diversion channels (201) are sequentially connected along the incoming water flow direction; The flow areas of the plurality of water diversion channels (201) decrease sequentially along the inlet water flow direction.

4. The water inlet screen according to claim 3, characterized in that: The plurality of water diversion channels (201) can enable the incoming water to flow in an S-shape within the water inlet screen.

5. A reverse osmosis membrane unit, characterized in that: include: A reverse osmosis membrane (1) having a first surface and a second surface opposite to each other; A water inlet screen sandwiched between the first surfaces of the two layers of the reverse osmosis membrane (1) to form a water diversion channel with the reverse osmosis membrane (1), wherein the water inlet screen is the water inlet screen according to any one of claims 1 to 4; A pure water guide cloth (3) is arranged on the second surface of the reverse osmosis membrane (1).

6. A reverse osmosis membrane element, characterized in that: include: Central tube (5); A plurality of reverse osmosis membrane units as claimed in claim 5; wherein a plurality of the reverse osmosis membrane units are wound around the outside of the central tube (5) in the order from close to the central tube (5) to far from the central tube (5); the reverse osmosis membrane element has a first end and a second end opposite to each other in the axial direction; a circumferential seal (10) is arranged on the outer circumferential surface of the first end and the outer circumferential surface of the second end; a first radial seal (8) is arranged on the end surface of the first end, and a second radial seal (9) is arranged on the end surface of the second end; The portion of the end surface of the first end that does not cover the first radial seal (8) forms a raw water inlet (202), and the portion of the end surface of the second end that does not cover the second radial seal (9) forms a concentrated water outlet (203); A pure water outlet (7) is formed between the two circumferential seals (10).

7. The reverse osmosis membrane element according to claim 6, characterized in that: In the radial direction of the central tube (5), the length of the water inlet screen body (2) is L, the length of the raw water inlet (202) is L1, and the length of the concentrated water outlet (203) is L2; Among them, L / 15≤L2<L1≤L / 2.

8. The reverse osmosis membrane element according to claim 7, characterized in that: The plurality of water diversion diversion channels (201) in the water diversion channel include a first water diversion diversion channel (2011), a second water diversion diversion channel (2012) and a third water diversion diversion channel (2013); the first water diversion diversion channel (2011) has a width of H1, the second water diversion diversion channel (2012) has a width of H2, and the third water diversion diversion channel (2013) has a width of H3; Among them, L1≥H1>H2>H3≥L2.

9. The reverse osmosis membrane element according to claim 6, characterized in that: The end surface of the first end and the end surface of the second end are both configured as annular surfaces; The first radial seal (8) and the second radial seal (9) are both constructed as annular sealing walls; The pure water outlet (7) is constructed as a strip-shaped outlet extending axially along the central tube (5); wherein the annular diameters of the end faces of the first end and the second end are both R, the annular diameters of the first radial seal (8) are r1, and the annular diameters of the second radial seal (9) are r2, and R-r1>R-r2.

10. The reverse osmosis membrane element according to claim 6, characterized in that: The side walls at both ends and the peripheral side wall of the central tube (5) are both constructed as closed wall surfaces.

11. A filter element, characterized in that: include: A reverse osmosis membrane element as described in any one of claims 6 to 10.

12. A filtering system, characterized in that: include: The filter element as claimed in claim 11.

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