Multiple filtration reverse osmosis membrane elements

Abstract

The present invention discloses a multiple-filtration type reverse osmosis membrane element, which belongs to the field of filtration and purification equipment. The reverse osmosis membrane element includes: a secondary filtration component detachably arranged in a housing, the secondary filtration component includes: two groups of filter elements connected in series through a connecting component, the filter elements include: a central tube with water-permeable holes arranged on the tube wall; and a filter membrane layer, the filter membrane layer is arranged on the outside of the central tube, and the liquid flows in the filter membrane layer and the central tube through the water-permeable holes. By connecting the two groups of filter elements in series through the connecting component, the device integrates the secondary reverse osmosis filtration into a membrane element, realizing the secondary or multiple filtration function of a single membrane element, which can not only obtain output fresh water with a lower salt content, but also streamline the equipment and reduce the volume, providing convenience for some small and medium-sized factories or laboratories with insufficient space.

Description

Technical Field

[0001] The present invention relates to the field of purification and filtering equipment, in particular to a multiple-filtration type reverse osmosis membrane element. Background Art

[0002] Reverse osmosis membranes are artificial semipermeable membranes with specific properties that mimic biological semipermeable membranes. They are the core component of reverse osmosis technology. The principle of reverse osmosis technology is to separate substances from water under the influence of a pressure higher than the osmotic pressure of the solution, based on the fact that other substances cannot pass through the semipermeable membrane.

[0003] Working Principle of Reverse Osmosis Membrane: Reverse osmosis is a technology that uses the pressure difference across a filter membrane to separate influent into freshwater (also known as permeate) and concentrated water (also known as concentrate). The filter core made from reverse osmosis membrane is called a reverse osmosis membrane element. The reverse osmosis desalination capacity, referred to as the desalination rate, is calculated by subtracting the salt content of the freshwater from the salt content of the influent, and then dividing the result by the salt content of the influent.

[0004] Existing reverse osmosis membrane elements filter the incoming water only once. Given a specific rejection rate for the membrane element, if the incoming water has a high salt content, the resulting freshwater will also have a high salt content. In applications where the incoming water is highly saline or where a lower salt content is required for the produced freshwater, the incoming water must be filtered repeatedly to produce high-quality freshwater that meets the required quality. Consequently, existing reverse osmosis membrane element multi-filtration systems suffer from complex piping, bulky design, and excessive floor space. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a multiple filtration type reverse osmosis membrane element.

[0006] The technical solution of the present invention is: a multiple filtration type reverse osmosis membrane element, comprising:

[0007] A secondary filter assembly detachably disposed within the housing, the secondary filter assembly comprising:

[0008] Two groups of filter elements connected in series via a connecting assembly, the filter elements comprising:

[0009] A central tube, the central tube being located in the exact center and having water-permeable holes arranged on the tube wall of the central tube; and

[0010] The filter membrane layer is arranged outside the central tube, and the liquid flows in the filter membrane layer and the central tube through the water-permeable holes.

[0011] Furthermore, the two groups of filter elements are coaxially connected in series along their central axes.

[0012] Furthermore, the connection assembly includes: a water inlet water diversion cover, a middle water diversion cover and a water outlet support cover arranged in sequence from top to bottom;

[0013] A water inlet splitter cover, comprising a water inlet splitter plate, a primary concentrated water pipe penetrating the center of the outer end surface of the water inlet splitter plate, a water inlet extension ring disposed on the inner end surface of the water inlet splitter plate, and a filter element disposed within the water inlet extension ring;

[0014] An intermediate water diversion cover, the intermediate water diversion cover comprising an intermediate water diversion plate, an intermediate water diversion hole for the central tube to pass through is provided at the center of the intermediate water diversion plate, intermediate extension rings are provided at the upper and lower ends of the intermediate water diversion plate, a filter element is provided in the intermediate extension rings, and a primary water inlet hole is further provided on the side wall of one of the intermediate extension rings, and the intermediate extension ring provided with the primary water inlet hole faces the water inlet water diversion cover; and

[0015] The water outlet support cover includes a water outlet plate, a water outlet hole for the central pipe to pass through is arranged in the center of the water outlet plate, a wastewater outlet is arranged on the plate surface of the water outlet plate, and a water outlet support ring is arranged at the upper end surface of the water outlet plate, and a filter element is arranged in the water outlet support ring.

[0016] Furthermore, the inlet extension ring, intermediate extension ring, and outlet support ring are all provided with stop rings on their circumferential outer walls. This ensures a stable installation process. A filter membrane layer is provided on the inner circumference of each ring, intermediate extension ring, and outlet support ring, and a ring of sealing tape is installed at the connection between the ring and the filter membrane layer. This sealing tape not only secures the ring but also isolates it, preventing water from flowing directly through the gap between the two without being filtered by the filter membrane layer.

[0017] Furthermore, a water retaining ring is provided on the outer circumference of the middle water diversion cover, thereby ensuring that the middle water diversion cover can separate the upper and lower parts; and the water retaining ring is preferably a lip-shaped sealing ring, with the lip facing the water inlet diversion cover.

[0018] Furthermore, a sealing ring is provided on the inner wall of the middle water diversion hole, thereby ensuring the sealing performance between two adjacent filtrations.

[0019] Furthermore, the wastewater outlet is fan-shaped, and at least two wastewater outlets are evenly distributed with the outlet as the center. This structural arrangement ensures that the wastewater flows out in a timely and effective manner.

[0020] Furthermore, the central tube is a hollow tube, and one end of the central axis of the central tube is a closed end and the other end is an open end. The closed ends are both facing the water inlet diversion cap, and the inlet water flows into the central tube after being filtered by the provided filter element.

[0021] Furthermore, the filter membrane layer is spirally wound around the circumferential outer side of the central tube. This spiral winding arrangement ensures that the filter membrane layer is arranged so as to achieve a good filtering effect.

[0022] Furthermore, the filter membrane layer includes at least two groups of reverse osmosis membranes, a water inlet guide net, a reverse osmosis membrane, and a freshwater guide cloth, stacked in sequence. The reverse osmosis membrane, freshwater guide cloth, and reverse osmosis membrane complex are connected by sealant at the sides, with the sealant applied at edges perpendicular and parallel to the central tube, forming a continuous U-shaped sealant, with the U-shaped opening facing and in contact with the central tube. Specifically, the reverse osmosis membrane, freshwater guide cloth, and reverse osmosis membrane complex are sealed with sealant at three edges to form a filter bag, with the bag opening facing the central tube. Multiple filter bags are stacked and sequentially wound around the central tube. The final structure also includes a water inlet guide net attached between two adjacent filter bags, with the gap formed between the water inlet guide net and the filter bag serving as the internal water flow channel.

[0023] Furthermore, an outer layer of adhesive tape is provided on the outer side of the filter membrane layer wound around the central tube. The provision of the outer layer of adhesive tape ensures the shaping of the filter membrane layer.

[0024] Furthermore, the surface of the water inlet guide net is provided with a guide groove, and the guide groove is linear. By providing the guide groove, it is ensured that the water can smoothly enter the filtering space when entering.

[0025] Furthermore, the direction of the guide groove is parallel to the axis of the central tube to control the flow rate of the water flow.

[0026] Furthermore, when the direction of the guide groove is perpendicular to the axis of the central tube, sealing strips are provided between the water inlet guide net and the reverse osmosis membranes on both sides. The sealing strips are perpendicular to the axis of the central tube and are distributed on the upper and lower sides of the water inlet guide net. This can also control the water flow.

[0027] Furthermore, the water inlet diversion net is woven from multiple strands of ultra-fine fiber bundles, with several parallel fiber bundles on one side and a cross-grid fiber bundle on the other side. This different structure on both sides is caused by the weaving method.

[0028] The beneficial technical effect of the present invention is that two groups of filter elements are connected in series through a connecting component, and after the raw water enters the first group of filter elements, it flows out in two streams, one is clean water and flows to the second group of filter elements, and the other is waste water and flows out of the first group of filter elements; after the second group of filter elements filters the clean water from the first group of filter elements, it also flows out in two streams, one of which is clean water and flows out for storage, and the other is waste water and flows out; if there are three or more groups of filter elements, and so on; this device can integrate two or more reverse osmosis filtration into one membrane element, realizing the secondary or multiple filtration function of a single membrane element, which can not only obtain output fresh water with lower salt content but also streamline equipment and reduce volume, providing convenience for some small and medium-sized factories or laboratories with insufficient space. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of two groups of coaxial filter elements connected in series.

[0030] Figure 2 It is a cross-sectional schematic diagram of the reverse osmosis membrane element in the housing.

[0031] Figure 3 This is a schematic diagram of the water inlet and water diversion cover.

[0032] Figure 4 It is a schematic diagram of the middle water diversion cover.

[0033] Figure 5 This is a schematic diagram of the outer side of the middle water diversion cover.

[0034] Figure 6 Schematic diagram of the water outlet support cover.

[0035] Figure 7 is a schematic diagram of a filter element.

[0036] Figure 8 This is a diagram of the sealant setting.

[0037] Figure 9 It is a microscopic diagram of the water inlet diversion network.

[0038] Figure 10 This is a schematic diagram when the guide groove is perpendicular to the central tube.

[0039] Figure 11 This is a schematic diagram when the guide tube is parallel to the central tube.

[0040] In the picture:

[0041] 1. Shell,

[0042] 2. Filter element, 21. Center tube, 211. Water permeable hole, 22. Filter membrane layer, 221. Reverse osmosis membrane, 222. Water inlet diversion net, 2221. Diversion groove, 223. Fresh water diversion cloth, 23. Outer tape,

[0043] 3. Connecting assembly, 31. Water inlet manifold cover, 311. Water inlet manifold plate, 312. Primary concentrated water pipe, 313. Water inlet extension ring,

[0044] 32. Middle water distribution cover, 321. Middle water distribution plate, 322. Middle water distribution hole, 323. Middle extension ring, 324. Primary water inlet hole,

[0045] 33. Water outlet support cover, 331. Water outlet plate, 332. Water outlet hole, 333. Wastewater outlet, 334. Water outlet support ring,

[0046] 34. Water retaining ring. DETAILED DESCRIPTION

[0047] In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0048] See attached Figure 1-11 In this embodiment, a multiple filtration type reverse osmosis membrane element includes:

[0049] A secondary filter assembly is detachably disposed in the housing 1, and the secondary filter assembly includes:

[0050] Two groups of filter elements 2 are connected in series through a connecting assembly 3, and the filter elements 2 include:

[0051] The central tube 21 is located in the center, and a water-permeable hole 211 is set on the tube wall of the central tube 21; and the filter membrane layer 22 is set on the outside of the central tube 21, and the liquid flows in the filter membrane layer 22 and the central tube 21 through the water-permeable hole 211.

[0052] Furthermore, the two groups of filter elements 2 are coaxially connected in series along their central axes.

[0053] Furthermore, the connection assembly 3 includes: a water inlet water distribution cover 31, an intermediate water distribution cover 32 and a water outlet support cover 33 arranged in sequence from top to bottom; see the attached Figure 3 The water inlet splitting cover 31 includes a water inlet splitting plate 311, a primary concentrated water pipe 312 is provided through the center of the outer end surface of the water inlet splitting plate 311, a water inlet extension ring 313 is provided on the inner end surface of the water inlet splitting plate 311, and a filter element 2 is provided in the water inlet extension ring 313;

[0054] See attached Figure 4-5 The intermediate water diversion cover 32 includes an intermediate water diversion plate 321. An intermediate water diversion hole 322 for the central tube 21 to pass through is provided at the center of the intermediate water diversion plate 321. Intermediate extension rings 323 are provided at the upper and lower ends of the intermediate water diversion plate 321. The filter element 2 is provided in the intermediate extension ring 323. At the same time, a primary water inlet hole 324 is further provided on the side wall of one of the intermediate extension rings 323. The intermediate extension ring 323 provided with the primary water inlet hole 324 faces the water inlet diversion cover 31.

[0055] and

[0056] See attached Figure 6 The water outlet support cover 33 includes a water outlet plate 331. A water outlet hole 332 for the central tube 21 to pass through is provided at the center of the water outlet plate 331. A wastewater outlet 333 is provided on the plate surface of the water outlet plate 331. At the same time, a water outlet support ring 334 is provided at the upper end surface of the water outlet plate 331, and a filter element 2 is provided in the water outlet support ring 334.

[0057] The three covers are directly connected to the shell and their function is to provide support and ensure stability with the shell.

[0058] Furthermore, stop rings are provided on the circumferential outer walls of the water inlet extension ring 313, the intermediate extension ring 323, and the water outlet support ring 334. The stop rings ensure a stable installation process. A filter membrane layer is also provided on the circumferential inner sides of the water inlet extension ring 313, the intermediate extension ring 323, and the water outlet support ring 334. A ring of sealing tape is provided at the connection between the rings and the filter membrane layer. This sealing tape not only secures the rings but also isolates them, preventing water from flowing directly through the gap between them without being filtered by the filter membrane layer.

[0059] For further information, see the attached Figure 5 A water retaining ring 34 is provided on the circumferential outer side of the middle water diversion cover 32. The provision of the water retaining ring 34 ensures that the middle water diversion cover 32 separates the upper and lower parts; and the water retaining ring 34 here is preferably a lip-shaped sealing ring, and the lip here faces the water inlet diversion cover 31.

[0060] Furthermore, a sealing ring is provided on the inner wall of the middle water diversion hole 322. The sealing ring ensures the sealing performance between two adjacent filtrations.

[0061] For further information, see the attached Figure 6 The wastewater outlet 333 is fan-shaped, and at least two wastewater outlets 333 are evenly distributed with the water outlet as the center. That is, the setting of this structure ensures that the wastewater flows out in a timely and effective manner.

[0062] For further information, see the attached Figure 7 The central tube 21 is a hollow tube, and one end of the central axis of the central tube 21 is a closed end and the other end is an open end. The closed ends are all facing the water inlet water separation cap 31, and the inlet water flows into the central tube 21 after being filtered by the filter element 2.

[0063] Furthermore, the filter membrane layer 22 is spirally wound around the circumferential outer side of the central tube 21. This spiral winding arrangement ensures that the filter membrane layer 22 is arranged to achieve a good filtering effect.

[0064] For further information, see the attached Figure 7-8 The filter membrane layer 22 includes at least two groups of reverse osmosis membranes 221, a water inlet guide net 222, a reverse osmosis membrane 221, and a fresh water guide cloth 223, which are stacked in sequence. At the same time, the sides of the complex consisting of the reverse osmosis membrane 221, the fresh water guide cloth 223, and the reverse osmosis membrane 221 are connected by sealant, and the sealant is arranged on the edges perpendicular to and parallel to the central tube 21 to form a U-shaped continuous sealant, and the U-shaped opening faces the central tube 21 and contacts the central tube 21. That is, the complex consisting of the reverse osmosis membrane 221, the fresh water guide cloth 223 and the reverse osmosis membrane 221 is sealed with sealant on three edges to form a filter bag, with the bag opening facing the central tube 21, and multiple filter bags are stacked and wound on the central tube 21 in sequence; at the same time, the final structure also reflects that a water inlet guide net 222 is attached between two adjacent filter bags, and the gap formed by the water inlet guide net 222 and the filter bag is the internal water flow channel.

[0065] For further information, see the attached Figure 7 An outer layer of adhesive tape 23 is also provided on the outside of the filter membrane layer 22 wound around the central tube 21. The provision of the outer layer of adhesive tape 23 ensures the shaping of the filter membrane layer 22 and prevents the loosening of the material.

[0066] For further information, see the attached Figure 9 The surface of the water inlet guide net 222 has a guide groove 2221, and the guide groove 2221 is linear. By setting the guide groove 2221, it is ensured that when water enters, it can smoothly enter the filtering space.

[0067] For further information, see the attached Figure 11 The direction of the guide groove 2221 is parallel to the axis direction of the central tube 21. Control the flow rate of the water flow.

[0068] For further information, see the attached Figure 10 When the direction of the guide groove 2221 is perpendicular to the axis of the central tube 21, sealing strips are provided between the water inlet guide net 222 and the reverse osmosis membranes 221 on both sides. The sealing strips are perpendicular to the axis of the central tube 21 and are distributed on the upper and lower sides of the water inlet guide net 222. This can also control the water flow.

[0069] Furthermore, the water inlet guide net 222 is woven from multiple strands of ultrafine fiber bundles, with several parallel fiber bundles on one side and a grid of intersecting fiber bundles on the other. This different structure on both sides is due to the weaving method. This novel water inlet guide net configuration ensures a thinner thickness, improved flow rate, and better water quality. This linear flow channel configuration further maximizes the performance of the reverse osmosis membrane, effectively improving filtration quality.

[0070] In addition to the coaxial series connection, the two sets of filter elements can also be connected in series using a concentric inner and outer arrangement.

[0071] The two groups of filter elements 2 are connected in series through the connecting component 3. After the raw water enters the first group of filter elements 2, it flows out in two streams, one of which is clean water and flows to the second group of filter elements 2, and the other is waste water and flows out of the first group of filter elements 2; after the second group of filter elements 2 filters the clean water from the first group of filter elements 2, it also flows out in two streams, one of which is clean water and flows out for storage, and the other is waste water and flows out; if there are three or more groups of filter elements 2, and so on; this device can integrate two or more reverse osmosis filtration into one membrane element, realizing the secondary or multiple filtration function of a single membrane element, which can not only obtain output fresh water with lower salt content but also streamline equipment and reduce volume, providing convenience for some small and medium-sized factories or laboratories with insufficient space. Example 1

[0072] A secondary filtration type reverse osmosis membrane element composed of two groups of filter elements in series

[0073] For details, please refer to the attached Figure 1 and 2 After the raw water flows into the shell, it flows into the first set of filter elements from bottom to top through the primary water inlet hole of the middle water diversion cover, and is divided into two streams after being processed by the filter membrane layer. One stream enters the central tube after being processed by the reverse osmosis membrane, and the other stream flows out from the primary concentrated water pipe at the upper end.

[0074] The specific filtration process is as follows: the raw influent flows along the water channel between the inlet guide mesh and the filter bag to the concentrate outlet. Pressure from the raw influent on the reverse osmosis membrane creates two separate streams. One stream, fresh water that has passed through the reverse osmosis membrane, is guided by the fresh water guide fabric, passes through multiple permeable holes on the central tube, and then enters the central tube, flowing to the next filter element. The other stream, concentrate, which has not passed through the reverse osmosis membrane, flows through the water channel to the concentrate outlet of the filter element.

[0075] Since the central tube of the first set of filter elements is inserted along the middle water diversion hole, the fresh water that has been filtered once will enter the second set of filter elements for a second filtration. At the same time, the fresh water that has been filtered once is also processed by the filter membrane layer and divided into two streams. One stream enters the central tube of the second filtration after being processed by the reverse osmosis membrane, and the other stream flows out from the water outlet hole at the lower end.

[0076] Assuming a single reverse osmosis filtration has a 95% salt rejection rate, meaning 5% of the salt will pass through. The 5% that passes through the first filtration is then filtered out again in the second filtration, removing 95%. Theoretically, the final permeate is 5% * 5% = 0.25% of the original influent. This is a good result and can meet the needs of laboratories or small to medium-sized factories. Example 2

[0077] This embodiment 2 is improved on the basis of embodiment 1. The primary concentrated water pipe above is connected to the raw water inlet, and the raw water inlet flows from top to bottom through the first group of filter elements. The central pipe is also connected to the second group of filter elements as a fresh water pipe, and the wastewater filtered once is discharged through the primary water inlet hole.

[0078] This structural design can facilitate installation when three or more filter elements are used in combination, which can be achieved by stacking and using intermediate water distribution covers.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multiple filtration type reverse osmosis membrane element, characterized in that: include: A secondary filter assembly is detachably arranged in the housing (1), and the secondary filter assembly comprises: Two groups of filter elements (2) connected in series via a connecting assembly (3), the filter elements (2) comprising: A central tube (21), the central tube (21) being located in the exact center, and a water-permeable hole (211) being provided on the tube wall of the central tube (21); and A filter membrane layer (22), wherein the filter membrane layer (22) is arranged outside the central tube (21), and liquid flows through the filter membrane layer (22) and the central tube (21) through the water-permeable holes (211); The connection assembly (3) comprises: a water inlet water diversion cover (31), an intermediate water diversion cover (32), and a water outlet support cover (33) arranged in sequence from top to bottom; The water inlet splitting cover (31) comprises a water inlet splitting plate (311), a primary concentrated water pipe (312) is provided through the center of the outer end surface of the water inlet splitting plate (311), a water inlet extension ring (313) is provided on the inner end surface of the water inlet splitting plate (311), and a first group of filter elements is provided in the water inlet extension ring (313); The intermediate water diversion cover (32) comprises an intermediate water diversion plate (321), an intermediate water diversion hole (322) for the central tube (21) of the first group of filter elements to pass through is provided at the center of the intermediate water diversion plate (321), intermediate extension rings (323) are provided at the upper and lower ends of the intermediate water diversion plate (321), the first group of filter elements and the second group of filter elements are provided in the intermediate extension rings (323) at both ends, and a primary water inlet hole (324) is provided on the side wall of one of the intermediate extension rings (323), and the intermediate extension ring (323) provided with the primary water inlet hole (324) faces the water inlet diversion cover (31); and The water outlet support cover (33) comprises a water outlet plate (331), a water outlet hole (332) for the central tube (21) of the second group of filter elements to pass through is provided at the center of the water outlet plate (331), a wastewater outlet (333) is provided on the plate surface of the water outlet plate (331), and a water outlet support ring (334) is provided at the upper end surface of the water outlet plate (331), and the second group of filter elements is provided in the water outlet support ring (334); The central tubes (21) of the two groups of filter elements (2) are both hollow tubes, and one end of the central axial direction of the central tube (21) is a closed end, and the other end is an open end, and the closed ends are both facing the water inlet water separation cover (31).

2. The multi-filtration reverse osmosis membrane element according to claim 1, characterized in that: The two groups of filter elements (2) are coaxially connected in series along their central axes.

3. The multi-filtration reverse osmosis membrane element according to claim 1, characterized in that: A water retaining ring (34) is provided on the circumferential outer side of the middle water diversion cover (32).

4. The multi-filtration type reverse osmosis membrane element according to claim 1, characterized in that: The filter membrane layer (22) is spirally wound around the circumferential outer side of the central tube (21).

5. The multi-filtration type reverse osmosis membrane element according to claim 1, characterized in that: The filter membrane layer (22) comprises at least two groups of reverse osmosis membranes (221), a water inlet guide net (222), a reverse osmosis membrane (221), and a fresh water guide cloth (223) which are sequentially stacked. The sides of the composite body consisting of the reverse osmosis membrane (221), the fresh water guide cloth (223), and the reverse osmosis membrane (221) are connected by a sealant, and the sealant is arranged on the edge perpendicular to and parallel to the central tube (21), forming a continuous sealant in the shape of a U, and the U-shaped opening faces the central tube (21) and contacts the central tube (21). An outer layer of adhesive tape (23) is also arranged on the outside of the filter membrane layer (22) wound around the central tube (21).

6. The multi-filtration type reverse osmosis membrane element according to claim 5, characterized in that: The surface of the water inlet guide net (222) is provided with a guide groove (2221), and the guide groove (2221) is linear.

7. The multi-filtration type reverse osmosis membrane element according to claim 6, characterized in that: The direction of the guide groove (2221) is parallel to or perpendicular to the axial direction of the central tube (21); when the direction of the guide groove (2221) is perpendicular to the axial direction of the central tube (21), a sealing strip is further provided between the water inlet guide net (222) and the reverse osmosis membranes (221) on both sides, and the sealing strip is perpendicular to the axial direction of the central tube (21) and is distributed on the upper and lower sides of the water inlet guide net (222).

8. The multi-filtration type reverse osmosis membrane element according to claim 5, characterized in that: The water inlet diversion net (222) is woven from a plurality of ultrafine fiber bundles, and one side of the water inlet diversion net (222) presents a plurality of parallel fiber bundles, and the other side presents a cross-grid-shaped fiber bundle.

Images