A replaceable dual-layer filter element with a segmented negative porosity outer layer structure

Abstract

This invention relates to the field of fluid treatment and filtration technology, and provides a replaceable dual-layer filter element with a segmented negative porosity outer layer structure. The dual-layer filter element includes an inner filter element and an outer filter assembly coaxially sleeved on the outside of the inner filter element. The inner filter element and the outer filter assembly are connected by an annular clamp. The outer filter assembly includes at least three detachable filter segments, each segment connected end-to-end along the axial direction, and the porosity of each segment increases along the water flow direction, forming a negative porosity gradient filtration structure. This solution divides the outer filter assembly into several filter segments, each with a different porosity, and the porosity increases from the inlet to the depth of the outer filter assembly. The gradient structure disperses clogging points, allowing contaminants to be evenly deposited in each segment, achieving contaminant distribution along the depth, improving the filter element's clogging tolerance and overall filtration efficiency.

Description

Technical Field

[0001] This invention relates to the field of fluid treatment and filtration technology, specifically to a replaceable dual-layer filter element with a segmented negative porosity outer layer structure. Background Technology

[0002] In existing industrial filtration systems, filter elements typically employ a single, homogeneous filter layer. The inlet end experiences the greatest particle impact, causing contaminants to rapidly accumulate on the surface, resulting in a sharp increase in local pressure drop. Meanwhile, the utilization rate of deeper filter media is insufficient, leading to a significant reduction in overall lifespan. Some improved solutions use double-layer or multi-layer composite filter media, but the layers are permanently bonded. Generally, the outer layer is easily contaminated, while the inner layers remain relatively clean. Because contamination of the outer layer causes a significant increase in pressure drop across the filter element, it necessitates complete replacement. This not only increases maintenance workload but also raises operating costs.

[0003] Meanwhile, existing research has shown that rationally controlling the spatial distribution of porosity helps to achieve the distribution of pollutants along the depth. Therefore, there is an urgent need for a dual-layer filter element with different spatial distributions of porosity, which can improve the dirt-holding capacity through gradient optimization and enable selective replacement of the outer filter element to reduce operation and maintenance costs. Summary of the Invention

[0004] To address the problems existing in the background technology, this invention proposes a replaceable dual-layer filter element with a segmented negative porosity outer layer structure, which disperses the clogging points and realizes the distribution of pollutants along the depth. At the same time, it achieves the effects of surface coarse filtration, deep fine filtration, and inner fine filtration, breaking the long-held traditional concept that only by increasing the number of composite filter media layers can the filtration effect be improved.

[0005] To achieve the above objectives, the present invention adopts the following solution: A replaceable dual-layer filter element with a segmented negative porosity outer layer structure includes an inner layer filter element and an outer layer filter assembly coaxially sleeved on the outside of the inner layer filter element. The inner layer filter element and the outer layer filter assembly are connected by an annular clamp. The outer layer filter assembly includes at least three detachable filter segments, each filter segment is connected end to end along the axial direction, and the porosity of each filter segment increases along the water flow direction to form a negative porosity gradient filtration structure.

[0006] Optionally, in the filter segment, the porosity of the j-th segment is... satisfy: , in, The initial porosity at the inlet. It is an adjustable gradient parameter.

[0007] Optionally, the filter segment includes an inlet high-density segment, an intermediate transition segment, and a deep low-density segment connected in sequence by threads. The porosity of the inlet high-density segment is 0.4, the porosity of the intermediate transition segment is 0.5, and the porosity of the deep low-density segment is 0.6.

[0008] Optionally, the inner filter element is a hollow cylinder with micropores evenly distributed on its surface. The upper end of the inner filter element is provided with a closed end cap, and the bottom end is an open structure. The outer surface of the closed end cap of the inner filter element is equipped with a handle with anti-slip texture.

[0009] Optionally, the inner filter element is made of stainless steel sintered mesh or fiber woven mesh.

[0010] Optionally, the quick-release structure is a ring clamp, which is configured to close and lock with a single rotation action. It includes a clamp body, a buckle arm hinged to the clamp body, a locking groove on the clamp body, and a locking member at the end of the buckle arm. The locking member is configured to form a self-locking mechanism by cooperating with the locking groove when the buckle arm is rotated to the closed position.

[0011] Optionally, the bottom of the inner filter element is provided with a threaded section that axially protrudes from the outer filter assembly. The end of the threaded section near the outer filter assembly is provided with a first flange with a quarter-circular cross-section. The bottom of the side wall of the outer filter assembly is provided with a second flange with a quarter-circular cross-section. The first flange and the second flange are joined together to form a combined flange with a semi-circular cross-section. The clamp body is sleeved on the combined flange. The inner wall of the clamp body is provided with an annular groove that matches the combined flange for axial positioning. An elastic sealing ring is also embedded at the joint of the first flange and the second flange.

[0012] Optionally, the porosity of the inner filter element is less than the porosity of any filter segment of the outer filter assembly.

[0013] Optionally, each of the filter segments is integrally injection molded from polypropylene.

[0014] Optionally, the method of using the dual-layer filter element includes the following steps: Step 1: Insert the inner filter element upwards from the bottom opening of the outer filter assembly, and push the inner filter element until the first flange of its threaded section joins with the second flange at the bottom of the outer filter assembly to form a combined flange, while compressing the elastic sealing ring between them. Step 2: Place the clamp radially around the outside of the combined flange, and make the annular groove on its inner wall fully engage with the arc surface of the combined flange. The locking member and the locking groove cooperate to form a self-locking clamp, thereby achieving reliable axial positioning and sealing of the inner filter element and the outer filter assembly. Step 3: When the outer filter assembly is clogged, loosen the ring clamp and replace the outer filter assembly separately. The inner filter element can be reused.

[0015] The beneficial effects of this invention are as follows: First, this solution divides the outer filter assembly into several filter segments, and each filter segment has a different porosity. The porosity increases from the inlet of the outer filter assembly to the depth. The gradient structure disperses the clogging points, which allows pollutants to be evenly deposited in each segment, realizing the distribution of pollutants along the depth and improving the clogging tolerance of the filter element and the overall filtration efficiency.

[0016] Moreover, the inner filter element and the outer filter assembly are connected by a ring clamp. The two separate inner and outer filter elements do not need to be replaced as a whole after the outer filter assembly is contaminated, which reduces operating costs.

[0017] In addition, the porosity of the inner filter element is less than that of any filtration segment of the outer filter assembly. The fine filtration of the inner filter element ensures the accuracy of the final effluent, achieving the effects of surface coarse filtration, deep fine filtration, and inner fine filtration. This breaks the long-held traditional concept that only by increasing the number of composite filter media layers can the filtration effect be improved. Attached Figure Description

[0018] Figure 1 This is a side view of the overall structure of the present invention; Figure 2 This is an exploded view of the overall structure of the present invention; Figure 3 This is a diagram illustrating the assembly process of the overall structure in an embodiment of the present invention. Figure 4 For the present invention Figure 3 Enlarged view of A in the image; Figure 5 This is a schematic diagram of the clamp structure in an embodiment of the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the clamp structure in an embodiment of the present invention. Figure 2 .

[0019] The following are the labels in the diagram: 1. Inner filter element; 2. Closed end cap; 3. Handle; 4. Inlet high-density section; 5. Intermediate transition section; 6. Deep low-density section; 7. Clamp; 701. Clamp body; 702. Buckle arm; 703. Locking groove; 704. Locking element; 705. Annular groove; 8. First flange; 9. Second flange; 10. Threaded section. Detailed Implementation

[0020] To make the present invention clearer and more understandable, the present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are only one implementation method and do not represent all embodiments.

[0021] Example 1 Combination Figure 1-6 This embodiment provides a replaceable dual-layer filter element with a segmented negative porosity outer layer structure, including an inner layer filter element 1 and an outer layer filter assembly coaxially sleeved on the outside of the inner layer filter element 1. The inner layer filter element 1 and the outer layer filter assembly are connected by a quick-release structure. The outer layer filter assembly includes at least three detachable filter segments, each filter segment is connected end to end along the axial direction, and the porosity of each filter segment increases along the water flow direction to form a negative porosity gradient filtration structure.

[0022] When porosity is constant, contaminants tend to concentrate and clog the inlet area, leading to premature clogging and rendering the deep filtration function unusable. This embodiment divides the outer filter assembly into several sub-segments, each with a different porosity. The porosity increases progressively from the inlet to the depth of the outer filter assembly, creating a gradient structure that disperses clogging points. This allows contaminants to be evenly deposited in each segment, improving anti-clogging performance. Furthermore, the inner filter element 1 and the outer filter assembly are connected via a quick-release structure. These two separate inner and outer filter elements do not require complete replacement after the outer filter assembly becomes contaminated, reducing operating costs.

[0023] In this embodiment, while adhering to the principle of monotonically increasing porosity along the flow direction, linear segmentation is preferably adopted to divide the outer filter assembly into several filter sub-segments. Therefore, the porosity of the j-th segment... satisfy: , in, The initial porosity at the inlet. The gradient parameters are adjustable. It should be understood that the outer filter assembly in this embodiment can also be discretized using other monotonically increasing functions (such as exponential / power law) depending on the operating conditions to achieve similar pollutant depth distribution and lifespan improvement effects.

[0024] In one embodiment, the outer filter assembly is divided into three sections, each comprising a high-density inlet section 4, an intermediate transition section 5, and a deep low-density section 6, connected sequentially by threads. The inlet section is a high-density filter layer with low porosity and small pore size, serving as the first filtration barrier for fluid entry. The negative porosity gradient of the outer layer causes large particles to be trapped in the high-density inlet section 4, while small particles migrate to the deep low-density section 6 for capture, thus increasing the depth of pollutant distribution. Furthermore, each of the filter sections is integrally injection molded from polypropylene.

[0025] Furthermore, as a preferred embodiment, when the porosity of the inlet high-density section 4 is 0.4, the porosity of the intermediate transition section 5 is 0.5, and the porosity of the deep low-density section 6 is 0.6, the filtration efficiency is outstanding. It should be understood that the outer filter assembly can be divided into multiple segments, and the porosity of each filter sub-segment must satisfy the above porosity formula.

[0026] Specifically, the inner filter element 1 is a hollow cylinder with evenly distributed micropores on its surface, made of sintered stainless steel mesh or woven fiber mesh. The inner filter element 1 has a closed end cap 2 at its upper end and an open structure at its bottom. Furthermore, the porosity of the inner filter element 1 is less than that of any filtration segment of the outer filter assembly, ensuring the precision of the final effluent through the fine filtration of the inner filter element 1. For easy installation and disassembly, a handle 3 with anti-slip texture is installed on the outer surface of the closed end cap 2 of the inner filter element 1.

[0027] Specifically, the quick-release structure is a ring-shaped clamp 7, which is configured to close and lock with a single rotation. It includes a clamp body 701, a latching arm 702 hinged to the clamp body 701, and a locking groove 703 on the clamp body 701. A locking element 704 is provided at the end of the latching arm 702. The locking element 704 is configured to self-lock by engaging with the locking groove 703 when the latching arm 702 rotates to the closed position. This clamp 7 not only saves disassembly time, but also allows for independent operation between the outer filter assembly and the inner filter element 1, without relying on their respective structures. Therefore, when the outer filter assembly is contaminated, it does not need to be replaced entirely, reducing operating costs. This clamp structure is existing technology and will not be described in detail here.

[0028] Specifically, the inner filter element 1 has a threaded section 10 at its bottom that axially protrudes from the outer filter assembly. One end of the threaded section 10 near the outer filter assembly has a first flange 8 with a quarter-circular cross-section. The bottom sidewall of the outer filter assembly has a second flange 9 with a quarter-circular cross-section extending outwards. The first flange 8 and the second flange 9 are joined together to form a combined flange with a semi-circular cross-section. The clamp body 701 is fitted over the combined flange. The inner wall of the clamp body 701 has an annular groove 705 that matches the combined flange for axial positioning. An elastic sealing ring is also embedded at the joint of the first flange 8 and the second flange 9. The first flange 8 and the second flange 9 provide axial positioning during the installation of the inner and outer filter elements. It should be noted that the bottom sidewall of the outer filter assembly in this embodiment specifically refers to the bottom sidewall of the deep low-density section 6. Furthermore, the combined flange and annular groove in the embodiment have a self-guiding function during docking. Even with slight deviations, the inclined surface can guide the inner and outer filter elements to automatically slide into the correct position, facilitating assembly. Moreover, the combined flange and the radial fixing of the clamp 7 work together to form a mechanical interlocking structure, which can withstand the axial impact from fluid pressure and prevent the inner and outer filter elements from axially separating during operation.

[0029] Example 2 This embodiment provides a method for using the dual-layer filter element of Embodiment 1, namely, a method for using a replaceable dual-layer filter element with a segmented negative porosity outer layer structure, including the following steps: Step 1: Insert the inner filter element 1 upwards from the bottom opening of the outer filter assembly, and push the inner filter element 1 until the first flange 8 of its threaded section 10 aligns with the second flange 9 at the bottom of the outer filter assembly to form a combined flange. At the same time, compress the elastic sealing ring between them. At this point, the handle 3 has extended out of the inlet high-density section 4. During the process, it is necessary to ensure that the central axis of the inner filter element 1 coincides with the central axis of the outer filter assembly to avoid the filter element tilting due to misalignment.

[0030] Step 2: Place the clamp 7 radially around the outside of the combined flange, and make the annular groove 705 on its inner wall fully engage with the arc surface of the combined flange. The locking member 704 and the locking groove 703 cooperate to form a self-locking clamp, thereby achieving reliable axial positioning and sealing of the inner filter element 1 and the outer filter assembly.

[0031] Step 3: When the outer filter assembly is clogged, loosen clamp 7 and replace the outer filter assembly separately. The filter element can be reused. Remove the clogged outer filter element separately. Inspect the inner filter element 1. If there is no damage to the appearance or the flow rate has not decreased significantly, it can be reused. Put the new outer filter element back on according to step 1 and then lock it with clamp 7.

[0032] The outer filter assembly is designed to prevent clogging, while the inner filter element 1 can be reused multiple times, reducing consumable costs. The design of independently assembling the outer filter assembly and the inner filter element 1, combined with the quick-locking function of the annular clamp 7 and the axial positioning of the combined flange, ensures that individual replacement operations do not require adjustment of the inner layer positioning, thus guaranteeing the stability of filtration accuracy after reuse.

[0033] The specific embodiments of the present invention have been described in detail above with reference to the figures, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A replaceable double-layer filter element with a segmented negative porosity outer layer structure, characterized in that: The filter includes an inner filter element (1) and an outer filter assembly coaxially sleeved on the outside of the inner filter element (1). The inner filter element (1) and the outer filter assembly are connected by a quick-release structure. The outer filter assembly includes at least three detachable filter segments. Each filter segment is connected end to end along the axial direction, and the porosity of each filter segment increases along the water flow direction to form a negative porosity gradient filtration structure.

2. The replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 1, characterized in that, In the filter segment, the porosity of segment j is... satisfy: ， in, The initial porosity at the inlet. It is an adjustable gradient parameter.

3. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 2, characterized in that: The filter segment includes an inlet high-density segment (4), an intermediate transition segment (5), and a deep low-density segment (6) connected in sequence by threads. The porosity of the inlet high-density segment (4) is 0.4, the porosity of the intermediate transition segment (5) is 0.5, and the porosity of the deep low-density segment (6) is 0.

6.

4. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 3, characterized in that: The inner filter element (1) is a hollow cylinder with micropores evenly distributed on its surface. The upper end of the inner filter element (1) is provided with a closed end cap (2), and the bottom end is an open structure. The outer surface of the closed end cap (2) of the inner filter element (1) is equipped with a handle (3) with anti-slip texture.

5. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 4, characterized in that: The inner filter element (1) is made of stainless steel sintered mesh or fiber woven mesh.

6. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 1, characterized in that: The quick-release structure is a ring clamp (7). The clamp (7) is configured to close and lock by a single rotation action. It includes a clamp body (701), a buckle arm (702) is hinged to the clamp body (701), a locking groove (703) is provided on the clamp body (701), and a locking member (704) is provided at the end of the buckle arm (702). The locking member (704) is configured to form a self-locking mechanism by cooperating with the locking groove (703) when the buckle arm (702) is rotated to the closed position.

7. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 6, characterized in that: The inner filter element (1) has a threaded section (10) that protrudes axially from the outer filter assembly at its bottom. The threaded section (10) has a first flange (8) with a quarter-circular cross-section at one end near the outer filter assembly. The outer filter assembly has a second flange (9) with a quarter-circular cross-section at the bottom of its side wall. The first flange (8) and the second flange (9) are joined together to form a combined flange with a semi-circular cross-section. The clamp body (701) is fitted over the combined flange. The inner wall of the clamp body (701) has an annular groove (705) that matches the combined flange for axial positioning. An elastic sealing ring is also fitted at the joint of the first flange (8) and the second flange (9).

8. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 1, characterized in that: The porosity of the inner filter element (1) is less than the porosity of any filter segment of the outer filter assembly.

9. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 1, characterized in that: Each of the filter segments is integrally injection molded from polypropylene.

10. A replaceable double-layer filter element with a segmented negative porosity outer layer structure according to claim 7, characterized in that: The method of using the dual-layer filter element includes the following steps: Step 1: Insert the inner filter element (1) upward from the bottom opening end of the outer filter assembly, push the inner filter element (1) until the first flange (8) of its threaded section (10) and the second flange (9) at the bottom of the outer filter assembly are joined to form a combined flange, and compress the elastic sealing ring between them. Step 2: Place the clamp (7) radially around the outside of the combined flange, and make the annular groove (705) on its inner wall fully engage with the arc surface of the combined flange. The locking member (704) and the locking groove (703) cooperate to form a self-locking inner filter element (1) and outer filter assembly. Step 3: When the outer filter assembly is clogged, loosen the ring clamp (7), replace the outer filter assembly separately, and reuse the inner filter element (1).

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