High-flux melt-blown filter element

Abstract

The utility model discloses a high-flux melt-blown filter element which comprises a rough filtration layer and a fine filtration layer, the filtration precision of the fine filtration layer is larger than that of the rough filtration layer, the rough filtration layer and the fine filtration layer are both formed by bonding a plurality of composite fibers playing a role in filtration, and the composite fibers are hollow and are in a three-dimensional spiral shape with the uniform outer diameter. A containing cavity is formed in the hollow interior of the three-dimensional spiral composite fiber, the composite fiber comprises a core layer and a skin layer wrapping the periphery of the core layer, in the cross section of the composite fiber, the cross section area of the core layer is larger than that of the skin layer, the core layer and the skin layer are eccentrically arranged, the core layer deviates towards the inner circumferential face of the three-dimensional spiral composite fiber, and the skin layer is arranged on the inner circumferential face of the three-dimensional spiral composite fiber. The skin layers of the adjacent composite fibers are adhered to each other, and the wire diameter of the composite fibers in the rough filtering layer is larger than that of the composite fibers in the fine filtering layer. According to the scheme, the impurity intercepting capacity of the filter element is enhanced, the pollutant containing space and the filtering flux in the filter element are increased, the filter element is prevented from being blocked, and the service life of the filter element is prolonged.

Description

Technical Field

[0001] The utility model relates to the field of meltblown filters, in particular to a high-flux meltblown filter. Background Art

[0002] A meltblown filter is a tubular filter made of non-toxic and odorless polypropylene particles through processes such as heating and melting, spinning, drawing, and receiving and forming. Common meltblown filters, such as those with polypropylene as the main raw material, are called PP meltblown filters. Meltblown filters are not only widely used in large-scale water purification, but also have excellent chemical compatibility, being suitable for filtering strong acids, strong alkalis, and organic solvents. At the same time, they also have advantages such as strong dirt-holding capacity, long service life, and low cost. The porosity of the filter determines its flux. A filter with high flux can, on the one hand, increase the fluid passing rate, thereby improving the filtration efficiency and being able to adapt to the filtration of large-volume fluids. On the other hand, since the filter continuously intercepts impurities during the fluid filtration process, as more impurities are retained in the filter layer, the possibility of filter clogging will gradually increase. Therefore, the dirt-holding performance of the filter determines its service life. Existing meltblown filters, such as the utility model patent with the authorization publication number CN210583857U, the dirt-holding space in the filter layer is mainly formed at the gaps formed by the interlaced bonding of different fibers. And as the fiber density increases, the support of the filter improves, but its dirt-holding space gradually decreases. To improve the service life and flux of the filter, it is necessary to further increase the dirt-holding space of the filter on the premise of ensuring the filtration accuracy. Summary of the Utility Model

[0003] Therefore, to solve the above problems, the utility model provides a high-flux meltblown filter.

[0004] The utility model is realized through the following technical solutions:

[0005] A high-flux meltblown filter includes a coarse filtration layer and a fine filtration layer. The filtration accuracy of the fine filtration layer is greater than that of the coarse filtration layer. Both the coarse filtration layer and the fine filtration layer are formed by bonding a number of composite fibers that play a filtering role. The composite fibers are in a three-dimensional spiral shape with a hollow interior and a uniform outer diameter. And a receiving cavity is formed inside the hollow of the three-dimensional spiral composite fibers. Each composite fiber includes a core layer and a skin layer wrapped around the outer periphery of the core layer. In the cross-section of the composite fiber, the cross-sectional area of the core layer is greater than that of the skin layer. The core layer and the skin layer are eccentrically arranged, and the core layer is offset towards the inner peripheral surface of the three-dimensional spiral composite fiber. The skin layers between adjacent composite fibers are adhesively bonded to each other. The filament diameter of the composite fibers in the coarse filtration layer is greater than that of the composite fibers in the fine filtration layer. The filament diameter of the composite fibers in the coarse filtration layer is 20um - 40um, and the filament diameter of the composite fibers in the fine filtration layer is 3um - 20um.

[0006] Preferably, both the coarse filtration layer and the fine filtration layer include two or more composite fibers with different filament diameters. The filament diameters of the two or more composite fibers with different filament diameters in the coarse filtration layer are all 20 μm - 40 μm, and the filament diameters of the two or more composite fibers with different filament diameters in the fine filtration layer are all 3 μm - 20 μm.

[0007] Preferably, it further includes at least one intermediate filtration layer, and the filament diameter of the composite fibers in the intermediate filtration layer is 3 μm - 40 μm.

[0008] Preferably, the volume ratio of the composite fibers with a filament diameter of 20 μm - 40 μm to the composite fibers with a filament diameter of 3 μm - 20 μm in the intermediate filtration layer is 1:1.

[0009] Preferably, the volume ratio of the core layer to the skin layer is 20:80 - 80:20.

[0010] Preferably, both the fine filtration layer and the coarse filtration layer are tubular. The inner diameter of the coarse filtration layer is equal to the outer diameter of the fine filtration layer, and the coarse filtration layer is coaxially arranged on the outer periphery of the fine filtration layer. A central hole is provided inside the fine filtration layer.

[0011] Preferably, the fine filtration layer, the intermediate filtration layer, and the coarse filtration layer are all tubular and are coaxially arranged in sequence from the inside out. The inner diameter of the intermediate filtration layer is equal to the outer diameter of the fine filtration layer, the inner diameter of the coarse filtration layer is equal to the outer diameter of the intermediate filtration layer, and a central hole is provided inside the fine filtration layer.

[0012] Preferably, internal threads are provided on the inner wall surface of the central hole, and external threads are provided on the outer peripheral surface of the coarse filtration layer.

[0013] The beneficial effects of the technical solution of the present invention are mainly reflected in:

[0014] 1. Both the coarse filtration layer and the fine filtration layer are bonded by several filtering composite fibers. The composite fibers are three-dimensional helical with a hollow and uniform outer diameter, and a containing cavity is formed inside the hollow. Therefore, in the coarse filtration layer and the fine filtration layer, in addition to the dirt-containing space at the gaps formed by the interlacing and bonding of different fibers, it also includes the containing cavity inside each composite fiber. On the one hand, it enhances the impurity interception ability of the filter element, on the other hand, it increases the dirt-containing space inside the filter element, improves the filtration flux of the filter element, and avoids the blockage of the filter element, thereby prolonging the service life of the filter element.

[0015] 2. The cross-sectional area of the core layer of the composite fiber is larger than that of the skin layer. The core layer and the skin layer are eccentrically arranged, and the core layer is offset towards the inner circumferential surface of the three-dimensional helical composite fiber, so that the composite fiber forms a three-dimensional helix with a uniform outer diameter. Further, part of the skin layer material adheres and solidifies between adjacent fibers to form a composite fiber support structure. The rigidity and shrinkage characteristics of the core layer material support and maintain a considerable part of the curled shape, and the inside of the curled space of the composite fiber constitutes an accommodation cavity. Compared with conventional single-component filter elements, these numerous filter cavities improve the dirt-holding capacity and extend the service life of the filter element.

[0016] 3. In a preferred embodiment, the high-flux meltblown filter element sequentially includes a coarse filter layer, an intermediate filter layer, and a fine filter layer. Among them, the filament diameter of the composite fiber in the coarse filter layer is 20um - 40um, the filament diameter of the composite fiber in the fine filter layer is 3um - 20um, and both the coarse filter layer and the fine filter layer include two or more composite fibers with different filament diameters. The filament diameter of the composite fiber in the intermediate filter layer is 3um - 40um, and the volume ratio of the composite fiber with a filament diameter of 20um - 40um to the composite fiber with a filament diameter of 3um - 20um in the intermediate filter layer is 1:1. On the one hand, a filter element structure with gradually changing filtration accuracy can be formed. On the other hand, there are multiple composite fibers with different filament diameters in each filter layer, which can further improve the filtration effect of the filter element and ensure the interception of impurities of different sizes. Description of the Drawings

[0017] Figure 1 is a cross-sectional view of the high-flux meltblown filter element in an embodiment of the present invention;

[0018] Figure 2 is a schematic structural diagram of the composite fiber in the present invention;

[0019] Figure 3 is a schematic diagram of the bonding state between adjacent composite fibers in the present invention;

[0020] Figure 4 is a schematic diagram of the distribution of the composite filter element of the coarse filter layer, the intermediate filter layer, and the fine filter layer in an embodiment of the present invention. Detailed Embodiments

[0021] To clearly and detailedly show the purpose, advantages, and features of the present invention, it will be illustrated and explained through the non-limiting description of the following preferred embodiments. This embodiment is only a typical example of applying the technical solution of the present invention, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

[0022] At the same time, it is stated that in the description of the solution, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "front", "back", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplification of 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. Therefore, it should not be construed as a limitation to the present utility model.

[0023] In addition, the terms "first" and "second" in this solution are only used for descriptive purposes and cannot be construed as indicating or implying a ranking of importance or implicitly specifying the quantity of the indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the present utility model, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0024] The present utility model discloses a high-throughput meltblown filter element, as Figure 1 shown, which includes a coarse filtration layer 1 and a fine filtration layer 2. The filtration accuracy of the fine filtration layer 2 is greater than that of the coarse filtration layer 1. As Figures 2 - 4 shown, both the coarse filtration layer 1 and the fine filtration layer 2 are bonded by a number of composite fibers that play a filtering role. The composite fibers are three-dimensional helical shapes with a hollow interior and a uniform outer diameter. And the hollow interior of the three-dimensional helical composite fibers forms an accommodation cavity. When the fluid passes through the filter element, in addition to being intercepted at the gaps between adjacent composite fibers, the impurities in the fluid can also be retained in the accommodation cavities inside each composite fiber. At the same time, fluid channels can be formed at the gaps between adjacent composite fibers and inside the accommodation cavities of each composite fiber, thereby ensuring the high-throughput filtration of the filter element.

[0025] As Figure 2 shown, each composite fiber includes a core layer and a skin layer wrapped around the outer periphery of the core layer. In the cross-section of the composite fiber, the cross-sectional area of the core layer is larger than that of the skin layer. The core layer and the skin layer are eccentrically arranged, and the core layer is offset towards the inner peripheral surface of the three-dimensional helical composite fiber. A three-dimensional helical structure similar to a spring structure is formed by the contraction of the core layer. The skin layers between adjacent composite fibers are adhesively bonded to each other, so that the overlapping of different composite fibers forms a meltblown fiber support structure. The filament diameter of the composite fibers in the coarse filtration layer 1 is larger than that of the composite fibers in the fine filtration layer 2. The filament diameter of the composite fibers in the coarse filtration layer 1 is 20um - 40um, and the filament diameter of the composite fibers in the fine filtration layer 2 is 3um - 20um. By controlling the filament diameter of the composite fibers, the filtration accuracy of different filtration layers is controlled.

[0026] In some embodiments, the material of the cortical layer is PP (polypropylene) with a melting point of about 120 °C, and the material of the core layer is high shrinkage PP with a melting point of about 140 °C. The boiling water shrinkage rate is 30-50% (the boiling water shrinkage rate refers to the percentage of the length difference of the fiber measured before and after boiling in boiling water for 20 minutes divided by the length before boiling). The temperature of the just-sprayed composite fiber is relatively high. Utilizing the characteristic of the high shrinkage rate of the core layer material, the core layer material rapidly shrinks under the action of high temperature, driving the cortical layer material to jointly form a three-dimensional helical coiled shape similar to a spring structure. Under the action of the surface temperature and pressure of the filter element, part of the cortical layer material adheres and solidifies between adjacent fibers. The rigidity and shrinkage characteristics of the core layer material support and maintain a considerable part of the coiled shape, and the interior of the coiled space of the composite fiber constitutes an accommodation cavity. Compared with conventional single-component filter elements, these numerous filter cavities improve the dirt-holding performance and extend the service life of the filter element. In some embodiments, the volume ratio of the core layer to the cortical layer is 20:80 - 80:20. By appropriately increasing the volume proportion of the core layer, the coiling degree of the composite fiber can be improved.

[0027] In some embodiments, both the coarse filter layer 1 and the fine filter layer 2 include two or more composite fibers with different filament diameters. The filament diameters of the two or more composite fibers with different filament diameters in the coarse filter layer 1 are all 20 μm - 40 μm, and the filament diameters of the two or more composite fibers with different filament diameters in the fine filter layer 2 are all 3 μm - 20 μm.

[0028] In some embodiments, it further includes at least one intermediate filter layer 3. The filament diameter of the composite fiber in the intermediate filter layer 3 is 3 μm - 40 μm. The number of the intermediate filter layer 3 can be increased according to requirements. When there are multiple intermediate filter layers 3, the filtration accuracy of different intermediate filter layers 3 can also be adjusted by controlling the filament diameter of the composite fiber in different intermediate filter layers 3 or adjusting the volume ratio of the composite fiber with a smaller filament diameter in different intermediate filter layers 3, which will not be elaborated here. As Figure 4 shown, in one embodiment, the intermediate filter layer 3 includes both composite fibers with a filament diameter of 20 μm - 40 μm and composite fibers with a filament diameter of 3 μm - 20 μm. The volume ratio of the composite fibers with a filament diameter of 20 μm - 40 μm to the composite fibers with a filament diameter of 3 μm - 20 μm in the intermediate filter layer 3 is 1:1.

[0029] In one embodiment, the high-flux meltblown filter element includes that both the fine filter layer 2 and the coarse filter layer 1 are tubular. The inner diameter of the coarse filter layer 1 is equal to the outer diameter of the fine filter layer 2, and the coarse filter layer 1 is coaxially arranged on the outer periphery of the fine filter layer 2. A central hole 7 is arranged inside the fine filter layer 2. Among them, the fluid enters the filter element from the outer periphery of the coarse filter layer 1 and is output through the central hole 7 after being filtered.

[0030] In one embodiment, the high-flux meltblown filter element includes a fine filtration layer 2, an intermediate filtration layer 3, and the coarse filtration layer 1. The fine filtration layer 2, the intermediate filtration layer 3, and the coarse filtration layer 1 are all tubular and are coaxially arranged in sequence from inside to outside. The inner diameter of the intermediate filtration layer 3 is equal to the outer diameter of the fine filtration layer 2, and the inner diameter of the coarse filtration layer 1 is equal to the outer diameter of the intermediate filtration layer 3. A central hole 7 is provided inside the fine filtration layer 2. Fluid enters the filter element from the outer periphery of the coarse filtration layer 1 and passes through the coarse filtration layer 1, the intermediate filtration layer 3, and the fine filtration layer 2 in sequence, and then the filtered fluid is output through the central hole 7. Among them, the composite fiber filament diameter in the fine filtration layer 2 is the smallest, and the composite fiber distribution density is the highest. Correspondingly, the filtration accuracy and the support strength are also higher. The composite fiber filament diameter of the coarse filtration layer 1 is the largest. Therefore, the porosity between the composite fibers and the accommodation cavity space inside the composite fibers are also larger, and the dirt-holding space is also larger, so that the filter element has high-flux and high dirt-holding performance while ensuring a relatively high filtration accuracy.

[0031] As Figure 1 shown, in some embodiments, internal threads 6 are provided on the inner wall surface of the central hole 7 of the high-flux meltblown filter element, and external threads 5 are provided on the outer peripheral surface of the coarse filtration layer 1. The internal threads 6 and the external threads 5 can be raised structures or thread grooves. On the one hand, the internal and external threads 5 can increase the filtration area and further improve the filtration efficiency. On the other hand, the internal and external embossments can improve the overall support performance of the filter element and extend the service life of the product.

[0032] There are still various embodiments of the present invention. All technical solutions formed by equivalent transformation or equivalent substitution fall within the protection scope of the present invention.

Claims

1. High-throughput meltblown filter element, comprising a coarse filtration layer and a fine filtration layer, the filtration accuracy of the fine filtration layer being greater than that of the coarse filtration layer, characterized in that: The coarse filter layer and the fine filter layer are both formed by bonding a plurality of composite fibers that play a filtering role. The composite fibers are in a three-dimensional spiral shape with a hollow interior and a uniform outer diameter. A receiving cavity is formed inside the hollow of the three-dimensional spiral composite fibers. Each composite fiber includes a core layer and a skin layer wrapped around the outer periphery of the core layer. In the cross-section of the composite fiber, the cross-sectional area of the core layer is larger than that of the skin layer. The core layer and the skin layer are eccentrically arranged, and the core layer is offset towards the inner peripheral surface of the three-dimensional spiral composite fiber. The skin layers between adjacent composite fibers are adhesively bonded to each other. The filament diameter of the composite fibers in the coarse filter layer is larger than that of the composite fibers in the fine filter layer. The filament diameter of the composite fibers in the coarse filter layer is 20 μm - 40 μm, and the filament diameter of the composite fibers in the fine filter layer is 3 μm - 20 μm.

2. The high-throughput meltblown filter element according to claim 1, wherein: Both the coarse filter layer and the fine filter layer include two or more composite fibers with different filament diameters. The filament diameters of the two or more composite fibers with different filament diameters in the coarse filter layer are all 20 μm - 40 μm, and the filament diameters of the two or more composite fibers with different filament diameters in the fine filter layer are all 3 μm - 20 μm.

3. The high-throughput meltblown filter element according to claim 2, characterized in that: It further includes at least one intermediate filter layer. The filament diameter of the composite fibers in the intermediate filter layer is 3 μm - 40 μm.

4. The high-throughput meltblown filter element according to claim 3, characterized in that: The volume ratio of the composite fibers with a filament diameter of 20 μm - 40 μm to the composite fibers with a filament diameter of 3 μm - 20 μm in the intermediate filter layer is 1:

1.

5. The high-throughput meltblown filter element according to claim 1, characterized in that: The volume ratio of the core layer to the skin layer is 20:80 - 80:

20.

6. The high-throughput meltblown filter element according to claim 1, characterized in that: Both the fine filter layer and the coarse filter layer are tubular. The inner diameter of the coarse filter layer is equal to the outer diameter of the fine filter layer, and the coarse filter layer is coaxially arranged on the outer periphery of the fine filter layer. A central hole is provided inside the fine filter layer.

7. The high-throughput meltblown filter element according to claim 4, wherein: The fine filter layer, the intermediate filter layer, and the coarse filter layer are all tubular and are coaxially arranged in sequence from the inside out. The inner diameter of the intermediate filter layer is equal to the outer diameter of the fine filter layer, and the inner diameter of the coarse filter layer is equal to the outer diameter of the intermediate filter layer. A central hole is provided inside the filter element.

8. The high-throughput meltblown filter element according to claim 6 or 7, characterized in that: Internal threads are provided on the inner wall surface of the central hole, and external threads are provided on the outer peripheral surface of the filter element.

Images