CN112274999B

CN112274999B - Folding filter element

Info

Publication number: CN112274999B
Application number: CN201910685492.5A
Authority: CN
Inventors: 贾建东; 吕有权; 柯文静
Original assignee: Hangzhou Cobetter Filtration Equipment Co Ltd
Current assignee: Hangzhou Cobetter Filtration Equipment Co Ltd
Priority date: 2019-07-27
Filing date: 2019-07-27
Publication date: 2022-02-22
Anticipated expiration: 2039-07-27
Also published as: CN112274999A

Abstract

The invention provides a folding filter element, which comprises a central rod and a filter membrane arranged on the periphery of the central rod, wherein the filter membrane is folded to form folds, support nets are arranged on the upstream side and the downstream side of the filter membrane and are formed by warps and wefts which are vertical to each other, the warps have different intervals with fixed frequency distribution, the intervals are small, the warps are closely arranged, the action among a plurality of closely arranged warps is mutually strengthened, the warps and the wefts provide necessary structural stability for the support nets, adjacent warps with large intervals and adjacent wefts form large meshes together, and the large meshes have small resistance to fluid flow and are convenient for fluid to pass through. And the extending direction of the warp yarns is vertical to the extending direction of the pleated peaks, flow channels with different widths are formed among the warp yarns, and the extending direction of the flow channels is parallel to the flowing direction of the fluid, so that the speed of the fluid passing through the supporting net is further increased, and the filtering speed of the filter element is increased.

Description

Folding filter element

Technical Field

The invention relates to the technical field of filtration, in particular to a folding filter element, and more particularly to a folding filter element with a support net arranged on the upstream side and/or the downstream side of a filter membrane.

Background

In practical applications, support nets are usually disposed on two sides of the filter membrane, and the support nets are folded together with the filter membrane to form pleats, and then installed between the center rod and the housing to form the folded filter element. The support net can protect the filter membrane in the folding and mounting processes, and the damage of the folding machine to the filter membrane is reduced; in the final pleated filter element product, the support web spaces the filter membrane surfaces apart to form gaps between the pleat surfaces to form fluid flow channels that reduce the flow resistance of the fluid.

The supporting net with meshes woven by yarns is a type of supporting net which is widely applied at present, and warp yarns and weft yarns in a common weaving form are woven in a mutually perpendicular relationship, wherein the warp yarns and the weft yarns are woven in a constant density in a warp direction, and the weft yarns and the warp yarns are also woven in a constant density in a weft direction, namely, the distances between all the yarns in the warp direction are the same, and the distances between all the yarns in the weft direction are the same. However, the structural stability and mesh size of the support net in such a woven form are contradictory, and to improve the structural stability of the support net, the mesh size must be reduced, which causes a relatively large flow resistance to fluid flow; increasing the distance between the yarns, and thus the mesh size, to reduce the flow resistance of the fluid, results in a deterioration of the structural stability of the support net.

Therefore, there is a need to improve the existing support net and provide a pleated filter element, which can reduce the flow resistance to the fluid and increase the filtration rate of the pleated filter element while ensuring the good stability of the structure and the stability of the filtration performance of the pleated filter element.

Disclosure of Invention

The invention aims to provide a folding filter element, wherein a support net is arranged on the upstream side and/or the downstream side of a filter membrane of the folding filter element, and the support net has good structural stability so as to effectively support and protect the filter membrane and ensure the stability of the structure and the filtering performance of the filter element; in addition, the support net of the filter element has small resistance to the fluid flow, and provides a flow passage for guiding the fluid flow, thereby facilitating the rapid passing of the fluid and accelerating the filtering rate of the filter element.

In order to achieve the purpose, the invention adopts the following technical scheme:

a pleated filter element comprising a central core and a filter membrane located at the periphery of the central core, the filter membrane being pleated to form pleats having valley portions adjacent the side of the central core and crest portions adjacent the periphery, the filter membrane having an upstream side and a downstream side, the upstream side communicating with an inlet and the downstream side communicating with an outlet, at least one of the upstream and downstream sides of the filter membrane being provided with a support screen formed by warp yarns and weft yarns perpendicular to each other, the weft yarns being parallel to each other and having a constant pitch, the warp yarns being parallel to each other and having a pitch of different size distributed at a constant frequency, the warp yarns extending in a direction perpendicular to the extending direction of the crest, the warp yarns forming flow paths of different widths communicating the valley portions with the crest portions.

The structural stability and the mesh size of the existing support net are mutually contradictory, because the space between yarns must be reduced to improve the structural stability of the support net, correspondingly, the mesh size is reduced, and the reduction of the mesh size can cause larger resistance to fluid flow, thereby causing the low filtration rate of the filter element; in order to reduce the flow resistance of the fluid and to increase the spacing between the yarns, and thus the mesh size, the structural stability of the support net and the structural stability and filtration performance of the filter element are deteriorated.

The folding filter element provided by the invention is characterized in that the support net is arranged on the upstream side and/or the downstream side of the filter membrane, the support net is formed by warp yarns and weft yarns which are vertical to each other, the warp yarns take at least two yarns as a repeating unit, the warp yarns have different intervals, the warp yarns with smaller intervals are closely arranged, the interaction among a plurality of closely arranged warp yarns is mutually strengthened, the structural stability of the support net is improved together with the weft yarns, and the stability of the structure and the filtering performance of the filter element is further ensured. The area surrounded by two adjacent warp yarns and two adjacent weft yarns with larger spacing forms larger meshes, and the larger meshes are convenient for fluid to flow through and accelerate the filtering rate of the filter element.

And the extending direction of the warp yarns is vertical to the extending direction of the pleated peaks, so that flow channels with different widths and communicated with the pleated peaks and the pleated valleys are formed among the warp yarns, the extending direction of the flow channels is parallel to the flowing direction of the fluid, the flow channels can play a role of guiding the fluid to flow, the feeding fluid is quickly and uniformly distributed on the upstream surface of the filter membrane, the speed of the fluid flowing from the upstream side to the downstream side of the filter membrane is accelerated, and the filtering speed of the filter element is accelerated. Therefore, the supporting net can accelerate the speed of fluid passing through and further accelerate the filtering rate of the filter element on the premise of ensuring the structural stability.

Furthermore, the warp takes at least two yarns as a repeating unit, the warp has a first interval and a second interval, so as to form a first flow channel and a second flow channel, and the width of the first flow channel is 30% -80% of the width of the second flow channel.

In the support net, the yarns with the first spacing are closely arranged, and the interaction between the closely arranged warp yarns is strengthened, so that the yarns and the weft yarns provide the necessary structural stability for the support net. The second distance is larger, and the area surrounded by two adjacent warp yarns and two adjacent weft yarns in the second distance forms larger meshes which are convenient for fluid to flow through. The warp yarns of the first spacing and the second spacing correspondingly form a first flow channel and a second flow channel, and the extending directions of the first flow channel and the second flow channel are parallel to the flowing direction of the fluid, so that the effect of guiding the fluid to flow can be achieved, and the filtering rate of the filter element is increased.

Furthermore, the warp yarns take three yarns as a repeating unit, the distance between any two adjacent yarns in the repeating unit is a first distance, and the distance between two closest warp yarns in the adjacent repeating unit is a second distance.

The warp yarns within the repeat unit are spaced at a first spacing that is less than the first spacing, such that the warp yarns within the repeat unit are closely spaced, and the interaction between the closely spaced warp yarns enhances the structural stability necessary for the support grid in conjunction with the weft yarns. The distance between two adjacent warp yarns of the adjacent repeating units is a second distance, the second distance is larger, and the area surrounded by the two adjacent warp yarns and the two adjacent weft yarns with the second distance forms larger meshes which are convenient for fluid to flow through.

Furthermore, the warp yarns take three or four yarns as a repeating unit, the yarns in the repeating unit have a first spacing and a second spacing, and the spacing between two nearest warp yarns of adjacent repeating units is the second spacing.

The warp yarns have a first pitch and a second pitch, the first pitch being smaller, so that the warp yarns having a pitch of the first pitch are closely arranged in the repeat unit, the interaction between two closely arranged warp yarns being mutually enhanced to provide the necessary structural stability of the support screen together with the weft yarns. The distance between two adjacent warp yarns of the adjacent repeating unit is the second distance, and the warp yarns with the second distance are also arranged in the repeating unit, and due to the larger second distance, the area surrounded by the two adjacent warp yarns and the two adjacent weft yarns with the second distance forms larger meshes which are convenient for fluid to flow through.

Furthermore, the supporting net is formed by weaving warp yarns and weft yarns in an interpenetration mode.

Further, the supporting net is formed by fixing all warp yarns on the same side of the weft yarns.

Further, the warp yarns of the supporting net contact against the surface of the filter membrane; alternatively, the weft yarns of the support mesh contact against the surface of the filter membrane.

Further, the weft yarns of the support net contact against the surface of the filter membrane and the warp yarns abut together, thereby forming a spacing of twice the diameter of the warp yarns between adjacent pleats or within the same pleat.

Since the support net is formed by fixing all warp yarns parallel to each other to the same side of the weft yarns, when the weft yarns contact the surface of the filter membrane, the pleats formed by the support net and the filter membrane are installed between the center rod and the outer shell, the warp yarns of the support net abut against each other, so that a space which is twice as large as the diameter of the warp yarns is formed between adjacent pleats or inside the same pleat, flow passages with different widths are uniformly distributed in the space, the extending direction of the flow passages is parallel to the flowing direction of the fluid, and since the weft yarns are located between the warp yarns and the surface of the filter membrane, the feed fluid has no blocking effect of the weft yarns in the radial flowing direction of the fluid, so that the fluid can be rapidly and uniformly distributed on the whole upstream surface of the filter membrane along the extending direction of the flow passages, and the clean filtrate can also rapidly flow out of the whole downstream surface of the filter membrane.

Further, the spacing of the weft yarns is 1.2-2.5 times the first spacing of the warp yarns.

Further, the second spacing of the warp yarns is 1-5 times the diameter of the warp yarns.

When the second spacing of the warp yarns of the support net on the downstream side is too large, the area surrounded by two warp yarns and two adjacent weft yarns with the second spacing forms large meshes, and the downstream surfaces of the filter membranes corresponding to the large meshes are attached together due to being pressed, which is not favorable for discharging clean filtrate.

In order to solve the problems, the second spacing of the warp yarns is limited within the range of 1-5 times of the diameter of the warp yarns, so that the downstream surfaces of the filter membranes corresponding to the large meshes formed by the areas surrounded by two warp yarns with the second spacing and two adjacent weft yarns can be ensured not to be attached together by extrusion, namely, the whole areas of the downstream surfaces of the filter membranes are spaced to facilitate the quick discharge of clean filtrate.

The invention provides a folding filter element, which comprises a central rod and a filter membrane arranged on the periphery of the central rod, wherein the filter membrane is folded to form folds, the upstream side and the downstream side of the filter membrane are provided with support nets, the support nets are formed by warps and wefts which are vertical to each other, the warps have different intervals with fixed frequency distribution, the intervals are small, the warps are closely arranged, the action among a plurality of closely arranged warps is mutually strengthened, the warps and the wefts provide necessary structural stability for the support nets, adjacent warps with large intervals and adjacent wefts form large meshes together, and the large meshes have small resistance to fluid flow and are convenient for fluid to pass through. And the extending direction of the warp yarns is mutually vertical to the extending direction of the pleated peaks, flow channels with different widths are formed among the warp yarns, the extending direction of the flow channels is parallel to the flowing direction of the fluid, the flow channels can play a role in guiding the fluid to flow, so that the feeding fluid is quickly and uniformly distributed on the upstream surface of the filter membrane, the speed of the fluid flowing from the upstream side to the downstream side of the filter membrane is increased, and the filtering rate of the filter element is increased.

Drawings

The invention will be further described with reference to the accompanying drawings in which:

FIG. 1 is a schematic view of a pleated filter element according to the present invention;

FIG. 2 is a schematic structural view of a first support net according to the present invention;

FIG. 3 is a schematic structural view of a second support net according to the present invention;

FIG. 4 is a schematic structural view of a third support net according to the present invention;

FIG. 5 is a schematic structural view of a fourth support net according to the present invention;

FIG. 6 is a schematic structural view of a fifth support net according to the present invention;

FIG. 7 is a schematic structural view of a sixth supporting net according to the present invention;

FIG. 8 is a schematic structural view of a seventh supporting net according to the present invention;

FIG. 9 is a schematic structural view of an eighth support net according to the present invention;

FIG. 10 is a schematic structural view of a ninth supporting net according to the present invention;

fig. 11 is a schematic structural view of a tenth support net provided by the present invention.

In fig. 1-11, 1-folding filter element, 10-center rod, 11-filter membrane, 12-housing, 13-top cap, 130-interface, 14-first support net, 15-second support net, D1-first spacing, D2-second spacing.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

The pleated filter element 1 shown in fig. 1 includes a center rod 10, a filter membrane 11, a shell 12, and an upper end cap 13 and a lower end cap (not shown) at the upper end and the lower end of the pleated filter element 1, the filter membrane 11 is pleated and provided at the outer periphery of the center rod 10, the pleats have valleys near the center rod 10 side and crests near the outer periphery, the shell 12 is wrapped around the outer periphery of the filter membrane 11, and the center rod 10 and the shell 12 together serve to fix the filter membrane 11 and maintain the stability of the pleats. Both the center rod 10 and the outer shell 12 have evenly distributed apertures for the passage of fluid. The top cover 13 has a port 130 communicating with the central flow passage of the central rod 10 for allowing the flow of clean filtrate from the central flow passage of the central rod 10 or the flow of raw material liquid into the central flow passage of the central rod 10. The lower end cap is liquid-tight.

The filter membrane 11 has an upstream side communicating with the inlet and a downstream side communicating with the outlet. The upstream side of the filter membrane 11 is provided with a first support net 14. Alternatively, the downstream side of the filter membrane 11 is provided with a second support net 15. Alternatively, both the upstream side and the downstream side of the filter membrane 11 are provided with the first support net 14 and the second support net 15.

The first and second support nets 14 and 15 are formed of warp yarns and weft yarns perpendicular to each other, the weft yarns being parallel to each other with a constant pitch, the warp yarns being parallel to each other with a pitch having a different size distributed at a fixed frequency, and the extending directions of the warp yarns being perpendicular to the extending direction of the crests, flow paths having different widths communicating the crests and the valleys being formed between the warp yarns.

The first and second support nets 14 and 15 are formed of warp yarns and weft yarns perpendicular to each other, the warp yarns have intervals of different sizes, the warp yarns having smaller intervals are closely arranged, the interaction between the closely arranged plurality of warp yarns is mutually reinforced, and the first and second support nets 14 and 15 improve the structural stability together with the weft yarns, thereby ensuring the stability of the structure and filtering performance of the filter element 1. The area surrounded by two adjacent warp yarns and two adjacent weft yarns with larger spacing forms larger meshes, and the larger meshes are convenient for fluid to flow through, so that the filtering speed of the filter element 1 is increased. The mesh refers to a square hole formed in a region surrounded by two adjacent warp yarns and two adjacent weft yarns.

And the extending direction of the warp yarns is mutually vertical to the extending direction of the pleated peaks, so that flow channels with different widths and communicated with the pleated peaks and the pleated valleys are formed among the warp yarns, the extending direction of the flow channels is parallel to the flowing direction of the fluid, the flow channels can play a role of guiding the fluid to flow, the feeding fluid is quickly and uniformly distributed on the upstream surface of the filter membrane 11, the speed of the fluid flowing from the upstream side to the downstream side of the filter membrane 11 is accelerated, and the filtering speed of the filter element 1 is accelerated. Therefore, the first and second support nets 14 and 15 can increase the speed of fluid passing through and thus the filtering rate of the filter cartridge 1, while ensuring the structural stability of itself and the filter cartridge 1.

Specifically, the warp takes at least two yarns as a repeating unit, the warp has a first spacing and a second spacing, the first spacing is 30% -80% of the second spacing, a first flow channel and a second flow channel are further formed, and the width of the first flow channel is 30% -80% of the width of the second flow channel.

The specific forms of the first support net 14 and the second support net 15 are as follows 10.

The first type of supporting net shown in fig. 2 is formed by weaving warp yarns and weft yarns perpendicular to each other with their interlacement, parallel to each other, and with a constant pitch, for example, the constant pitch of the weft yarns is 0.625mm, 0.423 mm, 0.317 mm, or 0.30 mm, etc. The warp yarns are woven to be interlaced with the weft yarns in a repeating unit of three yarns, and have first and second pitches D1 and D2, and the first pitch D1 is 30% -80% of the second pitch D2. The spacing between any two adjacent warp yarns in a repeat unit is a first spacing D1, and the spacing between the nearest two warp yarns in an adjacent repeat unit is a second spacing D2. The warp and weft yarns used to form the first and second support nets 14 and 15 have a diameter of 0.05 mm to 0.2 mm, the pitch of the weft yarns is defined as 1.2 to 2.5 times the first pitch D1 of the warp yarns, the first pitch D1 is 30% to 80% of the second pitch D2, and the second pitch D2 of the warp yarns is defined as 1 to 5 times the diameter of the warp yarns.

Specifically, the first spacing D1 is 0.25 mm, and the second spacing D2 is 0.83 mm.

Alternatively, the first spacing D1 is 0.25 mm and the second spacing D2 is 0.45 mm.

Alternatively, the first spacing D1 is 0.25 mm and the second spacing D2 is 0.38 mm.

Alternatively, the first spacing D1 is 0.25 mm and the second spacing D2 is 0.31 mm.

In addition, the first spacing D1 is not limited to 0.25 mm, but may be varied as desired, for example, the first spacing D1 may also be 0.20 mm or 0.13 mm, etc., and the second spacing D2 is always determined according to the relationship that the first spacing D1 is 30% -80% of the second spacing D2, because when the ratio of the first spacing D1 to the second spacing D2 is 30% -80%, the first spacing D1 is significantly smaller than the second spacing D2, the spacing between any two adjacent warp yarns of the three warp yarns in the repeat unit is the first spacing D1, the first spacing D1 is smaller, the three warp yarns are tightly woven, the interaction between the three tightly woven warp yarns is mutually reinforced, and the weft yarns together provide the necessary structural stability of the support net. The distance between two nearest warp yarns of the adjacent repeating units is the second distance D2, the second distance D2 is larger, and the two nearest warp yarns are woven together with weft yarns in an interpenetration mode, so that large meshes are formed between the adjacent repeating units. Therefore, the supporting net can provide large meshes on the premise of ensuring the structural stability, reduce the flow resistance of the fluid and facilitate the fluid to flow through.

The second distance D2 between the warp yarns is 1-5 times the diameter of the warp yarns, so that the downstream surfaces of the filter membranes 11 corresponding to the areas surrounded by two warp yarns and two adjacent weft yarns with the second distance can ensure that the areas surrounded by the two warp yarns and the two adjacent weft yarns form large meshes and can not be attached together by pressing, i.e. the whole areas of the downstream surfaces of the filter membranes 11 are spaced apart, and the clean filtrate can be discharged quickly.

The second supporting net shown in fig. 3 is formed by weaving warp yarns and weft yarns perpendicular to each other in an interpenetration manner, and the weft yarns are parallel to each other and have a constant interval, for example, the constant interval of the weft yarns is 0.625mm, 0.423 mm, 0.317 mm or 0.30 mm, etc. The warp yarns are woven to be interlaced with the weft yarns in a repeating unit of four yarns, and have first and second pitches D1 and D2, and the first pitch D1 is 30% -80% of the second pitch D2. The spacing between the first and second warp yarns and the spacing between the third and fourth warp yarns in a repeat unit is a first spacing D1, and the spacing between the second and third warp yarns in a repeat unit and the spacing between the nearest two warp yarns in an adjacent repeat unit is a second spacing D2. The warp and weft yarns used to form the first and second support nets 14 and 15 have a diameter of 0.05 mm to 0.2 mm, the pitch of the weft yarns is defined as 1.2 to 2.5 times the first pitch D1 of the warp yarns, the first pitch D1 is 30% to 80% of the second pitch D2, and the second pitch D2 of the warp yarns is defined as 1 to 5 times the diameter of the warp yarns.

In addition, the first distance D1 is not limited to 0.25 mm, but may be changed as needed, for example, the first distance D1 may be 0.20 mm or 0.13 mm. The second spacing D2 is always determined by the first spacing D1 being 30% -80% of the second spacing D2, because the ratio of the first spacing D1 to the second spacing D2 is 30% -80%, the spacing between the first and second warp yarns and the spacing between the third and fourth warp yarns in the repeat unit are the first spacing D1, the first spacing D1 is smaller, the first and second warp yarns and the third and fourth warp yarns are tightly woven, the interaction between each two warp yarns of the tightly woven yarns strengthens each other, and the weft yarns together provide the necessary structural stability for the support net. The second and third warp yarns in the repeat unit and the nearest two warp yarns of an adjacent repeat unit are spaced apart a second spacing D2, the second spacing D2 being greater, thereby forming large openings between the second and third warp yarns in the repeat unit and between adjacent repeat units. Therefore, the supporting net can provide large meshes on the premise of ensuring the structural stability, reduce the flow resistance of the fluid and facilitate the fluid to flow through.

A third supporting net shown in fig. 4 is formed by weaving warp yarns and weft yarns perpendicular to each other with their wefts woven in an interlaced manner, the wefts being parallel to each other and having a constant pitch, for example, the constant pitch of the wefts is 0.625mm, 0.423 mm, 0.317 mm, or 0.30 mm. The warp yarns are woven to be interlaced with the weft yarns in a repeating unit of three yarns, and have first and second pitches D1 and D2, and the first pitch D1 is 30% -80% of the second pitch D2. The first warp yarn and the second warp yarn are spaced apart by a first spacing D1, the second warp yarn and the third warp yarn are spaced apart by a second spacing D2, and the closest two warp yarns of adjacent repeat units are also spaced apart by a second spacing D2. The warp and weft yarns used to form the first and second support nets 14 and 15 have a diameter of 0.05 mm to 0.2 mm, the pitch of the weft yarns is defined as 1.2 to 2.5 times the first pitch D1 of the warp yarns, the first pitch D1 is 30% to 80% of the second pitch D2, and the second pitch D2 of the warp yarns is defined as 1 to 5 times the diameter of the warp yarns.

In addition, the first distance D1 is not limited to 0.25 mm, but may be changed as needed, for example, the first distance D1 may be 0.20 mm or 0.13 mm. The second distance D2 is always determined according to the relationship that the first distance D1 is 30% -80% of the second distance D2, because the ratio of the first distance D1 to the second distance D2 is 30% -80%, the first distance D1 is significantly smaller than the second distance D2. In the repeating unit, the first distance D1 is smaller, the first warp yarn and the second warp yarn with the first distance D1 are tightly woven, the action between the two warp yarns with the tight weaving is mutually strengthened, and the warp yarns and the weft yarns are woven together in an interpenetration mode to provide the structural stability required by the supporting net. The second warp yarn and the third warp yarn which are arranged at the second spacing D2 in the repeating unit and the two closest warp yarns of the adjacent repeating unit are arranged loosely and woven with the weft yarns in an inserting mode, so that large meshes are formed between the second warp yarn and the third warp yarn in the repeating unit and the adjacent repeating unit, fluid can pass through the large meshes conveniently, and the flow resistance of the fluid is reduced.

Obviously, in this third type of support net, the distribution frequency of the macro-mesh openings is higher than that of the first and second type of support net.

A fourth supporting net shown in fig. 5 is formed by weaving warp yarns and weft yarns perpendicular to each other with their pitches being parallel to each other and constant, for example, the constant pitch of the weft yarns is 0.625mm, 0.423 mm, 0.317 mm, 0.30 mm, etc. The warp yarns are woven with the weft yarns in an alternating mode by taking four yarns as a repeating unit, the warp yarns have a first spacing D1 and a second spacing D2, and the first spacing D1 is 30% -80% of the second spacing D2. Within a repeat unit, any adjacent two of the first three warp yarns are spaced apart by a first spacing D1, the third warp yarn is spaced apart from the fourth warp yarn by a second spacing D2, and the nearest two warp yarns of an adjacent repeat unit are spaced apart by a second spacing D2. The warp and weft yarns used to form the first and second support nets 14 and 15 have a diameter of 0.05 mm to 0.2 mm, the pitch of the weft yarns is defined as 1.2 to 2.5 times the first pitch D1 of the warp yarns, the first pitch D1 is 30% to 80% of the second pitch D2, and the second pitch D2 of the warp yarns is defined as 1 to 5 times the diameter of the warp yarns.

In addition, the first distance D1 is not limited to 0.25 mm, but may be changed as needed, for example, the first distance D1 may be 0.20 mm or 0.13 mm. The second distance D2 is always determined according to the relationship that the first distance D1 is 30% -80% of the second distance D2, because the ratio of the first distance D1 to the second distance D2 is 30% -80%, the first distance D1 is significantly smaller than the second distance D2. In the repeating unit, the first three warp yarns with the first spacing D1 are tightly woven, and the first three tightly woven yarns are mutually strengthened and are woven with the weft yarns in an inserting manner to provide the structural stability required by the supporting net. In the repeating unit, the third warp yarn and the fourth warp yarn with the spacing of the second spacing D2 and the two closest warp yarns of the adjacent repeating unit are arranged loosely and woven with the weft yarns in an inserting manner, so that large meshes are formed between the third warp yarn and the fourth warp yarn and between the adjacent repeating units in the repeating unit, the large meshes are convenient for fluid to pass through, and the flow resistance of the fluid is reduced.

The fifth supporting net shown in fig. 6 is formed by weaving warp yarns and weft yarns perpendicular to each other in an interpenetration manner, and the weft yarns are parallel to each other and have a constant interval, for example, the constant interval of the weft yarns is 0.625mm, 0.423 mm, 0.317 mm or 0.30 mm, etc. The warp yarns are woven in four yarns as repeat units, the warp yarns have a first spacing D1 and a second spacing D2, and the first spacing D1 is 30% -80% of the second spacing D2. In the repeat unit, the spacing between the first warp yarn and the second warp yarn is a first spacing D1, the spacing between the second warp yarn and the third warp yarn and the spacing between the third warp yarn and the fourth warp yarn are a second spacing D2, and the spacing between the nearest two warp yarns of adjacent repeat units is a second spacing D2. The warp and weft yarns used to form the first and second support nets 14 and 15 have a diameter of 0.05 mm to 0.2 mm, the pitch of the weft yarns is defined as 1.2 to 2.5 times the first pitch D1 of the warp yarns, the first pitch D1 is 30% to 80% of the second pitch D2, and the second pitch D2 of the warp yarns is defined as 1 to 5 times the diameter of the warp yarns.

In addition, the first distance D1 is not limited to 0.25 mm, but may be changed as needed, for example, the first distance D1 may be 0.20 mm or 0.13 mm. The second distance D2 is always determined according to the relationship that the first distance D1 is 30% -80% of the second distance D2, because the ratio of the first distance D1 to the second distance D2 is 30% -80%, the first distance D1 is significantly smaller than the second distance D2. In the repeating unit, the first warp yarn and the second warp yarn with the first spacing D1 are tightly woven, the two actions of tight weaving are mutually reinforced, and the first warp yarn and the second warp yarn are woven together with weft yarns in an interpenetration mode to provide structural stability required by the supporting net. In the repeating unit, the second warp yarn, the third warp yarn, the fourth warp yarn and two closest warp yarns of the adjacent repeating unit with the space distance of D2 are arranged and loosened, and are woven with the weft yarns in an inserting mode, so that large meshes are formed among the second warp yarn, the third warp yarn, the fourth warp yarn and the adjacent repeating unit in the repeating unit, fluid can pass through the large meshes conveniently, and the flow resistance of the fluid is reduced.

The warp and weft yarns may be formed in other ways than by forming the first and second support nets 14 and 15 in an interlude weave. Such as the support mesh shown in fig. 7-11, by securing all of the warp yarns to the same side of the weft yarns without altering the spacing between the first five warp yarns, the spacing between the weft yarns, and the relationship between the warp and weft yarns.

Similar to the first five support nets, the latter five support nets, formed by all warp yarns fastened to the same side of the weft yarns, are reinforced by the interaction between the warp yarns at a first spacing D1, providing the necessary structural stability of the support net together with the weft yarns, and the adjacent warp yarns at a second spacing D2 form large meshes with the adjacent weft yarns, facilitating the rapid passage of fluid.

When the latter five kinds of support nets formed by fixing all the warp yarns to the same side as the weft yarns are disposed as the first and second support nets 14 and 15 on the upstream and downstream sides of the filter membrane 11, the warp yarns of the first and second support nets 14 and 15 contact the surface of the filter membrane 11.

Or more preferably, the latter five types of support nets formed by all the warp yarns fixed to the same side of the weft yarns are placed on the upstream and downstream sides of the filter membrane 11 as the first and second support nets 14 and 15, and the weft yarns of the first and second support nets 14 and 15 contact the surface of the filter membrane 11.

The first and second support nets 14 and 15 are formed by warp yarns all fixed to the same side of the weft yarn, when the weft yarn contacts the surface of the filter membrane 11, the pleats formed by the first and second support nets 14 and 15 and the filter membrane 11 are installed between the center rod 10 and the housing 12, the respective warp yarns of the first and second support nets 14 and 15 are abutted to form a space twice the diameter of the warp yarn inside the adjacent pleats or the same pleat, flow passages having different widths are uniformly distributed in the space, and the flow passages extend in a direction parallel to the flow direction of the fluid, and can function to guide the flow of the fluid, and since the weft yarn is located between the warp yarn and the surface of the filter membrane 11, the feed fluid is not blocked by the weft yarn in the direction of the radial flow, and can be quickly and uniformly distributed over the entire surface of the upstream side of the filter membrane 11 in the direction of the flow passages, while the clean filtrate can also flow out rapidly from the downstream side surface of the filter membrane 11.

While the preferred embodiments of the present invention have been illustrated and described in detail, it should be understood that various changes and modifications of the invention can be effected therein by those skilled in the art after reading the above teachings of the invention. Such equivalents are intended to fall within the scope of the claims appended hereto.

Claims

1. A pleated filter element comprising a central core and a filter membrane disposed about the periphery of the central core, the filter membrane pleated to form pleats having valleys adjacent the side of the central core and peaks about the periphery, the filter membrane having an upstream side and a downstream side, the upstream side communicating with an inlet and the downstream side communicating with an outlet, at least one of the upstream and downstream sides of the filter membrane having a support web, the pleated filter element comprising: the support net is formed by warp yarns and weft yarns which are perpendicular to each other, the weft yarns are parallel to each other and have constant intervals, the warp yarns are parallel to each other and have intervals distributed in a fixed frequency and different in size, the extending direction of the warp yarns is perpendicular to the extending direction of the crest, and flow channels with different widths and communicated with the crest and the trough are formed among the warp yarns.

2. The pleated filter element of claim 1, wherein the warp yarns are repeating units of at least two yarns, the warp yarns having a first pitch and a second pitch to form a first flow channel and a second flow channel, the first flow channel having a width of 30% to 80% of a width of the second flow channel.

3. A pleated filter element according to claim 2 wherein the warp yarns comprise three yarns in a repeat unit, any adjacent two yarns in the repeat unit having a first pitch and the nearest two warp yarns in an adjacent repeat unit having a second pitch.

4. A pleated filter element according to claim 2 wherein the warp yarns are in a repeat of three or four yarns, the yarns in the repeat having a first pitch and a second pitch, the two closest warp yarns of adjacent repeats being spaced at the second pitch.

5. A pleated filter element according to claim 3 or 4, characterized in that the support mesh is formed by weaving warp and weft yarns alternately.

6. A pleated filter element according to claim 3 or 4, characterized in that the support mesh is formed by warp yarns all fixed to the same side of the weft yarns.

7. A pleated filter element according to claim 6, characterized in that the warp yarns of the support mesh are in contact against the filter membrane surface; alternatively, the weft yarns of the support mesh contact against the surface of the filter membrane.

8. A pleated filter element according to claim 7 wherein the weft yarns of the support web contact against the filter membrane surface and the warp yarns abut together to form a spacing of twice the diameter of the warp yarns between adjacent pleats or the interior of the same pleat.

9. A pleated filter element according to claim 2 wherein the pitch of the weft yarns is 1.2 to 2.5 times the first pitch of the warp yarns.

10. A folding filter element according to claim 2 wherein said second pitch of the warp yarns is from 1 to 5 times the diameter of the warp yarns.