A folding filter cartridge and filter

Abstract

The utility model relates to filter structure technical field discloses a kind of folding filter core and filter, folding filter core includes shell, center pole, filter medium layer, end cap and sealing material;Shell and center pole coaxially are arranged, filter medium layer is set between shell and center pole, filter medium layer has fold peak, fold valley and leg, the both ends of leg are respectively connected adjacent fold peak and fold valley, fold peak and shell abut;Two end caps are respectively set in the both ends of filter medium layer, and simultaneously with filter medium layer, center pole and shell are connected, sealing material is set between end cap and filter medium layer;Several fold valleys include several low folds and several high folds, high fold and center pole abut, low fold is spaced apart from center pole.The utility model is set up low fold, prevent the gap between inner ring fold valley of filter medium layer too small, prevent sealing material too much concentration in filter medium layer outer ring, so that the sealing material formed after glue solidification is evenly distributed in filter medium layer end part.

Description

Technical Field

[0001] This utility model relates to the field of filtration structure technology, specifically to a pleated filter element and filter. Background Technology

[0002] Pleated filter cartridges, also known as pleated filter cartridges, offer high filtration precision and flow rate, effectively intercepting fine particles and colloidal debris with extremely high filtration efficiency.

[0003] Commonly used pleated filter cartridges are connected to end caps via thermoforming welding. However, thermoforming welding requires high precision and carries a significant risk of thermal stress; localized high temperatures can cause deformation or performance degradation of the heat-sensitive filter material. To address these issues, existing technologies use sealing materials to bond and seal the ends of the pleated filter cartridge to the end caps. However, to increase the effective filtration area, existing pleated filter cartridges have a high number of pleats, resulting in large gaps between the pleats on the outer ring and small gaps between the folds on the inner ring. This leads to insufficient space utilization and uneven distribution of the sealing material at the filter cartridge ends, resulting in varying sealing strength in different areas. Utility Model Content

[0004] In view of this, the present invention provides a pleated filter element and filter to solve the problems of insufficient space utilization and uneven distribution of sealing material at the ends of the existing pleated filter element, resulting in different sealing strength in different areas.

[0005] In a first aspect, this utility model provides a folded filter element, comprising a shell, a central rod, a filter media layer, end caps, and sealing material; the shell has a first perforation; the central rod is disposed inside the shell, the shell and the central rod are coaxially arranged, and the central rod has a second perforation; the filter media layer is disposed between the shell and the central rod, the filter media layer is annularly folded, the filter media layer has several peaks, several valleys, and several legs, and along the circumference of the filter media layer, the two ends of the legs are respectively connected to adjacent peaks and valleys, the peaks abutting against the shell; two end caps are provided, the two end caps are respectively disposed at both ends of the filter media layer, and simultaneously connected to the filter media layer, the central rod, and the shell; part of the sealing material is disposed between the end caps and the filter media layer; the several valleys include several low folds and several high folds, the high folds abut against the central rod, and the low folds are spaced apart from the central rod, so that the sealing material is evenly distributed at the ends of the filter media layer.

[0006] Beneficial effects: By setting low pleats, the large gaps between the pleats are fully utilized. Within the limited space between the central rod and the outer shell, the number of pleats in the filter media layer is increased, thereby increasing the effective filtration area of ​​the filter media layer. At the same time, the low pleat setting prevents the gaps between the inner ring pleats of the filter media layer from being too small, and prevents the sealing material from being concentrated too much on the outer ring of the filter media layer. It also ensures that the inner and outer rings of the filter media layer can hold the same amount of glue, so that the sealing material formed after the glue cures is evenly distributed at the end of the filter media layer, improving the sealing effect and strength between the filter media layer and the end cap.

[0007] In one optional embodiment, a plurality of the folds form an outer ring of the filter medium layer along the circumference of the filter medium layer, and a plurality of the high folds form an inner ring of the filter medium layer along the circumference of the filter medium layer. The ratio of the circumference of the outer ring to the circumference of the inner ring is X, and the ratio of the total number of folds to the total number of high folds is Y, satisfying X-0.5≤Y≤X+0.5.

[0008] Beneficial effects: Based on simplifying the pleating process, by setting the ratio of the total number of pleats to the total number of high pleats to be close to the ratio of the circumference of the outer ring to the circumference of the inner ring, the gap can be made uniform, which facilitates the uniform distribution of sealing material and improves the sealing effect and strength between the filter media layer and the end cap.

[0009] In one optional embodiment, the ratio of the circumference of the outer ring to the circumference of the inner ring is X, satisfying 1.4≤X≤2.2, and the ratio of the total number of folds to the total number of high folds is Y, satisfying 1.4≤Y≤2.2.

[0010] In one alternative embodiment, a portion of the sealing material is attached to the leg along the axial direction of the filter media layer to form an attachment area, the height of which is H, satisfying 2mm≤H≤8mm.

[0011] Beneficial effects: By controlling the height of the adhesion zone, while ensuring the shear strength between the sealing material and the filter media layer, excessive adhesive absorption height is avoided, preventing the top adhesive from forming a needle-like angle and reducing the risk of puncture of the sealing material.

[0012] In one alternative implementation, on the same leg, the highest height of the attachment area is Hmax, and the lowest height of the attachment area is Hmin, satisfying Hmax-Hmin≤3mm.

[0013] Beneficial effects: By controlling the height difference of the attachment area on the same leg, the distribution of sealing material at the end of the filter media layer is ensured to be more uniform, avoiding differences in sealing strength caused by too much or too little local sealing material, further improving the consistency and reliability of the seal between the filter media layer and the end cap, and reducing the risk of leakage caused by poor local sealing.

[0014] In one alternative embodiment, the sealing material is cured by adhesive, the viscosity of which is η, satisfying 1000cP≤η≤5000cP.

[0015] Beneficial effects: By controlling the viscosity of the adhesive, good bonding strength can be ensured while maintaining the integrity of the bonding interface, guaranteeing bonding sealing and structural stability.

[0016] In one optional embodiment, the Shore hardness of the sealing material is HA, satisfying 50≤HA≤95.

[0017] Beneficial effects: By controlling the Shore hardness of the sealing material, the overall strength and bonding strength between the sealing material and the filter membrane are ensured, while the sealing material has a certain degree of elasticity, preventing the sealing material from puncturing the filter membrane.

[0018] In one alternative embodiment, the filter media layer includes a support mesh and a filter membrane, the support mesh being sleeved on at least one side of the filter membrane.

[0019] In one optional embodiment, the filter membrane is any one of a regenerated cellulose filter membrane, a cellulose acetate filter membrane, a polytetrafluoroethylene filter membrane, and a polyamide composite membrane.

[0020] Secondly, this utility model also provides a filter, including the aforementioned pleated filter element. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the folded filter element according to an embodiment of the present utility model; Figure 2 This is a cross-sectional view of the folded filter element according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the half-section structure of the end cap of the folded filter element according to an embodiment of the present utility model; Figure 4 This is a schematic diagram of the structure of the filter media layer in an embodiment of the present invention; Figure 5 This is a top view of the filter media layer in an embodiment of the present invention. Figure 6This is a partial structural schematic diagram of the filter media layer in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 10. Outer shell; 20. Center rod; 30. Filter media layer; 31. Bending peak; 32. Bending valley; 321. Low pleat; 322. High pleat; 33. Leg; 34. Support mesh; 35. Filter membrane; 40. End cap; 50. Sealing material; 51. Attachment area. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] The following is combined Figures 1 to 6 The following describes embodiments of the present invention.

[0026] According to an embodiment of the present invention, in a first aspect, a folded filter element is provided, comprising a housing 10, a central rod 20, a filter media layer 30, and an end cap 40; the housing 10 has a first through hole; the central rod 20 is disposed inside the housing 10, and the housing 10 and the central rod 20 are coaxially arranged, and the central rod 20 has a second through hole; the filter media layer 30 is disposed between the housing 10 and the central rod 20, and the filter media layer 30 is annularly folded, having a plurality of peaks 31, a plurality of valleys 32, and a plurality of legs 33, wherein along the circumference of the filter media layer 30, the two ends of the legs 33 are respectively connected to adjacent peaks 31 and valleys 32, and the peaks 31 and the housing 10 are connected to the filter media layer 30. The filter media layer 30 has several folds 32, including several low folds 321 and several high folds 322. The high folds 322 abut against the central rod 20, and the low folds 321 are spaced apart from the central rod 20. Two end caps 40 are provided, which are respectively provided at both ends of the filter media layer 30 and connected to the filter media layer 30, the central rod 20 and the outer shell 10. Part of the sealing material 50 is provided between the end caps 40 and the filter media layer 30. The filter media layer 30 has several folds 321 and several high folds 322. The high folds 322 abut against the central rod 20, and the low folds 321 are spaced apart from the central rod 20, so that the sealing material 50 is evenly distributed at the end of the filter media layer 30.

[0027] Specifically, in this embodiment, such as Figure 2 As shown, the filter media layer 30, the central rod 20, and the outer shell 10 are aligned at both ends along the axial direction and are bonded to the end caps 40 on both sides by sealing material 50.

[0028] Specifically, the sealing material 50 is cured with adhesive.

[0029] By using the folded filter element of this embodiment, the large gaps between the folds 31 are fully utilized by setting low folds 321. Within the limited space between the central rod 20 and the outer shell 10, the number of folds in the filter media layer 30 is increased, thereby increasing the effective filtration area of ​​the filter media layer 30. At the same time, the setting of low folds 321 prevents the gaps between the inner ring folds 32 of the filter media layer 30 from being too small, and prevents the sealing material 50 from being too concentrated on the outer ring of the filter media layer 30. It also ensures that the inner and outer rings of the filter media layer 30 can hold the same amount of glue, so that the sealing material 50 formed after the glue cures is evenly distributed at the end of the filter media layer, thereby improving the sealing effect and strength between the filter media layer 30 and the end cap 40.

[0030] It should be noted that, in order to increase the effective filtration area, the pleated filter element in the relevant technology has a large number of pleats, which results in a large gap between the outer ring pleats 31 and the inner ring pleats 32, resulting in insufficient space utilization and uneven distribution of the sealing material 50 at the end of the filter element, leading to different sealing strengths in different areas.

[0031] In this application, all the folds 31 form an outer ring of the filter media layer 30 along the circumference of the filter media layer 30, and all the high pleats 322 form an inner ring of the filter media layer 30 along the circumference of the filter media layer 30. The circumference of the outer ring is significantly larger than that of the inner ring, but the number of high pleats 322 at the inner ring is less than the number of folds 31 at the outer ring, ensuring that the gap between each pleat at the position of the fold 31 and the position of the high pleat 322 is approximately the same. During the bonding process of the sealing material 50 with the filter media layer 30, the center rod 20 and the outer shell 10, due to the force of capillary action, the sealing material 50 will climb up the filter media layer 30 to a certain height. The uniform gap between the folds 31 and the high pleats 322 can ensure that their adhesive absorption height is closer, avoiding uneven distribution of adhesive absorption height of the sealing material 50 due to excessive gap at one position, thereby improving the sealing effect and strength between the filter media layer 30 and the end cap 40.

[0032] It should be noted that, as Figure 6 As shown, the low pleat 321 can include a variety of different lengths.

[0033] It should be noted that the first perforation of the outer casing 10 and the second perforation of the center rod 20 are used for the passage of the feed liquid.

[0034] It should be noted that, in order to facilitate the observation of the structure of the filter media layer, [the following is omitted]. Figures 4 to 6 The number of peaks and valleys in the data has been simplified.

[0035] In one embodiment, the ratio of the circumference of the outer ring to the circumference of the inner ring is X, and the ratio of the total number of folds 32 to the total number of high folds 322 is Y, satisfying X-0.5≤Y≤X+0.5.

[0036] Preferably, the ratio of the circumference of the outer ring to the circumference of the inner ring is X, satisfying 1.4≤X≤2.2, and the ratio of the total number of folds 32 to the total number of high folds 322 is Y, satisfying 1.4≤Y≤2.2.

[0037] It should be noted that, ideally, the closer the values ​​of X and Y are, the better the uniformity of the gap, which facilitates the uniform distribution of the sealing material 50. However, the closer the values ​​of X and Y are, the more difficult the pleating process of the filter media layer 30 becomes. Therefore, to simplify the pleating process, X and Y are made as close as possible.

[0038] Specifically, in this embodiment, the ratio Y = 2 of the total number of folds 32 to the total number of high folds 322, that is, as shown in the figure. Figure 3 and Figure 4 As shown, the ratio of the total number of high pleats 322 to the total number of low pleats 321 is 1.

[0039] It is worth noting that, based on the simplified pleating process, by setting the ratio of the total number of pleats 32 to the total number of high pleats 322 to be close to the ratio of the circumference of the outer ring to the circumference of the inner ring, the gap can be made uniform, which facilitates the uniform distribution of the sealing material 50 and improves the sealing effect and strength between the filter medium layer 30 and the end cap 40.

[0040] In this embodiment, as Figure 5 As shown, the filter media layer 30 includes a support mesh 34 and a filter membrane 35, with the support mesh 34 sleeved on at least one side of the filter membrane 35.

[0041] Specifically, in this embodiment, such as Figure 5 As shown, there are two support nets 34, which are respectively set on the inner and outer sides of the filter membrane 35.

[0042] Furthermore, filter membrane 35 is a regenerated cellulose filter membrane.

[0043] It should be noted that, in other alternative embodiments, the filter membrane 35 may also be selected as a cellulose acetate filter membrane, a polytetrafluoroethylene filter membrane, or a polyamide composite membrane.

[0044] In one embodiment, such as Figure 2 As shown, a portion of the sealing material 50 is disposed between the end cap 40 and the filter medium layer 30. The portion of the sealing material 50 is attached to the leg 33 along the axial direction of the filter medium layer 30 and forms an attachment area 51. The height of the attachment area 51 is H, which satisfies 2mm≤H≤8mm.

[0045] Specifically, in this embodiment, the height H of the attachment area 51 is 5mm.

[0046] It should be noted that in other alternative embodiments, the height of the attachment area 51 can also be other sizes within the optional range.

[0047] It should be noted that when H < 2 mm, the adhesive absorption height on leg 33 is too low, the shear strength of sealing material 50 and filter membrane 35 is low, and there is a risk that the two will detach from each other; when H > 8 mm, the sealing material 50 at the highest position on leg 33 will form a cone shape. The higher the height, the smaller the needle apex angle at the cone end, and the greater the risk that the sealing material 50 will puncture the filter membrane 35.

[0048] It is worth noting that by controlling the height of the attachment area 51, while ensuring the shear strength between the sealing material 50 and the filter medium layer 30, the adhesive suction height is avoided from being too high, preventing the top adhesive from forming a needle tip angle and reducing the risk of puncture of the sealing material 50.

[0049] Furthermore, on the same leg 33, the highest height of the attachment area 51 is Hmax, and the lowest height of the attachment area 51 is Hmin, satisfying Hmax-Hmin≤3mm.

[0050] Specifically, such as Figure 2 As shown, the sealing material 50 on the attachment area 51 is highly flat.

[0051] It should be noted that when Hmax-Hmin>3mm, the adhesion height of the sealing material 50 on the leg 33 varies greatly, resulting in uneven distribution of the sealing material 50 on the same leg 33. This leads to different sealing strengths at different locations, affecting the overall sealing performance of the filter media layer 30.

[0052] It is worth noting that by controlling the height difference of the attachment area 51 on the same leg 33, the distribution of the sealing material 50 at the end of the filter media layer 30 is more uniform, avoiding differences in sealing strength caused by too much or too little local sealing material 50, further improving the consistency and reliability of the seal between the filter media layer 30 and the end cap 40, and reducing the risk of leakage caused by poor local sealing.

[0053] Specifically, in this embodiment, the adhesive is polyurethane.

[0054] It should be noted that polyurethane contains a large number of NCO functional groups (NCO is the chemical abbreviation for isocyanate group, whose chemical structure is -N=C=O, and is the core functional group that constitutes isocyanate compounds), and regenerated cellulose filter membrane is a hydrophilic material with a large amount of glycerol attached to its surface. Due to the presence of water and glycerin, and the inherent properties of the substrate, the regenerated cellulose filter membrane naturally contains and is attached with a large number of active groups, including hydroxyl and amino groups. The bonding between the two is based on the synergistic effect of chemical reaction and physical action. The NCO functional groups in the sealing material 50 react with the active groups of the substrate to generate a three-dimensional network polymer containing urethane bonds and urea bonds, achieving chemical bonding. At the physical level, the liquid sealing material 50 penetrates into the micropores of the substrate, forming a mechanically interlocked structure. The strongly polar groups (such as ester bonds and ether bonds) in the adhesive layer molecules are tightly adsorbed to the surface of the substrate through van der Waals forces and hydrogen bonds. The flexible segments provided by the alcohol in the sealing material 50 give the adhesive layer elasticity, while the rigid segments formed by the isocyanate provide strength. The two work together to enable the adhesive layer to resist peel stress and buffer thermal expansion and contraction, ultimately forming a strong and durable adhesive layer at the interface, which is particularly good at cross-border bonding of heterogeneous materials (such as cellulose and thermoplastics).

[0055] In one embodiment, the sealing material 50 is cured by adhesive, the viscosity of which is η, satisfying 1000cP≤η≤5000cP.

[0056] Specifically, in this embodiment, the viscosity of the adhesive is η = 3000 cP.

[0057] It should be noted that, in other alternative embodiments, the viscosity of the adhesive can be adjusted within an optional range according to the actual situation.

[0058] It should be noted that when η < 1000 cP, the adhesive has excessive fluidity, and during the bonding process, the adhesive tends to penetrate upwards along the filter membrane 35, resulting in uneven distribution of the adhesive in the axial direction. This makes it difficult to maintain a stable distribution between the end of the filter membrane 35 and the end cap 40, thereby affecting the integrity of the bonding interface and reducing the sealing performance and structural stability. When η > 5000 cP, the adhesive has poor fluidity and reduced wetting performance, making it difficult to fully penetrate into the microporous structure of the filter material surface and between the end cap 40 material, resulting in a reduced bonding area and insufficient bonding strength.

[0059] It is worth noting that by controlling the viscosity of the adhesive, good bonding strength can be ensured while maintaining the integrity of the bonding interface, thus guaranteeing bonding seal and structural stability.

[0060] In one embodiment, the Shore hardness of the sealing material 50 is HA, satisfying 50≤HA≤95.

[0061] Specifically, in this embodiment, the Shore hardness HA of the sealing material 50 is 70.

[0062] It should be noted that, in other alternative embodiments, the Shore hardness of the sealing material 50 can be adjusted within an optional range according to the actual situation.

[0063] It should be noted that when HA < 50, the overall strength and bonding strength of the sealing material 50 and the filter membrane 35 are poor. Under the action of pressure difference during filtration, the filter membrane 35 may be damaged and detached, further affecting the sealing performance of the pleated filter element. When HA > 95, the Poisson's ratio v of the sealing material 50 is ≥ 0.4995. At this time, the sealing material 50 is regarded as a completely incompressible solid and almost loses its elasticity. Under the action of pressure difference, the legs 33 of the pleated filter element will generate an interaction force between the sealing material 50 and the filter membrane 35, increasing the risk of the sealing material 50 puncturing the filter membrane 35.

[0064] It is worth noting that by controlling the Shore hardness of the sealing material 50, while ensuring the overall strength and bonding strength of the sealing material 50 and the filter membrane 35, the sealing material 50 is guaranteed to have a certain degree of elasticity to prevent the sealing material 50 from puncturing the filter membrane 35.

[0065] According to an embodiment of the present invention, in a second aspect, a filter is provided, including the pleated filter element described above.

[0066] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A pleated filter element, characterized in that, include: The outer casing (10) has a first through hole. A center rod (20) is disposed inside the outer shell (10), the outer shell (10) and the center rod (20) are coaxially disposed, and a second through hole is provided on the center rod (20); A filter media layer (30) is disposed between the outer shell (10) and the central rod (20). The filter media layer (30) is in the shape of a ring fold. The filter media layer (30) has a number of peaks (31), a number of valleys (32) and a number of legs (33). Along the circumference of the filter media layer (30), the two ends of the legs (33) are respectively connected to the adjacent peaks (31) and valleys (32). The peaks (31) abut against the outer shell (10). End caps (40), two end caps (40) are provided, the two end caps (40) are respectively provided at both ends of the filter medium layer (30), and are simultaneously connected to the filter medium layer (30), the central rod (20) and the outer shell (10); A sealing material (50) is disposed between the end cap (40) and the filter media layer (30); The plurality of the folds (32) include a plurality of low folds (321) and a plurality of high folds (322), wherein the high folds (322) abut against the central rod (20), and the low folds (321) are spaced apart from the central rod (20) so that the sealing material (50) is evenly distributed at the end of the filter media layer (30).

2. The pleated filter element according to claim 1, characterized in that, A plurality of the folds (31) form an outer ring of the filter medium layer (30) along the circumference of the filter medium layer (30), and a plurality of the high folds (322) form an inner ring of the filter medium layer (30) along the circumference of the filter medium layer (30). The ratio of the circumference of the outer ring to the circumference of the inner ring is X, and the ratio of the total number of folds (32) to the total number of high folds (322) is Y, satisfying X-0.5≤Y≤X+0.

5.

3. The pleated filter element according to claim 2, characterized in that, The ratio of the circumference of the outer ring to the circumference of the inner ring is X, satisfying 1.4≤X≤2.

2. The ratio of the total number of folds (32) to the total number of high folds (322) is Y, satisfying 1.4≤Y≤2.

2.

4. The pleated filter element according to any one of claims 1-3, characterized in that, Part of the sealing material (50) is attached to the leg (33) along the axial direction of the filter medium layer (30) and forms an attachment area (51), the height of the attachment area (51) being H, satisfying 2mm≤H≤8mm.

5. The pleated filter element according to claim 4, characterized in that, On the same leg (33), the highest height of the attachment area (51) is Hmax, and the lowest height of the attachment area (51) is Hmin, satisfying Hmax-Hmin≤3mm.

6. The pleated filter element according to claim 4, characterized in that, The sealing material (50) is cured by adhesive, and the viscosity of the adhesive is η, which satisfies 1000cP≤η≤5000cP.

7. The pleated filter element according to claim 6, characterized in that, The Shore hardness of the sealing material (50) is HA, which satisfies 50≤HA≤95.

8. The pleated filter element according to any one of claims 1-3, characterized in that, The filter media layer (30) includes a support mesh (34) and a filter membrane (35), wherein the support mesh (34) is sleeved on at least one side of the filter membrane (35).

9. The pleated filter element according to claim 8, characterized in that, The filter membrane (35) is any one of regenerated cellulose filter membrane, cellulose acetate filter membrane, polytetrafluoroethylene filter membrane and polyamide composite membrane.

10. A filter, characterized in that, The pleated filter element includes any one of claims 1 to 9.

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