Filter and retention volume testing method thereof

Abstract

The invention discloses a filter and a retention volume testing method thereof, and the filter comprises: a filter body, the bottom of which is provided with a liquid outlet and the top of which is provided with a liquid inlet; a first groove is formed in the bottom end of the inner wall of the filter body; a positioning ring is arranged on the bottom wall of the filter element in a downward protruding manner, and the positioning ring is inserted and positioned in the first groove in a sealing manner, so that the distance between the bottom wall of the filter element and the bottom end of the inner wall of the filter body is reduced; the filter element is provided with a filter element liquid inlet hole and a filter element liquid outlet hole, and the filter element liquid outlet hole is communicated with the liquid outlet through the inner hole of the positioning ring. The first groove is formed in the bottom end of the inner wall of the filter body, and the positioning ring protruding downwards is arranged on the bottom wall of the filter element, so that after the positioning ring is hermetically inserted and positioned in the first groove, the distance between the bottom wall of the filter element and the bottom end of the inner wall of the filter body is remarkably reduced, the dead volume is reduced, the filtering efficiency is improved, and the service life of the filter element is prolonged. And the risk of product pollution caused by medium retention is also reduced.

Description

Technical Field

[0001] The invention relates to the technical field of filters, and in particular to a filter and a retention volume testing method thereof. Background Art

[0002] This section merely provides background information related to the present disclosure and may not constitute prior art.

[0003] Capsule filter, also known as integrated filter, is a common liquid and gas filtering device. It uses a folded filter membrane with a large filtering surface area, suitable for filtering larger volume solutions. At present, most of the capsule filters widely used in the market have a closed container with two joints on the container, one for liquid inlet and one for liquid outlet. In addition, two pipe joints are added for the needs of exhaust and discharge.

[0004] The Chinese utility model patent with the authorization announcement number CN221182326U discloses a folded filter element and a filter with high structural stability. In actual use, in order to filter the liquid entering the capsule filter as cleanly as possible, after the filtration is completed, the liquid in the filter is filtered to the maximum extent by adopting the method of liquid inlet directly above and liquid outlet directly below. However, there is a large space between the interface end cover of the filter and the filter housing and the base in the above scheme, forming a retention volume (i.e., dead volume). During the filtration process, the fluid in this space cannot flow or be updated effectively, and the medium located in this space will be retained, resulting in reduced filtration efficiency or product contamination. The medium in this space cannot be removed after filtration by the filter element, and can only be discharged through the reflux port after filtration, and cannot be effectively utilized. In particular, in the field of biomedical filtration, most of the materials to be filtered are small in quantity and expensive, and the use of the above filter brings economic losses to producers. Summary of the invention

[0005] In view of this, the present invention provides a filter and a retention volume testing method thereof to solve the problem of a large retention volume between the interface end cover of the current filter and the filter housing and base.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a filter, comprising:

[0008] A filter body, wherein a liquid outlet is provided at the bottom of the filter body, and a liquid inlet is provided at the top of the filter body; a first groove is provided at the bottom end of the inner wall of the filter body;

[0009] A filter element, wherein the bottom wall of the filter element protrudes downward and is provided with a positioning ring, and the positioning ring is seal-inserted and positioned in the first groove to reduce the distance between the bottom wall of the filter element and the bottom end of the inner wall of the filter body; the filter element has a filter element liquid inlet hole and a filter element liquid outlet hole, and the filter element liquid outlet hole is connected with the liquid outlet through the inner hole of the positioning ring.

[0010] The beneficial effects of the above filter are:

[0011] By providing a first groove at the bottom end of the inner wall of the filter body and providing a downwardly protruding positioning ring on the bottom wall of the filter element, after the positioning ring seal is inserted and positioned in the first groove, the distance between the bottom wall of the filter element and the bottom end of the inner wall of the filter body is significantly reduced, and the dead volume is reduced. Due to the reduction of dead volume, the medium located in this space is no longer easily retained, and can flow and update more effectively, which not only improves the filtration efficiency and recovery rate, but also reduces the risk of product contamination caused by medium retention.

[0012] In an optional embodiment, the distance between the bottom wall of the filter element and the bottom end of the inner wall of the filter body is less than 1.5 mm;

[0013] And / or, the distance between the side wall at the bottom end of the filter element and the inner wall of the filter body is 0.2-2 mm, preferably, the distance between the side wall at the bottom end of the filter element and the inner wall of the filter body is 0.2-1 mm.

[0014] The beneficial effects of the above technical solution are as follows: it helps to minimize the residual volume, ensures that the medium can be fully discharged, and reduces the retention of the medium in the filter. Reducing the residual volume helps to remove the residue more thoroughly during the cleaning process, improves the cleanliness of the filter, and reduces the risk of contamination. When the medium is filtering, because the spacing between the first platform and the second platform is very small, most of the medium will smoothly pass through the filter element and enter the liquid outlet, ensuring that the filtration efficiency is not affected. And controlling the spacing between the side wall of the bottom end of the filter element and the side wall of the filter body can ensure that the retention space outside the bottom end of the filter element and the bottom are small.

[0015] In an optional embodiment, the filter body comprises:

[0016] A base, wherein the top of the base is provided with an open groove, the bottom wall of the open groove forms a first platform, and the first platform is the bottom end of the inner wall of the filter body;

[0017] A liquid inlet connector, wherein the liquid inlet is arranged at the top of the liquid inlet connector;

[0018] The filter housing is arranged between the base and the liquid inlet connector.

[0019] In an optional embodiment, a first convex ring is provided on the bottom wall of the first groove, the height of the first convex ring is lower than the height of the first platform, and the first convex ring is fixedly connected to the positioning ring.

[0020] The beneficial effects of the above technical solution are as follows: the first convex ring is provided with an installation position for connecting with the positioning ring. When installing the positioning ring, the first convex ring can be welded to the positioning ring, which is convenient for the installation and positioning of the positioning ring, and ensures the stability and reliability of the filter element installation. The sealing connection between the first convex ring and the positioning ring forms a sealing structure, which enhances the sealing between the filter element and the filter body, and effectively prevents the medium from leaking from the gap between the two. The height of the first convex ring is lower than the height of the first platform, so that the positioning ring can be inserted into the first groove, thereby reducing the distance between the second platform and the first platform, thereby reducing the dead volume and improving the filtration efficiency and recovery rate.

[0021] In an optional implementation, the first convex ring is fixed to the positioning ring by welding; and a gap is provided between the first convex ring and the side wall of the first groove.

[0022] The beneficial effects of the above technical solution are: there is a gap between the first convex ring and the side wall of the first groove, which will not heat the material in the vicinity, and the gap can accommodate the overflow generated by welding the first convex ring and the positioning ring.

[0023] In an optional embodiment, a liquid inlet cavity is formed between the inner wall of the filter housing and the outer wall of the filter element, the filter element has multiple liquid inlet holes and is arranged on the side of the filter element, and the liquid inlet cavity is respectively connected to the liquid inlet port and the filter element liquid inlet hole.

[0024] In an optional embodiment, a second convex ring is disposed on the periphery of the bottom of the filter element, the second convex ring is disposed in the liquid inlet cavity, and the height of the second convex ring is lower than the height of the lowest liquid inlet hole of the filter element.

[0025] The beneficial effect of the above technical solution is that the second convex ring occupies the space between the interface end cover of the filter element and the third convex ring of the base, thereby reducing the retention volume between the two. In addition, the height of the second convex ring is lower than the height of the lowest filter element liquid inlet hole, which reduces the retention volume while not affecting the use state of the lowest filter element liquid inlet hole.

[0026] In an optional implementation, the second convex ring is disposed on the first platform and located inside the opening groove.

[0027] In an optional embodiment, a third convex ring is provided on the outer edge of the first platform, and the third convex ring is fixedly connected to the filter housing;

[0028] The second convex ring is spaced apart from the third convex ring, and at least one second groove is disposed on the top of the second convex ring.

[0029] The beneficial effect of the above technical solution is that at least one second groove is arranged on the top of the second convex ring, which can discharge the medium stored in the gap between the second convex ring and the third convex ring, thereby avoiding the formation of a retention volume in the gap between the second convex ring and the third convex ring.

[0030] In an optional implementation, the distance between the second convex ring and the side wall of the filter element is 0.2-2 mm.

[0031] In an optional embodiment, the second convex ring is arranged on the filter element.

[0032] In an optional embodiment, the filter element comprises:

[0033] A filter element body, wherein the filter element liquid inlet hole is arranged on the side wall of the filter element body;

[0034] A closed end cap, the closed end cap being arranged at the top end of the filter element body;

[0035] An interface end cover, the interface end cover is arranged at the bottom end of the filter element body, and the filter element liquid outlet hole is arranged on the interface end cover;

[0036] The outer diameter of the interface end cover is larger than the outer diameter of the filter element body, and the second convex ring is arranged at the top of the area where the interface end cover protrudes from the filter element body and covers the periphery of the filter element body.

[0037] The beneficial effect of the above technical solution is that arranging the second convex ring on the interface end cover can not only reduce the retention volume at the bottom of the liquid inlet cavity, but also improve the connection stability between the interface end cover and the filter element housing.

[0038] In an optional implementation, the distance between the second convex ring and the side wall of the base opening groove is 0.2-2 mm.

[0039] In an optional embodiment, a third groove is provided on the first platform, and the third groove is connected to the liquid inlet cavity; a reflux joint is provided on the filter body, and a reflux port is provided on the reflux joint, and the reflux port is connected to the third groove.

[0040] In an optional embodiment, the positioning ring is configured to be stepped, and the first groove is configured to be a stepped groove shape that matches the positioning ring; a third platform is provided on the first groove, and the height of the third platform is lower than the height of the first platform, and the height of the first convex ring is lower than the height of the third platform. The first convex ring is located on the inner side of the third platform, and the outer diameter of the first convex ring is smaller than the inner diameter of the third platform.

[0041] The beneficial effects of the above technical solution are:

[0042] On the one hand, the stepped design of the positioning ring and the first groove ensures that the two can be precisely aligned during installation, thereby ensuring that the positioning ring and the first convex ring can be precisely aligned, reducing the problem of poor welding effect caused by position deviation.

[0043] On the other hand, the stepped positioning ring and the first groove can make the gap between the interface end cover and the side wall of the first groove be set as a bent structure, which helps to prevent the air in the deep gap from being easily discharged when the capsule filter is filled with liquid, so that the liquid cannot completely enter and occupy the retention space, so that the actual value of the retention volume is smaller than the theoretical value. The stepped design and the bent structure help reduce the residual fluid at the bottom of the filter element, improve the cleanliness, and reduce the risk of contamination.

[0044] In an optional embodiment, the first convex ring and the positioning ring are fixed by a fusion welding process; and / or the base and the filter housing are fixed by a fusion welding process; the fusion welding process includes one or more of thermal welding, ultrasonic welding and eddy current welding.

[0045] In an optional embodiment, the base liquid inlet connector and the filter housing are both made of polypropylene, polyethersulfone, polytetrafluoroethylene or nylon.

[0046] In a second aspect, the present invention provides a method for testing the hold-up volume of a filter, comprising the following steps:

[0047] S1. Calculate the theoretical value of the hold-up volume V between the filter body and the filter element 理论 ;

[0048] S2. Weigh the dry filter and record the initial mass of the filter M0; pass the medium into the filter from the liquid inlet and discharge the medium from the filter from the liquid outlet; then pass airflow into the liquid inlet and discharge it from the liquid outlet; then weigh the filter again and record the final mass of the filter M1; calculate the actual value V of the holdup volume between the filter body and the filter element 实际 =(M1-M0) / ρ 介质 , where ρ 介质 is the density of the medium;

[0049] S3. Compare the theoretical hold-up volume with the actual hold-up volume to determine the performance of the filter.

[0050] The beneficial effect of the above filter is that by comparing the theoretical hold-up volume with the actual hold-up volume, the performance of the filter can be accurately evaluated to ensure its reliability and effectiveness in practical applications. The difference between the actual value and the theoretical value can help detect whether the filter has leaks and discover potential problems in a timely manner.

[0051] In an optional embodiment, the method further comprises the following steps:

[0052] According to steps S1 to S3, a theoretical volume value of a retention medium and an actual volume value of a retention medium of a conventional filter are calculated;

[0053] According to steps S1 to S3, a theoretical volume value of a retention medium and an actual volume value of a retention medium of the filter of the first aspect of the present invention are calculated;

[0054] The theoretical volume value of the retention medium of the traditional filter is compared with the theoretical volume value of the retention medium of the filter of the first aspect of the present invention, and the actual volume value of the retention medium of the traditional filter is compared with the actual volume value of the retention medium of the filter of the first aspect of the present invention to judge the performance of the filter.

[0055] In an optional embodiment, the medium introduced into the filter is pure water;

[0056] And / or, hot air at 60-80° C. is introduced into the liquid inlet, the flow rate of the hot air is 2-5 m / s, and the hot air introduction time is 10-15 minutes. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A cross-sectional view of a filter provided in Example 1 of the present invention;

[0059] Figure 2 A schematic diagram of the structure of a base in a filter provided in Example 1 of the present invention;

[0060] Figure 3 A cross-sectional view of a base in a filter provided in Example 1 of the present invention;

[0061] Figure 4 A cross-sectional view of a base in a filter provided in Example 2 of the present invention;

[0062] Figure 5A schematic diagram of the structure of a base in a filter provided in Example 2 of the present invention;

[0063] Figure 6 A cross-sectional view of a base in a filter provided in Example 3 of the present invention;

[0064] Figure 7 A cross-sectional view of another arrangement of the second convex ring in the filter provided by the present invention;

[0065] Figure 8 A cross-sectional view of another filter provided by the present invention;

[0066] Fig. 9 It is a schematic diagram of the structure of the filter element in a conventional filter;

[0067] Fig.10 This is a cross-sectional view of the current filter in Comparative Example 1.

[0068] Reference numerals:

[0069] 1. base, 11. first platform, 12. first groove, 13. first convex ring, 14. second convex ring, 15. third convex ring, 16. second groove, 17. third platform, 18. liquid outlet joint, 181. liquid outlet, 19. reflux joint, 191. reflux outlet, 110. third groove, 111. opening groove;

[0070] 2. filter element, 21. filter element housing, 211. filter element liquid inlet hole, 22. center tube, 221. through hole, 222. liquid collecting channel, 23. closed end cover, 24. interface end cover, 241. positioning ring, 242. second platform, 243. filter element liquid outlet hole, 25. filter membrane;

[0071] 3. filter housing, 31. liquid inlet cavity;

[0072] 4. Liquid inlet connector, 41. Liquid inlet. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0074] Capsule filter, also known as integrated filter, is a common liquid and gas filtering device. It uses a folded filter membrane with a large filtering surface area, suitable for filtering larger volume solutions. At present, most of the capsule filters widely used in the market have a closed container with two joints on the container, one for liquid inlet and one for liquid outlet. In addition, two pipe joints are added for the needs of exhaust and discharge.

[0075] The Chinese utility model patent with the authorization announcement number CN221182326U discloses a folded filter element and filter with high structural stability. In actual use, in order to filter the liquid entering the capsule filter as cleanly as possible, after the filtration is completed, the liquid inlet is directly above and the outlet is directly below, so as to filter the liquid in the filter to the maximum extent. However, there is a large space between the interface end cover of the filter and the filter housing and base in the above scheme, forming a dead volume. During the filtration process, the fluid in this space cannot flow or be updated effectively, and the medium located in this space will be retained, resulting in reduced filtration efficiency or product contamination.

[0076] The Chinese invention patent with the publication number CN115970385A discloses a capsule filter and its preparation method. By opening a reflux channel on the bottom cover of the filter, the liquid that cannot be filtered by the filter element will flow out and be collected through the reflux channel of the bottom cover of the filter. The above method can solve the problem of product contamination, that is, the cleaned liquid can be discharged. However, the device still has the problems of low filtration efficiency and large retention volume space. When there are more materials or the price of materials is cheap, the waste of materials in the retention volume space will not have a greater impact on production. However, in the field of biological filtration, most of the materials to be filtered are small in quantity and expensive in price. The use of the above filter will bring economic losses to the producer.

[0077] In summary, in order to ensure the flow efficiency of the filter, the current capsule filter sets a larger flow cavity between the filter element shell and the filter shell. However, due to the large residual volume at the bottom of the flow cavity, the recovery rate of the feed liquid is low, especially when the feed liquid is less or the feed liquid is more expensive, the problem is more serious.

[0078] Based on this, the present invention provides a filter, which provides a first groove on the first platform of the base, and a first convex ring lower than the height of the first platform is provided in the first groove, so that the gap between the first convex ring and the second platform of the interface end cover is significantly reduced, thereby reducing the dead volume and reducing the medium retention volume.

[0079] The first convex ring on the current filter protrudes from the first platform, resulting in a large retention volume between the first platform and the second platform after the first convex ring is welded to the positioning ring, which will lead to a low recovery rate of the feed liquid, especially when the feed liquid is less or more expensive, the problem is more serious.

[0080] Based on this, the present invention sets a first groove on the first platform on the base, and sets the first convex ring in the first groove, which will not only not affect the filtering efficiency of the filter, but also significantly reduce the residual volume space.

[0081] The specific embodiments of the present invention are described in detail below in conjunction with the filter of the first aspect of the present invention and the retention volume test method of the filter of the second aspect of the present invention.

[0082] According to an embodiment of the present invention, in a first aspect, a filter is provided, Figures 1 to 8 As shown, it includes a filter body and a filter element 2.

[0083] A liquid outlet joint 18 is provided at the bottom of the filter body, a liquid outlet port 181 is provided on the liquid outlet joint 18, and a liquid inlet port 41 is provided at the top of the filter body.

[0084] The filter element 2 has a filter element liquid inlet hole 211 and a filter element liquid outlet hole 243 . The filter element liquid outlet hole 243 is connected to the liquid outlet 181 through the inner hole of the positioning ring 241 .

[0085] The bottom end of the inner wall of the filter body is provided with a first groove 12, more specifically, the first groove 12 is provided at the center of the bottom end of the inner wall of the filter body. The bottom wall of the filter element 2 is protruding downward and provided with a positioning ring 241, and the positioning ring 241 is sealed and inserted into the first groove 12 to reduce the distance between the bottom wall of the filter element 2 and the bottom end of the inner wall of the filter body, thereby reducing the dead volume. Due to the reduction of the dead volume, the medium located in this space is no longer easily retained, and can flow and update more effectively, which not only improves the filtration efficiency and recovery rate, but also reduces the risk of product contamination caused by the retention of the medium.

[0086] In some embodiments, the filter element 2 includes a filter element body, a closed end cap 23 and an interface end cap 24. A plurality of filter element liquid inlet holes 211 are provided, and are respectively provided on the side walls of the filter element body. The closed end cap 23 is provided at the top of the filter element body. The interface end cap 24 is provided at the bottom of the filter element body, and the filter element liquid outlet hole 243 is provided on the interface end cap 24.

[0087] Fig. 9It is a schematic diagram of the structure of the filter element in a conventional filter. This embodiment adopts the same structural design. This embodiment mainly focuses on the relationship between the filter element housing and the filter body, so the structure inside the filter element is not shown in other figures. The filter element body of this embodiment includes a filter element housing 21, a central tube 22 and a filter membrane 25. The filter element housing 21 is set as a cylindrical structure, and the filter element liquid inlet 211 is set on the side wall of the filter element housing 21. The closed end cap 23 is a closed structure, and the closed end cap 23 is set at the top of the filter element housing 21. The interface end cap 24 is set at the bottom of the filter element housing 21, and the filter element liquid outlet is set on the interface end cap 24. The central tube 22 is vertically arranged inside the filter element housing 21, and a plurality of through holes 221 are set on the side wall of the central tube 22. The interior of the central tube 22 is set as a liquid collecting channel 222, and the liquid collecting channel 222 is respectively connected to the filter element liquid outlet and each through hole 221. A filter membrane accommodating cavity is formed between the outer wall of the central tube 22 and the inner wall of the filter element housing 21. The filter membrane 25 is disposed in the filter membrane accommodating cavity, and the filter membrane 25 is a folded filter membrane, so that the filter as a whole is a capsule filter. In this embodiment, the medium can enter the filter membrane accommodating cavity from the filter element liquid inlet hole 211 on the filter element housing 21, and after being filtered by the filter membrane 25, enter the liquid collecting channel 222 through the through hole 221 on the central tube 22, and then be transmitted to the filter element liquid outlet through the liquid collecting channel 222, and finally discharged.

[0088] In some embodiments, in combination Figure 3 As shown, the filter body includes a base 1, a liquid inlet connector 4 and a filter housing 3. An open slot 111 is provided at the top of the base 1, and the bottom wall of the open slot 111 forms a first platform 11, which is the bottom end of the inner wall of the filter body. The liquid inlet 41 is provided at the top of the liquid inlet connector 4. The filter housing 3 is provided between the base 1 and the liquid inlet connector 4. The bottom wall of the filter element 2 forms a second platform 242.

[0089] In this embodiment, the filter body is divided into three parts, the base 1 and the filter housing 3 are fixedly connected, and the filter housing 3 and the liquid inlet connector 4 are fixedly connected, which not only makes the connection between the parts more secure, but also improves the structural stability of the entire filter. The segmented design allows each part to be manufactured and installed independently, which is convenient for assembly and debugging on the production line. At the same time, if a part is damaged or needs to be replaced, it can be replaced separately without replacing the entire filter, reducing maintenance costs.

[0090] In some embodiments, a first convex ring 13 is disposed on the bottom wall of the first groove 12 . The height of the first convex ring 13 is lower than that of the first platform 11 . The first convex ring 13 corresponds to the positioning ring 241 and is fixedly connected thereto.

[0091] The first convex ring 13 provided in this embodiment provides an installation position for connecting with the positioning ring 241. When installing the positioning ring 241, the first convex ring 13 can be welded to the positioning ring 241, which is convenient for the installation and positioning of the positioning ring 241, and ensures the stability and reliability of the installation of the filter element 2. The sealing connection between the first convex ring 13 and the positioning ring 241 forms a sealing structure, which enhances the sealing between the filter element 2 and the filter body, and effectively prevents the medium from leaking from the gap between the two. The height of the first convex ring 13 is lower than the height of the first platform 11, so that the positioning ring 241 can be inserted into the first groove 12, thereby reducing the distance between the second platform 242 and the first platform 11, thereby reducing the dead volume and improving the filtration efficiency and recovery rate.

[0092] In some embodiments, the height difference between the first convex ring 13 and the first platform 11 is controlled to control the distance between the first platform 11 and the second platform 242 after the filter element 2 and the base 1 are welded. The distance between the bottom wall of the filter element 2 and the bottom end of the inner wall of the filter body is less than 1.5 mm, that is, the distance between the first platform 11 and the second platform 242 is less than 1.5 mm, at this time, the residual volume can be significantly reduced without affecting the filtering efficiency at all.

[0093] More specifically, the spacing between the first platform 11 and the second platform 242 is less than 1.5 mm, which helps to minimize the residual volume, ensure that the medium can be fully discharged, and reduce the retention of the medium in the filter. Reducing the residual volume helps to more thoroughly remove the residue during the cleaning process, improve the cleanliness of the filter, and reduce the risk of contamination. When the medium is filtering, because the spacing between the first platform 11 and the second platform 242 is very small, most of the medium will smoothly pass through the filter element 2 and enter the liquid outlet 181, ensuring that the filtering efficiency is not affected.

[0094] In some embodiments, the spacing between the side wall at the bottom end of the filter element 2 and the inner wall of the filter body is 0.2-2 mm. In this embodiment, controlling the spacing between the side wall at the bottom end of the filter element 2 and the side wall of the filter body can ensure that the retention space outside and at the bottom of the bottom end of the filter element 2 is small, so that the medium is not easily retained in the retention space outside and at the bottom of the bottom end of the filter element 2 during the filtration process, thereby improving the filtration efficiency. Controlling the minimum spacing between the side wall at the bottom end of the filter element 2 and the inner wall of the filter body to be above 0.2 mm will not affect the assembly between the filter element 2 and the filter body.

[0095] And according to the specific filtering requirements and application environment, the distance between the bottom side wall of the filter element 2 and the inner wall of the filter body can be fine-tuned to achieve the best filtering effect. Preferably, the distance between the bottom side wall of the filter element 2 and the inner wall of the filter body is 0.2-1mm. Within this range, the retention space (i.e., retention volume) is significantly reduced.

[0096] In some embodiments, the first convex ring 13 is fixed to the positioning ring 241 by welding. There is a gap between the first convex ring 13 and the side wall of the first groove 12. In this embodiment, due to the welding process, the material between the first convex ring 13 and the positioning ring 241 is fully melted during the contact between the welding wire and the heater. Since there is a gap between the first convex ring 13 and the side wall of the first groove, the material at the nearby position will not be heated, and the gap can accommodate the overflow generated by the welding of the first convex ring 13 and the positioning ring 241.

[0097] In some embodiments, a liquid inlet cavity 31 is formed between the inner wall of the filter housing 3 and the outer wall of the filter element 2, and a plurality of filter element liquid inlet holes 211 are provided and arranged on the side of the filter element 2, and the liquid inlet cavity 31 is respectively connected to the liquid inlet port 41 and the filter element liquid inlet hole 211.

[0098] In order to ensure the circulation efficiency of the filter, a larger circulation cavity is set between the filter element housing and the filter shell, but there is also a large retention volume at the bottom of the circulation cavity, that is, between the interface end cover of the filter element 2 and the third convex ring 15 of the base. In order to further reduce the retention volume, in some embodiments, a second convex ring 14 is set at the periphery of the bottom of the filter element 2, and the second convex ring 14 is set in the liquid inlet cavity 31, and the height of the second convex ring 14 is lower than the height of the lowest filter element liquid inlet hole 211. In this embodiment, the second convex ring 14 occupies the space between the interface end cover of the filter element 2 and the third convex ring 15 of the base, thereby reducing the retention volume between the two. In addition, the height of the second convex ring 14 is lower than the height of the lowest filter element liquid inlet hole 211, which reduces the retention volume while not affecting the use state of the lowest filter element liquid inlet hole 211.

[0099] The spacing between the second convex ring 14 and the interface end cover 24 is controlled to be 0.2-2 mm. The smaller the gap, the smaller the retention volume can be guaranteed, but in order to ensure that the outer shell of the filter element or the interface end cover 24 does not interfere with the base during welding, a minimum safety gap of 0.2 mm is set.

[0100] The height of the second convex ring 14 is H, and the height of the second convex ring 14 is controlled to be H=5-15 mm, so that it is lower than the height of the lowest filter element liquid inlet hole 211, and can also effectively reduce the retention volume.

[0101] In some embodiments, in combination Figures 1 to 3 As shown, the second convex ring 14 is disposed on the first platform 11 and is located inside the opening groove 111. In this embodiment, the second convex ring 14 is disposed on the first platform 11 and protrudes upwards. It can be integrally formed with the first platform 11 or fixed to the first platform 11 by welding.

[0102] Combination Figure 2 and Figure 3As shown, a third protruding ring 15 is provided on the outer edge of the first platform 11, the third protruding ring 15 is located on the inner side of the outer wall of the base 1, and the third protruding ring 15 is fixedly connected to the filter housing 3. Since the height of the third protruding ring 15 is relatively low, and the height of the second protruding ring 14 is higher than the third protruding ring 15, in order to facilitate the welding of the third protruding ring 15, the second protruding ring 14 and the third protruding ring 15 are spaced apart.

[0103] When the second convex ring 14 and the third convex ring 15 are spaced apart, the gap between the second convex ring 14 and the third convex ring 15 will also form a retention volume. In order to facilitate the discharge of the medium stored in the gap between the second convex ring 14 and the third convex ring 15, at least one second groove 16 is provided on the top of the second convex ring 14. In this embodiment, at least one second groove is provided on the top of the second convex ring 14, so that the medium stored in the gap between the second convex ring 14 and the third convex ring 15 can be discharged, thereby preventing the gap between the second convex ring 14 and the third convex ring 15 from forming a retention volume.

[0104] As an alternative embodiment, in combination Figure 7 and Figure 8 As shown, the second convex ring 14 is arranged on the filter element 2. The outer diameter of the interface end cover 24 is larger than the outer diameter of the filter element body, and the second convex ring 14 is arranged at the top of the area where the interface end cover 24 protrudes from the filter element body and is covered on the periphery of the filter element body. Providing the second convex ring 14 on the interface end cover 24 can not only reduce the retention volume at the bottom of the liquid inlet cavity, but also improve the connection stability between the interface end cover 24 and the filter element housing 3.

[0105] In some embodiments, the first platform 11 is provided with a third groove 110, which is connected to the liquid inlet cavity 31; the filter body is provided with a reflux joint 19, which is provided with a reflux port 191, which is connected to the third groove 110. The reflux port 191 is provided with a valve, which can be opened when discharging liquid, and closed when not discharging liquid.

[0106] In this embodiment, the reflux port 191 discharges the remaining unfiltered liquid in the retention volume through the third groove 110. Although this embodiment has significantly reduced the residual volume, it cannot completely reduce the residual volume for installation requirements, so a reflux joint 19 is still required to discharge the remaining small amount of medium that cannot be filtered. The filter element for welding is generally a disposable filter. Since the retention volume of this embodiment itself is small, the reflux joint 19 and the third groove 110 may also be selected not to be provided.

[0107] Since there is a gap between the first protruding ring 13 and the side wall of the first groove 12, it is difficult to ensure that the positioning ring 241 and the first protruding ring 13 are completely corresponding when the gap is large, which may lead to poor welding effect and affect the connection effect between the base 1 of the filter element 2. In order to solve this problem, in some embodiments, the positioning ring 241 is set to a stepped shape, and the first groove 12 is set to a stepped groove shape that matches the positioning ring 241.

[0108] In this embodiment, on the one hand, the stepped design of the positioning ring 241 and the first groove 12 ensures that the two can be accurately aligned during installation, thereby ensuring that the positioning ring 241 and the first convex ring 13 can be accurately aligned, reducing the problem of poor welding effect caused by position deviation. On the other hand, the positioning ring 241 and the first groove 12 set in a stepped shape can set the gap between the interface end cover and the side wall of the first groove 12 as a bending structure, which helps when the capsule filter is filled with liquid, the air deep in the gap is not easy to be discharged, and the liquid cannot completely enter and occupy the retention space, so that the actual value of the retention volume is smaller than the theoretical value. It should be noted that the premise of this effect is that the spacing between the first platform 11 and the second platform 242 is small, so as to ensure that the air is not easy to be discharged and reduce the actual retention volume. The stepped design and the bending structure help to reduce the residual fluid at the bottom of the filter element, improve the cleanliness, and reduce the risk of contamination.

[0109] More specifically, a third platform 17 is provided on the first groove 12, the height of the third platform 17 is lower than the height of the first platform 11, the height of the first convex ring 13 is lower than the height of the third platform 17, the first convex ring 13 is located on the inner side of the third platform 17, and the outer diameter of the first convex ring 13 is smaller than the inner diameter of the third platform 17. In this embodiment, since the height of the third platform 17 is lower than the height of the first platform 11, and the height of the first convex ring 13 is lower than the height of the third platform 17, this stepped design effectively reduces the retention volume between the filter element interface end cover and the base. The third platform 17 can support the filter element to a certain extent, ensuring the reliability of welding and the connection effect between the filter element base. The third platform 17 is in the shape of multiple steps, and the height and width of each step can be optimized according to the results of fluid mechanics simulation to form a more complex bending path, further hindering the fluid from entering the deep gap.

[0110] In some embodiments, the first convex ring 13 and the positioning ring 241 are fixed by a fusion welding process. The third convex ring 15 of the base 1 and the filter housing 3 are fixed by a fusion welding process. In this embodiment, the fusion welding process can provide a very high connection strength, ensuring that the connection between the first convex ring 13 and the positioning ring 241 and between the base 1 and the filter housing 3 is firm and reliable, and will not loosen due to long-term use or high-pressure environment. The fusion welding process can form a seamless connection, ensuring that there are no leakage points in the welding part, improving the sealing of the entire filter, and preventing liquid from leaking from the weld and affecting the filtering result.

[0111] The fusion welding process includes one or more of thermal welding, ultrasonic welding and eddy current welding. The fusion welding processes such as thermal welding, ultrasonic welding and eddy current welding can be applied to a variety of materials, including plastics, metals, etc., making the design more flexible and the appropriate welding method can be selected according to different materials.

[0112] In some embodiments, the liquid inlet connector 4 of the base 1 and the filter housing 3 are made of polypropylene, polyethersulfone, polytetrafluoroethylene or nylon.

[0113] The specific usage process of the above filter is as follows:

[0114] The medium is transported from the liquid inlet 41 to the liquid inlet cavity 31 (enclosed by the inner wall of the filter housing 3, the top surface of the base 1 and the outer wall of the filter element 2). The medium passes through the filter element 2 and enters the inside of the filter element 2, is filtered by the filter element 2, and then is discharged from the liquid outlet 181.

[0115] According to an embodiment of the present invention, in a second aspect, a method for testing the retention volume of a filter is provided. The method is performed based on the filter of the first aspect of the present invention, and comprises the following steps:

[0116] S1. Calculate the theoretical value V of the hold-up volume between the filter body and the filter element 2 理论 More specifically, the capsule filter of the present application is modeled by SolidWorks software, and the volume of the cavity between the base and the filter element below the bottom edge of the through hole at the lowest point of the filter element housing is selected as the theoretical value of the retention volume of the capsule filter.

[0117] S2. Place the dry filter on an electronic balance and weigh it, and record the initial mass M0 of the filter. Install the above filter vertically on the bracket with the liquid inlet 41 on top and the liquid outlet 181 on the bottom. Open the liquid inlet 41 and introduce the medium. After the medium is injected, close the liquid inlet 41 and let it stand for ten minutes. Then open the liquid inlet and the liquid outlet, and discharge the medium from the filter through the liquid outlet 181. The medium in the retained volume cannot be discharged normally because it is lower than the lowest through hole on the filter element housing. Then introduce airflow into the liquid inlet 41 and discharge it from the liquid outlet 181. Then place the filter on an electronic balance and weigh it again, and record the final mass M1 of the filter; calculate the actual value V of the retained volume between the filter body and the filter element 2 实际 =M1-M0 / ρ 介质 , where ρ 介质 is the density of the medium.

[0118] S3. Compare the theoretical hold-up volume with the actual hold-up volume to determine the performance of the filter. 理论 The actual value of the hold-up volume V 实际 If the difference is not large, it means that the filter has good performance, reasonable sealing and structural design; if the actual value is much larger than the theoretical value, it may mean that there are problems with the filter welding process, especially the poor control of the spacing between the first platform and the second platform, which leads to an increase in the actual retention volume value. It is necessary to further check and improve the welding process and adjust the actual retention volume.

[0119] The retention volume test method of the above-mentioned filter can accurately evaluate the performance of the filter by comparing the theoretical value of the retention volume with the actual value of the retention volume, thereby ensuring its reliability and effectiveness in practical applications.

[0120] In some embodiments, the following steps are also included:

[0121] According to steps S1 to S3, the theoretical volume value of the retention medium and the actual volume value of the retention medium of the conventional filter are calculated.

[0122] According to steps S1 to S3, the theoretical volume value of the retention medium and the actual volume value of the retention medium of the filter according to the first aspect of the present invention are calculated.

[0123] The theoretical volume value of the retention medium of the traditional filter is compared with the theoretical volume value of the retention medium of the filter of the first aspect of the present invention, and the actual volume value of the retention medium of the traditional filter is compared with the actual volume value of the retention medium of the filter of the first aspect of the present invention to judge the performance of the filter.

[0124] If the theoretical volume value of the retention medium of the filter of the first aspect of the present invention is significantly smaller than the theoretical volume value of the retention medium of the conventional filter, it means that the filter of the first aspect of the present invention has reduced the retention volume and improved the efficiency in design. If the actual volume value of the retention medium of the filter of the first aspect of the present invention is significantly smaller than the actual volume value of the retention medium of the conventional filter, it means that the filter of the first aspect of the present invention performs better in actual use, reduces the amount of retention medium, and improves the filtration efficiency and cleanliness.

[0125] In this embodiment, by comparing the theoretical value and the actual value, the performance improvement of the filter of the first aspect of the present invention in design and practical application can be clearly shown, and it is verified whether the filter design of the first aspect of the present invention has achieved the expected effect, and its reliability and effectiveness in practical application can be ensured.

[0126] In some embodiments, in order to reduce the influence of the filter medium of the pleated filter element on the test, when testing the actual value of the retention volume, the filter membrane 25 is not provided in the filter element 2, the medium introduced is pure water, and the rest are the same.

[0127] In some embodiments, the hot air with a temperature of 60-80° C. is introduced into the liquid inlet 41 , the flow rate of the hot air is 2-5 m / s, and the time for introducing the hot air is 10-15 minutes.

[0128] Example 1

[0129] Combination Figures 1 to 3 As shown, this embodiment discloses a filter, and the second convex ring 14 in this embodiment is arranged on the first platform 11. The gap between the control interface end cover 24 and the second convex ring 14 is 0.5 mm, and the outer diameter of the interface end cover 24 is 69 mm.

[0130] Example 2

[0131] Combination Figure 4 and Figure 5 As shown, this embodiment discloses a filter. The difference between this embodiment and embodiment 1 is that the second convex ring 14 is missing, and the gap between the interface end cover 24 and the third convex ring 15 is 8 mm.

[0132] Example 3

[0133] Combination Figure 6 As shown, this embodiment discloses a filter. The difference between this embodiment and Embodiment 1 is that the third groove 110 is not provided on the first platform.

[0134] Example 4

[0135] This embodiment discloses a filter. The difference between this embodiment and Embodiment 1 is that the gap between the control interface end cover 24 and the second convex ring 14 is 0.2 mm.

[0136] Example 5

[0137] This embodiment discloses a filter. The difference between this embodiment and Embodiment 1 is that the gap between the control interface end cover 24 and the second convex ring 14 is 1 mm.

[0138] Example 6

[0139] This embodiment discloses a filter. The difference between this embodiment and Embodiment 1 is that the gap between the control interface end cover 24 and the second convex ring 14 is 1.5 mm.

[0140] Example 7

[0141] This embodiment discloses a filter. The difference between this embodiment and Embodiment 1 is that the gap between the control interface end cover 24 and the second convex ring 14 is 2 mm.

[0142] Comparative Example 1

[0143] Combination Fig.10 As shown, comparative example 1 is a current capsule filter, and the gap between the interface end cover 24 and the third convex ring 15 of comparative example 1 is the same as that of embodiment 2, which is 8 mm. However, the first convex ring 13 protrudes from the first platform 11, and the height difference between the first platform 11 and the second platform 242 is relatively large, which is 10 mm.

[0144] The data on hold-up volume are as follows:

[0145]

[0146]

[0147] From the above hold-up volume data table, we can conclude that:

[0148] First, the theoretical volume value and the actual volume value of the retention medium in Comparative Example 1 are both large, greater than 30 ml, while the theoretical volume value and the actual volume value of the retention medium of the filter in the present invention are significantly smaller than those in Comparative Example 1, proving that the improved product has the beneficial effect of low retention volume.

[0149] Second, when the gap between the interface end cap 24 and the second convex ring 14 is set at 1.5mm and 2mm, the difference between the theoretical volume value of the retained medium and the actual volume value of the retained medium is not large; however, when the gap between the interface end cap 24 and the second convex ring 14 is set at 0.2mm-1mm, the actual volume value of the retained medium will be significantly smaller than the theoretical volume value of the retained medium. Among them, the principle that the actual volume value of the retained medium is significantly smaller than the theoretical volume value of the retained medium is that when the second convex ring 14 exists and the gap between the interface end cap 24 and the second convex ring 14 is small, the fluid will mainly impact the top surface of the second convex ring 14, and then penetrate into the gap between the interface end cap 24 and the second convex ring 14. In particular, the present invention sets the positioning ring 241 and the first groove 12 to be stepped, and makes the third platform 17 to be stepped, so that a tortuous flow path is formed between the positioning ring 241 and the first groove 12, thereby making it difficult for the fluid deep inside the gap to enter and the gas to be discharged, further reducing the actual value of the retained volume.

[0150] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A filter, characterized in that: include: A filter body, wherein a liquid outlet (181) is provided at the bottom of the filter body, and a liquid inlet (41) is provided at the top of the filter body; a first groove (12) is provided at the bottom end of the inner wall of the filter body; A filter element (2), wherein the bottom wall of the filter element (2) is protruding downward and is provided with a positioning ring (241), and the positioning ring (241) is sealingly inserted and positioned in the first groove (12) to reduce the distance between the bottom wall of the filter element (2) and the bottom end of the inner wall of the filter body; the filter element (2) has a filter element liquid inlet hole (211) and a filter element liquid outlet hole (243), and the filter element liquid outlet hole (243) is connected to the liquid outlet (181) through the inner hole of the positioning ring (241).

2. The filter according to claim 1, characterized in that The distance between the bottom wall of the filter element (2) and the bottom end of the inner wall of the filter body is less than 1.5 mm; And / or, the distance between the side wall of the bottom end of the filter element (2) and the inner wall of the filter body is 0.2-2 mm.

3. The filter according to claim 1, characterized in that The filter body comprises: A base (1), wherein an open groove (111) is provided at the top of the base (1), and the bottom wall of the open groove (111) forms a first platform (11), and the first platform (11) is the bottom end of the inner wall of the filter body; A liquid inlet connector (4), wherein the liquid inlet port (41) is arranged at the top of the liquid inlet connector (4); A filter housing (3) is provided between the base (1) and the liquid inlet connector (4).

4. The filter according to claim 3, characterized in that A first convex ring (13) is arranged on the bottom wall of the first groove (12); the height of the first convex ring (13) is lower than the height of the first platform (11); the first convex ring (13) is fixed to a positioning ring (241) by welding; and there is a gap between the first convex ring (13) and the side wall of the first groove (12).

5. The filter according to claim 3, characterized in that A liquid inlet cavity (31) is formed between the inner wall of the filter housing (3) and the outer wall of the filter element (2); a plurality of filter element liquid inlet holes (211) are provided and arranged on the side of the filter element (2); and the liquid inlet cavity (31) is respectively connected to the liquid inlet port (41) and the filter element liquid inlet hole (211).

6. The filter according to claim 5, characterized in that A second convex ring (14) is arranged on the periphery of the bottom of the filter element (2), the second convex ring (14) is arranged in the liquid inlet cavity (31), and the height of the second convex ring (14) is lower than the height of the lowest filter element liquid inlet hole (211).

7. The filter according to claim 6, characterized in that The second convex ring (14) is arranged on the first platform (11) and is located inside the opening groove (111).

8. The filter according to claim 7, characterized in that A third convex ring (15) is provided on the outer edge of the first platform (11), and the third convex ring (15) is fixedly connected to the filter housing (3); The second convex ring (14) and the third convex ring (15) are arranged at intervals, and at least one second groove (16) is arranged on the top of the second convex ring (14).

9. The filter according to claim 6, characterized in that The filter element (2) comprises: A filter element body, wherein the filter element liquid inlet hole (211) is arranged on a side wall of the filter element body; A closed end cover (23), wherein the closed end cover (23) is arranged at the top end of the filter element body; An interface end cover (24), wherein the interface end cover (24) is arranged at the bottom end of the filter element body, and the filter element liquid outlet hole (243) is arranged on the interface end cover (24); The outer diameter of the interface end cover (24) is greater than the outer diameter of the filter element body, and the second protruding ring (14) is arranged at the top of the area of ​​the interface end cover (24) protruding from the filter element body and is covered on the periphery of the filter element body.

10. The filter according to claim 6, characterized in that The first platform (11) is provided with a third groove (110), and the third groove (110) is connected to the liquid inlet cavity (31); the filter body is provided with a reflux joint (19), and the reflux joint (19) is provided with a reflux port (191), and the reflux port (191) is connected to the third groove (110).

11. The filter according to any one of claims 1 to 10, characterized in that: The positioning ring (241) is configured in a stepped shape, and the first groove (12) is configured in a stepped groove shape that matches the positioning ring (241).

12. A method for testing the hold-up volume of a filter, characterized in that: The method is carried out based on the filter according to any one of claims 1 to 11, and comprises the following steps: S1. Calculate the theoretical hold-up volume V between the filter body and the filter element (2) 理论 ; S2. Weigh the dried filter and record the initial mass M0 of the filter; introduce the medium into the filter from the liquid inlet (41) and discharge the medium from the filter from the liquid outlet (181); then introduce airflow into the liquid inlet (41) and discharge the airflow from the liquid outlet (181); then weigh the filter again and record the final mass M1 of the filter; calculate the actual value V of the holdup volume between the filter body and the filter element (2) 实际 =(M1-M0) / ρ 介质 , where ρ 介质 is the density of the medium; S3. Compare the theoretical hold-up volume with the actual hold-up volume to determine the performance of the filter.

13. The method for testing the hold-up volume of a filter according to claim 12, characterized in that: The medium passed into the filter is pure water; And / or, hot air at a temperature of 60-80° C. is introduced into the liquid inlet (41), the flow rate of the hot air is 2-5 m / s, and the time for introducing the hot air is 10-15 minutes.

Images