Terminal filter and preparation process

Abstract

The terminal filter is characterized in that the terminal filter comprises a shell and a filtering device, a filtering cavity is formed in the shell, an inlet and an outlet which are communicated with the filtering cavity are formed in the two ends of the shell respectively, and the filtering device is arranged in the part, between the inlet and the outlet, of the filtering cavity; the filtering device comprises a pre-filtering layer, a hollow fiber filter element, a first end seal and a second end seal, the pre-filtering layer is of a hollow columnar structure internally provided with a cavity, and the hollow fiber filter element is installed in the cavity of the pre-filtering layer; the first end seal is mounted at the first end of the pre-filtering layer and the first end of the hollow fiber filter element and right faces the inlet, and the second end seal is mounted at the second end of the pre-filtering layer and right faces the outlet. According to the invention, the cost is reduced and the reliability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluid medium filtration, and in particular to a terminal filter and a preparation process. BACKGROUND

[0002] A terminal filter is a device used to filter microparticles and microorganisms in liquid or gas, to ensure the purity of the liquid or gas input into the patient's body. In the medical field, terminal filters are widely used in various infusion devices, syringes, respirators and other medical devices. For example, during infusion, a terminal filter can filter out microparticles and microorganisms in the liquid to prevent them from entering the patient's body; in a respirator, a terminal filter can filter out dust, bacteria and other impurities in the air to provide purer air for the patient.

[0003] The basic structure of the current terminal filter requires two or more filters to be connected in series to achieve the functions of pre-filtering, bacteria-removing filtering and endotoxin-removing filtering. Taking infusion or dialysis applications as an example, generally speaking, a terminal filter usually consists of a pleated structure bacteria-removing filter and an endotoxin-removing hollow fiber filter. When the liquid passes through the two components of the terminal filter, the bacteria-removing filter blocks microparticles and microorganisms larger than its interception accuracy, while allowing substances smaller than its pore size to pass through. Then the sterile hemodialysis buffer further passes through the ultrafiltration level hollow fiber filter to remove the endotoxins that may cause serious clinical reactions, while allowing water, small molecule nutrients and various inorganic salt ions to pass through. This can ensure that the liquid input into the patient's body meets the safety purity standard, fully avoiding adverse consequences caused by microparticles, microorganisms and endotoxins entering the patient's body.

[0004] In the prior art, the logic of the terminal filter for processing dialysis liquid filtration or gas filtration is to process in segments with multiple devices each performing its own function, sequentially connecting a first tank, a bacteria-removing filter, a second tank, an endotoxin-removing filter, and finally connecting the equipment machine. The fluid medium in the first tank is a fluid medium in a rough configuration with bacteria, which is filtered by the bacteria-removing filter to become a fluid medium in a fine configuration without bacteria, and enters the second tank, from which it is sent to the endotoxin-removing filter to remove endotoxins, and then to the equipment machine for use. However, in medical operations, this complex operation (including multiple sets of equipment management and pipeline connection) has multiple risks to medical safety:

[0005] 1. The pre-treatment of multiple filters and supporting equipment increases the clinical error rate: the installation and use of the current terminal filter involves multiple steps and the cooperation of multiple medical staff, and an error in one step can result in the failure of the entire operation, and even cause irreversible harm to the patient;

[0006] 2, complex system and operation, let the ingredients process consume more time, prolong the secondary pollution long bacteria risk, also indirectly prolong the patient waiting time or medical treatment time, increase the patient infection risk;

[0007] 3, complex system very much depends on the cooperation between the equipment, the above system once two-stage filter speed mismatch each other, or a set of equipment failure, will greatly affect the dialysis center patient medication timely supply;

[0008] 4, consumables and pipeline complexity, increase the difficulty of maintenance management, also easy to let the medical staff tired, negligent, increase the risk of medical errors. SUMMARY

[0009] The purpose of the present application is to provide a terminal filter and preparation process, by using the structure and process, simplify the equipment structure, reduce the use difficulty and maintenance difficulty, also reduce the cost.

[0010] To achieve the above purpose, the technical scheme adopted by the present application is: a terminal filter, comprising a shell and a filter device, the shell is provided with a filter chamber, the two ends of the shell are respectively provided with an inlet and an outlet communicated with the filter chamber, the filter device is arranged in the filter chamber between the inlet and the outlet;

[0011] The filter device comprises a pre-filter layer, a hollow fiber filter core, a first end seal and a second end seal, the pre-filter layer is a hollow columnar structure with a cavity inside, the hollow fiber filter core is installed in the cavity of the pre-filter layer;

[0012] The first end seal is installed at the first end of the pre-filter layer and the hollow fiber filter core, and is arranged close to the inlet, the second end seal is installed at the second end of the pre-filter layer, and is arranged close to the outlet;

[0013] The fluid medium enters the filter chamber from the inlet, enters the cavity from the periphery of the pre-filter layer, and flows out from the outlet after being filtered by the hollow fiber filter core.

[0014] In the above technical scheme, the first end seal completely blocks the first end of the pre-filter layer and the hollow fiber filter core; the second end seal is an annular structure, and the second end seal completely blocks the second end of the pre-filter layer.

[0015] In the above technical scheme, the second end of the hollow fiber filter core is inserted into the second end seal, or the second end of the hollow fiber filter core passes through the second end seal and is arranged outside the second end seal;

[0016] And / or, the outer surface of the hollow fiber filter core arranged in the second end seal is connected with the inner surface of the second end seal.

[0017] In the technical scheme, the pre-filter layer is pleated to form a hollow columnar structure with a cavity, and the two ends of the cavity are communicated with the first end and the second end of the pre-filter layer respectively; the first end of the hollow fiber filter core is connected with the end face of the first end cover, and the second end of the hollow fiber filter core is arranged outside the second end of the pre-filter layer or is arranged flush with the end face of the second end cover.

[0018] In the technical scheme, the inner wall of the filter chamber is further provided with a first limiting piece and a second limiting piece, the first limiting piece and the second limiting piece are arranged close to the inlet and the outlet respectively, and the first limiting piece and the second limiting piece are arranged between the first end and the second end of the filter device.

[0019] The first limiting piece is a hollow structure, and the inner surface of the first limiting piece abuts against the outer surface of the pre-filter layer or the outer surface of the first end cover.

[0020] The outer surface of the second limiting piece is sealingly connected with the filter chamber, and the inner surface of the second limiting piece is sealingly connected with the outer surface of the pre-filter layer or the outer surface of the second end cover.

[0021] In the technical scheme, the pre-filter layer comprises a pre-filter membrane, a first support layer and a second support layer, the pre-filter membrane is arranged between the first support layer and the second support layer, the first support layer is arranged outside the pre-filter membrane, and the second support layer is arranged inside the pre-filter membrane.

[0022] In the technical scheme, the first support layer is a fiber-wound filter membrane.

[0023] And / or, the first support layer is a fiber-wound filter membrane made of glass fiber or polypropylene fiber.

[0024] In the technical scheme, the second support layer is a non-woven fabric support layer.

[0025] And / or, the second support layer is an ultrathin flexible non-woven fabric support layer.

[0026] In the technical scheme, the thickness of the first support layer is 150 microns to 250 microns.

[0027] And / or, the thickness of the second support layer is 30 microns to 120 microns.

[0028] In the technical scheme, the pre-filtering membrane is made of polyether sulfone, PVDF, regenerated cellulose, nylon, glass fiber, polypropylene fiber or polyester fiber.

[0029] The application further provides a terminal filtering device, which comprises the terminal filter.

[0030] In the technical scheme, the terminal filtering device comprises a tank, a conveying pump and the terminal filter, the tank stores the fluid medium to be treated, the conveying pump sends the fluid medium to be treated in the tank into the inlet through a pipeline and sends it out from the outlet after being filtered by the filtering device.

[0031] The application further provides a preparation process of the terminal filter, which is used for manufacturing the terminal filter and comprises the following steps:

[0032] S1, the hollow fiber filter core is arranged in the cavity in the pre-filtering layer;

[0033] S2, the first end seal and the second end seal are connected with the pre-filtering layer and the hollow fiber filter core respectively to obtain the filtering device;

[0034] S3, the filtering device is arranged in the shell.

[0035] In the step S2, the sealing process of the first end seal and the second end seal with the pre-filtering layer and the hollow fiber filter core is as follows:

[0036] A1, the hollow fiber filter core is arranged in the cavity in the pre-filtering layer, the first end of the hollow fiber filter core is flush with the first end of the pre-filtering layer, and the second end of the hollow fiber filter core extends out of the cavity of the pre-filtering layer to form a filtering device roughcast;

[0037] A2, the first end and the second end of the filtering device roughcast are sealed by sealing glue, the sealing glue on the two sides seals the first end and the second end of the filtering device roughcast, and the sealing glue on the first end of the filtering device roughcast after solidification forms the first end seal;

[0038] A3, the sealing glue on the second end of the filtering device roughcast is cut to expose the second end of the hollow fiber filter core extending out of the cavity, and the sealing glue on the second end of the filtering device roughcast after solidification and cutting forms the second end seal to obtain the filtering device.

[0039] In the technical scheme, the sealing glue is epoxy resin glue or polyurethane glue;

[0040] And / or, the sealing glue is fixed on the end of the filtering device roughcast in a flowable state by a tooling, and forms a solid sealing glue after being cooled and solidified.

[0041] Due to the above technical scheme, the present application has the following advantages compared with the prior art:

[0042] 1. In the present application, the hollow fiber filter element is installed inside the pre-filter layer, so that the fluid medium can be filtered once by the pre-filter layer, and after the first filtration is completed, the fluid medium after the first filtration is directly filtered twice by the hollow fiber filter element. Compared with the previous structure, the two filters with different functions, structures and materials are combined into one, realizing a filtering unit and a set of pipelines, replacing the terminal filtering device with complex filtering units and complex pipelines, effectively simplifying the fluid medium configuration, filtration and system maintenance operation, and greatly reducing the risk of subsequent patient medication.

[0043] 2. The present application can also effectively reduce the risk of infection.

[0044] 3. The present application simplifies the device structure and reduces the cost.

[0045] 4. The present application can also effectively save medical consumables, and the cost is more low, and can also reduce the occupation of equipment space. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a cross-sectional structure schematic view of the terminal filter in the first embodiment of the present application (the arrow is the flow direction of the fluid medium);

[0047] Figure 2 is a structure schematic view of the hollow fiber filter element installed in the pre-filter layer in the first embodiment of the present application;

[0048] Figure 3 is an exploded view of the filtering device in the first embodiment of the present application (the hollow fiber filter element is not shown);

[0049] Figure 4 is a structure schematic view of the fluid medium flowing into the filtering device in the first embodiment of the present application (the arrow is the flow direction of the fluid medium);

[0050] Figure 5 is a cross-sectional structure schematic view of the pre-filter layer in the first embodiment of the present application;

[0051] Figure 6 is a structure schematic view of the terminal filtering device in the first embodiment of the present application;

[0052] Figure 7 is a structure schematic view in the preparation process of the filtering device in the first embodiment of the present application (the hollow fiber filter element is installed into the cavity of the pre-filter layer);

[0053] Figure 8 is a structure schematic view in the preparation process of the filtering device in the first embodiment of the present application (the two ends are sealed with glue);

[0054] Figure 9 is the structural schematic diagram of the preparation process of the filtering device in embodiment one of the present application (the state after the second end seal cutting is completed).

[0055] 1, terminal filter; 11, shell; 12, filtering chamber; 13, inlet; 14, outlet; 15, first limiting piece; 16, second limiting piece; 17, exhaust port; 18, liquid discharge port;

[0056] 21, pre-filter layer; 22, hollow fiber filter core; 23, first end seal; 24, second end seal; 25, cavity; 210, pre-filter membrane; 211, first support layer; 212, second support layer;

[0057] 3, material tank; 4, conveying pump. DETAILED DESCRIPTION

[0058] The present application will be further described below in conjunction with the drawings and embodiments:

[0059] Embodiment one: referring to Figures 1-9 A terminal filter is shown, which comprises a shell 11 and a filtering device, the shell 11 is provided with a filtering chamber 12 inside, both ends of the shell 11 are respectively provided with an inlet 13 and an outlet 14 which are in communication with the filtering chamber 12, and the filtering device is arranged in the filtering chamber 12 between the inlet 13 and the outlet 14.

[0060] The filtering device comprises a pre-filter layer 21, a hollow fiber filter core 22, a first end seal 23 and a second end seal 24, the pre-filter layer 21 is a hollow columnar structure with a cavity 25 inside, and the hollow fiber filter core 22 is installed in the cavity 25 of the pre-filter layer 21.

[0061] The first end seal 23 is installed at the first end of the pre-filter layer 21 and the hollow fiber filter core 22 and is arranged opposite to the inlet 13, and the second end seal 24 is installed at the second end of the pre-filter layer 21 and is arranged close to the outlet 14.

[0062] The fluid medium enters the filtering chamber 12 from the inlet 13, enters the cavity 25 from the periphery of the pre-filter layer 21, and flows out from the outlet 14 after being filtered by the hollow fiber filter core 22.

[0063] In the present application, the pre-filter layer and the hollow fiber filter core are combined together. The fluid medium to be treated enters the filter chamber from the inlet. Due to the presence of the first end seal, the pre-filter layer and the first end of the hollow fiber ultrafiltration fiber are blocked (in the illustration, the inlet and the outlet are arranged at the top and the bottom of the shell respectively, the first end and the second end of the pre-filter layer are at the top and the bottom thereof respectively, and the first end and the second end of the hollow fiber filter core are at the top and the bottom thereof respectively). Therefore, the fluid medium to be treated cannot enter from the top of the pre-filter layer and the hollow fiber filter core. The fluid to be treated enters the filter chamber, is filtered once by the pre-filter layer (due to the presence of the second end seal, the fluid medium cannot flow down along the outer surface of the pre-filter layer and flow out from the outlet, but can only be filtered by the pre-filter layer), enters the cavity inside the pre-filter, is filtered again by the hollow fiber filter core, and flows out from the bottom (second end) of the hollow fiber filter core (since the bottom of the hollow fiber filter core is not blocked by the second end seal, the fluid medium can flow out from the bottom thereof), and flows out from the outlet. In this way, taking the fluid medium as dialysate as an example, particles and microorganisms larger than the interception precision of the pre-filter layer are filtered out (for example, sterilization), and substances smaller than the interception pore size are allowed to pass through and enter the cavity. Then, the hollow fiber filter core filters and removes bacterial endotoxins that can cause serious clinical reactions, and allows water, small molecule nutrients and various inorganic salt ions to pass through. This can ensure that the liquid for the user meets the safety purity standard, and can fully avoid adverse consequences caused by the entry of particles, microorganisms and bacterial endotoxins into the user. In this way, the pre-filter layer and the hollow fiber filter core with different structures can be combined, and a terminal filter can have the functions of pre-filtering, sterilization filtering and bacterial endotoxin filtering. At the same time, two filters with different functions, structures and materials can be combined into one filter unit and one set of pipeline, replacing the original complex filter unit and complex pipeline, greatly simplifying the operations of medical personnel such as preparation, filtering and system maintenance, greatly reducing the risk of medication for subsequent users, and effectively reducing costs. Moreover, during the filtering process, pre-filtering, sterilization filtering and bacterial endotoxin filtering are performed simultaneously, and there is no risk of speed mismatch between the two filters or failure of one of the filters affecting subsequent use. Of course, the above example of using dialysate as the fluid medium and applying it to the field of dialysis can also be used for respirators, air filtration, fluid medium being air, and can also be applied to other fields, such as water filtration, without specific limitation.

[0064] In the present embodiment, the hollow fiber filter core is composed of a plurality of hollow fibers forming a columnar mechanism. The hollow fibers are sealed at one end and open at the other end, and each hollow fiber has strong filtering capacity.

[0065] Referring to Figure 1 As shown, the first end seal 23 completely seals the first end of the pre-filter layer 21 and the hollow fiber filter core 22; the second end seal 24 is a ring structure, and the second end seal 24 completely seals the second end of the pre-filter layer 21.

[0066] In this embodiment, the first end seal completely seals the first end of the pre-filter layer and the hollow fiber filter core, and the second end seal completely seals the second end of the pre-filter layer. Fluid medium entering from the inlet into the filter chamber cannot directly enter the cavity or directly flow out of the outlet, but can only pass through the pre-filter layer, be filtered by the pre-filter layer, then enter the cavity, and then be filtered by the hollow fiber filter core again before flowing out from the bottom and being sent out through the outlet.

[0067] The second end of the hollow fiber filter core is inserted into the second end seal (this embodiment adopts this mode), or the second end of the hollow fiber filter core passes through the second end seal and is arranged outside the second end seal.

[0068] In this embodiment, the outer surface of the hollow fiber filter core arranged in the second end seal is connected with the inner surface of the second end seal.

[0069] In the present application, the bottom of the hollow fiber filter core is flush with the bottom of the pre-filter layer, or extends beyond the bottom of the pre-filter layer. Preferably, the bottom of the hollow fiber filter core can extend beyond the bottom of the pre-filter layer, and the top is flush with the top surface of the pre-filter layer. In this way, the hollow fiber filter core can fully re-filter the fluid medium that has been filtered by the pre-filter layer. In the present embodiment, the length of the hollow fiber filter core is slightly greater than the length of the pre-filter layer, and the top of the hollow fiber filter core is flush with the top of the pre-filter layer, and the bottom is flush with the bottom of the second end seal. Of course, there can also be a gap between the top of the hollow fiber filter core and the first end seal. Therefore, in the present embodiment, in order to prevent the hollow fiber filter core from being detached from the cavity, the top of the hollow fiber filter core is connected to the bottom surface of the first end seal, the bottom extends beyond the bottom of the pre-filter layer, and the inner surface of the second end seal is connected to the lower or bottom outer surface of the hollow fiber filter core. The hollow fiber filter core is axially positioned by the first end seal and the second end seal, preventing it from moving downward due to the pressure of the fluid medium during the filtering process, and ensuring its filtering effect and filtering performance. If the hollow fiber filter core moves downward by a certain amount, the fluid medium flowing below the second end seal may directly flow out from the outside of the hollow fiber filter core, rather than flowing out from the bottom, thereby reducing the filtering area of the hollow fiber filter core (the bottom is not fully used), affecting the filtering effect and filtering performance. However, the axial length of the hollow fiber filter core completely fills the axial direction of the cavity, which can fully ensure the filtering area of the hollow fiber filter core in the cavity, thereby ensuring the effect.

[0070] Referring to FIG. 1, Figure 1 , 3 As shown in FIG. 1, the pre-filter layer 21 is pleated to form a hollow columnar structure with a cavity 25, and the two ends of the cavity 25 are in communication with the first end and the second end of the pre-filter layer 21, respectively. The first end of the hollow fiber filter core 22 is connected to the end surface of the first end seal, and the length of the hollow fiber filter core has two types. The first type is that the second end of the hollow fiber filter core extends beyond the cavity and is arranged outside the second end of the pre-filter layer. The second type is that the second end of the hollow fiber filter core is flush with the end surface of the second end of the pre-filter layer.

[0071] The pre-filter layer is a filter material, which is rolled into a ring structure, and then pleated from the outside of the ring structure to the inside, and from the inside of the ring structure to the outside between adjacent inner protrusions, so as to realize the pleating. Alternatively, the filter material in an unfolded state is pleated into a wave-shaped structure, and then rolled into a ring structure. In this way, the pleating depth can be adjusted according to actual needs to adjust the filtering area of the pre-filter layer (the length of the filter material required is different due to different pleating depths. Since the outer diameter of the pre-filter layer and the corresponding filter is matched, the outer diameter is fixed, and the greater the pleating depth, the longer the length of the filter material, and the greater the filtering area. According to the filtering speed of the pre-filter layer and the hollow fiber filter element, the pleating depth and the diameter of the hollow fiber filter element with the corresponding diameter can be adjusted.

[0072] Referring to Figure 1 As shown, the inner wall of the filter chamber 12 is further provided with a first limiting piece 15 and a second limiting piece 16, the first limiting piece 15 and the second limiting piece 16 are respectively arranged close to the inlet 13 and the outlet 14, and the first limiting piece 15 and the second limiting piece 16 are arranged between the first end and the second end of the filter device;

[0073] The first limiting piece 15 is a hollow structure and does not block the flow of fluid medium, the inner surface of the first limiting piece 15 abuts against the outer surface of the pre-filter layer 21 (or the first limiting piece and the shell are an integral structure), or the inner surface of the first limiting piece 15 abuts against the outer surface of the first end seal 23;

[0074] The outer surface of the second limiting piece 16 is sealingly connected with the filter chamber 12 (or the second limiting piece and the shell are an integral structure), the inner surface of the second limiting piece 16 is sealingly connected with the outer surface of the pre-filter layer 21, or the inner surface of the second limiting piece 16 is sealingly connected with the outer surface of the second end seal 24.

[0075] In order to fix the filter device inside the filter chamber, make the filter device and the filter chamber coaxial, and control the flow direction of the fluid medium, there is a space between the pre-filter layer and the inner surface of the filter chamber, so that the fluid medium can enter the cavity after being filtered by the pre-filter layer from the outer surface of the pre-filter layer, and then flow out to the lower side of the second end seal from the outlet. Therefore, the first limiting member and the second limiting member are arranged to support and limit the filter device, so that the filter device and the filter chamber are coaxial, and there is a space between the outer surface of the filter device and the inner surface of the filter chamber. In one way, for example, the inner surface of the first limiting member abuts against the outer surface of the first end seal, and the inner surface of the first limiting member and the outer surface of the first end seal are fixedly connected, and the inner surface of the second limiting member is sealingly and fixedly connected with the outer surface of the second end seal. In this way, there is a space between the two ends of the filter device and the inlet and outlet, respectively. At the same time, since the first limiting member is a hollow structure, the fluid medium enters the filter chamber from the inlet. Due to the presence of the first end seal, the fluid medium cannot directly enter the cavity from the top. It flows downward between the first limiting member and the second limiting member and is outside the pre-filter layer. The bottom is limited by the second end seal and the second limiting member, so that the fluid medium enters the cavity after being filtered by the pre-filter layer, is filtered by the hollow fiber filter, and flows downward from the inner circle of the second end seal to the filter chamber below the second end seal, and then flows out from the outlet. In this way, the flow path of the fluid medium can be limited by the second limiting member, the second end seal and the first end seal, so that the fluid medium can only be filtered by the pre-filter layer and the hollow fiber filter once and then flow out from the outlet, thereby ensuring the filtering effect.

[0076] Referring to Figure 5 As shown in the figure, the pre-filter layer 21 includes a pre-filter membrane 210, a first support layer 211 and a second support layer 212. The pre-filter membrane 210 is arranged between the first support layer 211 and the second support layer 212. The first support layer 211 is arranged on the outer side of the pre-filter membrane 210. The second support layer 212 is arranged on the inner side of the pre-filter membrane 210. The inner side of the second support layer surrounds the cavity 25 constituting the columnar structure.

[0077] Among them, the pre-filter membrane is the main filtering material of the pre-filter layer, and the first support layer and the second support layer are used for supporting and shaping the pre-filter membrane. In the pre-filtering process, the pleated pre-filter membrane will not deform, preventing the pleats of the pre-filter layer from sticking to each other and affecting the filtering flux and filtering effect, thereby ensuring the filtering flux and filtering effect, and preventing premature clogging as much as possible.

[0078] The first support layer is a fiber-wound filter membrane; preferably, the first support layer is a fiber-wound filter membrane made of glass fiber or polypropylene fiber. The thickness of the first support layer is 150-250 microns, and the first support layer has a plurality of pores with a size of 1-20 microns, which not only serves as a support and shaping function, but also can preliminarily filter large particles in the fluid medium, reduce the filtering burden of the pre-filtering membrane, and prevent the pre-filtering membrane from being blocked as much as possible.

[0079] The second support layer is a non-woven fabric support layer; the second support layer is an ultra-thin flexible non-woven fabric support layer. The thickness of the second support layer is 30-120 microns, and the thickness of the second support layer is preferably 40 microns, 80 microns or 100 microns. Since the second support layer is an ultra-thin flexible non-woven fabric support layer, the thickness is small, and the material is flexible, which can reduce the space occupied by the pre-filtering layer after being pleated as much as possible.

[0080] Further, the first support layer is attached to the outer surface of the pre-filtering membrane, and the second support layer is attached to the inner surface of the pre-filtering membrane. The first support layer, the pre-filtering membrane and the second support layer form an integral structure, which can be pleated together and will not affect the impact of the fluid to cause the first support layer, the pre-filtering membrane layer and the second support layer to separate during use, thereby ensuring the filtering effect.

[0081] The pre-filtering membrane is made of polyether sulfone, PVDF, regenerated cellulose, nylon, glass fiber, polypropylene fiber or polyester fiber, which can ensure the pre-filtering effect.

[0082] The housing can be provided with an exhaust port 17 and a liquid discharge port 18 in communication with the filtering chamber. The exhaust port is arranged between the inlet and the first limiting member, and the liquid discharge port is arranged between the outlet and the second limiting member. The exhaust port and the liquid discharge port are normally closed, and the exhaust port is opened when it is necessary to discharge the useless gas in the filtering chamber. The liquid discharge port is opened when it is necessary to discharge the useless liquid in the filtering chamber.

[0083] The pre-filtering layer can adopt a pleated membrane with a filtering precision of 0.45 microns, and the hollow fiber filter core can be microfiltration (for example, bacteria-removing microfiltration with a filtering precision of 0.2 microns). Of course, the hollow fiber filter core can also be ultrafiltration (for example, ultrafiltration with a filtering precision of 6 kd / 10 kd, and the filtering precision can be 1 kd-500 kd, which can be selected or adjusted according to the actual application scenario).

[0084] Referring to Figure 6 The application also provides a terminal filtering device, which comprises the terminal filter 1.

[0085] The terminal filter device comprises a tank 3, a conveying pump 4 and a terminal filter 1, the tank 3 stores fluid medium to be treated, the conveying pump 4 sends the fluid medium to be treated in the tank 3 into the inlet 13 through a pipeline, and sends out the fluid medium from the outlet 14 after being filtered by the filter device.

[0086] The fluid medium sent out from the outlet can be used for a patient, and can be given to the patient by a dialysis machine or a breathing machine. In this structure, only one tank and one conveying pump are needed, compared with the previous two tanks and two conveying pumps, the pipeline usage is less, the pipeline connection is more indirect, the maintenance difficulty is lower, and the cost is lower.

[0087] The application further provides a preparation process of a terminal filter, which is used for manufacturing the terminal filter and comprises the following steps:

[0088] S1, the hollow fiber filter core is arranged in the cavity in the pre-filter layer;

[0089] S2, the first end seal and the second end seal are respectively connected with the pre-filter layer and the hollow fiber filter core, and the filter device is prepared;

[0090] S3, the filter device is arranged in the shell.

[0091] In the step S2, the sealing process of the first end seal, the second end seal, the pre-filter layer and the hollow fiber filter core is as follows:

[0092] A1, the hollow fiber filter core is arranged in the cavity in the pre-filter layer, the first end of the hollow fiber filter core is flush with the first end of the pre-filter layer, and the second end of the hollow fiber filter core extends out of the cavity of the pre-filter layer, so that a filter device roughcast is formed, as shown in Figure 7 ;

[0093] A2, the first end and the second end of the filter device roughcast are sealed by using sealing glue, the sealing glue on the two sides respectively seals the first end and the second end of the filter device roughcast, and the sealing glue on the first end of the filter device roughcast after solidification forms the first end seal, as shown in Figure 8 ;

[0094] A3, the sealing glue on the second end of the filter device roughcast is cut, so that the second end of the hollow fiber filter core extending out of the cavity is exposed, and the sealing glue on the second end of the filter device roughcast after solidification and cutting forms the second end seal, so that the filter device is prepared, as shown in Figure 9 .

[0095] The sealing glue is epoxy resin glue or polyurethane glue;

[0096] The sealing glue is fixed on the end of the filter device roughcast by a fixture in a flowable state, and forms a solid sealing glue after being cooled and solidified.

[0097] The hollow fiber is a structure with one end blocked and the other end open, and the medium can only flow out from the open end of the hollow fiber, wherein the opening size of the hollow fiber is smaller than the particle diameter of the sealant. In the present application, the two ends of the filter device rough blank can be packaged by glue pouring (through a glue pouring machine). In another way, in the initial state, the blocked end of the hollow fiber filter core is upward (in this embodiment, the first end is at the top and the second end is at the bottom), and the open end is downward, and the open end of the hollow fiber filter core extends out of the cavity below the bottom of the pre-filter layer. The tool can adopt a box body with an upward opening. First, the filter device rough blank is turned over, and the first end is downward. The end face of the first end is placed into the box body containing liquid sealant (the sealant in a flowable state is defined as liquid state in the initial state), and the end face of the first end is in contact with the liquid surface of the sealant or is placed a little below the liquid surface. After the sealant in the box body is solidified (it can be naturally cooled or accelerated cooling and solidification through a cooling device), the sealant is separated from the box body to form the first end seal (the depth of the sealant in the box body is the thickness of the first end seal, and the diameter of the box body matches the diameter of the preset first end seal). Then it is turned over, and the second end is downward. The second end is placed into the box body containing liquid sealant, and the second end of the hollow fiber filter core extending out of the cavity is completely immersed below the liquid surface of the sealant. The end face of the second end of the pre-filter layer is in contact with the liquid surface of the sealant or is placed a little below the liquid surface. After the sealant in the box body is solidified (it can be naturally cooled or accelerated cooling and solidification through a cooling device), the sealant is separated from the box body to form the second end seal in the initial state (the depth of the sealant in the box body is greater than the length of the hollow fiber filter core extending out of the cavity, and the diameter of the box body matches the diameter of the preset second end seal). Since the opening size of the hollow fiber is smaller than the particle diameter of the sealant, the sealant will not enter the hollow fiber, and the sealant will only block the opening, but will not block the inside of the hollow fiber. Then, a cutting device is used to cut the second end seal in the initial state. For example, the height of the second end seal in the initial state is h, the length of the hollow fiber filter core extending out of the cavity is h1, h>h1, the distance between the hollow fiber filter core and the bottom surface of the second end seal in the initial state is h2, and the thickness of the second end seal in the initial state to be cut is h3, h3 extends upward from the bottom surface of the second end seal in the initial state, h3 is greater than h2, but h3 is less than h, and the second end seal is formed after cutting. In this way, the second end seal can block the bottom surface of the pre-filter layer, but the opening of the bottom of the hollow fiber filter core can be exposed to facilitate the outflow of the medium.Of course, in order to prevent the sealant from entering the hollow fiber from the opening of the hollow fiber and causing blockage, the hollow fiber can be arranged reversely, that is, the opening faces upward and the blocked end faces downward, so that after the first end seal seals the opening of the hollow fiber, the medium cannot flow upward, and when the second end seal is sealed, the sealant at the second end seal cannot enter the hollow fiber because the bottom of the hollow fiber is blocked itself, and when the second end seal is subsequently cut, the hollow fiber blocking part is cut open, the inside of the hollow fiber is communicated with the bottom, so that the hollow fiber filter element after being sealed by the first end seal and the second end seal only has the bottom communicated therewith and the top is blocked, and the medium can only flow out from the bottom.

[0098] Of course, other ways can also be used to seal the two ends of the filter device roughcast by the sealant.

[0099] In this document, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, in addition to containing the listed elements, other elements not explicitly listed can also be contained.

[0100] In this document, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, in addition to containing the listed elements, other elements not explicitly listed can also be contained.

[0101] In the case of no conflict, the above-mentioned embodiments and features in the embodiments can be combined with each other.

[0102] The above is only the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A terminal filter, characterized in that: The invention comprises a housing and a filter device, wherein a filter chamber is provided in the housing, an inlet and an outlet communicating with the filter chamber are respectively provided at two ends of the housing, and the filter device is arranged in the filter chamber between the inlet and the outlet; The filtration device includes a pre-filtration layer, a hollow fiber filter element, a first end seal and a second end seal. The pre-filtration layer is a hollow columnar structure with a cavity inside. The hollow fiber filter element is installed in the cavity of the pre-filtration layer. The first end seal is installed at the first end of the pre-filter layer and the hollow fiber filter element and is disposed near the inlet, and the second end seal is installed at the second end of the pre-filter layer and is disposed near the outlet; The fluid medium enters the filter chamber from the inlet, enters the cavity from the periphery of the pre-filter layer, and flows out from the outlet after being filtered by the hollow fiber filter element.

2. The terminal filter according to claim 1, characterized in that: The first end seal completely blocks the pre-filter layer and the first end of the hollow fiber filter element; the second end seal is an annular structure, and the second end seal completely blocks the second end of the pre-filter layer.

3. The terminal filter according to claim 2, characterized in that: The second end of the hollow fiber filter element is inserted into the second end seal, or the second end of the hollow fiber filter element passes through the second end seal and is disposed outside the second end seal; And / or, the outer surface of the hollow fiber filter element disposed in the second end seal is connected to the inner surface of the second end seal.

4. The terminal filter according to claim 1, characterized in that: The pre-filter layer is pleated to form a hollow columnar structure with a cavity inside, and the two ends of the cavity are respectively connected to the first end and the second end of the pre-filter layer; the first end of the hollow fiber filter element is connected to the end face of the first end seal, and the second end of the hollow fiber filter element extends out of the cavity and is arranged outside the second end of the pre-filter layer, or the second end of the hollow fiber filter element is arranged flush with the end face of the second end of the pre-filter layer.

5. The terminal filter according to claim 1, characterized in that: A first stopper and a second stopper are further provided on the inner wall of the filter chamber, the first stopper and the second stopper are respectively provided close to the inlet and the outlet, and the first stopper and the second stopper are provided between the first end and the second end of the filter device; The first limiting member is a hollow structure, and the inner surface of the first limiting member abuts against the outer surface of the pre-filter layer, or the inner surface of the first limiting member abuts against the outer surface of the first end seal; The outer surface of the second limiter is sealed to the filter chamber, the inner surface of the second limiter is sealed to the outer surface of the pre-filter layer, or the inner surface of the second limiter is sealed to the outer surface of the second end seal.

6. The terminal filter according to claim 1, characterized in that: The pre-filter layer includes a pre-filter membrane, a first support layer and a second support layer. The pre-filter membrane is arranged between the first support layer and the second support layer. The first support layer is arranged on the outside of the pre-filter membrane, and the second support layer is arranged on the inside of the pre-filter membrane.

7. The terminal filter according to claim 6, characterized in that: The first supporting layer is a fiber-wound filter membrane; And / or, the first supporting layer is a fiber-wound filter membrane made of glass fiber or polypropylene fiber.

8. The terminal filter according to claim 6, characterized in that: The second supporting layer is a non-woven fabric supporting layer; And / or, the second supporting layer is an ultra-thin flexible non-woven fabric supporting layer.

9. The terminal filter according to claim 6, characterized in that: The thickness of the first supporting layer is 150 microns to 250 microns; And / or, the thickness of the second supporting layer is 30 micrometers to 120 micrometers.

10. The terminal filter according to claim 6, characterized in that: The pre-filtration membrane is made of polyethersulfone, PVDF, regenerated cellulose, nylon, glass fiber, polypropylene fiber or polyester fiber.

11. A terminal filtering device, characterized in that: The terminal filtering device comprises the terminal filter according to any one of claims 1 to 10.

12. The terminal filtering device according to claim 11, characterized in that: The terminal filtration equipment includes a material tank, a delivery pump and a terminal filter. The material tank contains a fluid medium to be treated. The delivery pump delivers the fluid medium to be treated in the material tank to the inlet through a pipeline, and the fluid is filtered by the filter device and then delivered from the outlet.

13. A process for preparing a terminal filter, characterized in that: For making the terminal filter according to any one of claims 1 to 10, the steps are: S1. Install the hollow fiber filter element into the cavity inside the pre-filtration layer; S2. Connecting the first end seal and the second end seal to the pre-filtration layer and the hollow fiber filter element respectively to prepare a filtration device; S3. Assemble the filter device in the housing.

14. The process for preparing the terminal filter according to claim 13, characterized in that: In step S2, the sealing process of the first end seal, the second end seal, the pre-filtration layer and the hollow fiber filter element is: A1. Install a hollow fiber filter element into the cavity inside the pre-filter layer, so that the first end of the hollow fiber filter element is flush with the first end of the pre-filter layer and the second end of the hollow fiber filter element extends outside the cavity of the pre-filter layer, thereby forming a filter device blank. A2. Filling and sealing the first and second ends of the filter device blank with sealant, wherein the sealant on both sides completely seals the first and second ends of the filter device blank, respectively. The solidified sealant on the first end of the filter device blank constitutes a first end seal; A3. Cut the sealant at the second end of the filter device rough blank to expose the second end of the hollow fiber filter element extending out of the cavity. The solidified and cut sealant at the second end of the filter device rough blank forms a second end seal to produce the filter device.

15. The process for preparing the terminal filter according to claim 14, characterized in that: The sealant is epoxy resin glue or polyurethane glue; And / or, the sealant is fixed to the end of the filter device blank through a tool in a flowable state, and forms a solid sealant after cooling and solidification.

Images