CN220071261U - Liquid circulation device for liquid filtration - Google Patents

Abstract

The utility model provides a liquid circulation device for filtering, which comprises a shell component and an inner membrane component, wherein the inner membrane component is arranged in the shell component. The shell assembly is provided with a first water outlet, the inner membrane assembly comprises an inner membrane shell, a filtering piece is arranged in the inner membrane shell, the inner membrane shell is provided with a second water outlet, and the second water outlet is communicated with the first water outlet. A first sealing ring is arranged between the outer shell component and the inner membrane shell, the two ends of the liquid circulation device are provided with the first sealing rings, and the first water outlet and the second water outlet are positioned between the two first sealing rings. Through all setting up first sealing washer at the both ends of liquid circulation device to make first delivery port and second delivery port be located between two first sealing rings, can play and separate first delivery port, second delivery port and unfiltered liquid, in order to prevent unfiltered liquid to reach first delivery port and be discharged through the clearance between shell component and the inner membranous shell, and then improve liquid circulation device's filter effect.

Description

Liquid circulation device for liquid filtration

Technical Field

The utility model relates to the technical field of filtration, in particular to a liquid circulation device for liquid filtration.

Background

The existing hollow fiber membrane filtration liquid circulation device is generally divided into an inner membrane component and a liquid circulation shell, wherein two ends of the inner membrane component are adhered with plastic outer rings with sealing grooves, and the sealing grooves of the plastic outer rings are matched and sealed with the liquid circulation shell. In the mode of bonding the plastic outer rings at the two ends of the inner membrane component, the processing technology is complex, the requirement on the matching precision of the inner membrane component and the plastic outer rings is high, the problem that the bonding joint is easy to crack and leak water exists, liquid is discharged from the water outlet without being filtered, and the filtering effect of the liquid circulation device is not ideal.

Disclosure of Invention

The utility model aims to provide a liquid circulation device for liquid filtration so as to improve the filtration effect of the liquid circulation device.

Embodiments of the present utility model are implemented as follows:

in a first aspect, embodiments of the present utility model provide a liquid flow-through device for filtration, including a housing assembly and an inner membrane assembly disposed within the housing assembly. The shell assembly is provided with a first water outlet, the inner membrane assembly comprises an inner membrane shell, a filtering piece is arranged in the inner membrane shell, the inner membrane shell is provided with a second water outlet, and the second water outlet is communicated with the first water outlet.

A first sealing ring is arranged between the outer shell component and the inner membrane shell, the two ends of the liquid circulation device are provided with the first sealing rings, and the first water outlet and the second water outlet are positioned between the two first sealing rings.

According to the technical scheme, the filtering piece in the inner membrane shell can filter liquid, and the liquid sequentially passes through the second water outlet and the first water outlet after being filtered and flows out. Through all setting up first sealing washer at the both ends of liquid circulation device to make first delivery port and second delivery port be located between two first sealing rings, can play and separate first delivery port, second delivery port and unfiltered liquid, in order to prevent unfiltered liquid to reach first delivery port and be discharged through the clearance between shell component and the inner membranous shell, and then improve liquid circulation device's filter effect.

In combination with the first aspect, in some embodiments, the housing assembly includes a housing and a transfer tube welded to both ends of the housing, the inner membrane shell is disposed within the housing and the transfer tube, and a first seal ring is disposed between one of the transfer tube and the inner membrane shell.

In the technical scheme, the unfiltered liquid is prevented from directly reaching the first water outlet by arranging the sealing ring between the switching tube and the inner membrane shell. The conversion tube is connected with the shell through welding, so that the precision requirements of the conversion tube and the shell are reduced, and the processing technology of the conversion tube and the shell can be simplified. In addition, as the conversion pipe and the shell are welded, no adhesive connection exists between the conversion pipe and the inner membrane shell, and therefore, the situation that gaps exist in the adhesive connection between the conversion pipe and the inner membrane shell can not occur.

With reference to the first aspect, in some embodiments, each of the transition ducts is provided with a first water outlet.

Because the transfer pipe sets up in the both ends of shell, liquid can get into liquid flow device from both ends and filter, all set up first delivery port through the transfer pipe at both ends, can make the both ends outflow from liquid flow device of filterable liquid, reduced the flow distance of liquid at liquid flow device.

In combination with the first aspect, in some embodiments, the housing assembly is connected with a water inlet pipe, the water inlet pipe is butted at an end of the conversion pipe away from the housing, the water inlet pipe is provided with a water inlet, the radial dimension of the water inlet end of the water inlet pipe is smaller, and the water inlet pipe is connected with the conversion pipe through a clamp after being butted, so that liquid passing through the water inlet enters the inner membrane shell.

Because the radial dimension of the water inlet end of the water inlet pipe is smaller, the connection between the liquid circulation device and other pipelines is realized conveniently. The water inlet pipe is connected with the conversion pipe through the clamp after being in butt joint, and the water inlet pipe can be conveniently disassembled and assembled.

With reference to the first aspect, in some embodiments, a second sealing ring is provided at the junction of the water inlet pipe and the transfer pipe, and the first sealing ring is located between the second sealing ring and the first water outlet.

Through setting up the second sealing washer, can reduce that liquid oozes from the junction of inlet tube and conversion pipe, effectively prevent that liquid from leaking.

In combination with the first aspect, in some embodiments, an end of the transfer tube connected to the water inlet tube is provided with a bevel, and the second sealing ring is in contact with the bevel and the outer wall of the inner membrane shell under the action of the water inlet tube.

In the above-mentioned technical scheme, through setting up the inclined plane at the inlet tube, the second sealing washer simultaneously with inclined plane and the outer wall contact of inner membranous shell, consequently, under the effect of inlet tube and inclined plane, can extrude the second sealing washer towards the inner membranous shell for sealed effect is better.

In combination with the first aspect, in some embodiments, an end of the conversion tube far away from the shell is provided with a first connecting ring protruding along a direction perpendicular to the water flow, an end of the water inlet tube far away from the water inlet is provided with a second connecting ring protruding, annular surfaces of the first connecting ring and the second connecting ring are in butt joint and fixed through a clamp, a third sealing ring is fixed between the first connecting ring and the second connecting ring, and the second sealing ring is located inside the third sealing ring.

In the technical scheme, the third sealing ring is arranged between the first connecting ring and the second connecting ring, so that the tightness between the conversion pipe and the water inlet pipe can be further improved, and liquid leakage is avoided. In addition, the third sealing ring has certain elasticity, and through setting up the third sealing ring between first go-between and second go-between, can be convenient for inlet tube and transfer pipe pass through the clamp and connect.

With reference to the first aspect, in some embodiments, the filter element includes a membrane wire and cured glue blocks respectively cured at two ends of the membrane wire, the two cured glue blocks are respectively cured at two ends of the inner membrane shell, and the two second water outlets are located between the two cured glue blocks.

Through set up the solidification piece of gluing at the both ends of membrane silk, can be convenient for be connected membrane silk and interior membrane shell, in addition, the solidification piece of gluing can also play the effect of shutoff of inner membrane shell both ends, makes liquid only can flow out from the second delivery port after the filtration of membrane silk.

In combination with the first aspect, in some embodiments, the inner walls of the two ends of the inner membrane shell are provided with annular grooves, and the cured glue pieces are also cured in the annular grooves.

The annular grooves are formed in the inner walls of the two ends of the inner membrane shell, and the solidified rubber blocks are also arranged in the annular grooves, so that the solidified rubber blocks are not easy to fall off from the two ends of the inner membrane shell.

With reference to the first aspect, in some embodiments, the liquid circulation device is a symmetrical structure, and the symmetry plane is perpendicular to the length direction of the liquid circulation device.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic perspective view of a liquid circulation device according to an embodiment of the present utility model;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 1;

FIG. 4 is a cross-sectional view of the left end of the fluid flow device shown in FIG. 1;

FIG. 5 is a cross-sectional view of a shift tube;

FIG. 6 is a schematic structural view of a housing assembly according to an embodiment of the present utility model;

fig. 7 is a schematic structural diagram of an inner membrane assembly according to an embodiment of the present utility model.

Icon: a 100-housing assembly; 110-a housing; 120-switching tube; 121-a first water outlet; 122-mounting slots; 123-inclined plane; 124-a first connection ring; 130-linker; 200-an inner membrane assembly; 210-an inner membrane shell; 211-a second water outlet; 212-an annular groove; 220-a filter; 230-curing the glue block; 300-a first sealing ring; 400-water inlet pipe; 410-a water inlet; 420-a second connecting ring; 500-a second sealing ring; 600-clamping hoop; 700-third sealing ring.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in use of the product of the application, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," "overhang," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The inventor of the present utility model found that in the conventional liquid circulation device, plastic outer rings are bonded to the outer sides of both ends of an inner membrane module, and the plastic outer rings are connected to a liquid circulation shell to form the liquid circulation device. In the existing liquid circulation device, as the plastic outer ring is in adhesive connection with the inner membrane component, in the use process, the environmental temperature where the liquid circulation device is located can be changed continuously, so that gaps can be formed in the adhesive between the plastic outer ring and the inner membrane component, and unfiltered liquid can flow out of the liquid circulation device through the gaps, and the filtering effect of the liquid circulation device is not ideal.

Based on this, the inventors of the present utility model provide a liquid flow-through device for filtration comprising an inner membrane assembly 200 and an outer housing assembly 100. The inner membrane assembly 200 is disposed inside the outer housing assembly 100, and the inner membrane assembly 200 includes an inner membrane shell 210 and a filter 220 disposed inside the inner membrane shell 210, wherein the filter 220 is used for filtering liquid. As shown in fig. 1 and 2, the inner membrane assembly 200 is provided with a second water outlet 211, the outer shell assembly 100 is provided with a first water outlet 121, and the first water outlet 121 is communicated with the second water outlet 211, so that filtered liquid can be discharged out of the liquid circulation device after passing through the second water outlet 211 and the first water outlet 121 in sequence.

In the liquid circulation device provided by the utility model, as shown in fig. 2 to 4, a first sealing ring 300 is further arranged between the inner membrane assembly 200 and the outer shell assembly 100, and two ends of the liquid circulation device are respectively provided with the first sealing ring 300, and the first water outlet 121 and the second water outlet 211 are respectively positioned between the two first sealing rings 300. By providing two first sealing rings 300 with the first water outlet 121 and the second water outlet 211 between the two first sealing rings 300, the first water outlet 121, the second water outlet 211 and unfiltered liquid can be separated such that the liquid flowing out through the first water outlet 121 and the second water outlet 211 is filtered liquid. The liquid circulation device provided by the utility model can effectively improve the filtering effect.

In the liquid circulation device provided by the utility model, the first sealing ring 300 is used for preventing unfiltered liquid from reaching the first water outlet 121 and the second water outlet 211 from the gap between the outer shell assembly 100 and the inner membrane assembly 200, so as to improve the filtering effect of the liquid circulation device. It should be apparent to those skilled in the art that the inner membrane assembly 200, the first seal ring 300 and the outer housing assembly 100 are sequentially disposed from inside to outside in the radial direction.

It should be noted that, in the present utility model, the number of the first water outlets 121 and the second water outlets 211 is not limited, and the number of the first water outlets 121 and the second water outlets 211 may be one or plural, and in the present utility model, the number of the first water outlets 121 and the second water outlets 211 is not related.

In some embodiments of the present utility model, as shown in fig. 4 and 6, the housing assembly 100 includes a housing 110 and a switching tube 120 connected to both ends of the housing 110, and both ends of the inner membrane assembly 200 are located inside the switching tube 120 and the middle portion is located inside the housing 110. The first seal ring 300 is disposed between the transfer tube 120 and the inner membrane assembly 200. In the present embodiment, since the first seal ring 300 is provided between the conversion pipe 120 and the inner membrane module 200, the mounting groove 122 for placing the first seal ring 300 is provided in the conversion pipe 120, and as shown in fig. 5, in some embodiments, the mounting groove 122 is an annular structure provided inside the conversion pipe 120.

The shell assembly 100 is formed by connecting the shell 110 and the conversion tube 120, so that the processing difficulty of the shell assembly 100 can be reduced. Further, the switching tube 120 is welded to both ends of the outer casing 110, and the switching tube 120 is welded to the outer casing 110, so that the machining precision of the switching tube 120, the outer casing 110 and the inner membrane casing 210 arranged inside the switching tube 120 can be reduced, and the machining difficulty of the whole liquid circulation device can be further reduced. Accordingly, the switching tube 120 and the housing 110 are both made of metal, preferably stainless steel, to improve the corrosion resistance of the fluid flow device.

In the above embodiment of the present utility model, since the housing assembly 100 is formed by welding the switching tube 120 and the housing 110, the thickness of the housing 110 and the switching tube 120 may be selected according to practical situations, that is, as shown in fig. 5, the thickness dimension of the housing assembly 100 in the length direction thereof may be inconsistent, so as to reduce the weight of the liquid circulation device. Of course, in some embodiments of the present utility model, the housing assembly 100 may also be of unitary construction, i.e., machined from tubular structural members that are uniform in thickness along their length.

In some embodiments of the present utility model, the first water outlet 121 is provided to the switching tube 120. As shown in fig. 2, 4 and 6, a connector 130 is connected to the switching tube 120 at the first water outlet 121 in order to facilitate the feeding of the filtered liquid into other pipes. By providing the adapter 130 to the transition pipe 120, the difficulty of machining can be reduced. Since the switching tube 120 is located at both ends of the housing 110, i.e., both ends of the liquid circulation device are provided with the first water outlet 121 and the connector 130, in order to discharge the filtered liquid. In the present utility model, the installation position of the first water outlet 121 is not limited, and the first water outlet 121 may be installed in the switching pipe 120 or the housing 110, as long as the first water outlet 121 is located between the first sealing rings 300 at both ends.

In some embodiments of the present utility model, to facilitate the transfer of liquid into the liquid circulation device through the conduit, the liquid circulation device further comprises a water inlet tube 400, the water inlet tube 400 being connected to the housing assembly 100, in particular, the water inlet tube 400 being in butt-joint with the switching tube 120 in the housing assembly 100 and being in butt-joint with an end of the switching tube 120 remote from the housing 110. The water inlet pipe 400 has a water inlet 410, and the radial dimension of the water inlet pipe 400 at one end of the water inlet 410 is smaller so as to connect the liquid circulation device with other pipelines, specifically, the inner diameter dimension of the water inlet pipe 400 at one end of the water inlet 410 is smaller, or the outer diameter dimension of the water inlet pipe 400 at one end of the water inlet 410 is smaller, which can be selected by those skilled in the art according to actual needs.

In the above embodiment, the switching tube 120 and the water inlet tube 400 are both tubular structures, and the abutting of the water inlet tube 400 and the switching tube 120 means that the lumen of the water inlet tube 400 is aligned with the lumen of the switching tube 120, so that the liquid entering the water inlet tube 400 through the water inlet 410 can smoothly flow into the switching tube 120.

Further, in some embodiments of the present utility model, the second sealing ring 500 is disposed at the junction of the water inlet pipe 400 and the conversion pipe 120, and by providing the second sealing ring 500, the liquid can be effectively prevented from seeping out between the water inlet pipe 400 and the conversion pipe 120. In addition, since the water inlet pipe 400 is connected to the end of the conversion pipe 120 far away from the outer shell 110, the first sealing ring 300 is disposed between the conversion pipe 120 and the inner membrane shell 210, so that unfiltered liquid directly contacts with the second sealing ring 500 after entering the inside of the outer shell assembly 100, and due to the existence of the second sealing ring 500, the liquid is difficult to pass through the second sealing ring 500 and then accumulate in the gap between the conversion pipe 120 and the inner membrane shell 210, so that stagnant water is prevented from accumulating between the conversion pipe 120 and the inner membrane shell 210, thereby being beneficial to reducing microorganism indexes.

Further, as shown in fig. 4 and 5, an inclined surface 123 is provided at one end of the switching tube 120 connected to the water inlet tube 400, and the second sealing ring 500 contacts with the inclined surface 123 and the outer wall of the inner membrane shell 210 under the action of the water inlet tube 400. That is, a section for accommodating the second sealing ring 500 is formed between the inclined surface 123 of the transfer pipe 120, the end surface of the water inlet pipe 400, and the outer side surface of the inner membrane shell 210, and the second sealing ring 500 is disposed at this position, so that the second sealing ring 500 can be pressed against the outer side surface of the inner membrane shell 210 along the inclined surface 123 of the transfer pipe 120 under the pressure applied by the end surface of the water inlet pipe 400, in addition to the above-described reduction of the biological index and prevention of the liquid from leaking from the junction between the water inlet pipe 400 and the transfer pipe 120, so that the second sealing ring 500 can have a better sealing effect.

Further, in some embodiments of the present utility model, the water inlet pipe 400 is detachably connected to the switching pipe 120. Illustratively, the connection between the water inlet pipe 400 and the conversion pipe 120 may be performed by using the clamp 600, or even a flange connection may be performed, and the connection between the water inlet pipe 400 and the conversion pipe 120 is not limited in the present utility model.

In the liquid circulation device provided in the above embodiment, the liquid enters the interior of the housing assembly 100 through the water inlet 410 and contacts the inner membrane assembly 200, and then flows out of the inner membrane shell 210 through the second water outlet 211 from the inner side of the inner membrane shell 210 after being filtered by the filter 220 in the inner membrane assembly 200, and then flows out through the first water outlet 121. Because the first sealing ring 300 is located at two ends of the liquid circulation device, the first water outlet 121 and the second water outlet 211 are located between the first sealing rings 300 at two ends, so that liquid entering from the water inlet 410 at one end of the liquid circulation device can be prevented from flowing from the gap between the outer shell assembly 100 and the inner membrane shell 210 to the first water outlet 121 under the condition of no filtration, that is, unfiltered liquid is prevented from being directly discharged from the first water outlet 121, and the filtration effect of the liquid circulation device is improved.

In one embodiment of the connection between the switching tube 120 and the water inlet tube 400 using the clip 600, as shown in fig. 2, 4 and 5, the end of the switching tube 120 away from the housing 110 is provided with a convex first connection ring 124, and the convex direction is perpendicular to the direction of the liquid entering the switching tube 120, i.e. perpendicular to the water flow direction. The end of the water inlet pipe 400, which is far from the water inlet 410, is provided with a convex second connecting ring 420, the convex direction of the second connecting ring 420 is consistent with that of the first connecting ring 124, and the annular surfaces of the second connecting ring 420 and the first connecting ring 124 are in butt joint and fixed through the clamp 600. The abutting connection of the second connection ring 420 and the ring surface of the second connection ring 420 means that the first connection ring 124 and the side surface of the second connection ring 420, which are planar, are disposed opposite to each other, so that the first connection ring 124 and the second connection ring 420 can be fixed by the clamp 600 after the water inlet pipe 400 is abutted with the conversion pipe 120, and further the water inlet pipe 400 is connected with the conversion pipe 120.

Further, a third sealing ring 700 is further disposed between the first connecting ring 124 and the second connecting ring 420, the third sealing ring 700 is located outside the second sealing ring 500, preferably, the third sealing ring 700 is a rubber structure, and as shown in fig. 4, after the first connecting ring 124 and the second connecting ring 420 are connected by the clamp 600, the gap between the first connecting ring 124 and the second connecting ring 420 can be filled due to the third sealing ring 700, so that the tightness between the water inlet pipe 400 and the conversion pipe 120 is better. The first sealing ring 300 and the second sealing ring 500 in the present utility model may be made of rubber sealing rings with certain elasticity.

In some embodiments of the utility model, the filter 220 comprises a plurality of membrane filaments, the membrane filaments being hollow, filiform structures, small molecular species within the membrane filaments being able to pass through the membrane filaments, large molecular species being retained within the membrane filaments. As shown in fig. 4 and 7, the filter 220 is disposed inside the outer film case, and both ends of the filter 220 are fixed to both ends inside the inner film case 210 by cured glue blocks 230. In some preferred embodiments, as shown in fig. 4 and 7, annular grooves 212 are formed at both ends of the inner wall of the inner membrane shell 210, and the cured rubber block 230 is also cured in the annular grooves 212, wherein the cured rubber block 230 may be partially cured in the annular grooves 212 or may be fully cured in the annular grooves 212. Since the cured rubber block 230 is partially or entirely cured in the annular groove 212, the cured rubber block 230 can be effectively prevented from falling off from the inside of the inner film shell 210. It should be understood by those skilled in the art that the curing agent gel block should block the end of the inner membrane shell 210 so that the liquid passing through the water inlet 410 can only enter the membrane filaments first and then pass through the membrane filaments, and the liquid is filtered by the membrane filaments and then sequentially discharged from the second water outlet 211 and the first water outlet 121.

Further, in some embodiments of the liquid circulation device provided by the present utility model, the liquid circulation device has a symmetrical structure, and the symmetry plane is perpendicular to the length direction of the liquid circulation device. That is, the outer case 110 and the inner film case 210 are symmetrical members, the conversion pipe 120 and the water inlet pipe 400 are symmetrically disposed at both ends of the outer case 110, and the fixing rubber blocks are symmetrically disposed at both ends of the inner film case 210.

In one embodiment of the liquid circulation device provided by the present utility model, as shown in fig. 3, the step of assembling the liquid circulation device includes the steps of welding the switching tube 120 at both ends of the housing 110 to obtain the housing assembly 100, then installing the inner membrane assembly 200 into the housing assembly 100, and finally connecting the water inlet tube 400 at both ends of the housing assembly 100 by means of the clip 600.

The process of filtering the liquid circulation device provided by the utility model comprises that liquid enters the liquid circulation device through the water inlet 410, then is filtered through the filter element 220 in the inner membrane assembly 200, and small molecular substances pass through the filter element 220 and then sequentially pass through the second water outlet 211 and the first water outlet 121, so that the liquid is finally discharged from the liquid circulation device, and the filtered liquid is obtained.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. A liquid flow-through device for filtration, the liquid flow-through device comprising a housing assembly and an inner membrane assembly, the inner membrane assembly being disposed within the housing assembly;

the shell assembly is provided with a first water outlet, the inner membrane assembly comprises an inner membrane shell, a filter piece is arranged in the inner membrane shell, the inner membrane shell is provided with a second water outlet, and the second water outlet is communicated with the first water outlet;

the inner membrane shell is characterized in that a first sealing ring is arranged between the outer shell assembly and the inner membrane shell, the first sealing rings are arranged at two ends of the liquid circulation device, and the first water outlet and the second water outlet are located between the two first sealing rings.

2. The fluid flow device of claim 1, wherein the housing assembly comprises a housing and a transfer tube welded to each end of the housing, the inner membrane shell is disposed within the housing and the transfer tube, and one of the transfer tubes is disposed between the inner membrane shell and one of the transfer tubes.

3. The liquid flow-through device according to claim 2, wherein each of the switching tubes is provided with the first water outlet.

4. The fluid flow device of claim 2, wherein the housing assembly is connected with a water inlet tube, the water inlet tube is butted at an end of the transfer tube away from the housing, the water inlet tube has a water inlet, the radial dimension of the water inlet end of the water inlet tube is smaller, and the water inlet tube is butted with the transfer tube and then connected with the transfer tube through a clamp so that fluid passing through the water inlet enters the inner membrane shell.

5. The liquid circulation device of claim 4, wherein a second sealing ring is arranged at the joint of the water inlet pipe and the conversion pipe, and the first sealing ring is positioned between the second sealing ring and the first water outlet.

6. The liquid circulation device according to claim 5, wherein an end of the switching tube connected to the water inlet tube is provided with an inclined surface, and the second sealing ring is in contact with the inclined surface and the outer wall of the inner membrane shell under the action of the water inlet tube.

7. The liquid circulation device according to claim 5, wherein a first connecting ring protruding outwards in the direction perpendicular to the water flow direction is arranged at one end of the conversion pipe away from the housing, a second connecting ring is protruding outwards at the end of the water inlet pipe away from the water inlet, the annular surfaces of the first connecting ring and the second connecting ring are in butt joint and fixed through the clamp, a third sealing ring is fixed between the first connecting ring and the second connecting ring, and the second sealing ring is located inside the third sealing ring.

8. The liquid circulation device according to claim 2, wherein the filter element comprises a membrane wire and cured glue blocks respectively cured at two ends of the membrane wire, two cured glue blocks are respectively cured at two ends of the inner membrane shell, and two second water outlets are positioned between the two cured glue blocks.

9. The liquid circulation device of claim 8, wherein the inner walls of the two ends of the inner membrane shell are provided with annular grooves, and the cured gel block is also cured in the annular grooves.

10. The fluid flow device of any one of claims 1-9, wherein the fluid flow device is symmetrical in configuration with a plane of symmetry perpendicular to the length of the fluid flow device.