CN110745978B - Filter element assembly and ultrafiltration water purifier - Google Patents

Abstract

The invention relates to a filter element assembly and an ultrafiltration water purifier, wherein the filter element assembly comprises a filter flask, a first-stage filter element and a second-stage filter element, the first-stage filter element and the second-stage filter element are both arranged in the filter flask, the first-stage filter element is of a cylindrical structure, the aperture of the cylindrical structure is gradually reduced in the direction from two ends to the middle part, the second-stage filter element is inserted into the first-stage filter element, and water entering the filter flask can be filtered by the first-stage filter element and the second-stage filter element and then discharged. The primary filter element and the secondary filter element are integrated in the filter flask, the primary filter element is arranged into a cylindrical structure, and then the secondary filter element is arranged in the primary filter element, so that the volume of the filter element assembly is reduced. Specifically, the pore diameter of the cylindrical structure gradually decreases in a direction from both ends toward the middle. Thereby increase in the limited space in the filter flask the filtration area of one-level filter core promotes the filter effect.

Description

Filter element assembly and ultrafiltration water purifier

Technical Field

The invention relates to the field of water purification, in particular to a filter element assembly and an ultrafiltration water purifier.

Background

Currently, in order to reduce the structural size of water purifiers, a multistage filter cartridge is integrated in one filter bottle. However, under the condition that the requirements on size limitation are increasingly improved, the space in the filter flask is limited, and the higher the integration level of the composite filter element is, the smaller the space which can be temporarily used by each stage of filter element is. And the undersize of each stage of filter element can negatively influence the water purifying effect. Therefore, how to ensure the filtering effect is important under the condition of meeting the high integration level.

Disclosure of Invention

Based on this, it is necessary to provide a filter element assembly and an ultrafiltration water purifier, which can improve the filtration effect while satisfying the high integration level.

The utility model provides a filter core subassembly, includes filter flask, one-level filter core and second grade filter core, the one-level filter core with the second grade filter core is all installed in the filter flask, the one-level filter core is tubular structure, just tubular structure's aperture reduces gradually in the direction that is close to the middle part by both ends, the second grade filter core is inserted and is established in the one-level filter core, get into water in the filter flask can be by the one-level filter core with the second grade filter core filters the back and discharges.

The above-mentioned scheme provides a filter element assembly, is in primary filter core and second grade filter core integration in the filter flask, and will the primary filter core sets up to tubular structure, tubular structure's aperture gradually changes, then installs the second grade filter core in the primary filter core, thereby reduces filter element assembly's volume. Specifically, the aperture of the primary filter element gradually decreases from two ends to a direction approaching the middle part. Thereby increase in the limited space in the filter flask the filtration area of one-level filter core promotes the filter effect.

In one embodiment, the first-stage filter element and the second-stage filter element are arranged along the axial direction of the filter flask, the first-stage filter element and the side wall of the filter flask are arranged at intervals to form a first filtering gap, the water inlet of the filter flask is communicated with the first filtering gap, and the water outlet of the second-stage filter element is communicated with the water outlet of the filter flask.

In one embodiment, the filter element assembly further comprises a support ring and a first support cover, the water inlet of the filter flask is arranged on the top wall of the filter flask, one end of the first-stage filter element, which is close to the top wall, is connected with or abutted against the outer edge of the support ring, the support ring is axially arranged on the filter flask at intervals with the top wall of the filter flask, the inner ring of the support ring is in sealing connection with the second-stage filter element, the outer ring of the support ring is arranged at intervals with the side wall of the filter flask, one end of the first-stage filter element, which is far away from the top wall, is connected with or abutted against the first support cover, and the outer ring of the first support cover is in sealing connection with the side wall of the filter flask.

In one embodiment, the first supporting cover is provided with a disassembly hole, the bottom end of the filter flask is provided with a bottle cap, the bottle cap is detachably connected with the side wall of the filter flask, one end of the secondary filter element is detachably connected with the top wall of the filter flask, and the other end of the secondary filter element penetrates through the disassembly hole and is connected with or abutted to the bottle cap.

In one embodiment, a sealing ring is arranged between the secondary filter element and the side wall of the disassembly hole.

In one embodiment, an extension cylinder is arranged on the surface, opposite to the bottle cap, of the first support cover, the aperture of the extension cylinder is identical to that of the disassembly hole, one end, far away from the first support cover, of the extension cylinder is abutted to the bottle cap, and the secondary filter element sequentially penetrates through the disassembly hole and the extension cylinder to be connected or abutted to the bottle cap.

In one embodiment, the primary filter element is cylindrical, and the filtering surface of the primary filter element is an arc surface gradually concave from two ends to the middle.

In one embodiment, a water outlet connector assembly is arranged in the filter flask, the water outlet connector assembly is arranged between the secondary filter element and the top wall of the filter flask, a water outlet passage is arranged in the water outlet connector assembly, one end of the water outlet passage is communicated with a water outlet of the secondary filter element, the other end of the water outlet passage is positioned in the water inlet, and the water outlet connector assembly is arranged with the side wall of the water inlet at intervals to form a water inlet gap communicated with the first filtering gap.

In one embodiment, the water outlet joint assembly comprises a fixed cylinder, a movable cylinder and an elastic resetting piece, one end of the fixed cylinder is communicated with a water outlet of the secondary filter element, the other end of the fixed cylinder extends to the water inlet, a hollow space of the fixed cylinder forms a water outlet passage, the elastic resetting piece is sleeved outside the fixed cylinder, the movable cylinder is sleeved outside the elastic resetting piece, the movable cylinder and the side wall of the water inlet are arranged at intervals to form a water inlet gap, the bottom end of the elastic resetting piece is in butt joint with the secondary filter element, the top end of the elastic resetting piece is in butt joint with the movable cylinder, a sealing position is arranged on the outer ring of the movable cylinder, the diameter of the sealing position is larger than that of the water inlet, and the elastic resetting piece can axially press the movable cylinder to the sealing position to seal the water inlet.

In one embodiment, the filter element assembly further comprises an intermediate cylinder and a second supporting cover, the second supporting cover is arranged in a space between the supporting ring and the top wall of the filter flask, the second supporting cover is connected with the water producing end of the secondary filter element, a perforation is arranged on the second supporting cover, the perforated hole wall extends to a direction close to the top wall of the filter element to form an auxiliary cylinder, the intermediate cylinder is sleeved outside the elastic resetting piece, the top end of the elastic resetting piece is abutted to the intermediate cylinder, one end of the intermediate cylinder close to the secondary filter element is inserted into the auxiliary cylinder, the intermediate cylinder and the auxiliary cylinder can move relatively in the axial direction, one end of the moving cylinder close to the supporting ring is sleeved outside the auxiliary cylinder, the moving cylinder and the auxiliary cylinder can move relatively in the axial direction, one end of the moving cylinder away from the supporting ring is sleeved outside the intermediate cylinder, and the outer wall of the intermediate cylinder is provided with an elastic resetting piece, and when the intermediate cylinder is pushed away from the second shoulder, and the second shoulder is pushed away from the filter element in the axial direction.

In one embodiment, the primary filter element comprises a melt blown PP cotton filter element or a polypropylene activated carbon fiber filter element.

In one embodiment, the secondary filter element is an ultrafiltration membrane filter element.

An ultrafiltration water purifier comprises the filter element assembly.

The above-mentioned scheme provides an ultrafiltration water purifier, through adopting the filter core subassembly in any one of the above-mentioned embodiments with first order filter core and second grade filter core integration in the filter flask to improve the integrated level of ultrafiltration water purifier. And when improving the integrated level, will the one-level filter core sets up to tubular structure, and the aperture reduces gradually in the direction that is close to the middle part by both ends to the filter area of one-level filter core has been increased in limited space, promoted the filter effect.

Drawings

FIG. 1 is a cross-sectional view of a filter cartridge assembly according to this embodiment;

FIG. 2 is a cross-sectional view of the cartridge assembly of another embodiment;

fig. 3 is an enlarged view of a portion of the cartridge assembly of fig. 2 at a.

Reference numerals illustrate:

10. A filter element assembly; 11. a filter flask; 111. a bottle cap; 12. a primary filter element; 121. a first filter gap; 13. a secondary filter element; 14. a support ring; 15. a first support cover; 151. an extension cylinder; 16. a water outlet joint assembly; 161. a water outlet passage; 162. a water inlet gap; 163. a fixed cylinder; 164. a moving cylinder; 165. an elastic reset piece; 166. an intermediate cylinder; 167. a second support cover; 20. a water inlet; 30. and a water outlet.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit or scope of the invention, which is therefore not limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

As shown in fig. 1 and 2, in one embodiment a filter cartridge assembly 10 is provided that includes a filter flask 11, a primary filter cartridge 12, and a secondary filter cartridge 13, the primary filter cartridge 12 and the secondary filter cartridge 13 each being mounted in the filter flask 11.

The primary filter element 12 is of a cylindrical structure, and the aperture of the cylindrical structure gradually decreases from two ends to a direction approaching the middle. Specifically, as shown in fig. 1 and 2, the primary filter element 12 is arcuate in cross-section taken by a cross-section through the axis. Or the section of the primary filter element 12 cut by the section passing through the axis is a folded line shape with corners.

For example, in one embodiment, as shown in fig. 1 and 2, the primary filter element 12 is cylindrical, and the filtering surface of the primary filter element 12 is an arc surface that is gradually concave from two ends toward the middle.

Further, the secondary filter element 13 is inserted into the primary filter element 12, and water entering the filter flask 11 can be filtered by the primary filter element 12 and the secondary filter element 13 and then discharged.

The above scheme provides the filter element assembly 10, with first order filter core 12 and second grade filter core 13 integration in filter flask 11, and will first order filter core 12 sets up to tubular structure, tubular structure's aperture gradually changes, then installs second grade filter core 13 in first order filter core 12 to reduce the volume of filter element assembly 10. Specifically, the pore diameter of the primary filter element 12 gradually decreases in a direction from both ends toward the middle. Thereby increasing the filtering area of the primary filter element 12 in the limited space in the filter flask 11 and improving the filtering effect.

Specifically, the water entering the filter flask 11 may be filtered by the primary filter element 12 and then filtered by the secondary filter element 13, or may be filtered by the secondary filter element 13 and then filtered by the primary filter element 12, which is not particularly limited herein.

And, the first-stage filter element 12 and the second-stage filter element 13 may be integrated with a multi-stage filter element, for example, the first-stage filter element 12 may be formed by sequentially stacking and sleeving the multi-stage filter element from inside to outside.

Further, as shown in fig. 1 and 2, in one embodiment, the primary filter element 12 and the secondary filter element 13 are disposed along an axial direction of the filter flask 11, and the primary filter element 12 is disposed at a distance from a sidewall of the filter flask 11 to form a first filter gap 121. The water inlet 20 of the filter flask 11 is communicated with the first filtering gap 121, and the water outlet of the secondary filter element 13 is communicated with the water outlet 30 of the filter flask 11.

The water entering from the water inlet 20 of the filter flask 11 reaches the first filtering gap 121, and then flows out from the water outlet 30 of the filter flask 11 after being filtered by the primary filter element 12 and the secondary filter element 13 in sequence.

Moreover, based on the fact that the aperture of the primary filter element 12 gradually decreases in the direction approaching the middle, that is, in the view angle shown in fig. 1 and 2, the primary filter element 12 is approximately in an up-down symmetrical structure, that is, the two ends of the primary filter element 12 are identical in size, so that the two ends of the primary filter element 12 do not need to be distinguished during installation, and convenience in installation is improved. In particular, when the filter element assembly 10 includes the support ring 14 and the first support cover 15, both ends of the primary filter element 12 can be correspondingly disposed with the support ring 14 and the first support cover 15 based on the same size, so that the assembly efficiency is improved, and the convenience of installation is improved.

Further, because the first filtering gap 121 is formed by the interval between the first stage filter element 12 and the sidewall of the filter flask 11, it is known that the space of the first filtering gap 121 near the middle of the first stage filter element 12 is larger, so that the water entering the first filtering gap 121 through the water inlet 20 is smoother in the first filtering gap 121, and the filtering efficiency is higher.

Specifically, the primary filter element 12 may be a melt blown PP cotton filter element, or a polypropylene activated carbon fiber filter element.

And the secondary filter element 13 may be an ultrafiltration membrane filter element. When the secondary filter element 13 is the ultrafiltration membrane filter element, the secondary filter element 13 can be arranged in a detachable form, so that the secondary filter element 13 is taken out for cleaning.

Further, as shown in fig. 1 and 2, in one embodiment, the cartridge assembly 10 further includes a support ring 14 and a first support cap 15. The water inlet 20 of filter flask 11 sets up the roof of filter flask 11, be close to on the first-order filter core 12 the one end of roof with the outer fringe of support ring 14 is connected or the butt, support ring 14 in the axial of filter flask 11 with the roof interval setting of filter flask 11, the inner circle of support ring 14 with second-order filter core 13 sealing connection, the outer lane of support ring 14 with the lateral wall interval setting of filter flask 11. One end of the primary filter element 12 far away from the top wall is connected with or abutted against the first supporting cover 15, and the outer ring of the first supporting cover 15 is in sealing connection with the side wall of the filter flask 11.

The water entering from the water inlet 20 flows into the first filtering gap 121 from the gap between the supporting ring 14 and the top wall of the filter flask 11, and is hermetically connected with the side wall of the filter flask 11 based on the outer ring of the first supporting cover 15, so that the water entering into the first filtering gap 121 can only enter the space enclosed by the first-stage filter element 12 after being filtered by the first-stage filter element 12, and is filtered by the second-stage filter element 13. The arrangement of the support ring 14 and the first support cover 15 thus ensures the proper operation of the cartridge water purification process.

Moreover, as described above, based on the fact that the apertures at both ends of the primary filter element 12 are substantially identical, both ends of the primary filter element 12 can be disposed in correspondence with the support ring 14 and the first support cover 15, thereby improving the convenience of installation.

Further, in one embodiment, as shown in fig. 1 and 2, the first supporting cover 15 is provided with a disassembling hole, the bottom end of the filter bottle 11 is provided with a bottle cap 111, the bottle cap 111 is detachably connected with the side wall of the filter bottle 11, one end of the secondary filter element 13 is detachably connected with the top wall of the filter bottle 11, and the other end of the secondary filter element 13 passes through the disassembling hole and is connected with or abutted against the bottle cap 111.

So that after a period of use, the bottle cap 111 can be removed, and then the secondary filter element 13 is taken out of the filter flask 11 for cleaning, thereby prolonging the service life. Specifically, the secondary filter element 13 and the top cover of the filter flask 11 may be detachably fastened, or may be in threaded connection. When the secondary filter element 13 needs to be detached and cleaned, the secondary filter element 13 is firstly separated from the top wall of the filter flask 11 by rotation or the like, and then the secondary filter element 13 is pulled out of the detaching hole.

Further, to improve the tightness between the secondary filter element 13 and the side wall of the disassembly hole, in one embodiment, a sealing ring is provided between the secondary filter element 13 and the side wall of the disassembly hole.

Further, in one embodiment, as shown in fig. 1 and 2, an extension cylinder 151 is disposed on a surface of the first support cover 15 opposite to the bottle cap 111, the aperture of the extension cylinder 151 is the same as that of the disassembly hole, one end of the extension cylinder 151 far away from the first support cover 15 abuts against the bottle cap 111, and the secondary filter element 13 sequentially passes through the disassembly hole and the extension cylinder 151 to be connected or abutted against the bottle cap 111.

The arrangement of the extension cylinder 151 enables the distance between the first supporting cover 15 and the bottle cap 111 to be controlled, or enables the bottle cap 111 to provide axial supporting force for the first supporting cover 15 after the bottle cap 111 is installed in place, so that the two ends of the primary filter element 12 can be reliably assembled with the supporting ring 14 and the first supporting cover 15, and the tightness of the first filtering gap 121 can be ensured.

Specifically, in one embodiment, as shown in fig. 1, the water inlet 20 and the water outlet 30 of the filter flask 11 are two openings respectively provided on the top wall of the filter flask 11.

Or as shown in fig. 2, the water outlet joint assembly 16 is arranged so that the water outlet 30 and the water inlet 20 of the filter flask 11 can be coaxially sleeved.

For example, in one embodiment, as shown in fig. 2 and 3, a water outlet connector assembly 16 is disposed in the filter flask 11, the water outlet connector assembly 16 is disposed between the secondary filter element 13 and the top wall of the filter flask 11, a water outlet passage 161 is disposed in the water outlet connector assembly 16, one end of the water outlet passage 161 is communicated with the water outlet of the secondary filter element 13, the other end of the water outlet passage 161 is located in the water inlet 20, and the water outlet connector assembly 16 is disposed at a distance from the side wall of the water inlet 20, so as to form a water inlet gap 162 communicated with the first filtering gap 121.

That is, the water outlet passage 161 formed in the water outlet connector assembly 16 enables the purified water formed at the water outlet of the secondary filter element 13 to be conducted away, and the gap between the water outlet connector assembly 16 and the sidewall of the water inlet 20 is used for the raw water. In the water purification, raw water enters the first filtering gap 121 through a water inlet gap 162 formed between the sidewall of the water inlet 20 and the water outlet joint assembly 16.

Further, as shown in fig. 3, in one embodiment, the water outlet connector assembly 16 includes a fixed cylinder 163, a moving cylinder 164 and an elastic restoring member 165, one end of the fixed cylinder 163 is communicated with the water outlet of the secondary filter element 13, the other end of the fixed cylinder 163 extends into the water inlet 20, the hollow space of the fixed cylinder 163 forms the water outlet channel 161, the elastic restoring member 165 is sleeved outside the fixed cylinder 163, the moving cylinder 164 is sleeved outside the elastic restoring member 165, the moving cylinder 164 and the side wall of the water inlet 20 are arranged at intervals to form the water inlet gap 162, the bottom end of the elastic restoring member 165 is abutted against the secondary filter element 13, the top end of the elastic restoring member 165 is abutted against the moving cylinder 164, the outer ring of the moving cylinder 164 is provided with a sealing position, the diameter of the sealing position is larger than the diameter of the water inlet 20, and the elastic restoring member 165 can axially press the moving cylinder 164 against the sealing position to seal the water inlet 20.

When the filter element assembly 10 is communicated with the water pipe, the movable cylinder 164 is subjected to external force, overcomes the elastic force of the elastic restoring member 165, and moves towards the direction approaching to the secondary filter element 13, so that the water inlet gap 162 is conducted, and raw water can flow into the first filter gap 121 from the water inlet gap 162 to perform a filtering process. When the filter element needs to be replaced, after the water pipe is detached from the filter element assembly 10, the movable cylinder 164 moves away from the secondary filter element 13 under the pressing action of the elastic reset piece 165, so that the movable cylinder 164 moves to the sealing position to be in contact with the side wall of the water inlet 20, and the water inlet gap 162 is blocked, so that the effect of preventing water leakage is achieved. The convenience of replacing the filter element is improved.

Specifically, the elastic restoring member 165 may directly abut against the movable cylinder 164, or may indirectly abut against the movable cylinder through an intermediate member.

For example, in one embodiment, as shown in fig. 2 and 3, the cartridge assembly 10 further includes an intermediate barrel 166 and a second support cover 167. The second supporting cover 167 is disposed in a space between the supporting ring 14 and the top wall of the filter flask 11, the second supporting cover 167 is connected with a water producing end of the secondary filter element 13, a perforation is disposed on the second supporting cover 167, a hole wall of the perforation extends to a direction close to the top wall of the filter element to form an auxiliary cylinder, the middle cylinder 166 is sleeved outside the elastic restoring member 165, the top end of the elastic restoring member 165 is abutted to the middle cylinder 166, one end of the middle cylinder 166 close to the secondary filter element 13 is inserted into the auxiliary cylinder, the middle cylinder 166 and the auxiliary cylinder can move relatively in the axial direction, one end of the moving cylinder 164 close to the supporting ring 14 is sleeved outside the auxiliary cylinder, the moving cylinder 164 and the auxiliary cylinder can move relatively in the axial direction, one end of the moving cylinder 164 far away from the supporting ring 14 is sleeved outside the middle cylinder 166, and the outer wall of the middle cylinder 166 is provided with a shoulder, and when the elastic restoring member 165 pushes the middle cylinder 166 away from the secondary filter element 13 to the second shoulder 164 in the direction away from the second filter element 13.

When the filter element assembly 10 is detached from the water pipe, the elastic reset piece 165 is pressed against the middle cylinder 166 in a direction away from the secondary filter element 13, so that the movable cylinder 164 is indirectly pushed by the shoulder of the middle cylinder 166, the sealing position is in contact with the side wall of the water inlet 20, the blocking of the water inlet gap 162 is realized, and the condition that water in the filter element assembly 10 leaks when the filter element is replaced is avoided.

Further, in another embodiment, an ultrafiltration water purifier is provided comprising the filter element assembly 10 described above.

The above-described aspects provide an ultrafiltration water purifier, in which the primary filter element 12 and the secondary filter element 13 are integrated in the filter flask 11 by using the filter element assembly 10 described in any of the above embodiments, thereby improving the integration level of the ultrafiltration water purifier. And when improving the integrated level, will the one-level filter core 12 sets up to tubular structure, and the aperture reduces gradually in the direction that is close to the middle part from both ends to the filter area of one-level filter core 12 has been increased in limited space, the filtration effect is promoted.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (11)

1. The filter element assembly is characterized by comprising a filter flask, a first-stage filter element and a second-stage filter element, wherein the first-stage filter element and the second-stage filter element are both arranged in the filter flask, the first-stage filter element is of a cylindrical structure, the aperture of the cylindrical structure gradually decreases in the direction from two ends to the middle part, the second-stage filter element is inserted into the first-stage filter element, and water entering the filter flask can be filtered by the first-stage filter element and the second-stage filter element and then discharged; the section of the primary filter element cut by the section of the axis is arc-shaped, or the section of the primary filter element cut by the section of the axis is folded line-shaped with a corner;

the first-stage filter element and the second-stage filter element are arranged along the axial direction of the filter flask, and the first-stage filter element and the side wall of the filter flask are arranged at intervals to form a first filter gap;

The water inlet of the filter flask is arranged on the top wall of the filter flask, a water outlet connector assembly is arranged in the filter flask and is arranged between the secondary filter element and the top wall of the filter flask, a water outlet passage is arranged in the water outlet connector assembly, one end of the water outlet passage is communicated with a water outlet of the secondary filter element, the other end of the water outlet passage is positioned in the water inlet, and the water outlet connector assembly is arranged with the side wall of the water inlet at intervals to form a water inlet gap communicated with the first filtering gap;

The water outlet joint assembly comprises a fixed cylinder, a movable cylinder and an elastic resetting piece, wherein one end of the fixed cylinder is communicated with a water outlet of the secondary filter element, the other end of the fixed cylinder extends to the water inlet, a hollow space of the fixed cylinder forms a water outlet passage, the elastic resetting piece is sleeved outside the fixed cylinder, the movable cylinder is sleeved outside the elastic resetting piece, the movable cylinder and the side wall of the water inlet are arranged at intervals to form a water inlet gap, the bottom end of the elastic resetting piece is in butt joint with the secondary filter element, the top end of the elastic resetting piece is in butt joint with the movable cylinder, a sealing position is arranged on the outer ring of the movable cylinder, the diameter of the sealing position is larger than that of the water inlet, and the elastic resetting piece can axially press the movable cylinder to the sealing position to seal the water inlet.

2. The filter cartridge assembly of claim 1, wherein the water inlet of the filter flask is in communication with the first filter gap and the water outlet of the secondary filter cartridge is in communication with the water outlet of the filter flask.

3. The filter element assembly according to claim 2, further comprising a support ring and a first support cap, wherein one end of the primary filter element near the top wall is connected or abutted to an outer edge of the support ring, the support ring is arranged at intervals with the top wall of the filter flask in an axial direction of the filter flask, an inner ring of the support ring is in sealing connection with the secondary filter element, an outer ring of the support ring is arranged at intervals with a side wall of the filter flask, one end of the primary filter element far away from the top wall is connected or abutted to the first support cap, and an outer ring of the first support cap is in sealing connection with the side wall of the filter flask.

4. A filter element assembly according to claim 3, wherein the first support cap is provided with a disassembly hole, the bottom end of the filter flask is provided with a bottle cap, the bottle cap is detachably connected with the side wall of the filter flask, one end of the secondary filter element is detachably connected with the top wall of the filter flask, and the other end of the secondary filter element passes through the disassembly hole and is connected with or abutted against the bottle cap.

5. The filter cartridge assembly of claim 4, wherein a seal ring is disposed between the secondary filter cartridge and the sidewall of the removal aperture.

6. The filter element assembly according to claim 4, wherein an extension tube is provided on a surface of the first support cover opposite to the bottle cap, the aperture of the extension tube is the same as that of the disassembly hole, one end of the extension tube away from the first support cover is abutted to the bottle cap, and the secondary filter element sequentially passes through the disassembly hole and the extension tube to be connected or abutted to the bottle cap.

7. The filter cartridge assembly of any one of claims 1 to 6, wherein the primary filter cartridge is cylindrical and the filter face of the primary filter cartridge is arcuate with a gradual inward recess from both ends toward the middle.

8. The filter element assembly according to claim 3, further comprising an intermediate cylinder and a second support cover, wherein the second support cover is disposed in a space between the support ring and the top wall of the filter flask, the second support cover is connected with a water producing end of the secondary filter element, a perforation is disposed on the second support cover, a hole wall of the perforation extends in a direction close to the top wall of the filter element to form an auxiliary cylinder, the intermediate cylinder is sleeved outside the elastic reset piece, the top end of the elastic reset piece is abutted to the intermediate cylinder, one end of the intermediate cylinder close to the secondary filter element is inserted into the auxiliary cylinder, the intermediate cylinder and the auxiliary cylinder can move relatively in an axial direction, one end of the moving cylinder close to the support ring is sleeved outside the auxiliary cylinder, the moving cylinder and the auxiliary cylinder can move relatively in an axial direction, one end of the moving cylinder away from the support ring is sleeved outside the intermediate cylinder, and the outer wall of the intermediate cylinder is provided with an elastic reset piece, when the intermediate cylinder is pushed away from the secondary filter element, and the intermediate cylinder is pushed away from the second shoulder in a direction away from the filter element.

9. The filter cartridge assembly of any one of claims 1 to 6, wherein the primary filter cartridge comprises a melt blown PP cotton filter cartridge or a polypropylene activated carbon fiber filter cartridge.

10. The filter cartridge assembly of any one of claims 1 to 6, wherein the secondary filter cartridge is an ultrafiltration membrane cartridge.

11. An ultrafiltration water purifier comprising a cartridge assembly according to any one of claims 1 to 10.