CN220951224U - Composite filter element and water purification equipment - Google Patents

Abstract

The utility model relates to the technical field of water purification, and discloses a composite filter element and water purification equipment. The composite filter element comprises a filter flask, a central tube and a rear filter element, wherein the central tube is arranged in the filter flask, and a water passing groove is formed in the bottom of the central tube; the rear filter element is detachably arranged in the central tube, the water passing groove is communicated with an inlet of the rear filter element, and a purified water outlet is arranged at the top of the rear filter element. Through arranging the water passing groove at the bottom of the central pipe, water flowing through the central pipe can enter the rear filter element from the bottom of the central pipe and flow out from the purified water outlet arranged at the top of the rear filter element, so that the space in the central pipe is fully utilized, and the utilization rate of the central pipe is improved; in addition, enter into the rear-mounted filter core through the bottom of center tube, can realize that the bottom erodees in the center tube, avoid forming the dead angle in the center tube bottom, eliminate redundant ponding position in the water route, and can also increase the filtration area of rear-mounted filter core, improve the filter effect.

Description

Composite filter element and water purification equipment

Technical Field

The utility model relates to the technical field of water purification, in particular to a composite filter element and water purification equipment.

Background

The water purifying equipment is one kind of water treating apparatus for eliminating harmful matters from tap water to obtain drinking water.

In prior art, the filter element component of water purification equipment generally includes bottle, center tube and roll-type membrane, and the center tube sets up in the bottle inside, and roll-type membrane winds to establish on the center tube, and forms raw water channel between the inner wall of roll-type membrane and bottle, and the center tube is for having upper shed hollow structure, and is provided with the water hole that is linked together with its inside cavity on the lateral wall of center tube. The raw water enters the raw water channel and can be filtered by the coiled membrane to form pure water, and the pure water enters the hollow cavity of the central tube through the water passing holes on the side wall of the central tube and flows out from the upper opening of the central tube. By adopting the arrangement mode, dead angles at certain positions exist at the inner bottom of the central tube, residual water at the dead angle positions cannot be accumulated for a long time, peculiar smell is easily generated when the residual water cannot be washed, the water taste of a user is affected, and the use experience of the user is poor.

Therefore, there is a need to propose a composite filter element to solve the above-mentioned problems.

Disclosure of utility model

Based on the above problems, a first object of the present utility model is to provide a composite filter element, which can fully utilize the hollow space of a central tube, perform post-filtration on pure water, ensure the water taste of a user, and promote the use experience of the user.

The second object of the utility model is to provide a water purifying device, which can avoid the phenomenon of bad water taste caused by dead angle positions of a central tube by applying the composite filter element, and improve the use experience of users.

In order to achieve the above object, the following technical scheme is provided:

The utility model provides a composite filter element, comprising:

A filter flask;

The central tube is arranged in the filter flask, and a water trough is arranged at the bottom of the central tube;

The rear filter element is detachably arranged in the central tube, the water passing groove is communicated with an inlet of the rear filter element, and a purified water outlet is formed in the top of the rear filter element.

As a preferable scheme of the composite filter element provided by the utility model, the water passing groove is a notch arranged at the bottom of the central tube.

As a preferable scheme of the composite filter element provided by the utility model, the number of the water passing grooves is multiple.

As a preferable scheme of the composite filter element provided by the utility model, the side wall of the central tube is provided with the water guide groove extending along the axial direction of the central tube, and the water guide groove, the water passing groove and the purified water outlet are sequentially communicated.

As a preferable scheme of the composite filter element provided by the utility model, the central tube comprises a main tube and a supporting tube which are arranged up and down and are connected, the water guide groove is arranged on the main tube, the water passing groove is arranged at the bottom of the supporting tube, the diameter of the supporting tube is smaller than that of the main tube, a water passing pressure cavity is formed between the supporting tube and the filter flask, and two ends of the water passing pressure cavity are respectively communicated with the water guide groove and the water passing groove.

As a preferable scheme of the composite filter element provided by the utility model, the central tube further comprises a sleeve, the sleeve is sleeved at one end of the main tube, which is close to the supporting tube, and a water guide hole is formed between the sleeve (303) and the water guide groove in a surrounding mode.

As a preferable scheme of the composite filter element provided by the utility model, the main pipe, the supporting pipe and the sleeve are of an integrated structure.

As a preferable scheme of the composite filter element provided by the utility model, the number of the water guide grooves is multiple, and the water guide grooves are arranged at intervals along the circumferential direction of the central tube.

As a preferable scheme of the composite filter element provided by the utility model, the composite filter element further comprises a filter membrane filter element, wherein the filter membrane filter element is wound outside the central tube, and the pure water outlet of the filter membrane filter element is higher than the water passing groove.

In order to achieve the above purpose, the utility model also provides water purifying equipment, which comprises a machine body and the composite filter element, wherein the composite filter element is arranged in the machine body.

The beneficial effects of the utility model are as follows:

According to the composite filter element provided by the utility model, the water trough is arranged at the bottom of the central tube, water flowing through the central tube can enter the rear filter element from the bottom of the central tube and flow out from the purified water outlet arranged at the top of the rear filter element, so that the space in the central tube is fully utilized, and the utilization rate of the central tube is improved; in addition, enter into the rear-mounted filter core through the bottom of center tube, can realize that the bottom erodees in the center tube, avoid forming the dead angle in the center tube bottom, eliminate redundant ponding position in the water route, and can also increase the filtration area of rear-mounted filter core, improve the filter effect.

According to the water purifying equipment provided by the utility model, the phenomenon of poor water taste caused by dead angle positions of the central tube can be avoided by applying the composite filter element, and the use experience of a user is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following description will briefly explain the drawings needed in the description of the embodiments of the present utility model, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the contents of the embodiments of the present utility model and these drawings without inventive effort for those skilled in the art.

FIG. 1 is a schematic cross-sectional view of a composite filter cartridge provided by an embodiment of the present utility model;

FIG. 2 is a schematic cross-sectional view of a center tube provided by an embodiment of the present utility model;

FIG. 3 is a schematic structural view of a central tube according to an embodiment of the present utility model;

FIG. 4 is a schematic bottom view of a center tube according to an embodiment of the present utility model;

FIG. 5 is a schematic view of a portion of a composite filter element according to an embodiment of the present utility model;

FIG. 6 is an exploded view of a composite filter cartridge according to an embodiment of the present utility model;

FIG. 7 is a schematic view of an assembly of a post-cartridge with a second bracket provided by an embodiment of the present utility model;

fig. 8 is an assembly schematic diagram of a post-filter element, a second bracket, a central tube, and a filter membrane filter element provided by an embodiment of the present utility model.

In the figure:

1-a filter flask; 11-a bottle body; 111-an accommodation chamber; 1111-raw water cavity; 1112-a water pressure chamber; 112-a barrier; 12-bottle cap; 121-a raw water waterway; 122-a purified water channel; 123-a wastewater waterway;

2-a filter membrane cartridge;

3-a central tube; 301-a main pipe; 302-supporting the tube; 303-a sleeve; 31-a hollow chamber; 32-passing a water tank; 33-supporting the boss; 331-a first sealing groove; 34-a water guide groove; 341-water guide holes;

4-a rear filter element;

51-a first seal; 52-a second seal; 53-a third seal;

61-a first scaffold; 62-a second bracket; 621-second sealing groove.

Detailed Description

In order to make the technical problems solved by the present utility model, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present utility model will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present utility model, but not all embodiments. 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 fall within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices 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," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixed or removable, for example; can be mechanically or electrically 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.

Fig. 1 shows a schematic cross-sectional view of the composite filter element provided in this embodiment. As shown in fig. 1, the embodiment provides a composite filter element, which comprises a filter flask 1, a central tube 3 and a rear filter element 4, wherein the central tube 3 is arranged in the filter flask 1, and a water trough 32 is arranged at the bottom of the central tube 3; the rear filter element 4 is detachably arranged in the central tube 3, the water passing groove 32 is communicated with the inlet of the rear filter element 4, and the top of the rear filter element 4 is provided with a purified water outlet. Through arranging the water passing groove 32 at the bottom of the central tube 3, water flowing through the central tube 3 can enter the rear filter element 4 from the bottom of the central tube 3 and flow out from a purified water outlet arranged at the top of the rear filter element 4, so that the space in the central tube 3 is fully utilized, and the utilization rate of the central tube 3 is improved; in addition, enter into the post-filter element 4 through the bottom of center tube 3, can realize that the bottom is erodeed in the center tube 3, avoid forming the dead angle in the center tube 3 bottom, eliminate redundant ponding position in the water route, and can also increase the filtration area of post-filter element 4, improve the filter effect.

Further, the composite filter element further comprises a filter membrane filter element 2, and the filter membrane filter element 2 is wound outside the central tube 3. Raw water enters the filter flask 1, is filtered for the first time through the filter membrane filter element 2 to form pure water, enters the rear filter element 4 from the bottom of the central tube 3 to be filtered for the second time to form pure water, and flows out of a pure water outlet at the top of the rear filter element 4 for users to drink. The purified water after twice filtration has better taste and purer purity, and can better meet the demands of users.

Optionally, the filter membrane filter element 2 is an RO reverse osmosis filter element or an NF nanofiltration filter element, so that viruses, bacteria, heavy metals, ions, organic matters and the like in raw water can be effectively removed, the water quality is improved, and the water quality is enabled to be purer. The rear filter element 4 is an activated carbon filter element or a mineralized filter element with an adsorption function so as to remove peculiar smell in the pure water and ensure the taste of the water.

It should be noted that, in the present embodiment, untreated water is referred to as "raw water", such as tap water taken in from municipal pipelines; the water after the filter membrane filter element 2 is treated is called as pure water, and the water after the post filter element 4 is treated is called as pure water; the terms "raw water", "pure water" and "purified water" used in the examples should not be interpreted in their literal sense.

Optionally, the pure water outlet of the filter cartridge 2 has a height higher than that of the water passing tank 32. The design can enable pure water generated after filtration through the filter membrane filter element 2 to enter the hollow cavity chamber 31 of the central tube 3 and flow through the rear filter element 4, so that flushing is performed on the inner bottom of the central tube 3, dead angles are avoided to be formed in the central tube 3, redundant ponding parts in a waterway are eliminated, the situation that the flushing on the inner bottom of the central tube 3 cannot cause peculiar smell of drinking water for a long time is prevented, a water making channel of the drinking water can be prolonged, and the flow rate of purified water is improved.

Fig. 2 shows a schematic cross-sectional view of the center tube 3 provided in the present embodiment. Fig. 3 shows a schematic structural view of the center tube 3 provided in the present embodiment. Fig. 4 shows a schematic bottom view of the central tube 3 provided in the present embodiment. As shown in fig. 2-4 and fig. 1, the number of the water passing grooves 32 is plural, and the plural water passing grooves 32 simultaneously receive pure water generated after being filtered by the filter membrane filter element 2, so that the water passing efficiency can be ensured, and the accumulation time of the pure water between the central tube 3 and the filter flask 1 is prevented from being excessively long, and the water quality is prevented from being influenced. In this embodiment, the number of the water passing grooves 32 is two, and the two water passing grooves 32 are symmetrically arranged at the bottom of the central tube 3, so that the smooth passing of pure water is ensured, and the strength of the central tube 3 is also ensured.

A water guide groove 34 extending in the axial direction is provided in the side wall of the center tube 3, and the water guide groove 34, the water passing groove 32, and the hollow chamber 31 of the center tube 3 are sequentially communicated. The water guide groove 34 on the central tube 3 may guide pure water generated after filtering through the filter membrane cartridge 2 so that it flows into the hollow chamber 31 of the central tube 3 through the water guide groove 32 in the extending direction of the water guide groove 34. Alternatively, the number of the water guide grooves 34 is plural, and the plural water guide grooves 34 are arranged at intervals along the circumferential direction of the center tube 3 so as to guide the pure water generated at each position on the filter membrane cartridge 2.

Specifically, the center tube 3 includes a main tube 301 and a support tube 302 which are disposed one above the other and connected, a water guide groove 34 is provided on the main tube 301, the filter cartridge 2 is wound around the main tube 301, and a water passing groove 32 is provided at the bottom of the support tube 302. In order to realize stable support of the central tube 3 to the filter membrane filter element 2, the central tube 3 further comprises a sleeve 303, the sleeve 303 is sleeved at one end of the main tube 301 close to the support tube 302, and a water guide hole 341 is formed between the sleeve 303 and the water guide groove 34 in a surrounding mode. The filter membrane filter element 2 is wound on the sleeve 303, so that the contact area between the central tube 3 and the filter membrane filter element 2 can be increased, and the connection stability of the filter membrane filter element 2 and the central tube 3 is improved. Optionally, to further ensure stable installation between the filter cartridge 2 and the central tube 3, a support boss 33 is provided on the outer wall of the sleeve 303, and the filter cartridge 2 is supported on the support boss 33.

In the present embodiment, the main pipe 301, the support pipe 302, and the sleeve 303 are of an integral structure. The design can save the time of mutual assembly among a plurality of parts, improve the assembly efficiency and ensure the integrity of the central tube 3.

Fig. 5 shows a schematic view of a part of the structure of the composite filter element provided in this embodiment. As shown in fig. 5 and in combination with fig. 1, a receiving chamber 111 is provided in the filter flask 1, and the filter membrane cartridge 2, the central tube 3 and the post filter cartridge 4 are all located in the receiving chamber 111. Further, a baffle 112 is arranged at the inner bottom of the accommodating chamber 111, the central tube 3 is connected with the baffle 112 in a sealing way, the accommodating chamber 111 is divided into a raw water cavity 1111 and a water passing pressure cavity 1112, the filter membrane filter element 2 is positioned in the raw water cavity 1111 and forms a raw water channel with the cavity wall of the raw water cavity 1111, and the raw water channel is communicated with a raw water source; the pure water outlet of the filter membrane filter element 2, the water guide groove 34, the water passing pressure 1112 and the water passing groove 32 are sequentially communicated to form a pure water channel, and pure water filtered by the filter membrane filter element 2 can enter the hollow cavity 31 through the pure water channel and be subjected to post-filtration by the post-filter element 4. Wherein, the water purifying outlet of the rear filter element 4 is communicated with the outlet of the water purifying equipment so as to be used for the user to take the purified water.

By arranging the central tube 3 in sealing connection with the baffle 112, the raw water cavity 1111 and the water passing pressure cavity 1112 can be blocked, and the phenomenon of water channeling between the two cavities is avoided, so that the quality of pure water is influenced. Optionally, in this embodiment, the central tube 3 is further provided with a first sealing groove 331, and the first sealing groove 331 accommodates the first sealing member 51, and two sides of the first sealing member 51 can abut against the central tube 3 and the baffle 112, respectively. The sealing connection between the central tube 3 and the baffle member 112 is realized through the first sealing member 51, so that the structure is simple, the materials are conveniently obtained, and the manufacturing cost is lower. Optionally, the first seal 51 is a rubber seal. Of course, in other embodiments, the first sealing groove 331 may be provided on the barrier 112, and the above effect can be achieved as well. Optionally, the baffle 112 is an annular protrusion disposed at the bottom inside the accommodating chamber 111.

Specifically, in the present embodiment, the outer diameter of the support tube 302 is smaller than the outer diameter of the main tube 301, and a water pressure chamber 1112 is defined between the stepped structure formed between the support tube 302 and the main tube 301, the inner bottom of the accommodating chamber 111, and the barrier 112. Through setting up stay tube 302, stay tube 302 can the butt in the interior bottom of holding cavity 111, for center tube 3 provides the supporting role, guarantees center tube 3's stability, and can make water pressure chamber 1112 have sufficient space and hold the pure water after the filtration of filter membrane filter core 2, in addition, water pressure chamber 1112's volume is less, can also produce the pressure effect to the pure water that flows into in it to make it flow into center cavity 31 through basin 32 fast.

Fig. 6 shows an exploded schematic view of the composite filter element provided by the present embodiment. As shown in fig. 6 and in combination with fig. 1, the filter flask 1 includes a flask body 11 and a flask cover 12, the flask body 11 has a hollow structure with a flask opening at an upper end, and the hollow structure of the flask body 11 forms the accommodating chamber 111; the bottle cap 12 is covered at the opening of the filter bottle, a raw water channel 121 and a purified water channel 122 are arranged on the bottle cap 12, the raw water channel 121 is communicated with the raw water channel, and the other end of the raw water channel 121 is communicated with a raw water source; the water purification waterway 122 is communicated with a water purification outlet of the rear filter element 4, and the other end of the water purification waterway 122 is communicated with an outlet of the water purification equipment.

Optionally, in this embodiment, the bottle cap 12 is welded to the bottle body 11, which is convenient for processing and is firmly connected. Of course, in other embodiments, the bottle cap 12 may be detachably connected to the bottle body 11, which can achieve the above effects. Illustratively, the bottle cap 12 is connected to the bottle body 11 by a threaded connection or a snap-fit connection.

Specifically, the composite filter element further includes a first bracket 61 and a second bracket 62, the first bracket 61 is connected to the top of the filter membrane filter element 2, a through first central hole is provided on the bottle cap 12, and the first bracket 61 is disposed in the first central hole in a penetrating manner and forms the raw water waterway 121 with the hole wall of the first central hole. The second bracket 62 is connected with the upper part of the rear filter element 4, the first bracket 61 is provided with a through second central hole, the second bracket 62 is arranged in the second central hole in a penetrating way and forms a wastewater waterway 123 with the hole wall of the second central hole, and the wastewater waterway 123 is communicated with the wastewater outlet of the filter membrane filter element 2; the second bracket 62 is provided with a third through-hole, and the third through-hole forms the purified water channel 122. After filtering through the filter membrane cartridge 2, a part of the wastewater is generated, and the wastewater can flow out through the wastewater waterway 123. The other end of the wastewater waterway 123 can be connected with a wastewater treatment device to use the part of wastewater for irrigation, field watering and the like, thereby avoiding the waste of water resources.

Fig. 7 shows an assembly schematic of the post-filter element 4 and the second bracket 62 provided in this embodiment. Fig. 8 shows an assembly schematic of the post-filter cartridge 4, the second bracket 62, the center tube 3 and the filter cartridge 2 provided in this embodiment. As shown in fig. 7-8 in combination with fig. 1, a second seal 52 is provided between the second bracket 62 and the hollow chamber 31. The second sealing member 52 can prevent water channeling between the wastewater channel 123 and the hollow chamber 31, and can affect the quality of pure water.

It is noted that in this embodiment, the compression of the second seal 52 serves as an axial sealing connection between the second carrier 62 and the center tube 3. During assembly, an operator can hold the second bracket 62 by hand and place the second bracket in the hollow cavity 31 of the central tube 3, and the second sealing piece 52 is used for fixing the second bracket and the hollow cavity, so that compared with the welding and fixing mode in the prior art, the fixing structure has the advantages of convenience in disassembly and assembly and no tooling cost, and can improve the production efficiency; in addition, when the bottle cap 12 is detachably connected with the bottle body 11, a user can also take the bottle cap 12 off the bottle body 11, so that the rear filter element 4 can be replaced conveniently. In this embodiment, the second sealing member 52 is a rubber sealing ring, so that the sealing effect is good, and the materials are easy to obtain.

Optionally, in this embodiment, a second sealing groove 621 is further provided on the second support 62, and the second sealing groove 621 accommodates the second sealing member 52 therein, and two sides of the second sealing member 52 can abut against the second support 62 and the cavity wall of the hollow chamber 31, respectively. The second sealing groove 621 can realize the accommodation and the limit of the second sealing piece 52, and prevent the second sealing piece 52 from falling off. Of course, in other embodiments, the second sealing groove 621 may be provided on the cavity wall of the hollow chamber 31, which can achieve the above effect as well.

In order to realize stable connection between the second bracket 62 and the rear filter element 4, a second accommodating groove is further formed in the second bracket 62, and the rear filter element 4 is partially accommodated in the second accommodating groove. Optionally, a third seal 53 is also provided between the rear filter insert 4 and the bottom of the second receiving recess. The two sides of the third sealing piece 53 are adhered to the bottoms of the rear filter element 4 and the second accommodating groove respectively, so that the connection is stable, and the sealing effect between the hollow cavity 31 and the wastewater waterway 123 can be further improved.

Similarly, referring to fig. 1, a first accommodating groove is further formed in the first bracket 61, and the filter membrane cartridge 2 is partially accommodated in the first accommodating groove, so that the connection effect between the first bracket 61 and the filter membrane cartridge 2 is improved.

The assembly process of the composite filter element is briefly described below in connection with fig. 1-8: 1) The second bracket 62 is connected to the top of the rear filter element 4, then the rear filter element 4 is placed in the hollow cavity 31 of the central tube 3 by holding the second bracket 62 by hand, and the second bracket is connected in an axial sealing manner by compression of the second sealing piece 52; 2) Winding the filter membrane filter element 2 on the outer side walls of the main pipe 301 and the sleeve 303, and then installing a first bracket 61 on the top of the filter membrane filter element 2, so that part of the filter membrane filter element 2 is limited in a first accommodating groove of the first bracket 61; 3) Placing the integrated structure in step 2) into the accommodating chamber 111 of the bottle 11 and connecting as an axial seal by compression of the first seal 51; 4) The bottle cap 12 is covered at the opening of the filter flask of the bottle body 11, so that the whole composite filter element is assembled, the assembly is simple, convenient and quick, the tooling cost is avoided, and the production efficiency is high.

The water purification process of the composite filter element (the arrow direction in fig. 1 is the water flow direction) is briefly described below with reference to fig. 1 to 8: 1) Raw water enters the first chamber 1111 through the raw water channel 121, and is filtered in the filter membrane cartridge 2; 2) Pure water filtered by the filter membrane filter element 2 sequentially passes through the water guide groove 34 and the water passing groove 32 to enter the hollow cavity chamber 31, the pure water entering the hollow cavity chamber 31 can be subjected to post-filtration in the post-filter element 4, and the filtered pure water can flow out of the pure water waterway 122 for a user to take; 3) The wastewater generated after the filtration by the filter membrane cartridge 2 flows out of the wastewater waterway 123.

The embodiment also provides a water purifying device, which comprises a machine body and the filter element assembly, wherein the filter element assembly is arranged in the machine body. This water purification unit is through using above-mentioned filter core subassembly, and convenient equipment, production efficiency is high, and can avoid appearing that center tube 3 exists the phenomenon that the water taste that the dead angle position leads to is poor, promotes user's use experience.

Note that the above is only a preferred embodiment of the present utility model and the technical principle applied. It will be understood by those skilled in the art that the present utility model is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the utility model. Therefore, while the utility model has been described in connection with the above embodiments, the utility model is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the utility model, which is set forth in the following claims.

Claims (10)

1. A composite filter cartridge, comprising:

a filter flask (1);

A central tube (3) arranged in the filter flask (1), wherein a water trough (32) is arranged at the bottom of the central tube (3);

The rear filter element (4) is detachably arranged in the central tube (3), the water passing groove (32) is communicated with an inlet of the rear filter element (4), and a purified water outlet is formed in the top of the rear filter element (4).

2. The composite filter element according to claim 1, wherein the water trough (32) is a notch provided in the bottom of the central tube (3).

3. A composite filter element according to claim 2, wherein the number of water passing channels (32) is a plurality.

4. The composite filter element according to claim 1, wherein a water guide groove (34) extending in the axial direction of the central tube (3) is provided on the side wall of the central tube, and the water guide groove (34), the water passing groove (32) and the purified water outlet are sequentially communicated.

5. The composite filter element according to claim 4, wherein the central tube (3) comprises a main tube (301) and a support tube (302) which are arranged up and down and are connected, the water guide groove (34) is arranged on the main tube (301), the water passing groove (32) is arranged at the bottom of the support tube (302), the diameter of the support tube (302) is smaller than that of the main tube (301), a water passing pressure cavity (1112) is formed between the support tube (302) and the filter flask (1), and two ends of the water passing pressure cavity (1112) are respectively communicated with the water guide groove (34) and the water passing groove (32).

6. The composite filter element according to claim 5, wherein the central tube (3) further comprises a sleeve (303), the sleeve (303) is sleeved at one end of the main tube (301) close to the support tube (302), and a water guide hole (341) is formed between the sleeve (303) and the water guide groove (34).

7. The composite filter cartridge of claim 6, wherein the main tube (301), the support tube (302) and the sleeve (303) are of unitary construction.

8. A composite filter element according to claim 4, wherein the number of water guide channels (34) is plural, and the plurality of water guide channels (34) are arranged at intervals along the circumferential direction of the central tube (3).

9. The composite filter element according to any one of claims 1-8, further comprising a filter membrane filter element (2), the filter membrane filter element (2) being wound outside the central tube (3), the pure water outlet of the filter membrane filter element (2) being higher than the water trough (32).

10. A water purification apparatus comprising a body and a composite filter cartridge according to any one of claims 1-9, the composite filter cartridge being mounted within the body.