CN104556448B - Water cleaning systems - Google Patents

Abstract

The invention discloses a water purification system, comprising: a composite filter element, the composite filter element has a raw water inlet, a pretreatment water outlet, a pressurized pretreatment water inlet, a pure water outlet and a concentrated water outlet, the composite filter element It includes a pretreatment filter element and a filter membrane assembly, the pretreatment filter element is spaced between the raw water inlet and the pretreatment water outlet, and the filter membrane assembly is arranged between the pressurized pretreatment water inlet and the pure water outlet Between the water outlet and the concentrated water outlet; the water outlet valve, the water outlet valve is connected to the pure water outlet of the composite filter element; the waste water valve, the waste water valve is connected to the concentrated water outlet of the composite filter element; add a pump, and increase the pre-loading of the pump and the composite filter element respectively The treatment water outlet is connected with the pressurized pretreatment water inlet. The water purification system according to the embodiment of the present invention is convenient for assembly and maintenance.

Description

water purification system

technical field

The invention relates to the technical field of water treatment equipment manufacturing, in particular to a water purification system.

Background technique

The water purification system in the related art adopts PP (polypropylene fiber) cotton as a pre-filter element, and then connects RO (reverse osmosis) filter elements in series, and performs water purification treatment by multi-stage filter elements. The pipeline connections of the entire water purification system are complex, inconvenient to install and replace, and there are many joints connected, so there are many risk points of water leakage. In addition, the service life of multi-stage filter elements is inconsistent. Users need to replace as many as 3 to 5 filter elements. Frequent purchase of filter elements requires professional replacement, which affects user experience and high cost.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, the present invention proposes a water purification system, which is convenient for assembly and maintenance.

The water purification system according to an embodiment of the present invention includes: a composite filter element, the composite filter element has a raw water inlet, a pretreatment water outlet, a pressurized pretreatment water inlet, a pure water outlet and a concentrated water outlet, the composite filter element It includes a pretreatment filter element and a filter membrane assembly, the pretreatment filter element is spaced between the raw water inlet and the pretreatment water outlet, and the filter membrane assembly is arranged between the pressurized pretreatment water inlet and the pure water outlet Between the water outlet and the concentrated water outlet; the water outlet valve, the water outlet valve is connected to the pure water outlet of the composite filter element; the waste water valve, the waste water valve is connected to the concentrated water outlet of the composite filter element; increase pump, and the increasing pump is respectively connected with the pretreatment water outlet and the pressurized pretreatment water inlet of the composite filter element.

According to the water purification system of the embodiment of the present invention, the composite filter element can be used for filtration, which can replace the multi-stage filter element in the existing water purification system, which can not only simplify the pipeline connection, facilitate installation and replacement, but also reduce the number of joints, thereby reducing water leakage risk point. Moreover, the composite filter element integrates the pretreatment filter element and the filter membrane assembly, and only the composite filter element needs to be replaced during replacement, which eliminates the inconvenience of frequently replacing different filter elements and greatly reduces the cost of use.

In addition, the water purification system according to the above-mentioned embodiments of the present invention may also have the following additional technical features:

According to an embodiment of the present invention, the composite filter element further includes a bottle body, the raw water inlet, the pretreatment water outlet, the pressurized pretreatment water inlet, the pure water outlet and the concentrated water The water outlet is formed on the bottle body, the pretreatment filter element and the filter membrane assembly are both arranged in the bottle body, and the filter membrane assembly is nested in the pretreatment filter element.

According to an embodiment of the present invention, the water purification system further includes a flushing drain valve and a water inlet valve. The water ports are connected, one end of the flushing drain valve is connected between the increasing pump and the water inlet valve, and the other end is connected with the outlet of the waste water valve.

According to an embodiment of the present invention, the water outlet valve is directly connected to the pure water outlet of the composite filter element.

According to an embodiment of the present invention, the filter membrane assembly includes a water collection pipe in the abdominal cavity connected to the water outlet of the pure water and a filter membrane wound on the water collection pipe in the abdominal cavity. The upper pretreatment water inlet at the upper end of the filter membrane and the lower pretreatment water inlet leading to the lower end of the filter membrane are provided at the lower end, the upper pretreatment water inlet and the lower pretreatment water inlet are respectively connected to the lower pretreatment water inlet The pressurized pretreatment water inlet is connected, the side wall of the abdominal cavity water collecting pipe is provided with a pure water water inlet hole, and the pure water water collecting pipe has a pure water inlet connecting the pure water water inlet hole and the pure water outlet. Water outlet channel.

According to an embodiment of the present invention, the pressurized pretreatment water inlet is arranged at the lower end of the abdominal cavity water collection pipe, and there is a water inlet in the abdominal cavity water collection pipe that communicates with the pressurized pretreatment water inlet, the upper pretreatment water inlet, and the upper pretreatment water inlet. The water hole and the pretreatment water inlet channel of the lower pretreatment water inlet hole.

According to an embodiment of the present invention, the abdominal water collecting pipe includes: a water collecting pipe body, the pretreatment water inlet channel and the pure water outlet channel are arranged in the water collecting pipe body, and the pure water inlet hole is arranged in the water collecting pipe body. On the side wall of the water collecting pipe body, the upper end of the water collecting pipe body communicates with the pure water outlet; the upper end cover, the upper end cover is sleeved on the upper end of the water collecting pipe body and connected to the water collecting pipe body The upper pretreatment water inlet hole is defined between them; the lower end cover is sleeved on the lower end of the water collection pipe body and the lower pretreatment water inlet hole is defined between the water collection pipe body, Wherein, the filter membrane is wound on the water collecting pipe body and the upper and lower ends are clamped between the upper end cover and the lower end cover.

According to an embodiment of the present invention, there are multiple pure water inlet holes arranged at intervals along the circumferential direction and the axial direction of the side wall of the water collecting pipe body.

According to an embodiment of the present invention, the pure water outlet channel is arranged around the pretreatment water inlet channel.

According to an embodiment of the present invention, the pretreatment water inlet channel includes: a vertical section, the lower end of which is connected to the lower pretreatment water inlet hole; a horizontal section, the middle part of which is connected to the lower pretreatment water inlet hole. The upper end of the vertical section communicates with the upper pretreatment water inlet hole at both ends respectively.

According to an embodiment of the present invention, the pretreatment filter element includes a PP non-woven wrapping outer layer and an activated carbon carbon rod inner layer or includes a PP outer layer, an activated carbon rod middle layer and an ultrafiltration inner layer or a PP inner layer.

According to an embodiment of the present invention, the filter membrane is a reverse osmosis membrane, an ultrafiltration membrane or a nanofiltration membrane.

Description of drawings

Fig. 1 is a schematic diagram of a water purification system according to an embodiment of the present invention, wherein arrows show the direction of water flow during water production.

Fig. 2 is a schematic diagram of a water purification system according to an embodiment of the present invention, wherein the arrows show the direction of water flow during flushing.

Fig. 3 is a cross-sectional view of a composite filter element of a water purification system according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of the peritoneal water collection pipe of the composite filter element of the water purification system according to an embodiment of the present invention.

Reference signs: water purification system 100, composite filter element 1, pretreatment filter element 11, filter membrane assembly 12, peritoneal water collection pipe 121, water collection pipe body 1211, upper end cap 1212, lower end cap 1213, filter membrane 122, bottle body 13, raw water Water inlet 101, pretreatment water outlet 102, pressurized pretreatment water inlet 103, pure water outlet 104, concentrated water outlet 105, upper pretreatment water inlet 1061, lower pretreatment water inlet 1062, pure water inlet Hole 107, pure water outlet channel 108, pretreatment water inlet channel 109, vertical section 1091, horizontal section 1092, outlet valve 2, waste water valve 3, increasing pump 4, flushing drain valve 5, water inlet valve 6.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

As shown in FIGS. 1 to 4 , a water purification system 100 according to an embodiment of the present invention includes: a composite filter element 1 , a water outlet valve 2 , a waste water valve 3 and an increasing pump 4 .

Specifically, the composite filter element 1 has a raw water inlet 101, a pretreatment water outlet 102, a pressurized pretreatment water inlet 103, a pure water outlet 104 and a concentrated water outlet 105, and the composite filter element 1 includes a pretreatment filter element 11 and a filter membrane Assemblies 12, the pre-treatment filter element 11 is spaced between the raw water inlet 101 and the pre-treatment water outlet 102, and is used for roughly filtering the raw water. The filter membrane assembly 12 is arranged between the pressurized pretreatment water inlet 103 and the pure water outlet 104 and the concentrated water outlet 105. The water outlets 105 are spaced apart, so that after the pretreatment filter element 11 is filtered, the pressurized pretreatment water inlet 103 enters the filter membrane assembly 12 for filtration, and the filtered pure water is discharged from the pure water outlet 104, and the filtered concentrated water The concentrated water is discharged from the water outlet 105 for re-filtering the water filtered by the pre-treatment filter element 11 .

The water outlet valve 2 is connected with the pure water outlet 104 of the composite filter element 1 for outputting pure water. The waste water valve 3 is connected to the concentrated water outlet 105 of the composite filter element 1 for discharging waste water. The additional pump 4 is respectively connected to the pretreatment water outlet 102 and the pressurized pretreatment water inlet 103 of the composite filter element 1 to provide power to improve water purification efficiency.

According to the water purification system 100 of the embodiment of the present invention, the composite filter element 1 can be used to replace the multi-stage filter element in the existing water purification system, which can not only simplify the pipeline connection, facilitate installation and replacement, but also reduce the number of joints, thereby Reduce the risk of water leakage points. Moreover, the composite filter element 1 integrates the pretreatment filter element 11 and the filter membrane assembly 12, and only the composite filter element 1 needs to be replaced during replacement, which eliminates the inconvenience of frequent replacement of different filter elements and greatly reduces the cost of use.

As shown in Figure 3, in some embodiments of the present invention, the composite filter element 1 also includes a bottle body 13, a raw water inlet 101, a pretreatment water outlet 102, a pressurized pretreatment water inlet 103, a pure water outlet 104 and a concentrated The water outlet 105 is formed on the bottle body 13 , the pretreatment filter element 11 and the filter membrane assembly 12 are both arranged in the bottle body 13 , and the filter membrane assembly 12 is nested in the pretreatment filter element 11 . Therefore, the filter membrane assembly 12 and the filter element 11 are integrated together, avoiding the use of multiple filter elements for filtering in the water purification process, thereby avoiding the problem of frequent replacement of filter elements due to the different life spans of various filter elements, which is convenient for users. In addition, integrating multiple filter elements together can improve the stability and service life of the composite filter element 1 .

Of course, multiple split filter elements or other types of filter elements can also be used, all of which are within the protection scope of the present invention.

As shown in Fig. 1 and Fig. 2, in some embodiments of the present invention, the water purification system 100 also includes a flushing drain valve 5 and a water inlet valve 6, and the two ends of the water inlet valve 6 are connected with the increasing pump 4 and the composite filter element 1 respectively. One end of the flushing drain valve 5 is connected between the increasing pump 4 and the water inlet valve 6 and the other end is connected with the outlet of the waste water valve 3 . Therefore, the composite filter element 1 can be flushed by opening the flushing and drain valve 5, which facilitates the use of the composite filter element 1.

Specifically, during the use of the water purification system 100 , the composite filter element 1 is easily blocked by impurities, especially the filter membrane module 12 . The high filtration accuracy of the filter membrane module 12 causes its container to be blocked. As shown in Figure 2, when the composite filter element 1 needs to be flushed, it is necessary to close the water inlet valve 6 and open the flushing and draining valve 5 and the waste water valve 3, so that the water flow will be discharged along the increasing pump and the flushing and draining valve 5, thereby achieving composite The flushing process of the filter element 1 (especially the filter membrane assembly 12) is easy to use and high in efficiency.

Preferably, the outlet valve 2 is an outlet solenoid valve, the waste water valve 3 is a waste water ratio solenoid valve, the increasing pump 4 is a diaphragm pump, the flushing and draining valve 5 is a flushing and draining solenoid valve, and the water inlet valve 6 is a water inlet solenoid valve.

The water purification system in the related art needs to be equipped with a pressure tank to store water. The pressure tank takes up a lot of space, and the space utilization rate is not high. Moreover, the pure water in the pressure tank can not be used up for a long time and is prone to secondary pollution by the rubber in the tank. . In order to solve these problems, in one embodiment of the present invention, the water outlet valve 2 is directly connected to the pure water outlet 104 of the composite filter element 1 . In other words, there is no water storage device such as a pressure tank between the water outlet valve 2 and the composite filter element 1, and pure water can be taken at any time, thereby avoiding the problem of secondary pollution caused by the traditional water purification system 100 being provided with a water storage container.

Referring to Fig. 3 and Fig. 4, in some embodiments of the present invention, the filter membrane assembly 12 includes an abdominal water collection pipe 121 connected to the pure water outlet 104 and a filter membrane 122 wound on the abdominal water collection pipe 121, and the peritoneal water collection pipe 121 The upper end is provided with an upper pretreatment water inlet 1061 leading to the upper end of the filter membrane 122, and the lower end of the peritoneal water collecting pipe 121 is provided with a lower pretreatment water inlet 1062 leading to the lower end of the filter membrane 122, the upper pretreatment water inlet 1061 and the lower The pretreatment water inlets 1062 communicate with the pressurized pretreatment water inlets 103 respectively, and the side wall of the abdominal cavity water collection pipe 121 is provided with a pure water water inlet hole 107, and the abdominal cavity water collection pipe 121 has a pure water water inlet hole 107 and a pure water The pure water outlet channel 108 of the water outlet 104.

Therefore, the membrane filter module 12 is provided with an upper pretreatment water inlet 1061 and a lower pretreatment water inlet 1062, and the upper pretreatment water inlet 1061 and the lower pretreatment water inlet 1062 can pass through pretreated water at the same time. Filtration, so that the water purification effect of the composite filter element 1 can be improved, so that the composite filter element 1 can filter out more pure water at the same time. In addition, since the composite filter element 1 of this new structure is adopted to improve the water filtration efficiency of the water purification system 100,

3 and 4, in some embodiments of the present invention, the pressurized pretreatment water inlet 103 is arranged at the lower end of the abdominal cavity water collection pipe 121, and the abdominal cavity water collection pipe 121 has a pressurized pretreatment water inlet 103, an upper pretreatment The pretreatment water inlet channel 109 of the treatment water inlet hole 1061 and the lower pretreatment water inlet hole 1062 . Therefore, the pressurized pretreatment water inlet 103, the upper pretreatment water inlet 1061 and the lower pretreatment water inlet 1062 are connected together through the pretreatment water inlet channel 109, so that the water flow can be filtered through the filter membrane module 12 quickly, Therefore, the water purification efficiency of the composite filter element 1 can be further improved.

Further, the abdominal water collecting pipe 121 includes: a water collecting pipe body 1211 , an upper end cover 1212 and a lower end cover 1213 . Specifically, the pretreatment water inlet channel 109 and the pure water outlet channel 108 are arranged in the water collecting pipe body 1211, the pure water inlet hole 107 is arranged on the side wall of the water collecting pipe body 1211, and the upper end of the water collecting pipe body 1211 is connected with the pure water The water outlet 104 is connected. The upper end cover 1212 is sheathed on the upper end of the water collecting pipe body 1211 and defines an upper pretreatment water inlet hole 1061 between the water collecting pipe body 1211 . The lower end cover 1213 is arranged at the lower end of the water collecting pipe body 1211 and defines the lower pretreatment water inlet hole 1062 between the water collecting pipe body 1211, wherein the filter membrane 122 is wound on the water collecting pipe body 1211, and the upper and lower sides of the filter membrane 122 The end is clamped between the upper end cap 1212 and the lower end cap 1213. Therefore, the structure of the abdominal water collecting pipe 121 is simplified, the production and assembly of the composite filter element 1 is facilitated, and the assembly efficiency of the composite filter element 1 is improved.

Preferably, the pure water outlet channel 108 is arranged around the pretreatment water inlet channel 109 . The integration degree of the composite filter element 1 is improved, which not only makes the assembly of the composite filter element 1 convenient, but also reduces the failure rate of the composite filter element 1 .

Further, the pretreatment water inlet channel 109 includes a vertical section 1091 and a horizontal section 1092 . The lower end of the vertical section 1091 communicates with the lower pretreatment water inlet hole 1062 . The middle part of the horizontal section 1092 communicates with the upper end of the vertical section 1091 and both ends communicate with the upper pretreatment water inlet 1061 respectively. This makes the structure of the pretreatment water inlet channel 109 simple and facilitates the flow of water.

Referring to FIG. 4 , in some embodiments of the present invention, there are a plurality of pure water inlet holes 107 arranged at intervals along the circumferential direction and the axial direction of the side wall of the water collecting pipe body 1211 . Therefore, the purified water can quickly enter the water collecting pipe body 1211 , further improving the water purification efficiency of the composite filter element 1 .

In some embodiments of the present invention, the pretreatment filter element 11 includes a wound outer layer of PP non-woven fabric and an inner layer of activated carbon rods, or includes an outer layer of PP, a middle layer of activated carbon rods, and an inner layer of ultrafiltration or an inner layer of PP.

Further, the filter membrane 122 is a reverse osmosis membrane, an ultrafiltration membrane 122 or a nanofiltration membrane 122 .

As shown in FIGS. 1 to 4 , the filter elements of the water purification system 100 are concentrated in the composite filter element 1 . The whole composite filter element 1 is composed of a pretreatment filter element 11 and a filter membrane assembly 12 roll-type membrane elements. Wherein, the pretreatment filter element 11 includes 2 layers. Distributed from outside to inside along the radial direction of the filter core are PP non-woven fabric winding layers and activated carbon rod layers. The filter membrane assembly 12 nested in the inner layer of the pretreatment filter element is formed by winding a diaphragm, a central water collection pipe, and the like.

3 and 4, the filter membrane module 12 of the present invention adopts the principle of flow measuring membrane, and its water collection pipe body 1211 is a sleeve structure, and water can enter the filter membrane 122 from the top and bottom simultaneously through the inner tube of the sleeve , the waste water flows out from the side of the filter membrane 122 (reverse osmosis membrane, etc.), and the pure water filtered by the filter membrane 122 flows out through the outer pipe of the water collection pipe body 1211 .

The integrated design of the composite filter element 1 of the present invention, the pre-treatment and post-treatment filter elements are designed to have the same service life, and the filter element can be replaced at one time after it expires, which solves the troubles of consumers who need to frequently replace different filter elements; There are no joints between treatments, and there are few water leakage points; the filter membrane 122 adopts flow-measuring membrane technology, which increases the water production, and can realize instant drinking without pressure tanks or other water storage containers, which improves water quality and at the same time Saves space under the kitchen.

The pretreatment filter element is formed by stacking PP cotton filter element and CB filter element or by stacking arrangement of 5mm PP cotton filter element, CB filter element and 1mm PP surface filter element or by stacking arrangement of wound PP cotton filter element, CB filter element and UF filter element Or formed by layered arrangement of PP cotton filter element, CB filter element and UF filter element, etc.

In addition, the filter membrane 122 of the present invention can be a reverse osmosis membrane (reverse osmosis, and RO membrane), and other forms of nanofiltration membranes and ultrafiltration membranes can also be used.

The waterway system can be designed as a system with or without a pump;

The filter element can be used as a whole product, not just a component;

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship indicated by "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or element Must be in a particular orientation, be constructed in a particular orientation, and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (9)

1. A water purification system, characterized in that, the water purification system comprises: A composite filter element, the composite filter element has a raw water inlet, a pretreatment water outlet, a pressurized pretreatment water inlet, a pure water outlet and a concentrated water outlet, the composite filter element includes a pretreatment filter element and a filter membrane assembly, the pretreatment The treatment filter element is spaced between the raw water inlet and the pretreatment water outlet, and the filter membrane assembly is arranged between the pressurized pretreatment water inlet and the pure water outlet and the concentrated water outlet. The membrane assembly includes an abdominal water collection pipe connected to the pure water outlet and a filter membrane wound on the abdominal water collection pipe. The upper end of the abdominal water collection pipe is provided with an upper pretreatment water inlet leading to the upper end of the filter membrane. And the lower end is provided with the lower pretreatment water inlet hole leading to the lower end of the filter membrane, the upper pretreatment water inlet hole and the lower pretreatment water inlet hole are respectively connected with the pressurized pretreatment water inlet, the A pure water inlet hole is provided on the side wall of the abdominal cavity water collecting pipe, and a pure water outlet channel connecting the pure water inlet hole and the pure water outlet is provided in the abdominal cavity water collecting pipe; A water outlet valve, the water outlet valve is connected to the pure water outlet of the composite filter element; A waste water valve, the waste water valve is connected to the concentrated water outlet of the composite filter element; A booster pump, the booster pump is connected to the pretreatment water outlet and the booster pretreatment water inlet of the composite filter element respectively, The pressurized pretreatment water inlet is arranged at the lower end of the abdominal cavity water collection pipe, and there is a water inlet in the abdominal cavity water collection pipe that communicates with the pressurized pretreatment water inlet, the upper pretreatment water inlet hole and the lower pretreatment water inlet. Pre-treatment water inlet channels for water inlet holes. 2. The water purification system according to claim 1, wherein the composite filter element also includes a bottle body, the raw water inlet, the pretreatment water outlet, the pressurized pretreatment water inlet, the The pure water outlet and the concentrated water outlet are formed on the bottle body, the pretreatment filter element and the filter membrane assembly are both arranged in the bottle body, and the filter membrane assembly is nested in the pretreatment Process inside the filter. 3. The water purification system according to claim 1, characterized in that, the water purification system also includes a flushing drain valve and a water inlet valve, and the two ends of the water inlet valve are connected with the compound pump and the water inlet valve respectively. The pressurized pretreatment water inlet of the filter element is connected, one end of the flushing drain valve is connected between the increasing pump and the water inlet valve, and the other end is connected with the outlet of the waste water valve. 4. The water purification system according to claim 1, wherein the water outlet valve is directly connected to the pure water outlet of the composite filter element. 5. The water purification system according to claim 1, wherein the abdominal water collecting pipe comprises: The water collecting pipe body, the pretreatment water inlet channel and the pure water outlet channel are arranged in the water collecting pipe body, the pure water inlet hole is arranged on the side wall of the water collecting pipe body, and the water collecting pipe body The upper end communicates with the pure water outlet; An upper end cover, the upper end cover is sleeved on the upper end of the water collecting pipe body and defines the upper pretreatment water inlet hole between the water collecting pipe body; a lower end cover, the lower end cover is sleeved on the lower end of the water collecting pipe body and defines the lower pretreatment water inlet hole between the water collecting pipe body, Wherein, the filter membrane is wound on the water collecting pipe body and the upper and lower ends are clamped between the upper end cover and the lower end cover. 6 . The water purification system according to claim 5 , wherein there are a plurality of pure water inlet holes arranged at intervals along the circumferential direction and the axial direction of the side wall of the water collecting pipe body. 7 . 7. The water purification system according to claim 4, wherein the pure water outlet channel is arranged around the pretreatment water inlet channel. 8. The water purification system according to claim 4, wherein the pretreatment water inlet channel comprises: a vertical section, the lower end of which is in communication with the lower pretreatment water inlet; A horizontal section, the middle part of the horizontal section communicates with the upper end of the vertical section and the two ends respectively communicate with the upper pretreatment water inlet hole. 9. The water purification system according to claim 1, wherein the pretreatment filter element comprises a PP non-woven wrapping outer layer and an activated carbon rod inner layer or comprises a PP outer layer, an activated carbon rod middle layer and an ultrafiltration Inner layer or PP inner layer, the filter membrane is reverse osmosis membrane, ultrafiltration membrane or nanofiltration membrane.