CN218530012U

CN218530012U - Liquid purification system

Info

Publication number: CN218530012U
Application number: CN202223120570.3U
Authority: CN
Inventors: 邱星城; 阳高; 段细伟; 姚利俊
Original assignee: Sichuan Feitaiyou Petrochemical Equipment Co ltd
Current assignee: Sichuan Feitaiyou Petrochemical Equipment Co ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-02-28
Anticipated expiration: 2032-11-23

Abstract

The application discloses liquid purification system, including the self-cleaning filter, the self-cleaning filter intercommunication has the feed liquor pipe, the feed liquor pipe is used for letting in the unpurified liquid that comes from upstream equipment, the self-cleaning filter is arranged in filtering the mechanical impurities in the unpurified liquid, the self-cleaning filter is connected with the connecting pipe, the connecting pipe is connected with the carbon filter, the carbon filter is arranged in filtering the organic matter in the unpurified liquid, carbon filter bottom is connected with the fluid-discharge tube, the fluid-discharge tube is used for discharging the liquid after purifying, self-cleaning filter bottom is connected with the recovery tube, the recovery tube is connected with the recovery filter, the recovery filter is used for filtering the liquid that contains mechanical impurities who comes out from the self-cleaning filter, the recovery filter still is connected with the drain pipe, the drain pipe other end is connected in the drain pipe lateral wall, this application has the automatic cleaning function of liquid, the liquid loss rate is low, adsorb organic matter kind is many and the big advantage of adsorption capacity.

Description

Liquid purification system

Technical Field

The application relates to the technical field of industrial liquid purification, in particular to a purification system capable of recovering liquid.

Background

In the chemical industry, a pure solvent or a solution prepared from a plurality of solvents and water is usually adopted to separate and purify chemical products, and in the use process of liquid, the performance of the liquid is reduced due to corrosion of equipment and pipelines, solid impurities brought in from the outside and other harmful impurities generated by deterioration of the liquid, so that the normal operation of the device and the quality of the produced products are influenced.

SUMMERY OF THE UTILITY MODEL

The main aim at of this application provides a liquid clean system, aims at solving the liquid pollution problem, improves liquid quality, reduces the liquid loss, saves production running cost, reduces operating personnel amount of labour, the steady operation of guarantee device.

In order to realize the above-mentioned purpose, the application provides a liquid purification system, including the self-cleaning filter, the self-cleaning filter intercommunication has the feed liquor pipe, the feed liquor pipe is used for letting in the unpurified liquid that comes from upstream equipment, the self-cleaning filter is arranged in filtering the mechanical impurities in the unpurified liquid, the self-cleaning filter is connected with the connecting pipe, the connecting pipe is connected with the carbon filter, the carbon filter is arranged in purifying the organic matter in the unpurified liquid, carbon filter bottom is connected with the fluid-discharge tube, the fluid-discharge tube is used for discharging the liquid after the purification, self-cleaning filter bottom is connected with the recovery pipe, the recovery pipe is connected with the recovery filter, the recovery filter is used for purifying the liquid that contains mechanical impurities that comes out from the self-cleaning filter, the recovery filter still is connected with the drain pipe, the drain pipe other end is connected in the drain pipe lateral wall.

Optionally, a preparation pipe is connected between the liquid inlet pipe and the recovery pipe, a first control valve is arranged on the preparation pipe, and a second control valve is arranged at a section of the liquid inlet pipe close to the self-cleaning filter.

Optionally, the recovery filter includes a first jar of body, first jar of body bottom is connected with the blow off pipe, be provided with the blowoff valve on the blow off pipe, first jar of internal portion is provided with netted cartridge filter, netted cartridge filter top is connected with the baffle, netted cartridge filter top is equipped with opening and link up the baffle, netted cartridge filter bottom is connected with the support frame, and netted cartridge filter bottom seals, the support frame all is connected in first jar internal wall with the baffle, netted cartridge filter encloses with first jar of internal wall and becomes to hold the chamber, the recovery tube with hold the chamber intercommunication, the drain pipe is connected in the lateral wall that first jar of body lies in and holds the chamber top.

Optionally, a recovery valve is arranged on the liquid outlet pipe, a backwashing pipe is connected to a section of the liquid outlet pipe between the recovery valve and the recovery filter, and a backwashing valve is arranged on the backwashing pipe.

Optionally, a first differential pressure transmitter is connected between a section of the recovery pipe close to the first tank and a section of the liquid outlet pipe close to the first tank, the side wall of the first tank above the accommodating cavity is connected with an exhaust pipe, and the exhaust pipe is provided with an exhaust valve.

Optionally, the self-cleaning filter comprises a second tank body, a filter screen cylinder is arranged in the second tank body, a filter cavity is enclosed by the filter screen cylinder and the inner wall of the second tank body, the connecting pipe is communicated with the filter cavity, the liquid inlet pipe is connected to the side wall, located above the filter cavity, of the second tank body, a hollow pipe is arranged in the filter screen cylinder, the bottom of the hollow pipe is communicated with the recovery pipe, the side wall of the hollow pipe is communicated with a plurality of suction nozzles, the suction nozzles are attached to the inner wall of the filter screen cylinder, and a plurality of suction ports are formed in the suction nozzles.

Optionally, the inner wall of the second tank body is provided with a first supporting plate and a second supporting plate, the filter screen cylinder is arranged on the first supporting plate, the second supporting plate is positioned above the filter screen cylinder, the hollow pipe penetrates through the first supporting plate and the second supporting plate in a movable mode, the top of the hollow pipe is connected with a rotating shaft, and the rotating shaft extends out of the top of the second tank body in a movable mode and is connected with a rotating motor.

Optionally, a second differential pressure transmitter is connected between a section of the liquid inlet pipe close to the self-cleaning filter and a section of the connecting pipe close to the self-cleaning filter, and a third control valve is arranged on the recovery pipe.

Optionally, the carbon filter comprises a third tank, the liquid discharge pipe is connected to the bottom of the third tank, an activated carbon filler layer is arranged in the third tank, two layers of upper and lower wire mesh plates respectively positioned at the upper and lower ends of the activated carbon filler layer are arranged in the third tank, and an activated carbon fiber filler layer positioned at the bottom of the lower wire mesh plate is also arranged in the third tank.

Optionally, a regulating valve is provided on the drain.

The beneficial effect that this application can realize is as follows:

this application can be from the unpurified liquid of upstream equipment through self-cleaning filter and carbon filter in proper order, mechanical impurity and organic matter in the liquid are got rid of, then obtain the liquid accessible fluid-discharge tube discharge of after purifying and recycle, after pressure differential or the length of operation time of self-cleaning filter reach the setting value, can get into the recovery filter through the recovery tube with the liquid that contains mechanical impurity in the self-cleaning filter, carry out the aftertreatment and purify the back, the liquid that obtains partial purification again converges into in the drain pipe through the drain pipe, consequently, this application can purify the liquid that produces in the self-cleaning filter and reprocess, with the rate of recovery that improves liquid, thereby liquid loss has been reduced.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings that are needed in the detailed description of the present application or the technical solutions in the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic diagram of a liquid purification system according to an embodiment of the present application;

FIG. 2 is a schematic structural view of a recovery filter in an embodiment of the present application;

FIG. 3 is a schematic diagram of a self-cleaning filter according to an embodiment of the present application;

FIG. 4 is a schematic structural view (front side) of a mouthpiece in an embodiment of the present application;

FIG. 5 is a schematic structural view of a carbon filter in an embodiment of the present application;

fig. 6 is a comparison of structural models of activated carbon fibers and activated carbon.

Reference numerals:

110-self-cleaning filter, 111-second tank, 112-screen cylinder, 113-filter chamber, 114-hollow tube, 115-suction nozzle, 116-first support plate, 117-second support plate, 118-rotating shaft, 119-rotating motor, 120-liquid inlet pipe, 130-connecting pipe, 140-carbon filter, 141-third tank, 142-activated carbon packing layer, 143-upper screen plate, 144-lower screen plate, 145-activated carbon fiber packing layer, 150-liquid outlet pipe, 160-recovery pipe, 170-recovery filter, 171-first tank, 172-drain pipe, 173-screen filter cylinder, 174-partition plate, 175-support frame, 176-holding chamber, 180-liquid outlet pipe, 190-preparation pipe, 210-first control valve, 220-second control valve, 230-recovery valve, 240-backwash pipe, 250-backwash valve, 260-first differential pressure, 270-exhaust pipe, 280-exhaust valve, 290-second differential pressure, 310-drain valve, 320-third control valve, 330-regulating valve.

The implementation, functional features and advantages of the objectives of the present application will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that all the directional indicators (such as upper, lower, left, right, front, and rear … …) in the embodiment of the present application are only used to explain the relative position relationship between the components, the motion situation, and the like in a specific posture, and if the specific posture is changed, the directional indicator is changed accordingly.

In this application, unless expressly stated or limited otherwise, the terms "connected," "secured," and the like are to be construed broadly, and thus, for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B", including either A or B or both A and B. In addition, technical solutions between the embodiments may be combined with each other, but must be based on the realization of the technical solutions by a person skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope claimed in the present application.

Examples

Referring to fig. 1 to 5, the present embodiment provides a liquid purification system, including a self-cleaning filter 110, the self-cleaning filter 110 is connected to a liquid inlet pipe 120, the liquid inlet pipe 120 is used for introducing unpurified liquid from a flash tank, the self-cleaning filter 110 is used for filtering mechanical impurities in the unpurified liquid, the self-cleaning filter 110 is connected to a connecting pipe 130, the connecting pipe 130 is connected to a carbon filter 140, the carbon filter 140 is used for filtering organic matters in the unpurified liquid, a liquid outlet pipe 150 is connected to the bottom of the carbon filter 140, the liquid outlet pipe 150 is used for discharging purified liquid, a recovery pipe 160 is connected to the bottom of the self-cleaning filter 110, the recovery pipe 160 is connected to a recovery filter 170, the recovery filter 170 is used for purifying sewage containing mechanical impurities coming out of the self-cleaning filter 110, the recovery filter 170 is further connected to a liquid outlet pipe 180, and the other end of the liquid outlet pipe 180 is connected to a side wall of the liquid outlet pipe 150.

In the present embodiment, unpurified liquid from the flash tank (not shown) passes through the self-cleaning filter 110 and the carbon filter 140 in sequence through the liquid inlet pipe 120 to remove mechanical impurities and organic matters in the liquid, and then the obtained purified liquid can be discharged through the liquid outlet pipe 150 for recycling, and when the pressure difference of the self-cleaning filter 110 reaches a set value, the sewage containing mechanical impurities in the self-cleaning filter 110 can be introduced into the recovery filter 170 through the recovery pipe 160, and after the sewage is reprocessed and purified, the partially purified liquid obtained again can be collected into the liquid outlet pipe 150 through the liquid outlet pipe 180, so that the sewage generated in the self-cleaning filter 110 can be purified and reprocessed in the present embodiment to improve the recovery degree of the liquid, thereby reducing the liquid loss and reducing the cost.

It should be noted that the self-cleaning filter 110 is equivalent to coarse filtration, and the filtered mechanical impurities refer to sediments or suspended matters which are insoluble in oil and specified solvents in petroleum or petroleum products, such as silt, dust, scrap iron, fibers and certain insoluble salts; the carbon filter 140 is equivalent to fine filtration, and mainly filters organic substances in the liquid, such as foaming factors and the like; the purified liquid may be passed through drain 150 to downstream equipment or facilities; the flow and the process of the liquid can be controlled by the action of the pump, and the pump is arranged at the proper position of each node according to the flow direction of the liquid.

As an alternative embodiment, a preparation pipe 190 is connected between the liquid inlet pipe 120 and the recycling pipe 160, a first control valve 210 is arranged on the preparation pipe 190, and a second control valve 220 is arranged at a section of the liquid inlet pipe 120 close to the self-cleaning filter 110.

In this embodiment, when the self-cleaning filter 110 is out of order and needs to be repaired online, the second control valve 220 can be closed, and the first control valve 210 can be opened to allow unpurified liquid to enter the preparation pipe 190 through the liquid inlet pipe 120 and then enter the recovery filter 170 through the recovery pipe 160, and the recovery filter 170 can be used as a temporary filter to ensure the continuous operation of the system, and to avoid the shutdown of the system due to the failure of the self-cleaning filter 110, thereby ensuring the production efficiency.

As an alternative embodiment, the recycling filter 170 includes a first tank 171, a drain pipe 172 is connected to the bottom of the first tank 171, a drain valve 310 is disposed on the drain pipe 172, a mesh-shaped filter cartridge 173 is disposed inside the first tank 171, a partition 174 is connected to the top of the mesh-shaped filter cartridge 173, an opening is disposed at the top of the mesh-shaped filter cartridge 173, the opening penetrates through the partition 174, a support frame 175 is connected to the bottom of the mesh-shaped filter cartridge 173, the bottom of the mesh-shaped filter cartridge 173 is closed, the support frame 175 and the partition 174 are both connected to the inner wall of the first tank 171, an accommodating cavity 176 is defined by the mesh-shaped filter cartridge 173 and the inner wall of the first tank 171, the recycling pipe 160 is communicated with the accommodating cavity 176, and the drain pipe 180 is connected to the side wall of the first tank 171 above the accommodating cavity 176.

In this embodiment, the unpurified liquid or the sewage containing mechanical impurities from the self-cleaning filter 110 can first enter the containing chamber 176 in the first tank 171 through the recycling pipe 160, and then pass through the mesh filter cartridge 173 to adsorb the impurities, because the bottom of the mesh filter cartridge 173 is closed, the liquid passing through the mesh filter cartridge 173 will not flow out from the bottom thereof, so that the filtered liquid flows from the opening at the top of the mesh filter cartridge 173 to the outlet pipe 180 to be discharged, and the impurities are thrown into the support 175 to be accumulated at the bottom of the first tank 171, where the support 175 is of an unclosed structure and has a gap, when the impurities are accumulated more, i.e. when the pressure difference between the liquid inlet and the liquid outlet of the recycling filter 170 is detected to exceed the standard, the drain valve 310 is opened to discharge the liquid with accumulated impurities through the drain pipe 172.

As an alternative embodiment, a recovery valve 230 is arranged on the liquid outlet pipe 180, a backwashing pipe 240 is connected to a section of the liquid outlet pipe 180 between the recovery valve 230 and the recovery filter 170, and a backwashing valve 250 is arranged on the backwashing pipe 240.

In this embodiment, when the pressure difference reaches the upper limit due to a large amount of impurities in the recovery filter 170, the recovery valve 230 is closed, the backwashing valve 250 is opened, a flushing medium (e.g., clean water) is introduced through the backwashing pipe 240, the mesh filter cartridge 173 is backwashed after the flushing medium enters the recovery filter 170, and the flushing water is collected to the bottom of the first tank 171, so that the impurities in the bottom of the first tank 171 are discharged through the drain pipe 172.

As an alternative embodiment, a first differential pressure transmitter 260 is connected between a section of the recycling pipe 160 close to the first tank 171 and a section of the liquid outlet pipe 180 close to the first tank 171, a gas outlet pipe 270 is connected to a side wall of the first tank 171 above the accommodating cavity 176, and a gas outlet valve 280 is arranged on the gas outlet pipe 270.

In this embodiment, the differential pressure of the recovery filter 170 can be detected in real time by the first differential pressure transmitter 260, after the differential pressure exceeds the standard, the exhaust valve 280 can be opened, exhaust is performed through the exhaust pipe 270, or the blowoff valve 310 is opened, impurities are discharged through the blowoff pipe 172, the effect of balancing pressure can be achieved, the pressure regulating mode can be flexibly selected according to specific conditions, and the operation can be performed at the same time.

It should be noted that the differential pressure transmitter is a typical self-balancing detecting instrument, and it utilizes the working principle of negative feedback to overcome the influence of adverse factors such as component materials and processing techniques. The differential pressure transmitter is used for preventing medium in a pipeline from directly entering the transmitter, and the pressure sensing diaphragm is connected with the transmitter through a capillary filled with fluid. It is used to measure the liquid level, flow and pressure of liquid, gas or steam, and then convert it into 4-20 mA DC signal for output.

As an optional implementation mode, the self-cleaning filter 110 comprises a second tank 111, a filter screen cylinder 112 is arranged in the second tank 111, a filter cavity 113 is defined by the filter screen cylinder 112 and the inner wall of the second tank 111, a connecting pipe 130 is communicated with the filter cavity 113, a liquid inlet pipe 120 is connected to the side wall of the second tank 111 above the filter cavity 113, a hollow pipe 114 is arranged in the filter screen cylinder 112, the bottom of the hollow pipe 114 is communicated with a recovery pipe 160, the side wall of the hollow pipe 114 is communicated with a plurality of suction nozzles 115, the suction nozzles 115 are attached to the inner wall of the filter screen cylinder 112, and a plurality of suction ports are arranged on the suction nozzles 115.

In the present embodiment, the self-cleaning filter 110 is based on the principle of "self-suction": the pressure at the position of the suction nozzle 115 is higher than the pressure of the sewage outlet at the bottom of the second tank 111, when the liquid inlet pipe 120 continuously conveys the filter medium (i.e. unpurified liquid), the filtered sewage containing impurities (equivalent to impurity enrichment) is sucked into the hollow pipe 114 from the suction nozzle 115 under the action of water pressure, the suction nozzle 115 is provided with a plurality of suction ports, the adsorption effect is good, the sewage is collected at the bottom of the second tank 111 and finally can be discharged from the recovery pipe 160, and the liquid which is used for shouting the impurities is actively sucked without additional negative pressure formation at the sewage outlet at the bottom of the second tank 111, so that the self-sucking function is formed, and the liquid which penetrates through the filter screen cylinder 112 can enter the filter cavity 113 and is discharged from the connecting pipe 130, therefore, the self-cleaning filter 110 in the embodiment can solve the problem that the filter element of the traditional mechanical filter needs to be replaced, and has high practicability.

As an alternative embodiment, the inner wall of the second tank 111 is provided with a first supporting plate 116 and a second supporting plate 117, the filter cartridge 112 is disposed on the first supporting plate 116, the second supporting plate 117 is located above the filter cartridge 112, the hollow pipes 114 both movably penetrate through the first supporting plate 116 and the second supporting plate 117, the top of the hollow pipes 114 is connected with a rotating shaft 118, and the rotating shaft 118 movably extends out of the top of the second tank 111 and is connected with a rotating motor 119.

In this embodiment, the rotating motor 119 can drive the rotating shaft 118 and the hollow tube 114 to rotate, thereby driving the suction nozzle 115 to move along the inner wall of the filter screen cylinder 112, avoiding the blockage of the suction nozzle 115, ensuring the adsorption effect of the suction nozzle 115 on impurities, and the rotating motor 119 can adopt a stepping motor or a servo motor to meet the use requirements.

The self-cleaning filter 110 in the present embodiment is similar to the structure of the "an integrated self-cleaning purifier" in the utility model with the publication number CN217340467U, and the difference is only that: the suction nozzle 115 in this embodiment employs a plurality of suction ports like shower heads; the hollow tube 114 is rotated by a rotary motor 119.

In an alternative embodiment, a second differential pressure transmitter 290 is connected between a section of the liquid inlet pipe 120 adjacent to the self-cleaning filter 110 and a section of the connecting pipe 130 adjacent to the self-cleaning filter 110, and a third control valve 320 is disposed on the recycling pipe 160.

In this embodiment, the second differential pressure transmitter 290 can detect the differential pressure of the self-cleaning filter 110 in real time, and when the differential pressure exceeds a standard, the third control valve 320 can be opened to discharge the waste water from the bottom of the self-cleaning filter 110 through the recovery pipe 160, so as to achieve the effect of pressure balance.

As an alternative embodiment, the carbon filter 140 includes a third tank 141, the drain pipe 150 is connected to the bottom of the third tank 141, an activated carbon filler layer 142 is disposed in the third tank 141, two upper and lower

wire mesh plates

143 and 144 are disposed in the third tank 141, and an activated carbon fiber filler layer 145 is disposed in the third tank 141 and at the bottom of the lower wire mesh plate 144.

In this embodiment, both the upper screen plate 143 and the lower screen plate 144 can pass through liquid, and here, the upper screen plate 143 and the lower screen plate 144 can adopt a structure of a support frame and a screen, and the structural strength is high. Wherein, active carbon filler and activated carbon fiber filler all adopt prior art, and there is the difference between them in size, and wherein activated carbon fiber filler's effect lies in: (1) filtering activated carbon particles (from activated carbon filler); (2) filtering the organic matter; (3) The micropore is more, the filter effect is good (the active carbon filler is few micropore, big hole is more); therefore, the carbon filter 140 of the present embodiment uses a novel carbon adsorbent and has an optimized internal structure, thereby not only improving the adsorption capacity and the type of adsorbate, but also eliminating the generation of powder and the need for a post-filter. The structural model pair of activated carbon fiber and activated carbon is shown in fig. 6.

The characteristic parameters of the activated carbon fiber filler in the embodiment are as follows:

the adsorption saturation amount of ACF with the specific surface area of 1300m3/g to different organic matters at normal temperature is shown in the following table:

in an alternative embodiment, the drain 150 is provided with a regulating valve 330, the regulating valve 330 is mainly used for depressurizing the liquid, and a control valve can be further provided at a position of the drain 150 close to the carbon filter 140.

The above description is only a preferred embodiment of the present application, and not intended to limit the scope of the present application, and all the equivalent structures or equivalent processes that can be directly or indirectly applied to other related technical fields by using the contents of the specification and the drawings of the present application are also included in the scope of the present application.

Claims

1. The utility model provides a liquid purification system, its characterized in that, includes the self-cleaning filter, the self-cleaning filter intercommunication has the feed liquor pipe, the feed liquor pipe is used for letting in the unpurified liquid that comes from the upper reaches, the self-cleaning filter is arranged in filtering the mechanical impurity in the unpurified liquid, the self-cleaning filter is connected with the connecting pipe, the connecting pipe is connected with the carbon filter, the carbon filter is arranged in filtering the organic matter in the unpurified liquid, carbon filter bottom is connected with the fluid-discharge tube, the fluid-discharge tube is used for discharging the liquid after the purification, self-cleaning filter bottom is connected with the recovery tube, the recovery tube is connected with the recovery filter, the recovery filter is used for filtering the follow the self-cleaning filter comes out contain mechanical impurity's liquid, the recovery filter still is connected with the drain pipe, the drain pipe other end connect in the drain pipe lateral wall.

2. The liquid purification system of claim 1, wherein a preparation pipe is connected between the liquid inlet pipe and the recovery pipe, a first control valve is arranged on the preparation pipe, and a second control valve is arranged at a section of the liquid inlet pipe close to the self-cleaning filter.

3. The liquid purification system according to claim 1 or 2, wherein the recovery filter comprises a first tank body, a drain pipe is connected to the bottom of the first tank body, a drain valve is arranged on the drain pipe, a mesh-shaped filter cartridge is arranged in the first tank body, a partition plate is connected to the top of the mesh-shaped filter cartridge, an opening is formed in the top of the mesh-shaped filter cartridge and penetrates through the partition plate, a support frame is connected to the bottom of the mesh-shaped filter cartridge, the bottom of the mesh-shaped filter cartridge is closed, the support frame and the partition plate are both connected to the inner wall of the first tank body, an accommodating cavity is defined by the mesh-shaped filter cartridge and the inner wall of the first tank body, the recovery pipe is communicated with the accommodating cavity, and the drain pipe is connected to the side wall of the first tank body above the accommodating cavity.

4. The liquid purification system as claimed in claim 3, wherein a recovery valve is disposed on the outlet pipe, a backwash pipe is connected to a section of the outlet pipe between the recovery valve and the recovery filter, and a backwash valve is disposed on the backwash pipe.

5. The liquid purification system of claim 3, wherein a first differential pressure transmitter is connected between a section of the recovery pipe close to the first tank and a section of the liquid outlet pipe close to the first tank, and an exhaust pipe is connected to a side wall of the first tank above the accommodating cavity and provided with an exhaust valve.

6. The liquid purification system of claim 1, wherein the self-cleaning filter comprises a second tank, a filter screen cylinder is arranged in the second tank, the filter screen cylinder and the inner wall of the second tank form a filter chamber, the connecting pipe is communicated with the filter chamber, the liquid inlet pipe is connected to the side wall of the second tank above the filter chamber, a hollow pipe is arranged in the filter screen cylinder, the bottom of the hollow pipe is communicated with the recovery pipe, the side wall of the hollow pipe is communicated with a plurality of suction nozzles, the suction nozzles are attached to the inner wall of the filter screen cylinder, and a plurality of suction ports are arranged on the suction nozzles.

7. The liquid purification system of claim 6, wherein the inner wall of the second tank has a first support plate and a second support plate, the filter cartridge is disposed on the first support plate, the second support plate is disposed above the filter cartridge, the hollow tube movably penetrates the first support plate and the second support plate, the top of the hollow tube is connected with a rotation shaft, and the rotation shaft movably extends out of the top of the second tank and is connected with a rotating motor.

8. The liquid purification system as claimed in claim 1 or 6, wherein a second differential pressure transmitter is connected between a section of the liquid inlet pipe adjacent to the self-cleaning filter and a section of the connecting pipe adjacent to the self-cleaning filter, and a third control valve is disposed on the recovery pipe.

9. The liquid purification system of claim 1, wherein the carbon filter comprises a third tank, the liquid discharge pipe is connected to the bottom of the third tank, an activated carbon packing layer is arranged in the third tank, two layers of upper and lower wire mesh plates are arranged in the third tank, and are respectively positioned at the upper and lower ends of the activated carbon packing layer, and an activated carbon fiber packing layer is further arranged in the third tank and is positioned at the bottom of the lower wire mesh plate.

10. A liquid purification system as claimed in claim 1 or 9, wherein the drain is provided with a regulating valve.