CN110156199A - A washing machine waste water recycling system and treatment method - Google Patents

Abstract

The invention discloses a washing machine waste water recovery system and a treatment method. The washing machine waste water recovery system comprises a waste water collection tank, a flocculation device, a filtration system and a water production tank which are connected and connected in sequence through a waste water recovery pipeline; the waste water collection box collects the washing machine waste water. , the washing machine waste water is flocculated and purified by the flocculation device, filtered by the filtration system, and then recycled to the water production tank; the water production tank is connected to the filter device and the flocculation device through the backwash system in turn, and the backwash system uses the water in the water production tank to filter the system. And/or the flocculation unit is back flushed. By setting a backwashing system in the waste water recovery system, the flocculation device and the filtration system are backwashed, so that the dirt in the flocculation device and the filtration system can be cleaned in time, thereby avoiding the residual sediment in the washing machine waste water recycling process. Too much will cause the recycling system to block and affect the normal operation of the recycling system.

Description

A washing machine waste water recycling system and treatment method

technical field

The invention relates to the field of laundry, in particular to a washing machine waste water recycling system, and also to a processing method for the washing machine waste water recycling system.

Background technique

At present, traditional processes such as flocculation and precipitation, biochemical treatment and other methods are used in washing machine wastewater to remove suspended particles such as lint, hair, etc. in the wastewater, but the purification device will leave some sediment, and if it accumulates for a long time, the purification device may be blocked. The purification process of the washing machine has a low removal rate of chroma and bacteria, and seldom recovers the heat in the wastewater; in addition, the washing machine wastewater treatment equipment occupies a large area, the capital investment is high, and the degree of automation is low.

The existing technical solution discloses a washing sewage reuse device, which aims to provide a washing sewage reuse device that can effectively purify water quality and can be efficiently recycled. It includes a sewage pool, a first water pump, a filtering mechanism, and a clean water pool. The sewage pool is provided with a filter screen and the sewage pool is connected with the first water pump. The first water pump is connected with a filtering mechanism, and the filtering mechanism is connected to the clean water pool. There is a backwashing mechanism for backwashing the filtering mechanism. The backwashing mechanism includes a circulating water tank, a second water pump, and a backwashing waste water tank. The second water pump is connected to the filtering mechanism, and the circulating water tank is respectively connected with the clean water tank and the second water pump. , the industrial washing machine is connected, and the backwash waste water tank is connected with the filtering mechanism and the first water pump. However, the sewage recovery device of this application does not collect the heat of the washing sewage, and the backwashing structure is complicated, and only the ultrafiltration module is washed during backwashing.

The present invention has been made in view of this.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a washing machine waste water recycling system, so as to realize the reverse flushing of the flocculation device and the filtration system, so as to avoid the flocculation device and the filtration system being blocked by residual sediment, which affects the recovery. the purpose of the normal operation of the system.

In order to solve the above-mentioned technical problems, the basic conception of the technical scheme adopted in the present invention is:

A washing machine waste water recovery system, comprising a waste water collection tank, a flocculation device, a filtration system and a water production tank connected in sequence through a waste water recovery pipeline; , is recovered to the water production tank; the production water tank is connected with the filter device and the flocculation device in turn through the backwash system, and the backwash system uses the water in the water production tank to backwash the filter system and/or the flocculation device.

Further, the water flow direction of the backwash system is opposite to the water flow direction in the waste water recovery pipeline, the water production tank is connected to the filtration system and the flocculation device in turn through the backwash pipeline, and the production water tank is connected to the filter system. A third water pump that powers the backwash flow.

Further, the filtration system includes a sand filter, a multi-media filter, and an ultrafiltration module that are sequentially connected through the waste water recovery pipeline. The sand filter and the multi-media filter also pass through the backwash pipeline in the opposite direction to the filtered water flow. Conductive connection;

Preferably, the sand filter, the multi-media filter, and the ultrafiltration module are sequentially connected to the backwashing pipeline through the waste water recovery pipeline in a bidirectional manner.

Further, the upper ends of the sand filter and the multi-media filter are provided with a filtration inlet and a filtration outlet, and the lower end is provided with a backwash inlet and a backwash outlet, and the filtration outlet of the sand filter and the filtration inlet of the multi-media filter pass through waste water. The recovery pipeline is connected and connected to allow the filtered water to pass through; the backwash outlet of the multi-media filter and the backwash inlet of the sand filter are connected through the backwash pipeline in the opposite direction to the filtered water flow for backwashing water through.

Preferably, both the backwash inlet and the backwash outlet of the sand filter and the multi-media filter are provided with intercepting devices to prevent backwash water from flowing back.

Further, the flocculation device is provided with a drainage outlet, a water inlet and a water outlet, the flocculation device and the sand filter are connected in a bidirectional manner through the waste water recovery pipeline and the backwash pipeline, and the water outlet of the flocculation device is connected with the filter inlet of the sand filter. It is connected and conducted through the waste water recovery pipeline to allow the filtered water to pass through; the backwash outlet of the sand filter and the water inlet of the flocculation device are connected and conducted through the backwash pipeline in the opposite direction to the filtered water flow for the backwash water. pass.

Further, the water production tank is connected to the backwash inlet of the multi-media filter through the backwash pipeline, and under the action of the third water pump, the water in the water production tank flows into the multi-media filter from the backwash inlet of the multi-media filter.

Further, the dosing box and the water inlet of the flocculation device are connected through pipelines, and a dosing pump is arranged on the connecting pipeline between the flocculation device and the dosing box. Under the action of the dosing pump, the flocculant in the dosing box is added to the flocculation. In the device, the water in the flocculation device is flocculated and precipitated under the action of flocculation.

Further, a second water pump is provided on the waste water recovery pipeline connecting the water outlet of the flocculation device and the filter inlet of the sand filter. Under the action of the second water pump, the washing machine waste water in the flocculation device enters the sand filter through the waste water recovery pipeline for processing. filter.

Another object of the present invention is to provide a treatment method for the above-mentioned washing machine waste water recycling system. When the purification volume of washing machine waste water reaches the preset water volume, the filter system and the flocculation device are backwashed, the third water pump is started, and the water in the water production tank is backwashed. Under the action of the third water pump, the water flows into the filter system and the flocculation device through the connecting pipeline in turn, and washes the filter system and the flocculation device.

Further, the backwashed water flows into the flocculation device, the flocculation device recycles the backwash water, the dosing pump is started, and the flocculant in the dosing tank is added to the flocculation device under the action of the dosing pump, and the backwash water is mixed with the flocculation device. The flocculant reacts for flocculation and precipitation, and the flocculation device forms sediment and supernatant liquid. The flocculation device opens the drainage outlet to discharge the sediment directly. The supernatant liquid flows out from the water outlet of the flocculation device under the action of the second water pump and is filtered by the filtration system. , which is recycled to the production water tank again.

Preferably, after the backwash water backwashes the flocculation device, the flocculation device opens the drain outlet to discharge the backwash water directly.

After adopting the above-mentioned technical scheme, the present invention has the following beneficial effects compared with the prior art:

1. In the flocculation device, the washing machine wastewater is precipitated under the action of flocculation, so as to remove the larger suspended solids such as lint, hair and residual surfactant in the washing machine wastewater; and then the water after flocculation is filtered. Then, the clean water after flocculation is separated from the floc, and all the clean water after flocculation flows into the water production tank to be collected and reused.

2. When the waste water volume of the washing machine treated by the recycling system reaches the set value, the flocculation device and the filtration system are backwashed to clean up the dirt in the flocculation device and the filtration system in time, thereby avoiding the waste water recycling process due to the washing machine. Too much residual sediment will cause the recovery system to block and affect the normal operation of the recovery system.

3. After the washing machine wastewater is chemically treated and physically precipitated, the COD and chromaticity in the wastewater are oxidized by the active oxygen generated by the active oxygen generator, so that the wastewater purification is more comprehensive and thorough.

4. Through the intelligent water quality monitoring module, the water quality of the treated washing machine wastewater is detected in real time, so that the qualified rate of the recycled washing machine wastewater is high.

5. The heat exchange device set in the recovery system recovers the heat in the waste water and saves energy.

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

1 is a schematic structural diagram of a washing machine waste water recycling system in an embodiment of the present invention;

FIG. 2 is a schematic flow diagram of a washing machine waste water recycling system according to an embodiment of the present invention.

In the figure: 1. Dosing tank; 2. Dosing pump; 3. Waste water collection tank; 4. Heat exchange device; 5. First water pump; 6. Flocculation device; 7. Second water pump; 8. Sand filter 9. Multi-media filter; 10. Ultrafiltration module; 11. Water production tank; 12. Oxygen generator; 13. Intelligent water quality monitoring module; 14. Third water pump.

Detailed ways

Example 1

As shown in FIG. 1 , a washing machine waste water recovery system is introduced in this embodiment, which includes a waste water collection tank 3, a flocculation device 6, a filtration system and a water production tank 11 that are connected in sequence through a waste water recovery pipeline; a washing machine drain pipe and waste water The collection box 3 is connected, and the waste water collection box 3 collects washing machine waste water. The washing machine waste water is flocculated and purified by the flocculation device 6, and after being filtered by the filtration system, it is recycled to the water production tank 11; 6 are connected in sequence, and the backwash system uses the water in the water production tank 11 to backwash the filtration system and/or the flocculation device 6 .

By setting a backwashing system in the waste water recovery system, the flocculation device 6 and the filtration system are backwashed, so as to realize the timely cleaning of the dirt in the flocculation device 6 and the filtration system, thereby avoiding the residues in the washing machine waste water recycling process. Too much sediment leads to blockage of the recovery system and affects the normal operation of the recovery system.

In this embodiment, the backwashing system is arranged in the opposite direction to the water flow of the waste water recovery, the water production tank 11 is connected with the filtration system and the flocculation device 6 through the backwashing pipeline in turn, and the backwashing tank 11 is connected with the filtration system. A third water pump 14 is provided on the pipeline. Under the action of the third water pump 14, the water in the water production tank 11 flows into the filtration system and the flocculation device 6 in turn through the backwash pipeline, and flushes the filtration system and the flocculation device 6.

In this embodiment, the filtration system includes a sand filter 8, a multi-media filter 9, and an ultrafiltration module 10 that are connected in sequence through the waste water recovery pipeline. The sand filter 8 and the multi-media filter 9 also pass through the backwash pipe. The road is connected in the opposite direction to the filtered water flow;

Preferably, the sand filter 8 , the multi-media filter 9 , and the ultrafiltration module 10 are sequentially connected to the backwashing pipeline through the waste water recovery pipeline in a bidirectional manner.

In this embodiment, the filtration inlet and outlet of the sand filter 8 and the multi-media filter 9 are set at different positions from the inlet and outlet of the backwash water.

In this embodiment, the upper ends of the sand filter 8 and the multi-media filter 9 are provided with a filter inlet and a filter outlet, the lower ends are provided with a backwash inlet and a backwash outlet, and the filter outlet of the sand filter 8 and the multi-media filter The filter inlet of the filter is connected through the waste water recovery pipeline to allow the filtered water to pass through; the backwash outlet of the multi-media filter 9 and the backwash inlet of the sand filter 8 are in the opposite direction to the filtered water flow through the backwash pipeline. Conductive connection for the passage of backwash water.

In this embodiment, the backwash inlet and the backwash outlet of the sand filter 8 and the multi-media filter 9 are provided with intercepting devices to prevent backwash water from flowing back.

In this embodiment, the flocculation device 6 is provided with a drainage outlet, a water inlet and a water outlet, the flocculation device 6 and the sand filter 10 are connected in a bidirectional manner through the waste water recovery pipeline and the backwash pipeline, and the water outlet of the flocculation device 6 is connected to the The filtration inlet of the sand filter is connected through the waste water recovery pipeline to allow the filtered water to pass through; the backwash outlet of the sand filter 10 and the water inlet of the flocculation device are connected in the opposite direction to the filtered water flow through the backwash pipeline Conduction for the passage of backwash water.

In this embodiment, the water production tank 11 is connected to the backwash inlet of the multi-media filter 9 through a pipeline. Under the action of the third water pump, the water in the water production tank flows into the multi-media filter 9 from the backwash inlet of the multi-media filter 9. Media filter 9.

Real-time example 2

As shown in FIGS. 1 and 2 , this embodiment introduces a method for processing the waste water recycling system of the washing machine according to the above-mentioned Embodiment 1. When the treatment volume of waste water reaches the preset water volume, the backwash system uses the waste water in the water production tank. Water flushes the filtration system and flocculation unit.

In this embodiment, under the action of the third water pump, the backwash water enters the multi-media filter 9 and the sand filter 8 in turn through the back-wash pipeline, and washes the multi-media filter 9 and the sand filter 8. The residual sediment in the multi-media filter 9 and the sand filter 8 enters the flocculation device with the backwash water, and the backwash water washes the sand filter 8. After the backwash is completed, the flocculation device 6 directly discharges the backwash water. to the outside.

In this embodiment, the flocculation device 6 collects the backwash water in the backwash system. When the backwash water in the flocculation device 6 reaches a certain amount, the flocculation device 6 performs flocculation treatment on the backwash water, and the dosing pump 2 starts simultaneously. The flocculant in the dosing tank 1 enters the flocculation device 6 under the action of the dosing pump 2, and the backwash water reacts with the flocculant to flocculate and precipitate. The clear liquid is processed by the recycling system and recycled to the water production tank again.

In this embodiment, the filter system and the flocculation device 6 are flushed after the recovery system stops working, so as to prevent the residual sediment in the filter mechanism and the flocculation device 6 from breeding bacteria when the system is idle for a long time.

In this embodiment, the recovery system can be set to flush the filter system and the flocculation device 6 every time T1. The filtration system and the flocculation device 6 are regularly flushed to avoid system blockage due to too much residual sediment during the recycling process of washing machine wastewater, which affects the normal operation of the recycling system.

Embodiment 3

As shown in FIG. 1 , a washing machine waste water recycling system is introduced in the embodiment of the present invention, which includes a waste water collection tank 3, a flocculation device 6, a filtration system, and a water production tank 11 that are connected and conducted in sequence through pipelines; the waste water collection box 3 collects Washing machine waste water, after being flocculated and filtered by the flocculation device 6 and the filtration system, is recycled to the water production tank 11; the waste water collection tank 3 and the flocculation device 6 are connected with a heat exchange device 4 on the pipeline. heat is recovered.

In this embodiment, the heat exchange device 4 is also provided with a normal temperature water channel. When the normal temperature water flows through the heat exchange device 4, it absorbs the heat in the waste water of the washing machine to recycle the heat in the waste water of the washing machine. Preferably, the water production tank 11 and the heat exchange device 4 are connected through pipelines, and when the water in the water production tank 11 is reused, it flows through the heat exchange device 4 to absorb the heat of the washing machine waste water in the heat exchange device. The heat in the wastewater is recycled and utilized by the heat exchange device 4, which saves a lot of energy.

In this embodiment, the waste water collection tank 3 is provided with a liquid level detection device to detect the liquid level in the waste water collection tank. When the liquid level in the waste water collection tank reaches the set value, the waste water recovery system is started. Below the set value, the waste water recovery system is in standby and/or off state.

In this embodiment, the water inlet of the dosing box 1 and the flocculation device 6 are connected through pipelines, and a dosing pump 2 is arranged on the connecting pipeline between the flocculation device 6 and the dosing box 1. The flocculant in the medicine box 1 is added to the flocculation device 6 and reacts with the waste water of the washing machine to flocculate and precipitate the pollutants in the waste water of the washing machine. Through flocculation, larger suspended particles such as lint, hair, and residual surfactants in washing machine wastewater are removed.

In this embodiment, the recovery system further includes a first water pump 5 and a second water pump 7. The first water pump 5 is arranged on the connection pipeline between the waste water collection tank 3 and the water inlet of the flocculation device 6. Under the action of the first water pump 5, The washing machine waste water in the waste water collection tank 3 is transported to the flocculation device 6 through the pipeline for flocculation treatment; the second water pump 7 is arranged on the connection pipeline between the water outlet of the flocculation device 6 and the filtration system. The flocculated washing machine wastewater enters the filtration system for filtration treatment.

In this embodiment, an active oxygen generator 12 is provided on the connecting pipeline between the filtration system and the water production tank 11 . After ultrafiltration, the washing machine wastewater enters the active oxygen generator 12, and the active oxygen generator 12 generates living oxygen to oxidize the washing machine wastewater, remove the COD and chromaticity in the washing machine wastewater, and make the wastewater purification more thorough. Preferably, an ultraviolet germicidal lamp is provided on the connecting pipeline between the filtering system and the water production tank 11 . After ultrafiltration, the ultraviolet germicidal lamp is turned on to irradiate and sterilize the waste water of the washing machine. Washing machine wastewater is sterilized by ultraviolet germicidal lamp irradiation, which can remove bacteria in wastewater and improve the quality of purified water.

In this embodiment, an intelligent water quality monitoring module 13 is provided on the connecting pipeline between the filtration system and the water production tank 11, and the intelligent water quality monitoring module 13 can simultaneously test the temperature, turbidity, TDS and residual amount of organic matter in the washing machine after recycling and processing. , to determine whether the water quality of the recycled washing machine wastewater meets the standards. If the water quality meets the recycling standards, the recycled washing machine wastewater will enter the water production tank 11 for use; if the water quality does not meet the recycling standards, the recycled washing machine wastewater will flow back to flocculation. The device 6 continues to perform flocculation and filtration.

In this embodiment, the water production tank 11 is connected with a backwashing system, and the backwashing system uses the water in the water production tank to flush the filtration system and the flocculation device 6 . Backwashing the filtration system and the flocculation device 6 can collect and discharge the sediment remaining in the filtration mechanism and the flocculation device 6 in time, so as to avoid blocking the recovery system channel after the sediment accumulates and affect the normal operation of the recovery system.

In this embodiment, the filtration system includes a sand filter 8, a multi-media filter 9, and an ultrafiltration module 10 that are connected in sequence through pipelines. The sand filter 8, the multi-media filter 9, and the ultrafiltration module 10 convection in sequence. The washing machine wastewater is filtered.

In this embodiment, the filtration system further includes a reverse osmosis module, which can perform deep filtration on the ultra-filtered washing machine waste water; preferably, the washing machine waste water flows through the sand filter 8 and the multi-media filter 9 in sequence through pipelines , ultrafiltration module 10, reverse osmosis module.

In this embodiment, the flocculation device 6, the sand filter 8 and the multi-media filter 9 are provided with a backwash channel. Under the action of the third water pump 14, the water in the water production tank flows into the multi-media filter sequentially through the backwash pipeline. In the filter 9 , the sand filter 8 and the flocculation device 6 , the multi-media filter 9 , the sand filter 8 and the flocculation device 6 are washed.

Preferably, the ultrafiltration module 10 is provided with a backwash channel. Under the action of the third water pump 14, the water in the water production tank 11 flows into the ultrafiltration module 10, the multi-media filter 9, and the sand filter sequentially through the backwash pipeline. 8 and the flocculation device 6 , and rinse the ultrafiltration module 10 , the multimedia filter 9 , the sand filter 8 and the flocculation device 6 .

Embodiment 4

As shown in FIG. 2 , an embodiment of the present invention introduces a processing method of the washing machine recycling system according to the first embodiment. When the system executes the waste water recycling program, at least the heat in the washing machine waste water is recovered. When the washing machine waste water passes through the heat exchange device , transfer the heat to normal temperature water to recycle the heat in the wastewater. The heat recovery in the washing machine waste water makes full use of the heat energy in the washing machine waste water and saves energy.

In this embodiment, the waste water collection tank collects the waste water discharged by the washing machine after washing, and the liquid level detection device set in the waste water collection tank detects the liquid level in the waste water collection tank. When the liquid level in the waste water collection tank reaches the set value, the waste water is recovered The system starts to flocculate, filter and recycle the waste water from the washing machine; when the liquid level in the waste water collection tank is lower than the set value, the waste water recovery system is in a standby state and/or a shutdown state. Quantitative treatment of washing machine wastewater can fully purify the wastewater.

In this embodiment, after the waste water recovery system is activated, the washing machine waste water in the waste water collection tank and the normal temperature water in the water production tank flow into the heat exchange device. In the heat exchange device, the heat of the washing machine waste water is transmitted to the normal temperature water through the heat exchange device, thereby Recycle heat from wastewater.

In this embodiment, under the action of the first water pump, the waste water from the washing machine flows through the heat exchange device and then enters the flocculation device, the dosing pump is started, and the flocculant in the dosing tank enters the flocculation device under the action of the dosing pump, and the flocculant and the dosing pump enter the flocculation device. The washing machine wastewater reacts to flocculate and precipitate the pollutants in the washing machine wastewater; after the washing machine wastewater is flocculated and precipitated for a certain period of time, sediment and supernatant liquid are formed in the flocculation device, and the supernatant liquid enters the sand under the action of the second water pump. filter; the sediment in the flocculation device is directly discharged. Washing machine wastewater is chemically treated in a flocculation unit, and larger suspended solids such as lint, hair and residual surfactants in washing machine wastewater are removed.

In this embodiment, the sand filter, the multi-media filter and the ultrafiltration module sequentially filter the pollutants in the washing machine waste water that flows through. Washing machine wastewater is filtered through multiple layers to filter and retain flocs, particulates, microorganisms, bacteria, etc. in the wastewater.

In this embodiment, the waste water of the washing machine enters the active oxygen generator after ultrafiltration, and the active oxygen generated by the active oxygen generator oxidizes the washing machine to remove the residual pollutants in the waste water. The active oxygen generated by the active oxygen generator is used to oxidize bacteria, COD and chromaticity in the wastewater, so that the wastewater can be purified more thoroughly.

In this embodiment, after the waste water comes out of the active oxygen generator, it enters the intelligent water quality monitoring module, and the intelligent water quality monitoring module detects the water quality of the waste water and determines whether the purified washing machine waste water meets the recycling standard. If the water quality of the purified washing machine wastewater does not meet the recycling standard, the washing machine wastewater will be returned to the flocculation device, and the washing machine wastewater will continue to be purified by flocculation and filtration.

In this embodiment, the intelligent water quality monitoring module can simultaneously test the temperature, turbidity, TDS, and residual amount of organic matter in the washing machine wastewater, and can display the monitored water quality data in real time, and the operator can adjust the process through the displayed water quality information. process.

In this embodiment, when backwashing the filtration system and/or the flocculation device, the water in the water production tank flows into the filtration system under the action of the third water pump, and the sediment in the filtration device is washed, and the filtration system is executed for a certain period of time. After the backwashing is completed, the backwashing water flows into the flocculation device to flush the flocculation device. After the flushing is completed, the flushed water is directly discharged. Periodically flush the filtration system and flocculation unit to prevent residual sediment from clogging the system. Preferably, after the filtration system is backwashed for a certain period of time, the water enters the flocculation device, and the flocculation device recycles the flushing water.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the technology of this patent Within the scope of the technical solution of the present invention, personnel can make some changes or modifications to equivalent examples of equivalent changes by using the above-mentioned technical content, but any content that does not depart from the technical solution of the present invention, according to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments in the technical essence still fall within the scope of the solution of the present invention.

Claims (10)

1. A washing machine waste water recovery system, comprising a waste water collection tank, a flocculation device, a filtration system and a water production tank that are connected in sequence through a waste water recovery pipeline; After the filtration system is filtered, it is recycled to the water production tank; it is characterized in that: the water production tank is sequentially connected with the filter device and the flocculation device through the backwash system, and the backwash system uses the water in the water production tank to reverse the filter system and/or the flocculation device. to flush. 2. A washing machine waste water recovery system according to claim 1, wherein the water flow direction of the backwash system is opposite to the water flow direction in the waste water recovery pipeline, and the water production tank is connected to the filter system and the flocculation device through the backwash pipeline. The pipes are connected and conducted in sequence, and a third water pump that provides power for the backwashing water flow is arranged on the pipeline connecting and conducting the water production tank and the filtration system. 3. A washing machine waste water recovery system according to any one of claims 1-2, wherein the filter system comprises a sand filter, a multi-media filter, and an ultrafiltration module which are sequentially conducted through the waste water recovery pipeline, The sand filter and the multi-media filter are also connected in the opposite direction to the filtered water flow through the backwash pipeline; Preferably, the sand filter, the multi-media filter, and the ultrafiltration module are sequentially connected to the backwashing pipeline through the waste water recovery pipeline in a bidirectional manner. 4. A washing machine waste water recovery system according to any one of claims 1-3, characterized in that: the upper ends of the sand filter and the multi-media filter are provided with a filter inlet and a filter outlet, and the lower ends are provided with a backwash inlet It is connected with the backwash outlet, the filter outlet of the sand filter and the filter inlet of the multi-media filter through the waste water recovery pipeline, so that the filtered water can pass through; the backwash outlet of the multi-media filter is connected to the backwash of the sand filter. The flushing inlet is connected in the opposite direction to the filtered water flow through the backflushing pipeline, so that the backflushing water can pass through; Preferably, both the backwash inlet and the backwash outlet of the sand filter and the multi-media filter are provided with intercepting devices to prevent backwash water from flowing back. 5. A washing machine waste water recovery system according to any one of claims 1-4, characterized in that: the flocculation device is provided with a drain outlet, a water inlet and a water outlet, and the flocculation device and the sand filter are connected with the waste water recovery pipeline through the waste water recovery pipeline. The backwash pipeline is bidirectionally connected, and the water outlet of the flocculation device is connected to the filter inlet of the sand filter through the waste water recovery pipeline, so that the filtered water can pass through; the backwash outlet of the sand filter is connected to the inlet of the flocculation device. The water port is connected and conducted in the opposite direction to the filtered water flow through the backwash pipeline, so that the backwash water can pass through. 6. A washing machine waste water recovery system according to claim 4, characterized in that: the water production tank is connected to the backwash inlet of the multi-media filter through the backwash pipeline, and under the action of the third water pump, the water production tank The water in the multi-media filter flows into the multi-media filter from the backwash inlet of the multi-media filter. 7. A washing machine waste water recycling system according to any one of claims 1-6, characterized in that: the water inlet of the flocculation device and the flocculation device are connected and conducted through a pipeline, and the connecting pipeline between the flocculation device and the medicine addition box is provided with a Under the action of the dosing pump, the flocculant in the dosing box is added to the flocculation device, and the water in the flocculation device is flocculated and precipitated under the action of flocculation. 8. A washing machine waste water recovery system according to any one of claims 1-7, wherein a second water pump is provided on the waste water recovery pipeline connecting the water outlet of the flocculation device and the filter inlet of the sand filter, and a second water pump is provided on the second water pump. Under the action of the water pump, the washing machine waste water in the flocculation device enters the sand filter through the waste water recovery pipeline for filtration. 9. The treatment method of any one of claims 1 to 8, wherein the washing machine waste water recovery system is characterized in that: when the washing machine waste water purification amount reaches a preset water amount, the filter system and the flocculation device are backwashed, and the third water pump Start, the water in the water production tank flows into the filtration system and the flocculation device in turn through the backwash pipeline under the action of the third water pump, and flushes the filtration system and the flocculation device. 10. The processing method of a washing machine waste water recycling system according to claim 8, wherein the backwash water flows into the flocculation device, the flocculation device recycles the backwash water, the dosing pump is started, and the The flocculant is added to the flocculation device under the action of the dosing pump, and the backwash water reacts with the flocculant to flocculate and precipitate. The flocculation device forms sediment and supernatant liquid. The flocculation device opens the drainage outlet to discharge the sediment, and the supernatant liquid is discharged. Under the action of the second pump, the liquid flows out from the water outlet of the flocculation device and enters the filtration system. After being filtered by the filtration system, it is recycled to the water production tank again; Preferably, after the backwash water backwashes the flocculation device, the flocculation device opens the drain outlet to discharge the backwash water.