CN112744964A

CN112744964A - Water purifying device, self-cleaning filtering system and method

Info

Publication number: CN112744964A
Application number: CN202110069813.6A
Authority: CN
Inventors: 崔登凯; 刘青; 杨磊; 宫钦玉
Original assignee: Qingdao Haier Strauss Water Equipment Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Strauss Water Equipment Co Ltd; Haier Smart Home Co Ltd
Priority date: 2020-12-08
Filing date: 2021-01-19
Publication date: 2021-05-04
Also published as: CN215559587U

Abstract

The invention provides a water purifying device, a self-cleaning filtering system and a self-cleaning filtering method. According to the invention, concentrated water is electrolyzed, acid water, alkaline water and pure water are generated simultaneously, and the three kinds of water sequentially clean the RO membrane according to a set sequence (pure water is last), so that compared with physical cleaning, the efficiency is higher; according to the invention, the reverse osmosis membrane cleaned by acid water and alkaline water is cleaned by using pure water generated by the electrodialysis cleaning unit, so that concentrated water on the raw water side can be replaced while residual acid and alkaline are removed, ions in the concentrated water are prevented from passing through the membrane, and the problem of high TDS value of effluent caused by shutdown and restart of a water purification device is solved; the invention can also effectively reduce the generation of waste water.

Description

Water purifying device, self-cleaning filtering system and method

Technical Field

The invention belongs to the technical field of water purification, and particularly relates to a water purification device, a self-cleaning filtering system and a self-cleaning filtering method.

Background

With the increasing severity of environmental pollution and the increasing awareness of people's health, water purification devices have been widely used in people's daily life. In the prior art, water is generally purified by a reverse osmosis filter element or a super filter element to obtain pure water.

In the process of raw water filtration by the reverse osmosis technology, suspended matters and colloids with particle sizes lower than 1 mu m in water, including humic acid, sulfides, colloidal silica and other substances, are difficult to be filtered by upstream PP cotton and activated carbon, and can be accumulated on the surface of a Reverse Osmosis (RO) membrane-RO membrane to cause membrane pore blockage; in addition, inorganic salts, including salts formed by calcium and magnesium ions, are also trapped by the RO membrane and blocked in membrane pores, and the additional high pressure makes raw water pass through the membrane, so that the packing density of pollutants is increased. The accumulation of fouling on the membrane surface and the clogging of membrane pores are called membrane fouling, which causes the reduction of membrane permselectivity and water production efficiency and shortens the service life.

Reverse Osmosis (RO) membranes, which are the core components of water purification plants, are always subject to membrane fouling. Because of the water quality difference in different areas, after the water purifier is used for a period of time, the reverse osmosis membrane can be polluted and influenced by different degrees, but is limited by the membrane cleaning cost, the reverse osmosis membrane in the water purifier can be abandoned after the water purifier is used for a period of time, and the membrane component is replaced by a new membrane component, and the period is generally 2-3 years. In order to prolong the service life of the RO membrane, a related scheme has been proposed to clean the RO membrane by washing the membrane surface on the raw water side with raw water or pure water.

However, the existing water purifying apparatus still has the following problems:

1) pollution problem of reverse osmosis filter element membrane

The reverse osmosis membrane is mainly polluted by three reasons, namely that the activated carbon and the PP cotton unit in front of the membrane filtration unit cannot filter inorganic salt ions, small-particle-size colloids, polysaccharides, proteins, humic acid and other substances; secondly, the grain diameter of the reverse osmosis membrane almost only allows water molecules to permeate, and almost all substances which cannot be filtered by the active carbon and the PP cotton can be filtered; thirdly, the reverse osmosis membrane needs additional pressure, the density of a filter cake layer is increased, and membrane pollution is strengthened. The reverse osmosis membrane pollution control of the existing water purifying equipment mainly adopts two modes of accelerating the flow rate of water on the raw water side and introducing pure water to clean the raw water side membrane. The problem of accelerating the pollution of the raw water flow rate washing membrane is that the washing flow rate, pressure and frequency need to be strictly controlled, and the operation is complicated; pure water washing membranes have the problem of creating more waste water on the basis of the original amount of waste water. The common problem of both is that physical cleaning is difficult to remove the accumulated pollutants in the membrane pores and can cause a large amount of waste water or pure water to be converted into waste water.

2) Problem of increased TDS (Total dissolved solids) value of effluent caused by shutdown and restart of water purifying equipment

In the reverse osmosis membrane process, the concentration of pollutants on the raw water side is higher than that on the pure water side, and after the machine is stopped, ions on the raw water side can permeate through the membrane in a forward direction, so that when the water purifier is started again, the initial water outlet TDS value is too high. The shutdown of current water purification unit is restarted, and the high solution mode of initial play water TDS value guarantees mainly that the machine lasts system water after the outage, utilizes the pure water to replace the old water of raw water side, solves the pollutant and spreads the problem that the membrane caused the high TDS value of first cup of water, and this mode can cause more wasting of resources.

3) Reverse osmosis wastewater direct discharge

The reverse osmosis filtering membrane unit of the conventional water purifier directly discharges waste water, and particularly causes serious water resource waste for water purifiers with low net-to-waste ratio.

The filter device and the cleaning method thereof with the application number of CN201510235774.7 propose a filter device which comprises: a membrane shell; the separator has ion permeability and comprises one or more of an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, an ion exchange membrane or a bipolar membrane, and separates the membrane shell into a first cavity and a second cavity; a membrane element disposed in the first chamber; a first electrode disposed in the first chamber; a second electrode disposed in the second chamber. The device is designed into a roll shape, the center of the device is a cylindrical support part with a hole on the side wall, the isolating part is wound on the outer side or the inner wall of the support part, a first chamber is arranged in the cylinder, and a second chamber is arranged outside the cylinder. The cleaning method comprises the following steps: the positive and negative poles of the direct current power supply are respectively connected with the first electrode positioned in the first cavity and the second electrode positioned in the second cavity, so that the first electrode and the second electrode positioned on two sides of the isolating piece, water positioned in the first cavity and water in the second cavity form an electrolytic cell, the membrane element is cleaned by acid water or alkaline water generated by electrolysis in the first cavity, inorganic salt and scale substances in the reverse osmosis membrane element can be removed by acid washing, and organic salt and scale substances in the reverse osmosis membrane element can be removed by alkaline washing. However, the problem that this patent exists is that, the membrane element is directly placed in acid room or alkali room, and this can cause after the washing is accomplished, the raw water side TDS value is higher than before not rinsing, if the completion is shut down promptly to wash, can have more ion diffusion to cross the membrane, causes the start filtration side TDS value too high, secondary pollution problem promptly.

The above information disclosed in this background section is only for enhancement of understanding of the background of the application and therefore it may comprise prior art that does not constitute known to a person of ordinary skill in the art.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a self-cleaning filtering method and a self-cleaning filtering system, which are used for solving the technical problems of membrane pollution and high TDS value of effluent after shutdown and restart of the existing filtering system.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a self-cleaning filtration system, the system comprising:

the filtering membrane unit is used for filtering water and outputting pure water and concentrated water;

an electrodialysis cleaning unit for receiving the concentrated water and electrolyzing the concentrated water to generate acid water, alkaline water and pure water;

and the control unit is used for controlling the acid water, the alkaline water and the pure water to sequentially clean the filtering membrane unit, or controlling the alkaline water, the acid water and the pure water to sequentially clean the filtering membrane unit.

A self-cleaning filtration system as described above, the system comprising:

the water quality monitoring module is used for detecting the water quality of the pure water generated by the electrolysis of the electrodialysis cleaning unit;

the control unit is also used for connecting the pure water output end of the filtering membrane unit when the water quality reaches the standard.

The self-cleaning filtering system is characterized in that the control unit is also used for controlling acid water, alkaline water and pure water which are used for cleaning the filtering membrane unit to enter the electrodialysis cleaning unit and be discharged from the electrodialysis cleaning unit.

In the self-cleaning filtering method, the control unit is further used for controlling concentrated water received by the electrodialysis cleaning unit to be subjected to primary electrolysis and discharged through the electrodialysis cleaning unit after the filtration membrane unit is cleaned.

A self-cleaning filtration system as described above, the system comprising:

the water quantity detection module is used for detecting the water inflow of the filtering membrane unit, and the timing module is used for timing the water making time;

the control unit is also used for controlling the electrodialysis cleaning unit to clean the filtering membrane unit when the water inflow reaches a preset water amount or the water making time reaches a preset time.

In the self-cleaning filtering system, the filtering membrane unit is a reverse osmosis membrane or an ultrafiltration membrane.

The self-cleaning filtration system as described above, the electrodialysis cleaning unit comprising:

a housing;

a separator located in the shell, wherein the separator comprises a bipolar membrane, an anion exchange membrane and a cation exchange membrane, and the shell is divided by the separator to form an anode chamber, a pure water chamber, an alkali chamber, an acid chamber and a cathode chamber;

electrodes positioned within the housing, the electrodes including a first electrode and a second electrode, the first and second electrodes positioned in the anode and cathode chambers, respectively, or the first and second electrodes positioned on the housing, respectively;

the shell is provided with a water inlet which is respectively communicated with the anode chamber, the pure water chamber, the alkali chamber, the acid chamber and the cathode chamber, and the shell is provided with a pure water chamber water inlet which is communicated with the pure water chamber, an alkali chamber water outlet which is communicated with the alkali chamber and an acid chamber water outlet which is communicated with the acid chamber.

According to the self-cleaning filtering system, the water outlet of the pure water chamber, the water outlet of the alkali chamber and the water outlet of the acid chamber are connected with the filtering membrane unit through pipelines, and the pipelines are provided with electromagnetic valves.

The self-cleaning filtering system, the electrodialysis cleaning unit comprises a concentrated water pipeline, the concentrated water pipeline is connected with the water inlet through a first electromagnetic valve, the concentrated water pipeline is provided with a concentrated water inlet end and a concentrated water outlet end, the concentrated water inlet end is used for being connected with the filtering membrane unit, the anode chamber and the cathode chamber are connected with the concentrated water pipeline through a second electromagnetic valve,

according to the self-cleaning filtering system, the isolating pieces are all formed by supporting the opening supporting bodies, and the isolating pieces block the openings.

The self-cleaning filtration system as described above, the partition and the support form a membrane stack.

In the self-cleaning filtration system described above, the membrane stack is cubic or cylindrical.

In the self-cleaning filtration system described above, the volume of the casing and the membrane area of the electrodialysis cleaning unit are determined according to the membrane area of the filtration membrane unit.

As described above for the self-cleaning filtration system, the electrodes are connected to a power source via a switching element.

In the self-cleaning filtration system described above, the power source is a voltage and/or current adjustable device.

A water purification device comprises the self-cleaning filtering system.

The water purification device comprises a pre-filter unit arranged at the upstream of the filter membrane unit.

According to the water purifying device, the downstream of the water inlet end of the pure water chamber of the filtering membrane unit is provided with the activated carbon unit.

A self-cleaning filtering method comprises the following steps:

the filtering membrane unit filters water and outputs pure water and concentrated water;

an electrodialysis cleaning unit receives the concentrated water and electrolyzes the concentrated water to generate acid water, alkaline water and pure water;

and controlling the acid water, the alkaline water and the pure water to sequentially clean the filtering membrane unit, or controlling the alkaline water, the acid water and the pure water to sequentially clean the filtering membrane unit.

According to the self-cleaning filtering method, the pure water generated by the electrolysis of the electrodialysis cleaning unit is detected, and the pure water output end of the filtering membrane unit is connected when the pure water reaches the standard.

In the self-cleaning filtration method, the acid water, the alkaline water and the pure water after the filtration membrane unit is cleaned are controlled to enter the electrodialysis cleaning unit and to be discharged from the electrodialysis cleaning unit.

In the self-cleaning filtration method, the concentrated water received by the electrodialysis cleaning unit is controlled to be electrolyzed for the first time, and is discharged through the electrodialysis cleaning unit after the filtration membrane unit is cleaned.

In the self-cleaning filtration method, the water inflow amount or the water production time of the filtration membrane unit is detected, and when the water inflow amount reaches a preset water amount or the water production time reaches a preset time, the electrodialysis cleaning unit is controlled to clean the filtration membrane unit.

Compared with the prior art, the invention has the advantages and positive effects that: the self-cleaning filtering system comprises a filtering membrane unit, an electrodialysis cleaning unit and a control unit, wherein the filtering membrane unit is used for filtering water and outputting pure water and concentrated water, the electrodialysis cleaning unit is used for receiving the concentrated water and electrolyzing the concentrated water to generate acid water, alkaline water and pure water, and the control unit is used for controlling the acid water, the alkaline water and the pure water to sequentially clean the filtering membrane unit or controlling the alkaline water, the acid water and the pure water to sequentially clean the filtering membrane unit. According to the invention, concentrated water is electrolyzed, acid water, alkaline water and pure water are generated simultaneously, and the three kinds of water sequentially clean the RO membrane according to a set sequence (pure water is last), so that compared with physical cleaning, the efficiency is higher; according to the invention, the reverse osmosis membrane cleaned by acid water and alkaline water is cleaned by using pure water generated by the electrodialysis cleaning unit, so that concentrated water on the raw water side can be replaced while residual acid and alkaline are removed, ions in the concentrated water are prevented from passing through the membrane, and the problem of high TDS value of effluent caused by shutdown and restart of a water purification device is solved; the invention can also effectively reduce the generation of waste water.

The water purifying device comprises the self-cleaning filtering system, combines chemical cleaning and physical cleaning, has better cleaning effect, does not have acid and alkali residues, lightens membrane pollution, prolongs the service life of the membrane, and can ensure water safety; the reverse osmosis membrane cleaned by acid water and alkaline water is cleaned by pure water generated by the electrodialysis cleaning unit, so that concentrated water on the raw water side can be replaced while residual acid and alkaline are removed, ions in the concentrated water are prevented from passing through the membrane, and the problem of high TDS value of discharged water caused by shutdown and restart of the water purifying device is solved. In addition, the invention can effectively reduce the generation of waste water.

According to the self-cleaning filtering method, water is filtered by the filtering membrane unit and pure water and concentrated water are output, the electrodialysis cleaning unit receives the concentrated water and electrolyzes the concentrated water to generate acid water, alkaline water and pure water, and the control unit controls the acid water, the alkaline water and the pure water to sequentially clean the filtering membrane unit or controls the alkaline water, the acid water and the pure water to sequentially clean the filtering membrane unit. According to the invention, concentrated water is electrolyzed, acid water, alkaline water and pure water are generated simultaneously, and the RO membrane is sequentially cleaned by the three kinds of water according to a set sequence (pure water is last), so that compared with the physical cleaning, the efficiency is higher; according to the invention, the reverse osmosis membrane cleaned by acid water and alkaline water is cleaned by using pure water generated by the electrodialysis cleaning unit, so that concentrated water on the raw water side can be replaced while residual acid and alkaline are removed, ions in the concentrated water are prevented from passing through the membrane, and the problem of high TDS value of effluent caused by shutdown and restart of a water purification device is solved; the invention can also effectively reduce the generation of waste water.

Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flow chart of a water purifying apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an electrodialysis cleaning unit according to an embodiment of the invention.

Fig. 3 is a schematic structural diagram of an electrodialysis cleaning unit according to an embodiment of the invention.

Fig. 4 is a schematic diagram of an electrodialysis cleaning unit according to another embodiment of the invention.

FIG. 5 is a flow chart of a self-cleaning filtration method in accordance with an embodiment of the present invention.

In the figure, the position of the upper end of the main shaft,

1. a water inlet of the anode chamber;

1', a water outlet of the anode chamber;

2. a water inlet of the pure water chamber;

2', a water outlet of the pure water chamber;

3. a water inlet of the alkali chamber;

3', a water outlet of the alkali chamber;

4. a water inlet of the acid chamber;

4', a water outlet of the acid chamber;

5. a water inlet of the cathode chamber;

5', a water outlet of the cathode chamber;

6. a cation exchange membrane;

7. an anion exchange membrane;

8. a first housing portion;

9. bipolar membrane;

10. a second housing portion.

Detailed Description

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

With the popularization of water purification equipment, the filter element of the water purification equipment is a consumable material which needs to be replaced frequently, and the cost is high, so that how to reduce the pollution of the filter element membrane and prolong the service life of the filter element is an important development direction of the water purification equipment, and the water purification equipment is also one of the technical problems to be solved by the invention.

The following description will be given by taking the filter element as a reverse osmosis membrane filter element, but it is needless to say that the filter element is not limited to a reverse osmosis membrane filter element, and other types of membranes, including but not limited to ultrafiltration membranes, are also within the protection scope of the present invention, and the cleaning unit and the cleaning method of the present invention can also be used for cleaning.

As shown in fig. 1, the present embodiment provides a water purification apparatus including a self-cleaning filtration system, a pre-filter unit located upstream of the self-cleaning filtration system.

The pre-filter unit comprises PP cotton and active carbon and is used for preliminarily filtering impurities in water, raw water can be directly discharged after passing through the PP cotton and the active carbon and is used by a user, and the purified water can also enter the filter membrane unit of the self-cleaning filter system to be further filtered to obtain purified water. Namely, a purified water outlet end and a pipeline connected with the self-cleaning filtering system are arranged at the downstream of the activated carbon.

Of course, the pre-filter unit can be added with other units required by water purification, such as a PP cotton filter element with smaller particle size.

The present embodiment focuses on a self-cleaning filtration system:

as shown in fig. 1 to 3, the self-cleaning filtration system includes a filtration membrane unit, an electrodialysis cleaning unit, and a control unit. The following are specifically described below:

and the filtering membrane unit is used for filtering the water and outputting pure water and concentrated water. The filtration membrane unit of this embodiment is reverse osmosis membrane, and reverse osmosis membrane receives the pure water that the active carbon discharged and filters the pure water and produces pure water and dense water. Wherein, the pure water generated by the reverse osmosis membrane can be directly used by users, and the concentrated water enters the electrodialysis cleaning unit. Namely, a pure water outlet end and a pipeline-concentrated water pipeline connected with the electrodialysis cleaning unit are arranged at the downstream of the reverse osmosis membrane.

And the electrodialysis cleaning unit is used for receiving the concentrated water generated by the reverse osmosis membrane and electrolyzing the concentrated water to generate acid water, alkaline water and pure water.

Specifically, the electrodialysis cleaning unit comprises a shell, a separator and an electrode.

The housing, which in this embodiment is a cube, comprises opposing first 8 and second 10 housing portions.

And the separator is positioned in the shell. The separator comprises a Bipolar membrane (BPM) 9, an Anion Exchange Membrane (AEM) 7 and a Cation Exchange Membrane (CEM) 6, and the inside of the housing is partitioned by the separator to form an anode chamber, a purified water chamber, an alkali chamber, an acid chamber and a cathode chamber.

In this embodiment, as shown in fig. 2, the separator includes: anion exchange membrane AEM, cation exchange membrane CEM, bipolar membrane BPM, anion exchange membrane AEM. The shell is divided by a separator to form an anode chamber, a pure water chamber, an alkali chamber, an acid chamber and a cathode chamber.

Wherein, the separators (anion exchange membrane, cation exchange membrane and bipolar membrane) are respectively supported and formed by the perforated support body, and the separators (anion exchange membrane, cation exchange membrane and bipolar membrane) block the perforated holes and only allow corresponding ions to permeate.

The spacers form a membrane stack with the support. The ion exchange membrane and the support body can be made into a membrane stack meeting the water making principle according to the requirements, and the shape of the membrane stack is changed accordingly. Instead of the cubic membrane stack mentioned in this example, a cylindrical membrane stack can also be made.

In order to better illustrate the structure of the electrodialysis cleaning unit, fig. 3 is a simple three-dimensional structure diagram, which is not drawn to a strict scale, and the detailed structure size needs to be designed according to specific situations because the structure is used with other units. In addition, for the convenience of understanding, the shape of the membrane stack is designed to be a cubic structure in this embodiment, and in order to increase the membrane area, the device may also be designed to be a cylinder or any other device that can implement the technical principle proposed in this patent.

The volume of the shell of the electrodialysis cleaning unit and the areas of the bipolar membrane and the ion exchange membrane are determined according to the water flow of the whole machine, namely the size of the membrane area of the filtering membrane unit.

Of course, the membrane stack constituting the electrodialysis cleaning unit may be formed by more than one bipolar membrane, or may be formed by a plurality of bipolar membranes and ion exchange membranes, as shown in fig. 4, to form a membrane stack capable of discharging acid water, alkaline water and pure water.

And the electrodes are positioned in the shell and comprise a first electrode-anode and a second electrode-cathode, and the first electrode and the second electrode are respectively positioned in the anode chamber and the cathode chamber. Alternatively, to reduce the volume of the housing, electrodes may be attached to the housing, with a first electrode and a second electrode being located on the housing, respectively, in particular, the first electrode being located on the first housing part 8 and the second electrode being located on the second housing part 10.

The electrodes are connected to a power supply via a switching element. The power supply is a voltage and/or current adjustable device.

The shell is provided with water inlets which are respectively communicated with the anode chamber, the pure water chamber, the alkali chamber, the acid chamber and the cathode chamber, and the shell specifically comprises an anode chamber water inlet 1, a pure water chamber water inlet 2, an alkali chamber water inlet 3, an acid chamber water inlet 4 and a cathode chamber water inlet 5. The shell is also provided with a pure water chamber water outlet 2 ' communicated with the pure water chamber, an alkali chamber water outlet 3 ' communicated with the alkali chamber and an acid chamber water outlet 4 ' communicated with the acid chamber. The shell is also provided with an anode chamber water outlet 1 'communicated with the anode chamber and a cathode chamber water outlet 5' communicated with the cathode chamber.

In the embodiment, the water outlet 2 ' of the pure water chamber, the water outlet 3 ' of the alkali chamber and the water outlet 4 ' of the acid chamber are connected with the filtering membrane unit through pipelines, and the pipelines are provided with electromagnetic valves.

Specifically, the water outlet 2 ' of the pure water chamber, the water outlet 3 ' of the alkali chamber and the water outlet 4 ' of the acid chamber can be connected with the filtering membrane unit through a pipeline, a four-way electromagnetic valve is arranged on the pipeline, and the water outlet connected with the filtering membrane unit is controlled through the four-way electromagnetic valve.

Of course, the water outlet 2 ' of the pure water chamber, the water outlet 3 ' of the alkali chamber and the water outlet 4 ' of the acid chamber can also be connected with the filtering membrane unit through three pipelines, each pipeline is provided with an electromagnetic valve, and the water outlet connected with the filtering membrane unit is controlled by the electromagnetic valve.

Corresponding to the figure 2, the concentrated water RM entering each chamber of the electrodialysis cleaning unit through the water inlets 1-5 forms a solution containing single anions M & lt- & gt in the anode chamber between the first shell part 8 and the anion exchange membrane 7 close to the anode side in the figure 3 through electrolysis; a pure water chamber is formed between the anion exchange membrane 7 and the cation exchange membrane 6 which are close to the anode side; an alkali chamber is formed between the cation exchange membrane 6 and the bipolar membrane 9; an acid chamber is formed between the bipolar membrane 9 and the anion exchange membrane 7 close to the cathode side; the cathode compartment, which is located between the cathode side anion exchange membrane 7 and the cathode 10, forms a solution containing monocationic R +. And controlling acid water, alkaline water and pure water to discharge water according to a set water discharge sequence (pure water is last) through a four-way electromagnetic valve or three electromagnetic valves to perform RO membrane cleaning, converging single-ion solutions in the anode chamber and the cathode chamber, performing electric neutralization again to form a salt solution (wastewater) containing RM with higher concentration, and discharging the salt solution (wastewater) through a concentrated water outlet end of the electrodialysis cleaning unit.

And the control unit is used for controlling the acid water, the alkaline water and the pure water to sequentially clean the filtering membrane unit, or controlling the alkaline water, the acid water and the pure water to sequentially clean the filtering membrane unit. Wherein, no strong requirements are made on the water outlet sequence of the acid chamber and the alkali chamber, and pure water is finally discharged. The sour water can wash RO membrane surface inorganic pollution, and the buck can wash RO membrane surface organic pollution, and the sour alkaline water all can restrain the microorganism enrichment, and the pure water is last to be gone out the water and wash the sour alkaline water of remaining on the membrane surface, and the pure water can replace RO membrane raw water side dense water, prevents that the membrane is crossed to the ion in the dense water, has solved the problem that the play water TDS value that water purification equipment shut down the restart and caused is high.

The electrodialysis cleaning unit comprises a concentrated water pipeline, the concentrated water pipeline is used for conveying concentrated water containing salt RM in the figure 2, the concentrated water pipeline is provided with a concentrated water inlet end and a concentrated water outlet end, and the concentrated water inlet end is used for being connected with the filtering membrane unit and receiving the concentrated water discharged by the filtering membrane unit. The concentrated water pipeline is connected with the water inlets 1-5 through a first electromagnetic valve, and the anode chamber and the cathode chamber are connected with the concentrated water pipeline through a second electromagnetic valve.

The control unit is also used for controlling acid water, alkaline water and pure water which are used for cleaning the filtering membrane unit to enter the electrodialysis cleaning unit and to be discharged from the electrodialysis cleaning unit. In order to prevent the generation of byproducts or harmful substances, the control unit is also used for controlling concentrated water received by the electrodialysis cleaning unit to be subjected to primary electrolysis and discharged through the electrodialysis cleaning unit after the filtration membrane unit is cleaned.

Specifically, the control unit controls the first electromagnetic valve to be opened, the second electromagnetic valve and the four-way electromagnetic valve to be closed, when the concentrated water discharged from the RO unit containing salt RM (a general name of salt components in the concentrated water of the reverse osmosis unit does not represent any specific salt and can be dissociated into R + and M-) enters the cleaning unit, the electrolysis mode is started, as shown in FIG. 2, under the action of potential difference between a cathode and an anode, cations R + and anions M-are respectively diffused to the two poles, because the cation exchange membrane and the anion exchange membrane only allow the cations and the anions to permeate through, R + and M-in the pure water chamber respectively permeate through the ion exchange membrane to reach the alkali chamber and the anode chamber, under the action of electrolysis, H + and OH-generated by the dissociation of the two poles of the bipolar membrane are respectively diffused to the acid chamber and the alkali chamber, and in order to ensure charge conservation, M-in the cathode chamber reaches the acid chamber through, in the anode and cathode compartments, respectively, a single ion solution containing M-and R +, pure water is formed in the pure water compartment due to ion removal, and acid and alkaline water containing HM and ROH forms are formed in the acid and alkaline compartments. When the cleaning unit cleans the filtering membrane unit, the control unit controls the first electromagnetic valve to be closed, the second electromagnetic valve is opened, the four-way electromagnetic valve sequentially controls acid water, alkaline water and pure water to be discharged according to a set sequence, or sequentially controls the alkaline water, the acid water and the pure water to be discharged, the RO membrane is sequentially cleaned by controlling the four-way electromagnetic valve, the cleaned concentrated water enters the concentrated water pipeline and is discharged from the concentrated water outlet end, the discharged water of the anode chamber and the cathode chamber is mixed to realize electric neutralization, and the concentrated water pipeline is converged again and is discharged from the concentrated water outlet end.

In order to save water, the embodiment further comprises a water quality monitoring module for detecting the water quality of the pure water generated by the electrolysis of the electrodialysis cleaning unit; the control unit is also used for connecting the pure water output end of the filtering membrane unit when the water quality reaches the standard and supplying the pure water to a user for use.

The embodiment is further provided with a water quantity detection module or a timing module, wherein the water quantity detection module is used for detecting the water inflow of the filtering membrane unit, and the timing module is used for timing the water making time; the control unit is also used for controlling the electrodialysis cleaning unit to clean the filtering membrane unit when the water inflow reaches the preset water amount or the water making time reaches the preset time.

In the embodiment, raw water is sequentially filtered by PP cotton and activated carbon and then enters the RO reverse osmosis membrane, pure water after fine filtration flows out to be directly drunk, concentrated water flows into the electrodialysis cleaning unit, acid water and alkaline water after electrolysis return to the raw material liquid side of the RO membrane in sequence to carry out membrane cleaning, and after inorganic matters and colloid on the surface of the membrane are cleaned by the acid and alkaline water, the pure water outlet of the electrodialysis cleaning unit can be used for cleaning residual acid and alkaline liquid on the raw material liquid side of the RO membrane. The electrodialysis cleaning unit can be used for intermittent water production, in one cycle, when RO water production is finished, pure water is stored in the pure water tank, concentrated water enters the electrodialysis cleaning unit for electrolysis, generated acid-base water can be used for RO membrane cleaning, then pure water can be used for cleaning acid-base water on the RO raw water side, redundant waste water is directly discharged out of the system, and then the next water production cycle can be carried out. The electrodialysis cleaning unit can also be used for continuous water production, the control unit can be adopted for intelligent control, reverse osmosis concentrated water enters the electrodialysis cleaning unit, electrolyzed acid-base water and pure water are stored in the unit after electrolysis, redundant wastewater does not need to be directly discharged from an electrolysis system, and after water production is finished, the stored acid-base water and pure water sequentially clean the RO membrane. The two operation modes consider that the water inflow reaches the preset water amount or the water making time reaches the preset time, and when the conditions are not met, the electrodialysis cleaning unit is controlled to clean the filtering membrane unit when the water inflow reaches the preset water amount or the water making time reaches the preset time.

Preferably, an active carbon unit can be arranged at the downstream of the water inlet end of the pure water chamber of the filtering membrane unit so as to improve the taste.

The embodiment also provides a self-cleaning filtering method:

the electrodialysis cleaning unit receives the concentrated water and electrolyzes the concentrated water to generate acid water, alkaline water and pure water;

In order to save water, the pure water generated by the electrolysis of the electrodialysis cleaning unit is detected and is connected to the pure water output end of the filtering membrane unit when reaching the standard.

And controlling acid water, alkaline water and pure water which are used for cleaning the filtering membrane unit to enter the electrodialysis cleaning unit and discharge from the electrodialysis cleaning unit.

In order to prevent the generation of byproducts or harmful substances, concentrated water received by the electrodialysis cleaning unit is controlled to be electrolyzed for the first time, and the concentrated water is discharged through the electrodialysis cleaning unit after the filtration membrane unit is cleaned.

And detecting the water inflow or the water making time of the filtering membrane unit, and controlling the electrodialysis cleaning unit to clean the filtering membrane unit when the water inflow reaches a preset water amount or the water making time reaches the preset time.

Specifically, as shown in fig. 5, the control method of the present embodiment includes the following steps:

and S1, starting the water purifying equipment to operate. The filtering membrane unit filters the water and outputs pure water and concentrated water.

And S2, detecting the water inflow or water production time of the filtering membrane unit.

And S3, judging whether the water inflow reaches the preset water amount or the water making time reaches the preset time, if so, entering the step S4, and otherwise, entering the step S2.

And S4, electrolyzing the received concentrated water by the electrodialysis cleaning unit to generate acid water, alkaline water and pure water. At the moment, the control unit controls the first electromagnetic valve to be opened, the second electromagnetic valve to be closed and the four-way electromagnetic valve to be closed.

And S5, controlling acid water, alkaline water and pure water to clean the filtering membrane unit according to a preset sequence. Specifically, the acid water, the alkaline water and the pure water are controlled to sequentially clean the filtering membrane unit, or the alkaline water, the acid water and the pure water are controlled to sequentially clean the filtering membrane unit. The cleaning sequence is mainly controlled by controlling the conducting state of the four-way electromagnetic valve through the control unit.

S6, closing the first electromagnetic valve, and controlling acid water, alkaline water and pure water after the filtration membrane unit is cleaned to enter the electrodialysis cleaning unit and be discharged from a concentrated water outlet end of a concentrated water pipeline of the electrodialysis cleaning unit; and controlling the second electromagnetic valve to be opened, mixing the effluent of the anode chamber and the cathode chamber to realize electric neutralization, and then converging the mixture to a concentrated water pipeline again and discharging the mixture from a concentrated water outlet end.

Of course, a concentrated water discharge pipeline can be independently arranged, acid water, alkaline water and pure water which are used for cleaning the filtering membrane unit are directly discharged from the concentrated water discharge pipeline, the discharged water of the anode chamber and the cathode chamber is mixed to realize electric neutralization, and the mixed water is converged to the concentrated water discharge pipeline again to be discharged, so that the first electromagnetic valve is not needed.

And S7, detecting the pure water generated by the electrolysis of the electrodialysis cleaning unit, and connecting the pure water output end of the filtering membrane unit when the pure water reaches the standard.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. A self-cleaning filtration system, the system comprising:

2. The self-cleaning filtration system of claim 1, comprising:

3. The self-cleaning filtration system of claim 1, wherein the control unit is further configured to control the acid water, the alkaline water, and the pure water after cleaning the filtration membrane unit to enter and exit the electrodialysis cleaning unit.

4. The self-cleaning filtration method according to claim 3, wherein the control unit is further configured to control concentrated water received by the electrodialysis cleaning unit to be electrolyzed once and discharged through the electrodialysis cleaning unit after cleaning the filtration membrane unit.

5. The self-cleaning filtration system of claim 1, comprising:

6. The self-cleaning filtration system of any of claims 1-5, wherein the filtration membrane unit is a reverse osmosis membrane or an ultrafiltration membrane.

7. The self-cleaning filtration system of any of claims 1-5, wherein the electrodialysis wash unit comprises:

a housing;

8. The self-cleaning filtration system of claim 7, wherein the pure water chamber water outlet, the alkaline chamber water outlet and the acid chamber water outlet are connected to the filtration membrane unit through a pipeline, and the pipeline is provided with an electromagnetic valve.

9. A self-cleaning filtration system according to claim 7, wherein the electrodialysis cleaning unit comprises a concentrate line connected to the water inlet via a first solenoid valve, the concentrate line having a concentrate inlet end for connection to the filtration membrane unit and a concentrate outlet end, the anode and cathode compartments being connected to the concentrate line via a second solenoid valve.

10. The self-cleaning filtration system of claim 7, wherein the spacers are each formed from an open-cell support, the spacers sealing the open-cell.

11. The self-cleaning filtration system of claim 10, wherein the partition and the support form a membrane stack.

12. The self-cleaning filtration system of claim 11, wherein the membrane stack is cubic or cylindrical.

13. The self-cleaning filtration system of claim 7, wherein the housing volume and membrane area of the electrodialysis cleaning unit are determined according to the membrane area of the filtration membrane unit.

14. The self-cleaning filtration system of claim 7, wherein the electrodes are connected to a power source through a switching element.

15. The self-cleaning filtration system of claim 14, wherein the power source is a voltage and/or current tunable device.

16. A water purification apparatus comprising the self-cleaning filtration system of any one of claims 1-15.

17. The water purification apparatus of claim 16, comprising a pre-filter unit disposed upstream of the filter membrane unit.

18. The water purification apparatus of claim 17, wherein an activated carbon unit is disposed downstream of a water inlet end of the pure water chamber of the filtration membrane unit.

19. A self-cleaning filtering method is characterized in that:

20. The self-cleaning filtration method of claim 19, wherein the pure water electrolytically generated by the electrodialysis cleaning unit is detected and is connected to the pure water output terminal of the filtration membrane unit when reaching standards.

21. The self-cleaning filtration process of claim 19, wherein acid water, alkaline water and pure water that have washed the filtration membrane unit are controlled to enter and exit the electrodialysis cleaning unit.

22. The self-cleaning filtration process of claim 19, wherein the concentrated water received by the electrodialysis cleaning unit is controlled to be electrolyzed for the first time and discharged through the electrodialysis cleaning unit after cleaning the filtration membrane unit.

23. The self-cleaning filtration method according to claim 19, wherein the water inflow amount or the water production time of the filtration membrane unit is detected, and the electrodialysis cleaning unit is controlled to clean the filtration membrane unit when the water inflow amount reaches a preset water amount or the water production time reaches a preset time.