EDI (electrodeionization) membrane stack electrodeionization device

Abstract

The utility model discloses an EDI (Electrodeionization) membrane stack electrodeionization device, which relates to the technical field of water treatment, adopts a multi-section EDI membrane stack structure for desalting, and comprises an EDI membrane stack, the EDI membrane stack comprises at least one pair of fresh water plate and concentrated water plate which are oppositely arranged, the same number of positive membranes and negative membranes are alternately arranged between the fresh water plate and the concentrated water plate in sequence to form alternate fresh water chambers and concentrated water chambers, and flow guide nets are arranged on the positive membrane sides of the fresh water chambers and the positive membrane sides of the concentrated water chambers. Due to the fact that the flow guide nets are additionally arranged on the cation membrane side of the fresh water chamber and the cation membrane side of the concentrated water chamber, stirring and turbulence of water flow are improved, the concentration polarization phenomenon of the membrane surface caused in the cation migration process of the cation membrane can be avoided, and EDI membrane stack scaling is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to an EDI membrane stack electric desalination device. Background Art

[0002] EDI (continuous electrolytic desalination technology) is a pure water manufacturing technology that combines electrodialysis technology and ion exchange technology. In the EDI desalination process, through the action of the electric field, ions are directional migrated in the water, and the ions are removed through the ion exchange membrane to achieve the purpose of deep purification and desalination. Water molecules produce hydrogen ions and hydroxide ions under the action of the electric field, and the anion and hydroxyl ions are continuously regenerated, so that high-quality ultrapure water can be continuously produced without chemical regeneration during the EDI water production process. Traditional EDI water intake requires concentrated water and fresh water to be treated together. Concentrated water can take away the anions and cations that migrate from the fresh water side to prevent scaling. In EDI, the cations in the fresh water chamber migrate to the negative electrode through the cation membrane and are intercepted by the anion membrane in the concentrated chamber. The anions in the water migrate to the positive electrode direction through the anion membrane and are intercepted by the cation membrane in the concentrated chamber, so that the number of ions in the water passing through the dilute chamber gradually decreases to form fresh water. In the water in the concentrated chamber, due to the continuous influx of anions and cations in the concentrated chamber, the dielectric ion concentration continues to increase, becoming concentrated water, achieving the purpose of desalination, purification, concentration or refinement.

[0003] The EDI membrane stack is composed of alternating cation membranes and anion membranes. The cation membrane, anion membrane and cation-anion resins form a freshwater chamber unit. The concentrated water chamber is between two adjacent freshwater chambers. The anode, cathode and freshwater chamber are pole water chambers for removing electrode reaction products. In the prior art, there is an EDI membrane stack structure with one level and multiple sections. Such a structure can improve the stability of effluent water quality and product performance. After the water passes through the freshwater chamber to remove ions, it is deionized again through another freshwater chamber to achieve more thorough water purification. Then, during the migration of cations in the cation membrane, concentration polarization will occur on the surface of the cation membrane. The EDI membrane stack will scale after long-term use, affecting the effluent water quality and product performance. Utility Model Content

[0004] The utility model aims to provide an EDI membrane stack electric desalination device to improve the desalination structure using a multi-stage EDI membrane stack, where concentration polarization occurs on the surface of the cation membrane in the EDI membrane stack, leading to scaling of the EDI membrane stack.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an EDI membrane stack electro-desalination device, including an EDI membrane stack, the EDI membrane stack including at least one pair of fresh water plates and concentrated water plates placed opposite to each other, an equal number of cation membranes and anion membranes are alternately arranged between the fresh water plates and the concentrated water plates in sequence to form alternating fresh water chambers and concentrated water chambers, and a guide net is arranged on the cation membrane side of the fresh water chamber and the cation membrane side of the concentrated water chamber.

[0006] After adopting the above technical solution, the utility model has the following advantages:

[0007] Adding guide nets on the cation membrane side of the fresh water chamber and the cation membrane side of the concentrate chamber can accurately guide the flow of fresh water and concentrate water when the EDI membrane stack simultaneously processes fresh water and concentrate water, increase the agitation and turbulence of the water flow, avoid the concentration polarization phenomenon on the membrane surface caused by the migration of cations in the cation membrane, prevent scaling of the EDI membrane stack, and ensure the effluent quality and product performance of the machine;

[0008] The EDI membrane stack electro-desalination device adopts alternating fresh water chambers and concentrated water chambers. The alternating fresh water chambers and concentrated water chambers and the structural design of the cation membrane and anion membrane can improve the stability of the effluent water quality to ensure that the EDI membrane stack continuously produces high-quality ultrapure water; the use of cation membranes and anion membranes for ion exchange can effectively remove ions and impurities in the water without the use of chemical reagents and without causing secondary pollution.

[0009] The EDI membrane stack is designed with a one-stage two-stage or one-stage three-stage structure to improve the stability of effluent water quality and enhance product performance.

[0010] Furthermore, the EDI membrane stack electro-desalination device also includes a guide plate for dividing the EDI membrane stack into at least two parts, and the guide plate is provided with a guide flow hole, and the fresh water flows into the guide flow hole through the guide net.

[0011] By adopting the above-mentioned technical scheme, through the design of guide plates and diversion holes, the water flow has a good flow direction in the EDI membrane stack, which helps to improve the efficiency and effect of water treatment. The setting of guide plates and diversion holes can also evenly disperse the pressure of water flow in the EDI membrane stack, which can to a certain extent avoid the occurrence of high pressure accumulation of water flow in specific areas, reduce damage to the membrane stack and increase the service life of the membrane stack.

[0012] Furthermore, the membrane stack is a rectangular parallelepiped or a cylinder, the flow guide holes are arranged on opposite sides of the length or width of the rectangle, and the flow guide holes on adjacent guide plates are staggered.

[0013] By adopting the above-mentioned technical solution, by setting the diversion holes on both sides of the membrane stack, the water flow is guided to enter the membrane stack from different directions, thereby achieving a more uniform water flow distribution, and allowing the water flow to be fully stirred in the EDI membrane stack, flexibly changing the flow direction of the water flow in the EDI membrane stack, which helps the EDI membrane stack to fully participate in the ion removal process.

[0014] Furthermore, the EDI membrane stack electro-desalination device also includes a water distribution plate and an aluminum plate, the aluminum plate is rectangular or cylindrical, the water distribution plate and the aluminum plate are sequentially assembled at the two ends of the EDI membrane stack electro-desalination device, the water distribution plate is arranged between the aluminum plate and the EDI membrane stack, and the aluminum plate is provided with a water inlet; and / or, the aluminum plate is provided with a water outlet.

[0015] By adopting the above-mentioned technical solution, aluminum plates and water distribution plates are set at both ends of the EDI membrane stack electro-desalination device, which can maintain uniform distribution of water flow in the EDI membrane stack. The aluminum material has good corrosion resistance and can operate stably and long-term in the EDI membrane stack electro-desalination device. Aluminum is a lightweight material, which helps to reduce the weight of the entire device; inlet and outlet are set on the aluminum plate, which provides a way to connect with other components or pipelines; the combined structure of the aluminum plate and the water distribution plate is relatively simple, easy to manufacture and replace, and reduces the manufacturing and maintenance costs of the device.

[0016] Furthermore, the aluminum plate includes a non-porous aluminum plate and a porous aluminum plate, the non-porous aluminum plate is provided with a fresh water inlet and a concentrated water inlet, and the fresh water inlet and the concentrated water inlet are arranged on the first side of the length of the non-porous aluminum plate; the porous aluminum plate is provided with a produced water outlet and a concentrated water outlet, and the produced water outlet and the concentrated water outlet are arranged on the second side of the length of the porous aluminum plate.

[0017] By adopting the above-mentioned technical solution, fresh water and concentrated water are respectively provided with inlets and outlets at both ends of the EDI membrane stack electro-deionization device, which helps to maintain a stable flow inside the membrane stack and reduce the risks of problems such as membrane blockage and corrosion, so that the EDI membrane stack electro-deionization device can effectively control the water flow and distribute the water flow evenly.

[0018] Furthermore, the EDI membrane stack is provided with a water flow channel connected to the aluminum plate. After fresh water flows into the EDI membrane stack from the fresh water inlet for desalination, it is guided by the guide net and flows through the guide net until it completely passes through the EDI membrane stack and then flows out from the water production outlet; concentrated water flows into the EDI membrane stack from the concentrated water inlet, is guided by the guide net and completely passes through the EDI membrane stack and then flows out from the concentrated water outlet.

[0019] By adopting the above-mentioned technical solution, inlet and outlet, guide net and guide plate for guiding the different flow directions of fresh water and concentrated water are set in the EDI membrane stack electro-desalination device, which can effectively avoid ion cross-contamination between fresh water and concentrated water and maintain the purity of produced water. At the same time, it helps to optimize the distribution and flow rate of water flow in the EDI membrane stack, thereby improving the desalination efficiency of the EDI membrane stack.

[0020] Furthermore, the mesh size of the guide net is 40 to 100 meshes.

[0021] Using the above technical solution, the mesh size of the guide net is 40 to 100 meshes. Adding the guide net can increase the agitation and turbulence of the water flow, avoid the concentration polarization phenomenon on the membrane surface caused by the cation migration process of the cation membrane, and prevent scaling of the EDI membrane stack.

[0022] Furthermore, the guide net is made of stainless steel.

[0023] With the aforementioned technical solution, stainless steel is a material with excellent corrosion resistance, performs well when used in a wet or corrosive environment, and is not easily deformed or damaged during long-term use.

[0024] Furthermore, the fresh water chamber and the concentrated water chamber are both filled with ion fast migration substances.

[0025] By adopting the above-mentioned technical solution, filling the fresh water chamber and the concentrated water chamber with ion fast migration materials can increase the ion migration rate, increase the adsorption surface area, reduce the conductivity, increase the ion adsorption capacity, and improve the stability of the device.

[0026] Furthermore, the ion fast migration material is a mixed ion exchange resin of an anion exchange resin and a cation exchange resin.

[0027] The above-mentioned technical solution is adopted to mix anion exchange resin and cation exchange resin as a fast ion migration material, which has the advantages of efficient ion exchange, wide applicability, increased adsorption capacity, reduced ion leakage, improved device stability and flexible adjustment.

[0028] The functional ion exchange resins and ion membranes filled in the second or third sections of the EDI membrane stack design further direct the migration of ions that cannot be filtered in the first section. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The utility model is further described below in conjunction with the accompanying drawings:

[0030] Figure 1 It is an exploded view of the EDI membrane stack in Example 1;

[0031] Figure 2 Schematic diagram of the overall structure of the EDI membrane stack in Example 1 (I);

[0032] Figure 3 It is a partial exploded view of the EDI membrane stack in Example 1;

[0033] Figure 4 The overall structural diagram of the EDI membrane stack in Example 1 (II);

[0034] Figure 5 This is a flow diagram of fresh water in the EDI membrane stack in Example 1;

[0035] Figure 6 The diagram of the flow direction of concentrated water in the EDI membrane stack in Example 1;

[0036] Figure 7This is a schematic diagram of the overall structure of the EDI membrane stack in Example 2;

[0037] Figure 8 This is the flow diagram of fresh water in the EDI membrane stack in Example 2;

[0038] Fig. 9 The flow diagram of concentrated water in the EDI membrane stack in Example 2;

[0039] Figure numerals: EDI membrane stack-1, fresh water plate-11, concentrated water plate-12, guide plate-2, diversion hole-22, guide net-3, non-porous aluminum plate-4, concentrated water inlet-41, fresh water inlet-42, perforated aluminum plate-5, concentrated water outlet-51, produced water outlet-52, non-porous water distribution plate-6, perforated water distribution plate-7, screw-8, screw hole-81. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments.

[0041] The terms "first", "second", etc. (if any) in the specification and claims of the present utility model are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish a certain technical feature, it does not necessarily mean that it has "first". It should be understood that in the present utility model, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in the present utility model, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "Contains X, Y and Z", "Contains X, Y, Z" means that X, Y, and Z are all included, "Contains X, Y or Z" means that one of X, Y, and Z is included, and "Contains X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included.

[0042] The following specific embodiments are used to describe the technical solution of the utility model in detail. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0043] Embodiment 1:

[0044] like Figures 1 to 4As shown, the utility model provides an EDI membrane stack electro-desalination device, including an EDI membrane stack 1. In this embodiment, the EDI membrane stack is a one-stage three-stage structure. The EDI membrane stack 1 includes at least one pair of fresh water plates 11 and concentrated water plates 12 placed opposite to each other. An equal number of cation membranes and anion membranes are alternately arranged between the fresh water plates 11 and the concentrated water plates 12 to form alternating fresh water chambers and concentrated water chambers. A guide net 3 is provided on the cation membrane side of the fresh water chamber and the cation membrane side of the concentrated water chamber. The provision of the guide net 3 enables the EDI membrane stack electro-deionization device to accurately guide the flow direction of fresh water and concentrated water when performing water treatment. Under the guiding effect of the guide net 3, the agitation of the water flow is increased, and the concentration polarization phenomenon when the cations migrate in the cation membrane inside the EDI membrane stack 1 is reduced. The scaling problem on the cation membrane side of the fresh water plate 11 and the concentrated water plate 12 in the EDI membrane stack 1 due to the concentration difference is also improved, so as to ensure the water quality and product performance of the machine's outlet water; the EDI membrane stack electro-deionization device adopts alternating fresh water chambers and concentrated water chambers, which can improve the stability of the outlet water quality, so as to ensure that the EDI membrane stack 1 continuously produces high-quality ultrapure water; the use of cation membranes and anion membranes for ion exchange can effectively remove ions and impurities in water without the use of chemical reagents, and does not produce secondary pollution.

[0045] It is understandable that the EDI membrane stack is designed with a one-stage two-section or one-stage three-section structure to improve the stability of effluent water quality and enhance product performance.

[0046] In this embodiment, in addition to the EDI membrane stack 1, the EDI membrane stack 1 electro-desalination device also includes a water distribution plate and an aluminum plate. The aluminum plate and the water distribution plate are both rectangular plates of the same size as the EDI membrane stack 1 and are sequentially assembled at the two ends of the EDI membrane stack electro-desalination device, wherein the water distribution plate is arranged between the aluminum plate and the EDI membrane stack 1. Aluminum has good corrosion resistance and can operate stably for a long time in the EDI membrane stack electro-desalination device. Aluminum is a lightweight material, which helps to reduce the weight of the entire device. Because it is arranged at both ends of the EDI membrane stack electro-desalination device, a water inlet or outlet that cooperates with other components is arranged on the aluminum plate, providing a connection method for other components or pipelines, which helps to maintain a stable flow inside the membrane stack and reduce the risk of problems such as membrane blockage and corrosion, so that the EDI membrane stack electro-desalination device can effectively control water flow, evenly distribute water flow, reduce pressure loss, and facilitate maintenance and cleaning. The combined structure of the aluminum plate and the water distribution plate is relatively simple, easy to manufacture and replace, and reduces the manufacturing and maintenance costs of the device.

[0047] Specifically, the aluminum plate includes a non-porous aluminum plate 4 and a porous aluminum plate 5. The non-porous aluminum plate 4 is provided with a fresh water inlet 42 and a concentrated water inlet 41. The fresh water inlet 42 and the concentrated water inlet 41 are arranged on a first side of the length of the non-porous aluminum plate 4, and the aperture of the fresh water inlet 42 is larger than that of the concentrated water inlet 41; the porous aluminum plate 5 is provided with a produced water outlet 52 and a concentrated water outlet 51. The produced water outlet 52 and the concentrated water outlet 51 are arranged on a second side of the length of the porous aluminum plate 5, and the aperture of the produced water outlet 52 is larger than that of the concentrated water outlet 51.

[0048] In this embodiment, the EDI membrane stack electro-desalination device further includes a guide plate 2 for separating the EDI membrane stack into at least two parts, and the guide plate 2 is provided with a guide hole 22, and the fresh water flows through the guide net 3 to the guide hole 22. Through the design of the guide plate 2 and the guide hole 22, the water flow has a good flow direction in the EDI membrane stack 1, which helps to improve the water treatment efficiency and desalination effect. The setting of the guide plate 2 and the guide hole 22 also helps to evenly disperse the pressure in the EDI membrane stack 1, avoid high pressure accumulation in a specific area, reduce membrane damage and increase service life.

[0049] Specifically, in this embodiment, the EDI membrane stack 1 is a rectangular parallelepiped, and the flow guide holes 22 are arranged on opposite sides of the length or width of the rectangle, and the flow guide holes 22 on adjacent guide plates 2 are arranged in a staggered manner. By arranging the flow guide holes 22 on both sides of the membrane stack, the water flow is guided to enter the next EDI membrane stack 1 from different directions, thereby achieving a more uniform water flow distribution, and also allowing the water flow to be fully stirred in the EDI membrane stack 1, and the flow direction of the water flow in the EDI membrane stack 1 can be changed according to demand, which helps to ensure that the membranes at different positions in the EDI membrane stack 1 can fully participate in the deionization process and improve the performance of the entire membrane stack.

[0050] like Figure 5 and Figure 6 As shown, the flow direction of the fresh water in the EDI membrane stack electro-deionization device is A, and the flow direction of the concentrated water in the EDI membrane stack electro-deionization device is B. A water flow channel connected to the aluminum plate is provided in the EDI membrane stack 1. After the fresh water flows into the EDI membrane stack 1 from the fresh water inlet 42 for desalination, it is guided by the guide net 3, flows into the guide net 3 until it completely passes through all the EDI membrane stacks 1, and then flows out from the water production outlet 52; the concentrated water flows into the EDI membrane stack 1 from the concentrated water inlet 41, guides the guide net 3, and completely passes through the EDI membrane stack 1, and then flows out from the concentrated water outlet 51. In the EDI membrane stack electro-deionization device, an inlet and outlet, a guide net 3, and a guide plate 2 for guiding the flow of fresh water and concentrated water in different directions are provided, which can effectively avoid ion cross-contamination between fresh water and concentrated water, maintain the purity of produced water, and at the same time help optimize the distribution and flow rate of water flow, thereby improving the use efficiency of the membrane.

[0051] Specifically, in this embodiment, the mesh number of the guide net 3 is 40-100 meshes, and the mesh number of the guide net 3 is 40-100 meshes. Adding the guide net can increase the agitation and turbulence of the water flow, avoid the concentration polarization phenomenon on the membrane surface caused by the cation migration process of the cation membrane, and prevent the EDI membrane stack from scaling. It is understandable that the mesh number of the guide net is adjusted according to the specific water treatment requirements.

[0052] Specifically, the guide net 3 is made of stainless steel. Stainless steel is a material with excellent corrosion resistance and performs well when used in a wet or corrosive environment. The stainless steel guide net 3 has high strength and can be used for a long time in various environments without being easily deformed or damaged.

[0053] In addition, in this embodiment, both the fresh water chamber and the concentrated water chamber are filled with ion fast migration substances. Filling the fresh water chamber and the concentrated water chamber with ion fast migration substances can increase the ion migration rate, increase the adsorption surface area, reduce the conductivity, increase the ion adsorption capacity, and improve the stability of the device. The ion fast migration substance is a mixed ion exchange resin of anion exchange resin and cation exchange resin. Mixing anion exchange resin and cation exchange resin as ion fast migration substances has the advantages of efficient ion exchange, wide applicability, increased adsorption capacity, reduced ion leakage, improved device stability and flexible adjustment.

[0054] The functional ion exchange resins and ion membranes filled in the second or third sections of the EDI membrane stack design further direct the migration of ions that cannot be filtered in the first section.

[0055] Embodiment 2:

[0056] Based on the structure of the above embodiment, Figure 7 As shown, in this embodiment, the EDI membrane stack 1 is a one-stage two-stage structure. Since only one guide plate 2 is provided in the EDI membrane stack 1, during the water purification process of the EDI membrane stack electro-deionization device, the flow direction of water in the EDI membrane stack 1 is fixed, the flow direction of the fresh water in the EDI membrane stack electro-deionization device is C, and the flow direction of the concentrated water in the EDI membrane stack electro-deionization device is D.

[0057] Specifically, Figure 8 and 9As shown, the flow direction of the fresh water in the EDI membrane stack electro-deionization device is A, and the flow direction of the concentrated water in the EDI membrane stack electro-deionization device is B; the EDI membrane stack electro-deionization device includes a non-porous aluminum plate 4 arranged at the water inlet end and a porous aluminum plate 5 arranged at the water outlet end, the non-porous aluminum plate 4 and the porous aluminum plate 5 are both rectangular, the fresh water inlet 42 and the concentrated water inlet 41 are arranged on the first side of the length of the non-porous aluminum plate 4, wherein the aperture size of the concentrated water inlet 41 is smaller than the aperture size of the fresh water inlet 42; the concentrated water outlet 51 and the produced water outlet 52 are respectively arranged on the first side and the second side of the length of the porous aluminum plate 5, specifically, the concentrated water outlet 51 and the concentrated water inlet 41 are located on the same side of the EDI membrane stack electro-deionization device, the produced water outlet 52 and the fresh water inlet 42 are located on the different sides of the EDI membrane stack electro-deionization device, and the aperture size of the concentrated water outlet 51 is larger than the aperture size of the produced water outlet 52.

[0058] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. An EDI membrane stack electric desalination device, comprising an EDI membrane stack, characterized in that: The EDI membrane stack includes at least one pair of fresh water plates and concentrated water plates placed opposite to each other, wherein equal numbers of cation membranes and anion membranes are alternately arranged between the fresh water plates and the concentrated water plates to form alternating fresh water chambers and concentrated water chambers, and guide nets are arranged on the cation membrane sides of the fresh water chambers and the cation membrane sides of the concentrated water chambers.

2. The EDI membrane stack electric desalination device according to claim 1, characterized in that: The EDI membrane stack electric desalination device also includes a guide plate for dividing the EDI membrane stack into at least two parts, and the guide plate is provided with a guide flow hole, and the fresh water flows into the guide flow hole through the guide net.

3. The EDI membrane stack electric desalination device according to claim 2, characterized in that: The membrane stack is a rectangular parallelepiped or a cylinder, the flow guide holes are arranged on two opposite sides of the length or width of the rectangle, and the flow guide holes on adjacent guide plates are arranged in a staggered manner.

4. The EDI membrane stack electric desalination device according to claim 1, characterized in that: The EDI membrane stack electro-deionization device also includes a water distribution plate and an aluminum plate, the aluminum plate is rectangular or cylindrical, the water distribution plate and the aluminum plate are sequentially assembled at the two ends of the EDI membrane stack electro-deionization device, the water distribution plate is arranged between the aluminum plate and the EDI membrane stack, and the aluminum plate is provided with a water inlet; and / or, the aluminum plate is provided with a water outlet.

5. The EDI membrane stack electric desalination device according to claim 4, characterized in that: The aluminum plate includes a non-porous aluminum plate and a porous aluminum plate. The non-porous aluminum plate is provided with a fresh water inlet and a concentrated water inlet, and the fresh water inlet and the concentrated water inlet are arranged on the first side of the length of the non-porous aluminum plate; the porous aluminum plate is provided with a produced water outlet and a concentrated water outlet, and the produced water outlet and the concentrated water outlet are arranged on the second side of the length of the porous aluminum plate.

6. The EDI membrane stack electric desalination device according to claim 5, characterized in that: The EDI membrane stack is provided with a water flow channel connected to the aluminum plate. Fresh water flows into the EDI membrane stack from the fresh water inlet for desalination, and then flows through the flow guide net until it completely passes through the EDI membrane stack and then flows out from the water outlet. The concentrate water flows into the EDI membrane stack from the concentrate water inlet, and flows out from the concentrate water outlet after being completely passed through the EDI membrane stack by the guide net.

7. The EDI membrane stack electric desalination device according to claim 1, characterized in that: The mesh number of the guide net is 40 to 100 meshes.

8. The EDI membrane stack electric desalination device according to claim 1, characterized in that: The guide net is made of stainless steel.

9. The EDI membrane stack electric desalination device according to claim 1, characterized in that: The fresh water chamber and the concentrated water chamber are both filled with ion fast migration substances.

10. The EDI membrane stack electric desalination device according to claim 9, characterized in that: The ion fast migration material is a mixed ion exchange resin of an anion exchange resin and a cation exchange resin.

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