Electrodialysis device

Abstract

The utility model discloses an electrodialysis device which comprises a membrane stack assembly and a polar water tank, an anode chamber and a cathode chamber are respectively communicated with the polar water tank through a first liquid outlet pipe and a second liquid outlet pipe, the first liquid outlet pipe is provided with a first outlet for discharging liquid to the polar water tank, and the second liquid outlet pipe is provided with a second outlet for discharging liquid to the polar water tank. A liquid flow blocking device higher than the liquid level of the electrode liquid is arranged at the first outlet or the second outlet, the first outlet or the second outlet provided with the liquid flow blocking device is higher than the liquid level of the electrode liquid, and the liquid flow blocking device enables liquid flow between the first outlet and the second outlet to be discontinuous; when one of the first liquid outlet pipe and the second liquid outlet pipe flows back, the electrode liquid can be sprayed to the liquid flow blocking device, then the liquid flow blocking device can disperse the electrode liquid flowing back from the anode chamber or the cathode chamber, and an open circuit is formed between the dispersed liquid, so that the current of an electrodialysis membrane stack can be prevented from forming a loop through the electrode liquid, electric leakage is avoided, and the service life of the electrodialysis membrane stack is prolonged. And the current efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to an electrodialysis device. Background Art

[0002] Electrodialysis technology is an electrochemical separation technology widely used in water treatment, wastewater treatment and chemical separation processes. Its basic principle is to use the action of a direct current electric field to make the charged ions in the solution pass through a selectively permeable ion exchange membrane, so as to realize the separation or concentration of ions. Since the electrodialysis system usually requires continuous power input to maintain the electric field, the current electrodialysis system has the problem of high power consumption. Therefore, a new technical solution is needed to reduce the power consumption in the electrodialysis process and improve the power utilization rate of the electrodialysis system. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an electrodialysis device.

[0004] The technical solution of the utility model is as follows: it includes a membrane stack assembly and a pole water tank. The membrane stack assembly includes an anode chamber, a cathode chamber, a first plate frame, a second plate frame and a membrane stack. The cathode chamber and the anode chamber are respectively located on the left and right sides of the membrane stack. The first plate frame is arranged on the side of the anode chamber away from the cathode chamber, and the second plate frame is arranged on the side of the cathode chamber away from the anode chamber. An anode electrode is arranged inside the first plate frame, and a cathode electrode is arranged inside the second plate frame. A plurality of concentration chambers and a plurality of desalination chambers are formed inside the membrane stack, and the desalination chambers and the concentration chambers are arranged alternately along the left-right direction of the membrane stack. The pole water tank stores pole liquid and forms a pole liquid level. The pole water tank is respectively communicated with the cathode chamber and the anode chamber, and the pole liquid can be driven to circulate between the pole water tank and the anode chamber, and to circulate between the pole water tank and the cathode chamber; the anode chamber and the cathode chamber are respectively communicated with the pole water tank through a first liquid outlet pipe and a second liquid outlet pipe. The first liquid outlet pipe has a first outlet for discharging liquid to the pole water tank, and the second liquid outlet pipe has a second outlet for discharging liquid to the pole water tank. A liquid flow blocking device higher than the pole liquid level is arranged at the first outlet or the second outlet. The first outlet or the second outlet provided with the liquid flow blocking device is higher than the pole liquid level, and the liquid flow blocking device makes the liquid flow between the first outlet and the second outlet discontinuous; the first plate frame, the second plate frame, the liquid flow blocking device, the first liquid outlet pipe and the second liquid outlet pipe are all made of non-conductive materials.

[0005] Furthermore, the liquid flow blocking devices are provided at both the first outlet and the second outlet, and both the first outlet and the second outlet are higher than the level of the polar liquid.

[0006] Furthermore, it further includes a desalted water tank which stores desalted liquid and forms a desalted liquid level. The desalted water tank is communicated with the desalting chamber. The desalted liquid can be driven to circulate between the desalted water tank and the desalting chamber. The desalting chamber is communicated with the desalted water tank through a third liquid outlet pipe. The third liquid outlet pipe has a third outlet for discharging liquid to the desalted water tank. The third outlet is higher than the desalted liquid level. The liquid flow blocking device is also provided at the third outlet, and the liquid flow blocking device makes the liquid flow between the third outlet and the desalted liquid level discontinuous.

[0007] Furthermore, it further includes a concentrated water tank which stores concentrated liquid and forms a concentrated liquid level. The concentrated water tank is communicated with the concentration chamber. The concentrated liquid can be driven to circulate between the concentrated water tank and the concentration chamber. The concentration chamber is communicated with the concentrated water tank through a fourth liquid outlet pipe. The fourth liquid outlet pipe has a fourth outlet for discharging liquid to the concentrated water tank. The fourth outlet is higher than the concentrated liquid level. The liquid flow blocking device is also provided at the fourth outlet, and the liquid flow blocking device makes the liquid flow between the fourth outlet and the concentrated liquid level discontinuous.

[0008] Furthermore, the liquid flow blocking device includes a dispersing member, and the side of the dispersing member opposite to the outlet for discharging liquid is planar.

[0009] Furthermore, the liquid flow blocking device includes a dispersing member, and the side of the dispersing member opposite to the outlet for discharging liquid is convex-arc-shaped.

[0010] Furthermore, the liquid flow blocking device includes a dispersing member, and the side of the dispersing member opposite to the outlet for discharging liquid is concave-arc-shaped.

[0011] Furthermore, it further includes a water flow dispersing nozzle which is arranged at the outlet for discharging liquid opposite to the liquid flow blocking device.

[0012] Furthermore, the liquid flow blocking device includes a dispersing member and a bracket, and the pipe at the outlet provided with the dispersing member is connected to the dispersing member through the bracket.

[0013] Furthermore, the anode chamber is communicated with the polar water tank through a first liquid inlet pipe, and the cathode chamber is communicated with the polar water tank through a second liquid inlet pipe. A first pump is arranged on the first liquid inlet pipe, and a second pump is arranged on the second liquid inlet pipe.

[0014] According to the electrodialysis device of the present utility model, it has at least the following technical effects: a liquid flow blocking device is arranged in the electrode water tank. The electrode liquid in the anode chamber flows back into the electrode water tank through the first liquid outlet pipe, and the electrode liquid in the cathode chamber flows back into the electrode water tank through the second liquid outlet pipe, so that the anode chamber and the cathode chamber use different pipes for water outlet, avoiding sharing a single pipeline during backflow. When either the first liquid outlet pipe or the second liquid outlet pipe is in backflow, the electrode liquid can be sprayed onto the corresponding liquid flow blocking device. Furthermore, the liquid flow blocking device can disperse the electrode liquid flowing back from the anode chamber or the cathode chamber and disperse it into liquid droplets. An open circuit is formed between the dispersed droplets, so that the liquid in the first liquid outlet pipe and the liquid in the second liquid outlet pipe do not form a loop, thereby preventing a part of the current of the electrodialysis membrane stack from forming a loop through the electrode liquid, reducing leakage, improving the current efficiency, and achieving the purpose of reducing the current loss of the electrodialysis membrane stack.

[0015] Additional aspects and advantages of the present utility model will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The additional aspects and advantages of the present utility model will become apparent and be easily understood from the description of the technical solution in conjunction with the following drawings, where:

[0017] Figure 1 is a schematic structural diagram of the electrodialysis device of the technical solution of the present utility model;

[0018] Figure 2 is a schematic structural diagram of a dispersing member with a straight upper end in the cross-section installed on the first liquid outlet pipe;

[0019] Figure 3 is a schematic structural diagram of a dispersing member with a convex upper arc in the cross-section installed on the first liquid outlet pipe;

[0020] Figure 4 is a top view of the bracket connected to the first liquid outlet pipe and the dispersing member respectively;

[0021] Figure 5 is a front view of the bracket connected to the first liquid outlet pipe and the dispersing member respectively;

[0022] Figure 6 is a schematic structural diagram of a membrane stack assembly of the prior art.

[0023] Reference numerals: membrane stack assembly 100, anode chamber 110, first liquid inlet pipe 111, first pump 112, cathode chamber 120, second liquid inlet pipe 121, second pump 122, first plate frame 130, anode electrode 131, second plate frame 140, cathode electrode 141, membrane stack 150, concentration chamber 151, desalination chamber 152, cation exchange membrane 153, anion exchange membrane 154, electrode water tank 200, electrode liquid level 201, first liquid outlet pipe 300, second liquid outlet pipe 400, liquid flow blocking device 500, dispersing member 501, bracket 502, desalted water tank 600, desalination liquid level 601, third liquid outlet pipe 610, third liquid inlet pipe 620, third pump 630, concentrated water tank 700, concentration liquid level 701, fourth liquid outlet pipe 710, fourth liquid inlet pipe 720, fourth pump 730, water flow dispersing nozzle 800, water inlet pipe 1000, water outlet pipe 2000. Detailed implementation manners

[0024] The technical solutions of the present utility model will be described in detail below. Examples of the technical solutions are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The technical solutions described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0025] In the description of the present utility model, it should be understood that with regard to the orientation description, such as the upper, lower, front, rear, left, right, etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0026] In the description of the present utility model, the meaning of several is one or more, the meaning of a plurality is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0027] In the description of the present utility model, unless otherwise clearly defined, words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the technical field can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solutions.

[0028] The power consumption of electrodialysis is a very important technical index. During the electrodialysis process, the following algorithm exists for the power supply output current: I 总= I1 + I2 + I3 ···, where the ratio of the actually utilized current quantity to the actual output current cannot reach 100%. For example, Figure 6 As shown, there is leakage current I1 caused by the surface conduction of the membrane stack, leakage current I2 caused by the conduction of the flow channels of the membrane stack, leakage current I3 caused by the formation of a current loop through the electrode solution between the anode chamber 110 and the cathode chamber 120, or other leakage currents.

[0029] Specifically, as Figure 6 shown, the existing electrodialysis device includes an electrodialysis membrane stack and an electrode water tank. The electrodialysis membrane stack includes an anode chamber 110 and a cathode chamber 120. The anode chamber 110 has an anode water inlet and an anode water outlet, and the cathode chamber 120 has a cathode water inlet and a cathode water outlet. The water outlet of the electrode water tank is connected to the anode water inlet and the cathode water inlet through a water inlet pipe 1000, and a pump is provided on the water inlet pipe 1000. The water inlet of the electrode water tank is connected to the anode water outlet and the cathode water outlet through a water outlet pipe 2000. The electrode solution in the electrode water tank circulates into the anode chamber 110 and the cathode chamber 120 through the water inlet pipe 1000, the water outlet pipe 2000, and the pump. That is, the existing anode chamber 110 and cathode chamber 120 share a water outlet pipe 2000 and a water inlet pipe 1000. Therefore, the anode chamber 110 and the cathode chamber 120 conduct electricity through the water inlet pipe 1000 and the electrode water tank, generating leakage current I31, and the anode chamber 110 and the cathode chamber 120 conduct electricity through the water outlet pipe 2000 and the electrode water tank, generating leakage current I32. I3 = I31 + I32.

[0030] Refer to Figure 1As shown in the figure, the electrodialysis device provided in the embodiment of the present utility model includes a membrane stack assembly 100 and a pole water tank 200. The membrane stack assembly 100 includes an anode chamber 110, a cathode chamber 120, a first plate frame 130, a second plate frame 140, and a membrane stack 150. The cathode chamber 120 and the anode chamber 110 are respectively located on the left and right sides of the membrane stack 150. The first plate frame 130 is arranged on the side of the anode chamber 110 away from the cathode chamber 120, and the second plate frame 140 is arranged on the side of the cathode chamber 120 away from the anode chamber 110. An anode electrode 131 is arranged inside the first plate frame 130, and a cathode electrode 141 is arranged inside the second plate frame 140. A plurality of concentration chambers 151 and a plurality of desalination chambers 152 are formed inside the membrane stack 150. The desalination chambers 152 and the concentration chambers 151 are alternately arranged along the left-right direction of the membrane stack 150. The pole water tank 200 stores pole liquid and forms a pole liquid liquid level 201. The pole water tank 200 is respectively connected to the cathode chamber 120 and the anode chamber 110. The pole liquid can be driven to circulate between the pole water tank 200 and the anode chamber 110, and to circulate between the pole water tank 200 and the cathode chamber 120; the anode chamber 110 and the cathode chamber 120 are respectively communicated with the pole water tank 200 through a first liquid discharge pipe 300 and a second liquid discharge pipe 400. The first liquid discharge pipe 300 has a first outlet for discharging liquid to the pole water tank 200, and the second liquid discharge pipe 400 has a second outlet for discharging liquid to the pole water tank 200. A liquid flow blocking device 500 is provided at the first outlet or the second outlet, and the first outlet or the second outlet provided with the liquid flow blocking device 500 is higher than the pole liquid liquid level 201. The liquid flow blocking device 500 makes the liquid flow between the first outlet and the second outlet discontinuous; the first plate frame 130, the second plate frame 140, the liquid flow blocking device 500, the first liquid discharge pipe 300, and the second liquid discharge pipe 400 are all made of non-conductive materials. The above-mentioned liquid flow refers to a water-like water flow, which is equivalent to the liquid flow blocking device 500 making the water flow intermittent.

[0031] A liquid flow blocking device 500 is arranged in the anode water tank 200. The electrode liquid in the anode chamber 110 flows back into the anode water tank 200 through the first liquid outlet pipe 300, and the electrode liquid in the cathode chamber 120 flows back into the anode water tank 200 through the second liquid outlet pipe 400, so that the anode chamber 110 and the cathode chamber 120 use different pipes for discharging water, avoiding sharing a pipeline during reflux, extending the pipeline, increasing the electrode liquid resistance of the pipeline, reducing the current loss on this path, and when one of the first liquid outlet pipe 300 and the second liquid outlet pipe 400 is in reflux, the electrode liquid can be sprayed onto the corresponding liquid flow blocking device 500. Furthermore, the liquid flow blocking device 500 can disperse the electrode liquid flowing back from the anode chamber 110 or the cathode chamber 120 and disperse it into liquid droplets. An open circuit is formed between the dispersed droplets, so that the liquid in the first liquid outlet pipe 300 and the liquid in the second liquid outlet pipe 400 do not form a loop, thereby preventing a part of the current of the electrodialysis membrane stack 150 from forming a loop through the electrode liquid, reducing the leakage current I32, improving the current efficiency, and achieving the purpose of reducing the current loss of the membrane stack assembly 100.

[0032] During operation, the electrode liquid in the anode water tank 200 enters the anode chamber 110 and the cathode chamber 120, and an electrode reaction occurs in the membrane stack assembly 100. The electrode liquid in the anode chamber 110 flows back into the anode water tank 200 through the first liquid outlet pipe 300, and the electrode liquid in the cathode chamber 120 flows back into the anode water tank 200 through the second liquid outlet pipe 400. During the reflux process, the electrode liquid in the first liquid outlet pipe 300 or the electrode liquid in the second liquid outlet pipe 400 is driven to impact on the liquid flow blocking device 500, and the liquid flow blocking device 500 disperses the electrode liquid to form dispersed water flowers, which then fall to the bottom of the anode water tank 200.

[0033] For example, as Figure 1 shown, the first outlet of the first liquid outlet pipe 300 is higher than the electrode liquid level 201, and a liquid flow blocking device 500 is arranged at the first outlet, while no liquid flow blocking device 500 is arranged at the second outlet of the second liquid outlet pipe 400. The liquid flow blocking device 500 not only makes the liquid flow between the first outlet and the electrode liquid level 201 discontinuous, but also makes the liquid flow between the first outlet and the second outlet discontinuous. Among them, under the condition of ensuring that the liquid flow between the first outlet and the second outlet is discontinuous, the second outlet can be higher than the electrode liquid level 201 or lower than the electrode liquid level 201; or, the second outlet of the second liquid outlet pipe 400 is higher than the electrode liquid level 201, and the liquid flow blocking device 500 is arranged at the second outlet of the second liquid outlet pipe 400, and no liquid flow blocking device 500 is arranged at the first outlet of the first liquid outlet pipe 300. The liquid flow blocking device 500 not only makes the liquid flow between the second outlet and the electrode liquid level 201 discontinuous, but also makes the liquid flow between the first outlet and the second outlet discontinuous. Under the condition of ensuring that the liquid flow between the first outlet and the second outlet is discontinuous, the first outlet can be higher than the electrode liquid level 201 or lower than the electrode liquid level 201.

[0034] Further, the bipolar water tank 200 can share one pipeline and one pump to separately transport the bipolar liquid to the anode chamber 110 and the cathode chamber 120; the bipolar water tank 200 can also transport the bipolar liquid to the anode chamber 110 and the cathode chamber 120 through two pipelines and two pumps, that is, the bipolar water tank 200 is connected to the anode chamber 110 through one pipeline, and the bipolar water tank 200 is then connected to the cathode chamber 120 through another pipeline; the bipolar water tank 200 can also transport the bipolar liquid to the anode chamber 110 and the cathode chamber 120 through other forms. Further, pumps are provided on both the first liquid outlet pipe 300 and the second liquid outlet pipe 400 to better spray the liquid onto the liquid flow blocking device 500. Pumps may not be provided on the first liquid outlet pipe 300 and the second liquid outlet pipe 400, and the liquid outlet of the liquid outlet pipe depends on gravity or the power of the inlet pump.

[0035] Further, as Figure 1 shown, the membrane stack 150 includes a plurality of cation exchange membranes 153 and a plurality of anion exchange membranes 154. The plurality of cation exchange membranes 153 and the plurality of anion exchange membranes 154 are alternately arranged at intervals in the left - right direction. Desalination chambers 152 and concentration chambers 151 are respectively formed between the anion exchange membrane 154 and the adjacent cation exchange membranes 153 on the left and right sides. The desalination chambers 152 and the concentration chambers 151 constitute the membrane stack 150, and the membrane stack 150 is arranged between the anode chamber 110 and the cathode chamber 120; on the side of the first plate frame 130 away from the anode chamber 110, there is a positive electrode connector connected to the anode electrode 131, and on the side of the second plate frame 140 away from the cathode chamber 120, there is a negative electrode connector connected to the cathode electrode 141; both the first plate frame 130 and the second plate frame 140 are made of non - conductive PP plates with a thickness of 30 mm, a length of 400 mm, and a width of 200 mm.

[0036] Further, both the first liquid outlet pipe 300 and the second liquid outlet pipe 400 are made of acid - and alkali - resistant non - conductive PP pipes to improve the service life of the pipeline.

[0037] Further, liquid flow blocking devices 500 higher than the liquid level 201 of the bipolar liquid are provided at both the first outlet and the second outlet. Both the first outlet and the second outlet are higher than the liquid level 201 of the bipolar liquid, so that the bipolar liquid sprayed from the first liquid outlet pipe 300 is dispersed by one of the liquid flow blocking devices 500 and dispersed into droplets, and the bipolar liquid sprayed from the second liquid outlet pipe 400 is dispersed by the other liquid flow blocking device 500 and dispersed into droplets. The bipolar liquid sprayed from the first liquid outlet pipe 300 and the bipolar liquid sprayed from the second liquid outlet pipe 400 are both dispersed, ensuring that the bipolar liquid between the two does not form a loop.

[0038] Further, as Figure 1As shown, it further includes a demineralized water tank 600. The demineralized water tank 600 stores demineralized liquid and forms a demineralized liquid level 601. The demineralized water tank 600 is communicated with the demineralization chamber 152. The demineralized liquid can be driven to circulate between the demineralized water tank 600 and the demineralization chamber 152. The demineralization chamber 152 is communicated with the demineralized water tank 600 through a third liquid discharge pipe 610. The third liquid discharge pipe 610 has a third outlet for discharging liquid to the demineralized water tank 600. The third outlet is higher than the demineralized liquid level 601. A liquid flow blocking device 500 higher than the demineralized liquid level 601 is also provided at the third outlet. The liquid flow blocking device 500 makes the liquid flow between the third outlet and the demineralized liquid level 601 discontinuous.

[0039] By providing a liquid flow blocking device 500 at the outlet of the third liquid discharge pipe 610, it is possible to prevent the demineralized liquid in the third liquid discharge pipe 610 from forming an electric current loop with the demineralized liquid level 601.

[0040] During operation, the liquid in the demineralized water tank 600 enters the demineralization chamber 152, then sprays out from the third outlet of the third liquid discharge pipe 610 and sprays onto the liquid flow blocking device 500. The liquid flow blocking device 500 disperses the liquid into droplets, which then fall to the bottom of the demineralized water tank 600.

[0041] Furthermore, a pump is provided on the third liquid discharge pipe 610 to better spray the liquid onto the liquid flow blocking device 500. The third liquid discharge pipe 610 may also not be provided with a pump, and the liquid discharge of the liquid discharge pipe depends on gravity or the power of the inlet pump.

[0042] Furthermore, as Figure 1 shown, it further includes a concentrated liquid tank 700. The concentrated liquid tank 700 stores concentrated liquid and forms a concentrated liquid level 701. The concentrated liquid tank 700 is communicated with the concentration chamber 151. The concentrated liquid can be driven to circulate between the concentrated liquid tank 700 and the concentration chamber 151. The concentration chamber 151 is communicated with the concentrated liquid tank 700 through a fourth liquid discharge pipe 710. The fourth liquid discharge pipe 710 has a fourth outlet for discharging liquid to the concentrated liquid tank 700. The fourth outlet is higher than the concentrated liquid level 701. A liquid flow blocking device 500 higher than the concentrated liquid level 701 is also provided at the fourth outlet. The liquid flow blocking device 500 makes the liquid flow between the fourth outlet and the concentrated liquid level 701 discontinuous.

[0043] By providing a liquid flow blocking device 500 at the outlet of the fourth liquid discharge pipe 710, it is possible to prevent the water outlet end of the fourth liquid discharge pipe 710 from forming an electric current loop with the concentrated liquid level 701 through the concentrated liquid.

[0044] During operation, the liquid in the concentrated liquid tank 700 enters the concentration chamber 151, then sprays out from the fourth outlet of the fourth liquid discharge pipe 710 and sprays onto the liquid flow blocking device 500. The liquid flow blocking device 500 disperses the liquid into droplets, which then fall to the bottom of the concentrated liquid tank 700.

[0045] Further, a pump is provided on the fourth liquid outlet pipe 710 to better spray the liquid onto the liquid flow blocking device 500. The fourth liquid outlet pipe 710 may also not be provided with a pump, and the liquid outlet of the liquid outlet pipe is driven by gravity or the power of the inlet pump.

[0046] In some embodiments, as Figure 1 shown, the water outlet end of the desalted water tank 600 is communicated with the desalination chamber 152 through the third liquid inlet pipe 620, and a third pump 630 is provided on the third liquid inlet pipe 620. The desalted water tank 600 can also transport the desalted liquid to the desalination chamber 152 in other forms; the water outlet end of the concentrated water tank 700 is communicated with the concentration chamber 151 through the fourth liquid inlet pipe 720, and a fourth pump 730 is provided on the fourth liquid inlet pipe 720. The concentrated water tank 700 can also transport the concentrated liquid to the concentration chamber 151 in other forms. By providing the third liquid inlet pipe 620 and the fourth liquid inlet pipe 720, the desalted liquid and the concentrated liquid are circulated and supplied.

[0047] During operation:

[0048] As Figure 1 shown, raw water is respectively added to the desalted water tank 600 and the concentrated water tank 700, polar liquid is added to the polar water tank 200, the third pump 630 and the fourth pump 730 are started to circulate and transport the liquid in the desalted water tank 600, the liquid in the concentrated water tank 700 and the polar liquid in the polar water tank 200, and the DC power supply is started to supply power to the membrane stack assembly 100; the liquid in the desalted water tank 600 enters the desalination chamber 152 through the third liquid inlet pipe 620 and the third pump 630. In the membrane stack assembly 100, the anions and cations in the liquid in the desalination chamber 152 enter the concentration chamber 151 through the anion and cation exchange membranes under the action of the electric field, and then the solution in the desalination chamber 152 returns to the desalted water tank 600 through the third liquid outlet pipe 610; at the same time, the solution in the concentrated water tank 700 enters the concentration chamber 151 through the fourth liquid inlet pipe 720 and the fourth pump 730. Under the action of the electric field, after the concentration chamber 151 receives the anions and cations migrated from the desalination chamber 152, it returns to the concentrated water tank 700 through the fourth liquid outlet pipe 710.

[0049] Further, the third liquid outlet pipe 610, the fourth liquid outlet pipe 710, the third liquid inlet pipe 620 and the fourth liquid inlet pipe 720 are all made of acid and alkali resistant non-conductive PP material to improve the service life of the pipeline.

[0050] It can be understood that the outlets mentioned below include the first outlet, the second outlet, the third outlet and the fourth outlet, and the liquid flow blocking device 500 can be provided at the first outlet, the second outlet, the third outlet and the fourth outlet.

[0051] Further, as Figure 2As shown, the liquid flow blocking device 500 includes a dispersing member 501. The side of the dispersing member 501 opposite to the outlet of the liquid discharge is planar, so that the dispersing member 501 blocks the downward ejection of the liquid through its upper flat surface and disperses the liquid into droplets.

[0052] As Figure 2 shown, taking the first liquid discharge pipe 300 as an example, the dispersing member 501 is located directly below the first outlet of the first liquid discharge pipe 300. The upper side of the dispersing member 501 is planar. The first liquid discharge pipe 300 ejects the polar liquid onto the upper end surface of the dispersing member 501, causing the polar liquid to collide with the upper end surface of the dispersing member 501, and making the polar liquid sputter around the dispersing member 501 in a discontinuous state, generating corresponding dispersed water flowers.

[0053] Further, as Figure 3 shown, the liquid flow blocking device 500 includes a dispersing member 501. The side of the dispersing member 501 opposite to the outlet of the liquid discharge is in a convex arc shape, so that the dispersing plate 501 has a convex arc structure, so that no water accumulates in the middle and the dispersing effect is better.

[0054] As Figure 2 shown, taking the first liquid discharge pipe 300 as an example, the dispersing member 501 is located directly below the first outlet of the first liquid discharge pipe 300. The upper side of the dispersing member 501 is in a convex arc shape. The first liquid discharge pipe 300 ejects the polar liquid onto the upper end surface of the dispersing member 501, causing the polar liquid to collide with the upper end surface of the dispersing member 501, and making the polar liquid sputter around the dispersing member 501 in a discontinuous state, generating corresponding dispersed water flowers.

[0055] Further, as Figure 1 shown, the liquid flow blocking device 500 includes a dispersing member 501. The side of the dispersing member 501 opposite to the outlet of the liquid discharge is in a concave arc shape, so that the dispersing plate 501 has a concave arc structure, so that the liquid forms droplets in a parabolic manner and the liquid is more easily dispersed into droplets;

[0056] As Figure 1 shown, taking the first liquid discharge pipe 300 as an example, the dispersing member 501 is located directly below the first outlet of the first liquid discharge pipe 300. The upper side of the dispersing member 501 is in a concave arc shape. The first liquid discharge pipe 300 ejects the polar liquid onto the upper end surface of the dispersing member 501, causing the polar liquid to collide with the upper end surface of the dispersing member 501, and making the polar liquid sputter around the dispersing member 501 in a discontinuous state, generating corresponding dispersed water flowers.

[0057] In some embodiments, as Figure 4 shown, the dispersing member 501 is in a disc shape.

[0058] Further, as Figure 2As shown, it further includes a water flow dispersing nozzle 800. The water flow dispersing nozzle 800 is arranged at the outlet for discharging liquid opposite to the liquid flow blocking device 500, so that the nozzle can initially disperse the liquid and increase the water pressure, making it easier for the liquid to be dispersed into droplets when hitting the liquid flow blocking device 500, realizing two-stage water flow dispersion. For example, a water flow dispersing nozzle 800 is arranged at the water outlet end of the first liquid discharge pipe 300. The water flow dispersing nozzle 800 can also be arranged on a pipe where there is no liquid flow blocking device 500 at the outlet.

[0059] Further, as Figure 2 shown, the liquid flow blocking device 500 includes a dispersing member 501 and a bracket 502. The pipe at the outlet where the dispersing member 501 is arranged is connected to the dispersing member 501 through the bracket 502, so that the liquid flow blocking device 500 does not need to be fixed on the bipolar water tank 200. Furthermore, there is no need to set a fixing structure on the bipolar water tank 200, making the structure of the bipolar water tank 200 simple.

[0060] In some embodiments, as Figure 4 、 5 shown, taking the bracket 502 installed on the first liquid discharge pipe 300 as an example, the bracket 502 includes a plurality of connecting rods. The plurality of connecting rods are arranged at intervals along the circumferential direction of the first liquid discharge pipe 300. The upper ends of the connecting rods are fixedly connected to the first liquid discharge pipe 300, and the lower ends of the connecting rods are fixedly connected to the dispersing member 501.

[0061] Specifically, the number of connecting rods can be two, three or more than three.

[0062] Further, as Figure 1 shown, the anode chamber 110 is communicated with the bipolar water tank 200 through a first liquid inlet pipe 111, and the cathode chamber 120 is communicated with the bipolar water tank 200 through a second liquid inlet pipe 121. A first pump 112 is arranged on the first liquid inlet pipe 111, and a second pump 122 is arranged on the second liquid inlet pipe 121, so that the liquid inlet of the anode chamber 110 and the liquid inlet of the cathode chamber 120 are carried out separately, both through independent pipes and independent pumps for liquid inlet, without a connecting common part. Furthermore, the pipe is extended, the resistance of the pipe bipolar liquid is increased, and the current loss on this path can be reduced.

[0063] In some embodiments, as Figure 1 shown, the connection points of the first liquid inlet pipe 111 with the bipolar water tank 200 and the connection points of the second liquid inlet pipe 121 with the bipolar water tank 200 are both located at the bottom of the bipolar water tank 200. Or, on the premise of ensuring that the first liquid inlet pipe 111 and the second liquid inlet pipe 121 can extract the bipolar liquid inside the bipolar water tank 200, the connection points of the first liquid inlet pipe 111 with the bipolar water tank 200 and the connection points of the second liquid inlet pipe 121 with the bipolar water tank 200 can be arranged at other positions of the bipolar water tank 200, facilitating the separate output of the bipolar liquid to the anode chamber 110 and the cathode chamber 120.

[0064] Further, as Figure 1 shown, one of the first liquid outlet pipe 300 and the second liquid outlet pipe 400 extends into the polar water tank 200 and is located above the liquid flow blocking device 500. The liquid flow blocking device 500 can block the polar liquid sprayed downward from the first outlet or the second outlet. There is a gap between the liquid flow blocking device 500 and the side wall of the polar water tank 200. With the above arrangement, the polar liquid is dispersed more evenly, ensuring that the current of the membrane stack assembly 100 does not form a loop through the polar liquid. During operation, the polar liquid is sprayed downward onto the liquid flow blocking device 500. The liquid flow blocking device 500 disperses the polar liquid, and the dispersed liquid droplets then fall from the space between the liquid flow blocking device 500 and the side wall of the polar water tank 200 to the bottom of the polar water tank 200.

[0065] Taking the example that only the first liquid outlet pipe 300, the third liquid outlet pipe 610, and the fourth liquid outlet pipe 710 are provided with the dispersing member 501, the working principle of the present invention is as follows:

[0066] As Figure 1 shown, during use, raw water is respectively added to the desalted water tank 600 and the concentrated water tank 700, and polar liquid is added to the polar water tank 200. The third pump 630, the fourth pump 730, the first pump 112, and the second pump 122 are started to circulate and transport the liquid in the desalted water tank 600, the liquid in the concentrated water tank 700, and the polar liquid in the polar water tank 200. The DC power supply is started to supply power to the membrane stack assembly 100. The liquid in the desalted water tank 600 enters the desalination chamber 152 of the membrane stack assembly 100 through the third liquid inlet pipe 620 and the third pump 630. In the membrane stack assembly 100, the anions and cations in the liquid in the desalination chamber 152 enter the concentration chamber 151 through the anion and cation exchange membranes under the action of the electric field. Then, the solution in the desalination chamber 152 returns to the desalted water tank 600 through the third liquid outlet pipe 610. During the reflux process, the desalinated liquid in the desalination chamber 152 can impact the dispersing member 501 in the desalted water tank 600 under the action of the third pump 630. The dispersing member 501 disperses the desalinated liquid and the dispersed liquid droplets, and then they fall to the bottom of the desalted water tank 600. At the same time, the solution in the concentrated water tank 700 enters the concentration chamber 151 of the membrane stack assembly 100 through the fourth liquid inlet pipe 720 and the fourth pump 730. Under the action of the electric field, after the concentration chamber 151 receives the anions and cations migrated from the desalination chamber 152, it returns to the concentrated water tank 700 through the fourth liquid outlet pipe 710. During the reflux process, the concentrated liquid in the concentration chamber 151 can impact the dispersing member 501 in the concentrated water tank 700 under the action of the fourth pump 730. The dispersing member 501 disperses the concentrated liquid and the dispersed liquid droplets, and then they fall to the bottom of the concentrated water tank 700.

[0067] A part of the polar liquid in the polar liquid tank 200 enters the anode chamber 110 through the first liquid inlet pipe 111 and the first pump 112, and another part of the polar liquid in the polar liquid tank 200 enters the cathode chamber 120 through the second liquid inlet pipe 121 and the second pump 122. An electrode reaction occurs in the membrane stack assembly 100. The polar liquid in the anode chamber 110 returns to the polar liquid tank 200 through the first liquid outlet pipe 300, and the polar liquid in the cathode chamber 120 returns to the polar liquid tank 200 through the second liquid outlet pipe 400. During the return process, the polar liquid in the anode chamber 110 can impact the dispersing member 501 under the action of the first pump 112. The dispersing member 501 disperses the polar liquid and breaks up the liquid droplets, which then fall to the bottom of the polar liquid tank 200. The polar liquid in the cathode chamber 120 is directly discharged to the bottom of the polar liquid tank 200.

[0068] The following are some embodiments:

[0069] Embodiment 1

[0070] A domestic homogeneous ion exchange membrane is used, with a size of 126×310 mm, 40 pairs of anion and cation membranes. The polar liquid is transported into the anode chamber 110 through the first liquid inlet pipe 111 and the first pump 112, the polar liquid is returned to the polar liquid tank 200 through the first liquid outlet pipe 300, the polar liquid is transported into the cathode chamber 120 through the second liquid inlet pipe 121 and the second pump 122, the polar liquid is returned to the polar liquid tank 200 through the second liquid outlet pipe 400, and the polar liquid tank 200 is provided with a concave dispersing member 501.

[0071] 50 L of 0.2 mol / L NaCl solution is filled in the desalted water tank 600, 10 L of 0.2 mol / L NaCl solution is filled in the concentrated water tank 700, and 10 L of 0.4 mol / L NaCl solution is added to the polar liquid tank 200; fresh water is supplied to the desalted water tank 600, concentrated water is supplied to the concentrated water tank 700, and the third pump 630 and the fourth pump 720 are turned on. The flow rates of fresh water and concentrated water are 500 L / h, the flow rate of the polar liquid on both sides is 300 L / h, the initial voltage is set to 10 V, and the corresponding current is 12 A. When running for 60 min, the current decreases to 3 A.

[0072] The ion concentrations (g / L) in the concentration chamber and the desalination chamber of the electrodialysis membrane stack are shown in Table 1:

[0073]

[0074]

[0075] Prior art: Comparative Example 1

[0076] Using a domestic homogeneous ion exchange membrane with dimensions of 126×310 mm, 40 pairs of anion and cation membranes, the water outlet of the electrode tank is connected to the anode water inlet and the cathode water inlet through a water inlet pipe 1000. A pump is provided on the water inlet pipe 1000. The water inlet of the electrode tank is connected to the anode water outlet and the cathode water outlet through a water outlet pipe 2000. That is, the water inlet of the anode chamber and the cathode chamber share a water inlet pipe 1000, and the water outlet of the anode chamber and the cathode chamber share a water outlet pipe 2000.

[0077] Load 50 L of 0.2 mol / L NaCl solution into the desalted water tank, load 10 L of 0.2 mol / L NaCl solution into the concentrated water tank, and add 10 L of 0.4 mol / L NaCl solution into the electrode tank; supply fresh water to the fresh chamber, supply concentrated water to the concentrated chamber and turn on the pump. The flow rates of fresh water and concentrated water are 500 L / h, and the flow rate of the electrode solution on both sides is 300 L / h. Set the initial voltage to 10 V, and its corresponding current is 12.5 A. When running for 60 min, the current decreases to 3 A.

[0078] The ion concentrations (g / L) in the concentrated chamber and the fresh chamber of the electrodialysis membrane stack are shown in Table 4:

[0079]

[0080] As can be seen from the above two tables, the total current efficiency of the present invention has a lower loss compared to the total current efficiency of the prior art. Although the technical solutions of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these technical solutions without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An electrodialysis device, comprising a membrane stack assembly (100), the membrane stack assembly (100) including an anode chamber (110), a cathode chamber (120), a first plate frame (130), a second plate frame (140) and a membrane stack (150), the cathode chamber (120) and the anode chamber (110) being respectively located on the left and right sides of the membrane stack (150), the first plate frame (130) being disposed on a side of the anode chamber (110) away from the cathode chamber (120), the second plate frame (140) being disposed on a side of the cathode chamber (120) away from the anode chamber (110), an anode electrode (131) being provided inside the first plate frame (130), a cathode electrode (141) being provided inside the second plate frame (140), a plurality of concentration chambers (151) and a plurality of desalination chambers (152) being formed inside the membrane stack (150), the desalination chambers (152) and the concentration chambers (151) being alternately arranged in the left-right direction of the membrane stack (150), characterized in that, Further comprising: An electrode water tank (200) storing electrode liquid and forming an electrode liquid level (201), the electrode water tank (200) being respectively connected to the cathode chamber (120) and the anode chamber (110), and the electrode liquid being capable of being driven to circulate between the electrode water tank (200) and the anode chamber (110), and to circulate between the electrode water tank (200) and the cathode chamber (120); The anode chamber (110) and the cathode chamber (120) are respectively connected to the electrode water tank (200) through a first liquid discharge pipe (300) and a second liquid discharge pipe (400). The first liquid discharge pipe (300) has a first outlet for discharging liquid to the electrode water tank (200), and the second liquid discharge pipe (400) has a second outlet for discharging liquid to the electrode water tank (200). A liquid flow blocking device (500) higher than the electrode liquid level (201) is provided at the first outlet or the second outlet. The first outlet or the second outlet provided with the liquid flow blocking device (500) is higher than the electrode liquid level (201), and the liquid flow blocking device (500) makes the liquid flow between the first outlet and the second outlet discontinuous; The first plate frame (130), the second plate frame (140), the liquid flow blocking device (500), the first liquid discharge pipe (300) and the second liquid discharge pipe (400) are all made of non-conductive materials.

2. The electrodialysis device according to claim 1, characterized in that: The liquid flow blocking device (500) higher than the electrode liquid level (201) is provided at both the first outlet and the second outlet, and both the first outlet and the second outlet are higher than the electrode liquid level (201).

3. The electrodialysis device according to claim 1, characterized in that: Further comprising a desalted water tank (600) storing desalted liquid and forming a desalted liquid level (601), the desalted water tank (600) being connected to the desalting chamber (152), and the desalted liquid being capable of being driven to circulate between the desalted water tank (600) and the desalting chamber (152). The desalting chamber (152) is connected to the desalted water tank (600) through a third liquid discharge pipe (610). The third liquid discharge pipe (610) has a third outlet for discharging liquid to the desalted water tank (600). The third outlet is higher than the desalted liquid level (601), and the liquid flow blocking device (500) higher than the desalted liquid level (601) is also provided at the third outlet. The liquid flow blocking device (500) makes the liquid flow between the third outlet and the desalted liquid level (601) discontinuous.

4. The electrodialysis device according to claim 1, wherein: It further includes a concentrated water tank (700) which stores concentrated liquid and forms a concentrated liquid level (701). The concentrated water tank (700) is communicated with the concentration chamber (151), and the concentrated liquid can be driven to circulate between the concentrated water tank (700) and the concentration chamber (151). The concentration chamber (151) is communicated with the concentrated water tank (700) through a fourth liquid discharge pipe (710). The fourth liquid discharge pipe (710) has a fourth outlet for discharging liquid to the concentrated water tank (700). The fourth outlet is higher than the concentrated liquid level (701). A liquid flow blocking device (500) higher than the concentrated liquid level (701) is also provided at the fourth outlet. The liquid flow blocking device (500) makes the liquid flow between the fourth outlet and the concentrated liquid level (701) discontinuous.

5. The electrodialysis device according to any one of claims 1 to 4, characterized in that: The liquid flow blocking device (500) includes a dispersing member (501), and the side of the dispersing member (501) opposite to the outlet for discharging liquid is planar.

6. The electrodialysis device according to any one of claims 1 to 4, characterized in that: The liquid flow blocking device (500) includes a dispersing member (501), and the side of the dispersing member (501) opposite to the outlet for discharging liquid is in a convex arc shape.

7. The electrodialysis device according to any one of claims 1 to 4, characterized in that: The liquid flow blocking device (500) includes a dispersing member (501), and the side of the dispersing member (501) opposite to the outlet for discharging liquid is in a concave arc shape.

8. The electrodialysis device according to any one of claims 1 to 4, characterized in that: It further includes a water flow dispersing nozzle (800) which is arranged at the outlet for discharging liquid opposite to the liquid flow blocking device (500).

9. The electrodialysis device according to any one of claims 1 to 4, characterized in that: The liquid flow blocking device (500) includes a dispersing member (501) and a bracket (502). The pipe at the outlet provided with the dispersing member (501) is connected to the dispersing member (501) through the bracket (502).

10. The electrodialysis device according to claim 1, characterized in that: The anode chamber (110) is communicated with the electrode water tank (200) through a first liquid inlet pipe (111), and the cathode chamber (120) is communicated with the electrode water tank (200) through a second liquid inlet pipe (121). A first pump (112) is arranged on the first liquid inlet pipe (111), and a second pump (122) is arranged on the second liquid inlet pipe (121).

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