An electro-sorption device and system

Abstract

The present invention discloses an electro-adsorption device, which includes at least one electrode adsorption module. The electrode adsorption module includes an electrode adsorption layer, a flow channel and a current-carrying plate member. The first adsorption layer is located on the lower surface of the first current-carrying plate, the second adsorption layer is located on the upper surface of the third current-carrying plate, the third adsorption layer is located on the lower surface of the third current-carrying plate, and the fourth adsorption layer is located on the upper surface of the second current-carrying plate. The first adsorption layer and the second adsorption layer are arranged at intervals to form a first water flow channel, the third adsorption layer and the second adsorption layer are arranged at intervals to form a second water flow channel, and the outlet of the second water flow channel is communicated with the inlet of the first water flow channel to form a flow channel. Raw water flows in from the inlet of the second water flow channel and flows out from the outlet of the first water flow channel for desalination. The thickness of each adsorption layer gradually decreases along the water flow direction of the desalination process. The electro-adsorption device of the present invention has the advantages of simple and compact structure, long service life of the electrode adsorption layer and high desalination efficiency, and also discloses an electro-adsorption system.

Description

Technical Field

[0001] The present invention relates to the field of electroadsorption technology, and particularly to an electroadsorption device and system. Background Art

[0002] Electroadsorption (Capacitive Deionization, CDI) technology, as an efficient and sustainable method for desalination of seawater and high-salt wastewater, has received extensive attention in recent years. A CDI unit usually consists of a graphite current-carrying plate, electrodes, a separation material (such as an ion-exchange membrane or a porous membrane), and a water flow channel. As one of the core components of the CDI unit, the water flow channel is responsible for transporting the water to be treated and ensuring its flow between the electrodes. When a voltage is applied across the electrodes, the resulting potential difference causes the ions in the water to be adsorbed onto the electrode surface with the opposite charge or stored in the electric double layer region formed at the electrode / water interface, thereby achieving desalination of high-salt water. Therefore, the design of the water flow channel is crucial for improving the mass transfer efficiency, desalination performance, and water production capacity of the CDI unit.

[0003] In existing CDI devices, a traditional horizontally arranged water flow channel structure is adopted. For example, in Chinese Patent Document CN104817143A, as the treatment process progresses, the salt concentration of the water to be treated gradually decreases, resulting in uneven adsorption between the electrodes near the inlet and those near the outlet, causing different aging rates at the head and tail of the electrodes, which has an adverse impact on both the service life of the electrodes and the desalination efficiency. As Figure 10 and Figure 11 shown, after 5000 cycles of the existing CDI device, the aging degree of the head of the activated carbon electrode adsorption layer is significantly higher than that of the tail. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an electroadsorption device with a simple and compact structure, a long service life of the electrode adsorption layer, and high desalination efficiency. The present invention further provides an electroadsorption system with strong applicability, high treatment efficiency, and high working continuity.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] An electroadsorption device includes at least one electrode adsorption module, and the electrode adsorption module includes an electrode adsorption layer, a flow channel, and a current-carrying plate member.

[0007] The current-carrying plate member includes a first current-carrying plate and a second current-carrying plate arranged in parallel, and a third current-carrying plate disposed between the first current-carrying plate and the second current-carrying plate. The first current-carrying plate and the second current-carrying plate are respectively connected to a first power electrode, and the third current-carrying plate is connected to a second power electrode. The first power electrode and the second power electrode have opposite polarities.

[0008] The electrode adsorption layer includes a first adsorption layer, a second adsorption layer, a third adsorption layer and a fourth adsorption layer. The first adsorption layer is located on the lower surface of the first current-carrying plate, the second adsorption layer is located on the upper surface of the third current-carrying plate, the third adsorption layer is located on the lower surface of the third current-carrying plate, and the fourth adsorption layer is located on the upper surface of the second current-carrying plate;

[0009] The first adsorption layer and the second adsorption layer are arranged at intervals to form a first water flow channel. The third adsorption layer and the second adsorption layer are arranged at intervals to form a second water flow channel. The outlet of the second water flow channel is communicated with the inlet of the first water flow channel to form a flow channel. Raw water flows in from the inlet of the second water flow channel and flows out from the outlet of the first water flow channel for desalination.

[0010] The thicknesses of the first adsorption layer, the second adsorption layer, the third adsorption layer and the fourth adsorption layer gradually decrease along the water flow direction of the desalination process.

[0011] As a further improvement of the above technical solution:

[0012] On any cross-section perpendicular to the first current-carrying plate and the first water flow channel, the thickness of the second adsorption layer is d2, and the thickness of the first adsorption layer is d1, satisfying d2>d1; and / or

[0013] On any cross-section perpendicular to the second current-carrying plate and the second water flow channel, the thickness of the third adsorption layer is d3, and the thickness of the fourth adsorption layer is d4, satisfying d4>d3.

[0014] d1:d2 = 0.5 to 0.99:1; and / or

[0015] d3:d4 = 0.5 to 0.99:1.

[0016] The sum of the thicknesses of the first adsorption layer and the second adsorption layer at the inlet of the first water flow channel is s1, and the sum of the thicknesses of the first adsorption layer and the second adsorption layer at the outlet of the first water flow channel is s2, satisfying s2:s1 = 0.5 to 0.99:1; and / or

[0017] The sum of the thicknesses of the third adsorption layer and the fourth adsorption layer at the inlet of the second water flow channel is s1', and the sum of the thicknesses of the third adsorption layer and the fourth adsorption layer at the outlet of the second water flow channel is s2', satisfying s2':s1' = 0.5 to 0.99:1.

[0018] The third current-carrying plate is inclined relative to the first current-carrying plate or the second current-carrying plate;

[0019] The cross-sectional areas of the first water flow channel and / or the second water flow channel gradually decrease along the water flow direction of the desalination process.

[0020] During desalination, the cross-sectional area at the inlet of the first water flow channel is A1, and the cross-sectional area at the outlet is A2, satisfying A1:A2 = 1:0.8 - 0.99; and / or

[0021] During desalination, the cross-sectional area at the inlet of the second water flow channel is A1', and the cross-sectional area at the outlet is A2', satisfying A1':A2' = 1:0.8 - 0.99.

[0022] A plurality of water guiding protrusions are provided in the flow channel.

[0023] The central axis of the water guiding protrusion has an included angle α with the water flow direction of the flow channel, and α is between 10° and 70°.

[0024] A plurality of the electrode adsorption modules are stacked and connected up and down. Among adjacent electrode adsorption modules, the inlet of the second water flow channel in the upper electrode adsorption module is communicated with the outlet of the first water flow channel in the lower electrode adsorption module, and the second current-carrying plate in the upper electrode adsorption module is the first current-carrying plate in the lower electrode adsorption module.

[0025] An electro-adsorption system includes a raw water pipeline, a clear water pipeline, a concentrated water pipeline, and a plurality of the above-mentioned electro-adsorption devices. The raw water pipeline is communicated with the inlets of the second water flow channels at the bottom layer of each electro-adsorption device through a first valve and with the outlets of the first water flow channels at the top layer of each electro-adsorption device through a fourth valve. The clear water pipeline is communicated with the outlets of the first water flow channels at the top layer of each electro-adsorption device through a second valve. The concentrated water pipeline is communicated with the inlets of the second water flow channels at the bottom layer of each electro-adsorption device through a third valve.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] In the electro-adsorption device of the present invention, since the salt concentration of the raw water gradually decreases during desalination, by gradually reducing the thickness of each electrode adsorption layer along the water flow direction of the desalination process, the head and tail adsorption of each electrode adsorption layer is more uniform, the consistency of the adsorption process at the head and tail of each electrode adsorption layer is improved, the asymmetric aging at the head and tail of each electrode adsorption layer is reduced, the service life of the electrode adsorption layer is prolonged, and the desalination efficiency is improved; by arranging the third current-carrying plate between the first current-carrying plate and the second current-carrying plate, two sets of adsorption layers and two water flow channels are formed, and the structure is simple and compact; by reversing the raw water flow direction and the positive and negative poles of the power supply, the electro-adsorption device can be regenerated to restore the adsorption capacity of the electrode, and the regeneration process is simple.

[0028] The electro-sorption system of the present invention can achieve different working modes by controlling the opening and closing of different valves, and has strong applicability; multiple electro-sorption devices can be connected in parallel for synchronous desalination and regeneration, enabling the treatment of large-flow raw water with high treatment efficiency; the multiple electro-sorption devices connected in parallel can be divided into two groups for desalination and regeneration respectively, so that at least one group of electro-sorption devices is always performing desalination, ensuring high working continuity. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of the electro-sorption device during desalination in the first embodiment of the present invention.

[0030] Figure 2 It is a schematic structural diagram of the electro-sorption device during regeneration in the first embodiment of the present invention.

[0031] Figure 3 It is a schematic structural diagram of the electro-sorption device during desalination in the second embodiment of the present invention.

[0032] Figure 4 It is a schematic structural diagram of the electro-sorption device during regeneration in the second embodiment of the present invention.

[0033] Figure 5 It is a schematic structural diagram of the electro-sorption system in the third embodiment of the present invention.

[0034] Figure 6 It is a schematic structural diagram when two electro-sorption devices of the electro-sorption system in the third embodiment of the present invention are synchronously desalinating.

[0035] Figure 7 It is a schematic structural diagram when two electro-sorption devices of the electro-sorption system in the third embodiment of the present invention are synchronously regenerating.

[0036] Figure 8 It is a schematic structural diagram when two electro-sorption devices of the electro-sorption system in the third embodiment of the present invention are alternately desalinating and regenerating.

[0037] Figure 9 It is another schematic structural diagram when two electro-sorption devices of the electro-sorption system in the third embodiment of the present invention are alternately desalinating and regenerating.

[0038] Figure 10 It is an SEM image of the head of the activated carbon electrode adsorption layer of an existing CDI device after 5000 cycles.

[0039] Figure 11 It is an SEM image of the tail of the activated carbon electrode adsorption layer of an existing CDI device after 5000 cycles.

[0040] The reference numerals in the figure denote: 1. current-carrying plate member; 11. first current-carrying plate; 12. second current-carrying plate; 13. third current-carrying plate; 2. flow channel; 21. first water flow channel; 22. second water flow channel; 3. electrode adsorption layer; 31. first adsorption layer; 32. second adsorption layer; 33. third adsorption layer; 34. fourth adsorption layer; 4. water guide protrusion; 5. separation membrane; 61. raw water pipeline; 62. clean water pipeline; 63. concentrated water pipeline; 71. first valve; 72. second valve; 73. third valve; 74. fourth valve. Detailed implementation mode

[0041] The present invention will be further described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention 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 therefore should not be construed as a limitation to the present invention.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0044] In the present invention, unless otherwise clearly defined and limited, the terms "assembly", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Embodiment 1:

[0046] Figure 1 and Figure 2 shows the first embodiment of the electro-adsorption device of the present invention. The electro-adsorption device of this embodiment includes at least one electrode adsorption module, and the electrode adsorption module includes an electrode adsorption layer 3, a flow channel 2, and a current-carrying plate member 1.

[0047] The current-carrying plate member 1 includes a first current-carrying plate 11 and a second current-carrying plate 12 arranged in parallel, and a third current-carrying plate 13 disposed between the first current-carrying plate 11 and the second current-carrying plate 12. The first current-carrying plate 11 and the second current-carrying plate 12 are respectively connected to a first power electrode, and the third current-carrying plate 13 is connected to a second power electrode. The first power electrode and the second power electrode have opposite polarities;

[0048] The electrode adsorption layer 3 includes a first adsorption layer 31, a second adsorption layer 32, a third adsorption layer 33, and a fourth adsorption layer 34. The first adsorption layer 31 is located on the lower surface of the first current-carrying plate 11, the second adsorption layer 32 is located on the upper surface of the third current-carrying plate 13, the third adsorption layer 33 is located on the lower surface of the third current-carrying plate 13, and the fourth adsorption layer 34 is located on the upper surface of the second current-carrying plate 12;

[0049] The first adsorption layer 31 and the second adsorption layer 32 are spaced apart to form a first water flow channel 21, the third adsorption layer 33 and the second adsorption layer 32 are spaced apart to form a second water flow channel 22, and the outlet of the second water flow channel 22 communicates with the inlet of the first water flow channel 21 to form a flow channel 2. Raw water flows into the inlet of the second water flow channel 22 and flows out from the outlet of the first water flow channel 21 for desalination.

[0050] The thicknesses of the first adsorption layer 31, the second adsorption layer 32, the third adsorption layer 33, and the fourth adsorption layer 34 gradually decrease along the water flow direction of the desalination process.

[0051] In the electro-adsorption device of this embodiment, during desalination, as Figure 1 shown, the first current-carrying plate 1 and the second current-carrying plate 12 are respectively connected to the first power electrode, the third current-carrying plate 13 is connected to the second power electrode, and the voltage generated by the power supply is applied to the first current-carrying plate 1 and the second current-carrying plate 12 to generate an electric field, which promotes the ions in the raw water to be adsorbed onto the surface of the electrode adsorption layer 3 with the opposite charge or into the double-layer region formed at the electrode / water interface. The raw water flows into the inlet of the second water flow channel 22, passes through the second water flow channel 22 and the first water flow channel 21 in sequence, and the raw water after desalination forms clear water and flows out from the outlet of the first water flow channel 21; when the desalination efficiency drops below 30%, the electrode adsorption layer 3 needs to be regenerated. During regeneration, as Figure 2As shown, reverse the positive and negative leads of the power supply to change the current direction, that is, the first current-carrying plate 1 and the second current-carrying plate 12 are respectively connected to the second power electrode, and the third current-carrying plate 13 is connected to the first power electrode. Due to the repulsive force of the electric field, the ions on the electrode adsorption layer 3 are excluded and enriched into the raw water. The raw water flows reversely, that is, the raw water flows into from the outlet of the first water flow channel 21, successively passes through the first water flow channel 21 and the second water flow channel 22, and the raw water after regeneration forms concentrated water and flows out from the inlet of the second water flow channel 22, thereby restoring the adsorption capacity of the device. In the electro-adsorption device of this embodiment, since the salt concentration of the raw water will gradually decrease with the desalination process, by making the thickness of each electrode adsorption layer 3 gradually decrease along the water flow direction of the desalination process, the head and tail adsorption of each electrode adsorption layer 3 is more uniform, the consistency of the adsorption process at the head and tail of each electrode adsorption layer 3 is improved, the asymmetric aging at the head and tail of each electrode adsorption layer 3 is reduced, the service life of the electrode adsorption layer 3 is prolonged, and the desalination efficiency is improved; by arranging the third current-carrying plate 13 between the first current-carrying plate 1 and the second current-carrying plate 12, two groups of adsorption layers and two water flow channels are formed, and the structure is simple and compact; by reversing the raw water flow direction and the positive and negative poles of the power supply, the electro-adsorption device can be regenerated to restore the adsorption capacity of the electrode, and the regeneration process is simple.

[0052] Among them, the first adsorption layer 31 and the second adsorption layer 32 are a group of adsorption layers, and the third adsorption layer 33 and the fourth adsorption layer 34 are another group of adsorption layers. The first power electrode is the negative pole of the power supply, and the second power electrode is the positive pole of the power supply. Of course, in other embodiments, the first power electrode can also be the positive pole and the second power electrode can be the negative pole.

[0053] Preferably, in this embodiment, the electrode adsorption layer 3 is composed of one or more of activated carbon, carbon aerogel, graphene, carbon nanotubes, or porous carbon materials, etc., and the first current-carrying plate 1 and the second current-carrying plate 12 are graphite current-carrying plates.

[0054] Preferably, in this embodiment, the first current-carrying plate 11 and the second current-carrying plate 12 are horizontally arranged, so that the first water flow channel 21 and the second water flow channel 22 are in a horizontally arranged structure. Compared with the structure where the water flow channels are vertically arranged, the head loss is smaller and the energy consumption during the desalination process is smaller.

[0055] Preferably, in this embodiment, the outlet of the second water flow channel 22 and the inlet of the first water flow channel 21 are on the same side. Connecting the ports on the same side of the second water flow channel 22 and the first water flow channel 21 can reduce the connection distance between the second water flow channel 22 and the first water flow channel 21, and the head loss is less; the water flow enters the inlet of the first water flow channel 21 from the outlet of the second water flow channel 22 and flows in a snake shape, so that the flow path is longer under the same device volume and the layout is compact.

[0056] Further, in this embodiment, a separation membrane 5 is further provided on the electrode adsorption layer 3. The separation membrane 5 (such as an ion exchange membrane or a porous membrane, etc.) can allow specific types of ions to pass through while blocking other types of ions, enabling the separation membrane 5 to facilitate the separation and enrichment of target ions by the electrode adsorption layer 3 during the electrode adsorption process.

[0057] Further, in this embodiment, on any cross-section perpendicular to the first current-carrying plate 11 and the first water flow channel 21, the thickness of the second adsorption layer 32 is d2, and the thickness of the first adsorption layer 31 is d1, satisfying d2 > d1; and on any cross-section perpendicular to the second current-carrying plate 12 and the second water flow channel 22, the thickness of the third adsorption layer 33 is d3, and the thickness of the fourth adsorption layer 34 is d4, satisfying d4 > d3. The thickness of the lower electrode adsorption layer 3 of each group of adsorption layers is greater than that of the upper electrode adsorption layer 3, such that under the action of gravity, even though water flow and ions are more likely to contact the lower electrode and have insufficient contact with the upper electrode, due to the design with different thicknesses of the upper and lower electrode adsorption layers 3 in each group of adsorption layers, the aging of the upper and lower electrode adsorption layers 3 is balanced, improving the life consistency of the upper and lower electrode adsorption layers 3 in each group of adsorption layers, reducing the overall performance limitation, and saving materials; the gradual change design of the thickness of the head and tail of the electrode adsorption layer 3 in cooperation with the design with different thicknesses of the upper and lower electrode adsorption layers 3 realizes the uniform load of the electrode adsorption layer 3 during the entire desalination process, further extending the life of the electrode adsorption layer 3.

[0058] Further, in this embodiment, d1:d2 = 0.5 to 0.99:1; and d3:d4 = 0.5 to 0.99:1. When the thickness ratio of each group of adsorption layers of the electrode adsorption layer 3 is within this range, it is more conducive to extending the overall life of the electrode adsorption layer 3.

[0059] When other conditions are the same, such as the initial seawater salinity: 35000 mg / L; working voltage: 1.3 V; water flow rate: 1 m³ / h; material of the electrode adsorption layer 3: activated carbon; experimental temperature: 25 °C, the influence of different ratios of the adsorption layer thickness on the overall life of the electrode adsorption layer 3 is as follows: When the ratios of d1:d2 and d3:d4 are in the range of 0.5 to 0.99, the desalination efficiency of the electro-adsorption device reaches the best, and the average desalination rate is about 95%; within this range, the energy consumption of the electro-adsorption device is relatively low, and the energy consumption for treating each cubic meter of seawater is about 0.5 kWh / m³; the life consistency of the upper and lower electrode adsorption layers 3 in each group of adsorption layers is relatively high, and the average service life can reach more than 1000 hours. When d1:d2 < 0.5 or d3:d4 < 0.5, that is, the thickness of the upper electrode adsorption layer 3 in each group of adsorption layers is significantly smaller than that of the lower electrode adsorption layer 3, it will lead to insufficient adsorption capacity of the upper electrode adsorption layer 3, thus reducing the overall desalination efficiency, and the desalination rate may drop below 80%; the insufficient thickness of the upper electrode adsorption layer 3 will lead to an increase in the resistance during the electro-adsorption process, and the excessive load on the lower electrode adsorption layer 3 will lead to a higher voltage required to maintain the adsorption effect during the electro-adsorption process, thereby increasing the energy consumption, and the energy consumption for treating each cubic meter of seawater may increase to more than 0.7 kWh / m³; the insufficient thickness of the upper electrode adsorption layer 3 will lead to an accelerated aging rate, while the life of the lower electrode adsorption layer 3 is relatively long, resulting in inconsistent overall life of the electrode adsorption layer 3 and reducing the stability and reliability of the system. In this case, the average service life of the electrode adsorption layer 3 may drop below 500 hours. When d1:d2 > 0.99 or d3:d4 > 0.99, that is, the thickness of the upper electrode adsorption layer 3 is almost equal to or greater than that of the lower electrode adsorption layer 3, it will lead to an excessive load on the lower electrode adsorption layer 3, thus reducing the overall desalination efficiency, and the desalination rate may drop below 85%; the excessive load on the lower electrode adsorption layer 3 will lead to a higher voltage required to maintain the adsorption effect during the electro-adsorption process, thereby increasing the energy consumption, and the energy consumption for treating each cubic meter of seawater may increase to more than 0.6 kWh / m³; the excessive load on the lower electrode adsorption layer 3 will lead to an accelerated aging rate, while the life of the upper electrode adsorption layer 3 is relatively long, also resulting in inconsistent overall life of the electrode adsorption layer 3 and reducing the stability and reliability of the system. In this case, the average service life of the electrode adsorption layer 3 may drop below 700 hours.

[0060] Furthermore, in this embodiment, the sum of the thicknesses of the first adsorption layer 31 and the second adsorption layer 32 at the inlet of the first water flow channel 21 is s1, and the sum of the thicknesses of the first adsorption layer 31 and the second adsorption layer 32 at the outlet of the first water flow channel 21 is s2, satisfying s2:s1 = 0.5 to 0.99:1; and the sum of the thicknesses of the third adsorption layer 33 and the fourth adsorption layer 34 at the inlet of the second water flow channel 22 is s1', and the sum of the thicknesses of the third adsorption layer 33 and the fourth adsorption layer 34 at the outlet of the second water flow channel 22 is s2', satisfying s2':s1' = 0.5 to 0.99:1.

[0061] The salt concentration at the inlet of the water flow channel is higher, which means that more salt needs to be adsorbed, resulting in faster aging of the electrode adsorption material at the inlet. Designing the thickness of the electrode adsorption material at the inlet to be greater than that at the outlet can balance the aging rates of the electrode adsorption materials at the inlet and outlet, ensuring the stability and long life of the overall system; since the salt concentration at the inlet of the water flow channel is higher, the relative water body weight and volume are larger, which will exert a greater pressure on the electrode adsorption material at the inlet and easily cause structural deformation. Designing a larger thickness of the electrode material at the inlet can reinforce the structure at the inlet, reduce the structural deformation caused by pressure, and improve the stability and reliability of the system.

[0062] When other conditions are the same, taking the initial seawater salinity: 35000 mg / L; the working voltage of the electro-sorption device: 1.3 V; the water flow rate: 1 m³ / h; the material of the electrode adsorption layer 3: activated carbon; the experimental temperature: 25°C as an example, the influence of the ratio of the sum of the thicknesses of the electrode adsorption layer 3 at the channel inlet and outlet on the overall life of the electrode adsorption layer 3 is as follows: When s2:s1 and s2′:s1′ are in the range of 0.5 to 0.99, the desalination efficiency of the electro-sorption device reaches the best, and the average desalination rate is about 95%; the energy consumption of the electro-sorption device is low, and the energy consumption for treating each cubic meter of seawater is about 0.5 kWh / m³; the service life of the adsorption layer is long, and the average service life can reach more than 1000 hours. When s2:s1 < 0.5 or s2′:s1′ < 0.5, that is, the thickness of the electrode adsorption layer 3 at the outlet significantly decreases, which will lead to a decrease in the adsorption capacity of the electrode adsorption layer 3 at the outlet, thereby reducing the desalination efficiency. Experimental data show that in this case, the desalination rate may drop below 80%; the decrease in the thickness of the electrode adsorption layer 3 at the outlet will lead to an increase in the resistance during the electro-sorption process, thereby increasing the energy consumption, and the energy consumption for treating each cubic meter of seawater may increase to more than 0.7 kWh / m³; the aging rates of the electrode adsorption layer 3 at the inlet and outlet are inconsistent, and the low thickness of the electrode adsorption layer 3 at the outlet causes the structure to be easily deformed, and the average service life may drop below 500 hours. When s2:s1 > 0.99 or s2′:s1′ > 0.99, that is, the thickness of the electrode adsorption layer 3 at the outlet hardly changes or increases, which will lead to a decrease in the adsorption capacity of the electrode adsorption layer 3 at the inlet and a decrease in the adsorption efficiency of the electrode adsorption layer 3 at the outlet, and will also reduce the desalination efficiency, and the desalination rate may drop below 85%; a higher voltage is required to maintain the adsorption effect during the electro-sorption process, thereby increasing the energy consumption, and the energy consumption for treating each cubic meter of seawater may increase to more than 0.6 kWh / m³; the aging rates of the electrode adsorption layer 3 at the inlet and outlet are inconsistent, and the large pressure at the inlet causes the structure to be easily deformed, and the average service life of the electrode adsorption layer 3 may drop below 700 hours.

[0063] Furthermore, in this embodiment, the third current-carrying plate 13 is inclined relative to the first current-carrying plate 11 or the second current-carrying plate 12; the cross-sectional areas of the first water flow channel 21 and the second water flow channel 22 gradually decrease along the water flow direction of the desalination process. (It should be noted that when desalinating, the cross-sectional areas of the inlet of the first water flow channel 21 and the outlet of the second water flow channel 22 are not equal. In this embodiment, when desalinating, the cross-sectional area of the inlet of the first water flow channel 21 is approximately the same as the cross-sectional area of the inlet of the second water flow channel 22). Since the salt concentration of the raw water will gradually decrease with the progress of desalination and the water volume decreases, by gradually reducing the cross-sectional areas of the first water flow channel 21 and the second water flow channel 22, the uniform distribution of the water flow is promoted, the contact efficiency between the ions and the surface of the electrode adsorption layer 3 is enhanced, and thus the adsorption efficiency is improved.

[0064] Further, in this embodiment, the reduction rate of the cross-sectional areas of the first water flow channel 21 and the second water flow channel 22 matches the reduction rate of the water volume during the desalination process. The cross-sectional areas of the first water flow channel 21 and the second water flow channel 22 decrease proportionally with the water volume during the desalination process, further promoting the uniform distribution of water flow and thus enhancing the desalination efficiency. For example, adding 10 g of sodium sulfate to 100 mL of water will cause the volume to expand to approximately 104 mL, and as the salt concentration decreases, the volume and weight will also decrease proportionally. At the same time, by reasonably designing the cross-sectional area ratio, uniform loading of the electrode adsorption layer 3 and the separation membrane 5 can be achieved, reducing local overload and extending the service life of the device.

[0065] Further, in this embodiment, during desalination, the cross-sectional area at the inlet of the first water flow channel 21 is A1, and the cross-sectional area at the outlet is A2, satisfying A1:A2 = 1:0.8 to 0.99; and during desalination, the cross-sectional area at the inlet of the second water flow channel 22 is A1', and the cross-sectional area at the outlet is A2', satisfying A1':A2' = 1:0.8 to 0.99.

[0066] When other conditions are the same, for example, the initial seawater salinity: 35000 mg / L; the working voltage of the electro-adsorption device: 1.3 V; the water flow rate: 1 m³ / h; the material of the adsorption layer 3: activated carbon; the experimental temperature: 25 °C, the influence of the ratio of the cross-sectional areas at the inlet and outlet of the channel on the overall life of the electrode adsorption layer 3 is as follows: When A2:A1 and A2':A1' are in the range of 0.8 to 0.99, the desalination efficiency of the electro-adsorption device reaches the best, and the average desalination rate is about 95%; the energy consumption of the electro-adsorption device is relatively low, and the energy consumption per cubic meter of seawater treatment is about 0.5 kWh / m³; the structural stability of the electrode adsorption layer 3 and the separation membrane 5 is relatively high, and the service life can reach more than 1000 hours. When A2:A1 < 0.8 or A2':A1' < 0.8, that is, the cross-sectional area at the outlet is significantly smaller than that at the inlet, it will cause the water flow rate to increase. The high-speed water flow will reduce the effective contact time between water molecules and the electrode adsorption material, thereby reducing the desalination efficiency, and the desalination rate may drop below 80%; the acceleration of the water flow rate will cause an increase in the resistance during the electro-adsorption process, thereby increasing the energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to more than 0.6 kWh / m³; the pressure at the inlet and outlet is uneven, resulting in structural deformation of the adsorption material of the electrode adsorption 3 and the separation membrane 5, such as compression, deformation or rupture, and uneven loading of the electrode adsorption layer 3 and the separation membrane 5, further exacerbating the structural deformation and aging problems. When A2:A1 > 0.99 or A2':A1' > 0.99, that is, the cross-sectional area at the outlet is almost equal to or larger than that at the inlet, it will cause the water flow rate to be slow, which may lead to a decrease in the mass transfer efficiency during the electro-adsorption process, and also reduce the desalination efficiency, and the desalination rate may drop below 85%; the too slow water flow rate will cause a higher voltage to be required to maintain the adsorption effect during the electro-adsorption process, thereby increasing the energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to more than 0.6 kWh / m³.

[0067] Furthermore, in this embodiment, a plurality of water guiding protrusions 4 are provided in the flow channel 2. The water guiding protrusions 4 disturb the water flow in the flow channel, enhance the contact efficiency between ions and the surface of the electrode adsorption layer 3, and further improve the adsorption efficiency.

[0068] Further, in this embodiment, the central axis of the water guiding protrusion 4 forms an angle α with the water flow direction of the flow channel 2, and α is between 10° and 70°. An appropriate angle α can prevent the water flow from being too gentle or too turbulent, ensuring uniform distribution of the water flow in the flow channel 2 and improving the overall desalination efficiency. When the angle α is too small, the water flow is relatively gentle. Although the pressure on the electrode adsorption layer 3 and the separation membrane 5 is small, the contact efficiency between ions and the electrode adsorption layer 3 may be low, which may cause local overload, and the average service life of the electrode adsorption layer and the separation membrane 5 may be reduced to less than 500 hours. When the angle α is too large, the water flow is too turbulent and the pressure distribution is uneven, which may cause excessive local load on the electrode adsorption layer and the separation membrane 5, resulting in structural deformation and aging, and the average service life of the electrode adsorption layer and the separation membrane 5 may be reduced to less than 700 hours.

[0069] Specifically, the water guiding protrusion 4 is at least one of a circle, an ellipse, a rhombus, a rectangle, a cone, and a spindle. When the water guiding protrusion 4 is circular, there is no angle α. In this embodiment, it is a spindle.

[0070] For the electro-adsorption device of this embodiment, the desalination performance test is specifically as follows: The first current-carrying plate 11, the second current-carrying plate 12, and the third current-carrying plate 13 are all made of graphite plates of 30×30 cm 2 . The electrode adsorption layer 3 is composed of a porous activated carbon material. The thicknesses of the first adsorption layer 31 and the third adsorption layer 33 decrease from 0.5 cm to 0.3 cm from the inlet to the outlet of the water flow channel, and the thicknesses of the second adsorption layer 32 and the fourth adsorption layer 34 decrease from 0.8 cm to 0.4 cm from the inlet to the outlet of the water flow channel. The cross-sectional areas of the flow channels at the inlets and outlets of the first water flow channel 21 and the second water flow channel 22 decrease from 30 cm 2 to 29 cm 2 . The electrode adsorption layers 3 are separated by anion and cation exchange membranes. When the raw water is a NaCl solution with a solution concentration of 1 g / L and a flow rate of 150 mL / min, and the conductivity meters are used to monitor the conductivity of the inlet and outlet water, under the constant voltage mode of 1.2 V, after 20 cycles, the salt adsorption capacity of the electro-adsorption device of this embodiment remains 31.8 mg / g, and the desalination rate remains above 85%; while for the traditional horizontal flow channel structure with the same thickness of 0.5 cm for each electrode adsorption layer 3, after 20 cycles, the salt adsorption capacity is 25.1 mg / g, and the desalination rate is 74%. When the raw water is a NaCl solution with a solution concentration of 2 g / L, after 20 cycles, the salt adsorption capacity of the electro-adsorption device of this embodiment remains 39.5 mg / g, and the desalination rate remains above 89%; while for the traditional horizontal flow channel structure with the same thickness of 0.5 cm for each electrode adsorption layer 3, after 20 cycles, the salt adsorption capacity is 28.1 mg / g, and the desalination rate is 77%. Compared with the traditional horizontal flow channel structure, the electro-adsorption device of this embodiment has higher desalination performance and is beneficial to maintaining a longer electrode life.

[0071] Embodiment 2:

[0072] Figure 3 and Figure 4 Figure 2 shows the second embodiment of the electro - adsorption device of the present invention. The structure of the electro - adsorption device in this embodiment is basically the same as that in Embodiment 1, and the differences include: In this embodiment, there are two electrode adsorption modules, and the two electrode adsorption modules are stacked and connected up and down. Among adjacent electrode adsorption modules, the inlet of the second water flow channel 22 in the upper electrode adsorption module is communicated with the outlet of the first water flow channel 21 in the lower electrode adsorption module, and the second current - carrying plate 12 in the upper electrode adsorption module serves as the first current - carrying plate 11 in the lower electrode adsorption module.

[0073] For the electro - adsorption device in this embodiment, the inlet of the second water flow channel 22 in the upper electrode adsorption module is communicated with the outlet of the first water flow channel 21 in the lower electrode adsorption module to achieve the series combination of two electrode adsorption modules. During desalination, as Figure 3 shown, the raw water flows in from the inlet of the second water flow channel 22 in the lower electrode adsorption module, successively passes through the second water flow channel 22 and the first water flow channel 21 in the lower electrode adsorption module, the second water flow channel 22 and the first water flow channel 21 in the upper electrode adsorption module, and the raw water after desalination forms clear water and flows out from the outlet of the first water flow channel 21 in the upper electrode adsorption module. The rest is similar to the electro - adsorption device in Embodiment 1; during regeneration, as Figure 4 shown, the regeneration process is the same and will not be elaborated. For the electro - adsorption device in this embodiment, by communicating the inlet of the second water flow channel 22 in the upper electrode adsorption module with the outlet of the first water flow channel 21 in the lower electrode adsorption module, the series combination of multiple electrode adsorption modules can be realized. The structure is simple and reliable; the series - combined multiple electrode adsorption modules can make the flow path of water longer, improve the processing capacity, and can adapt to the adsorption scenarios of raw water with higher concentration and larger processing volume, with strong adaptability; through the modular combination method, the combination and decomposition are simple, and different numbers of electrode adsorption modules can be connected in series according to requirements to meet the water treatment requirements in different application scenarios, with strong applicability.

[0074] Of course, in other embodiments, more electrode adsorption modules can also be connected in series to extend the length of the water flow channel, with even stronger adaptability.

[0075] In this embodiment, when multiple electrode adsorption modules are combined, the second current-carrying plate 12 of the upper electrode adsorption module serves as the first current-carrying plate 11 of the lower electrode adsorption module. Only one of the second current-carrying plate 12 of the electrode adsorption module and the first current-carrying plate 11 of the adjacent electrode adsorption module is retained, saving costs. Of course, in other embodiments, the second current-carrying plate 12 of the electrode adsorption module and the first current-carrying plate 11 of the adjacent electrode adsorption module can also be connected in a splicing manner, and both can be connected to the positive and negative electrodes of the same power supply, with a simple and compact structure and convenient modular adjustment.

[0076] Embodiment 3:

[0077] Figure 5 and Figure 9 FIG. shows an embodiment of the electro-adsorption system of the present invention. The electro-adsorption system of this embodiment includes a raw water pipeline 61, a clear water pipeline 62, a concentrated water pipeline 63, and two electro-adsorption devices of Embodiment 2. The raw water pipeline 61 is connected to the inlet of the second water flow channel 22 at the bottom layer of each electro-adsorption device through a first valve 71 and to the outlet of the first water flow channel 21 at the top layer of each electro-adsorption device through a fourth valve 74. The clear water pipeline 62 is connected to the outlet of the first water flow channel 21 at the top layer of each electro-adsorption device through a second valve 72. The concentrated water pipeline 63 is connected to the inlet of the second water flow channel 22 at the bottom layer of each electro-adsorption device through a third valve 73.

[0078] The electro-adsorption system of this embodiment can achieve different working modes by controlling the opening and closing of different valves, as follows.

[0079] Synchronous desalination and regeneration of two electro-adsorption devices: During desalination, as Figure 5 and Figure 6 shown, open two first valves 71 and two second valves 72, close the third valve 73 and the fourth valve 74. The raw water in the raw water pipeline 61 flows into the inlets of the second water flow channels 22 at the bottom layer of the two electro-adsorption devices respectively. The raw water forms clear water after passing through the desalination of the electro-adsorption device and flows out from the outlet of the first water flow channel 21 at the top layer of the electro-adsorption device and into the clear water pipeline 62, realizing the parallel synchronous desalination of the two electro-adsorption devices. During regeneration, as Figure 7 shown, open two third valves 73 and two fourth valves 74, close the first valve 71 and the second valve 72. The raw water in the raw water pipeline 61 flows into the outlets of the first water flow channels 21 at the top layer of the two electro-adsorption devices respectively. The raw water forms concentrated water after passing through the regeneration of the electro-adsorption device and flows out from the inlet of the second water flow channel 22 at the bottom layer of the electro-adsorption device and into the concentrated water pipeline 63, realizing the parallel synchronous regeneration of the two electro-adsorption devices.

[0080] Alternate desalination and regeneration of two electro-adsorption devices: When the first electro-adsorption device performs desalination and the second electro-adsorption device performs regeneration, asFigure 8 As shown in the figure, open the first valve 71 and the two second valves 72 of the first electro-sorption device, close the third valve 73 and the fourth valve 74. The raw water in the raw water pipeline 61 is desalted by the first electro-sorption device to form clear water, which flows out from the clear water pipeline 62. Open the third valve 73 and the fourth valve 74 of the second electro-sorption device, close the first valve 71 and the second valve 72. The raw water in the raw water pipeline 61 is regenerated by the second electro-sorption device to form concentrated water, which flows out from the concentrated water pipeline 63; as Figure 9 As shown in the figure, when the first electro-sorption device is regenerated and the second electro-sorption device is desalting, open the third valve 73 and the fourth valve 74 of the first electro-sorption device, close the first valve 71 and the second valve 72. The raw water in the raw water pipeline 61 is regenerated by the first electro-sorption device to form concentrated water, which flows out from the concentrated water pipeline 63. Open the first valve 71 and the two second valves 72 of the second electro-sorption device, close the third valve 73 and the fourth valve 74. The raw water in the raw water pipeline 61 is desalted by the second electro-sorption device to form clear water, which flows out from the clear water pipeline 62.

[0081] The electro-sorption system of this embodiment can achieve different working modes by controlling the opening and closing of different valves, and has strong applicability; multiple electro-sorption devices can be connected in parallel for synchronous desalting and regeneration, which can treat raw water with a large flow rate and has high treatment efficiency; the multiple electro-sorption devices connected in parallel can be divided into two groups for desalting and regeneration respectively, so that at least one group of electro-sorption devices is always desalting, and the working continuity is high.

[0082] Of course, in other embodiments, the electro-sorption system can also include a larger number of electro-sorption devices, which can treat raw water with an even larger flow rate simultaneously, with higher treatment efficiency and stronger adaptability.

[0083] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the spirit and technical solution of the present invention. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. An electro-adsorption device, comprising at least one electrode adsorption module, characterized in that: The electrode adsorption module includes an electrode adsorption layer (3), a flow channel (2), and a current-carrying plate member (1). The current-carrying plate member (1) includes a first current-carrying plate (11) and a second current-carrying plate (12) arranged in parallel, and a third current-carrying plate (13) disposed between the first current-carrying plate (11) and the second current-carrying plate (12). The first current-carrying plate (11) and the second current-carrying plate (12) are respectively connected to a first power electrode, the third current-carrying plate (13) is connected to a second power electrode, and the first power electrode and the second power electrode have opposite polarities. The electrode adsorption layer (3) includes a first adsorption layer (31), a second adsorption layer (32), a third adsorption layer (33), and a fourth adsorption layer (34). The first adsorption layer (31) is located on the lower surface of the first current-carrying plate (11), the second adsorption layer (32) is located on the upper surface of the third current-carrying plate (13), the third adsorption layer (33) is located on the lower surface of the third current-carrying plate (13), and the fourth adsorption layer (34) is located on the upper surface of the second current-carrying plate (12). The first adsorption layer (31) and the second adsorption layer (32) are arranged at intervals to form a first water flow channel (21). The third adsorption layer (33) and the second adsorption layer (32) are arranged at intervals to form a second water flow channel (22). The outlet of the second water flow channel (22) is communicated with the inlet of the first water flow channel (21) to form a flow channel (2). Raw water flows in from the inlet of the second water flow channel (22) and flows out from the outlet of the first water flow channel (21) for desalination. The thicknesses of the first adsorption layer (31), the second adsorption layer (32), the third adsorption layer (33), and the fourth adsorption layer (34) gradually decrease along the water flow direction of the desalination process. The third current-carrying plate (13) is inclined with respect to the first current-carrying plate (11) or the second current-carrying plate (12). The cross-sectional areas of the first water flow channel (21) and the second water flow channel (22) gradually decrease along the water flow direction of the desalination process. A plurality of water guide protrusions (4) are provided in the flow channel (2).

2. The electro-adsorption device according to claim 1, wherein: On any cross-section perpendicular to the first current-carrying plate (11) and the first water flow channel (21), the thickness of the second adsorption layer (32) is d2, and the thickness of the first adsorption layer (31) is d1, satisfying d2 > d1; and / or On any cross-section perpendicular to the second current-carrying plate (12) and the second water flow channel (22), the thickness of the third adsorption layer (33) is d3, and the thickness of the fourth adsorption layer (34) is d4, satisfying d4 > d3.

3. The electro-adsorption device according to claim 2, wherein: d1:d2 = 0.5 to 0.99:1; and / or d3:d4 = 0.5 to 0.99:

1.

4. The electro-adsorption device according to claim 2, wherein: The sum of the thicknesses of the first adsorption layer (31) and the second adsorption layer (32) at the inlet of the first water flow channel (21) is s1, and the sum of the thicknesses of the first adsorption layer (31) and the second adsorption layer (32) at the outlet of the first water flow channel (21) is s2, satisfying s2:s1 = 0.5 to 0.99:1; and / or The sum of the thicknesses of the third adsorption layer (33) and the fourth adsorption layer (34) at the inlet of the second water flow channel (22) is s1', and the sum of the thicknesses of the third adsorption layer (33) and the fourth adsorption layer (34) at the outlet of the second water flow channel (22) is s2', satisfying s2':s1' = 0.5 to 0.99:

1.

5. The electro-adsorption device according to claim 1, wherein: During desalination, the cross-sectional area at the inlet of the first water flow channel (21) is A1, and the cross-sectional area at the outlet is A2, satisfying A1:A2 = 1:0.8 to 0.99; and / or During desalination, the cross-sectional area at the inlet of the second water flow channel (22) is A1', and the cross-sectional area at the outlet is A2', satisfying A1':A2' = 1:0.8 to 0.

99.

6. The electro-adsorption device according to claim 1, wherein: The central axis of the water guiding protrusion (4) has an included angle α with the water flow direction of the flow channel (2), and α is between 10° and 70°.

7. The electro-adsorption device according to any one of claims 1 to 6, characterized in that: A plurality of the electrode adsorption modules are stacked and connected up and down. Among adjacent electrode adsorption modules, the inlet of the second water flow channel (22) in the upper electrode adsorption module is communicated with the outlet of the first water flow channel (21) in the lower electrode adsorption module, and the second current-carrying plate (12) in the upper electrode adsorption module serves as the first current-carrying plate (11) in the lower electrode adsorption module.

8. An electro-adsorption system, characterized in that: It includes a raw water pipeline (61), a clear water pipeline (62), a concentrated water pipeline (63), and a plurality of electro-adsorption devices according to any one of claims 1 to 7. The raw water pipeline (61) is communicated with the inlet of the second water flow channel (22) at the bottom layer of each electro-adsorption device through a first valve (71) and with the outlet of the first water flow channel (21) at the top layer of each electro-adsorption device through a fourth valve (74). The clear water pipeline (62) is communicated with the outlet of the first water flow channel (21) at the top layer of each electro-adsorption device through a second valve (72), and the concentrated water pipeline (63) is communicated with the inlet of the second water flow channel (22) at the bottom layer of each electro-adsorption device through a third valve (73).

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