Electro-adsorption device and system

Abstract

An electro-adsorption device disclosed by the present invention comprises at least one electro-adsorption module, the electrode adsorption module comprises an electrode adsorption layer, a flow channel and a current-carrying plate, 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, and the third adsorption layer is located on the lower surface of the third current-carrying plate. The fourth adsorption layer is positioned on the upper surface of the second carrier 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 an outlet of the second water flow channel communicates with an inlet of the first water flow channel to form a flow channel; raw water flows into the outlet of the first water flow channel from the inlet of the second water flow channel and flows out for desalination, and the thickness of each adsorption layer is gradually reduced along the water flow direction in the desalination process. The electro-adsorption device has the advantages that the structure is simple and compact, the service life of the electrode adsorption layer is long, and the desalting efficiency is high. The invention further discloses an electro-adsorption system.

Description

Technical Field

[0001] The present invention relates to the technical field of electrosorption, and in particular to an electrosorption device and system. Background Art

[0002] Capacitive Deionization (CDI) technology has received widespread attention in recent years as an efficient and sustainable method for desalination of seawater and high-salinity wastewater. CDI units are usually composed of graphite current-carrying plates, electrodes, separators (such as ion exchange membranes or porous membranes), and water channels. As one of the core components of the CDI unit, the water channel is responsible for transporting the water to be treated and ensuring that it can flow between the electrodes. When a voltage is applied across the electrodes, the potential difference generated causes the ions in the water to be adsorbed onto the surface of the electrode with the opposite charge, or to be stored in the double layer region formed at the electrode / water interface, thereby achieving desalination of high-salinity water. Therefore, the design of the water channel is crucial to improving the mass transfer efficiency, desalination efficiency, and water production capacity of the CDI unit.

[0003] In the existing CDI device, the traditional horizontal water channel structure is adopted, such as the Chinese patent document CN104817143A. As the treatment process proceeds, the salt concentration of the water to be treated will gradually decrease, resulting in uneven adsorption between the electrode near the inlet and the electrode near the outlet, causing the aging speed of the electrode head and tail to be different, which has an adverse effect on the service life and desalination efficiency of the electrode. Fig.10 and Fig.11 As 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 electrosorption device with a simple and compact structure, a long electrode adsorption layer life and high desalination efficiency. The present invention further provides an electrosorption system with strong applicability, high treatment efficiency and high working continuity.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] An electrosorption device comprises at least one electrosorption module, wherein the electrosorption module comprises an electrode absorption layer, a flow channel and a current-carrying plate.

[0007] The current-carrying plate member comprises a first current-carrying plate and a second current-carrying plate arranged in parallel, and a third current-carrying plate arranged 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 supply electrode, the third current-carrying plate is connected to a second power supply electrode, and the first power supply electrode and the second power supply 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, wherein 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 connected to the inlet of the first water flow channel to form a flow channel, and raw water flows from the inlet of the second water flow channel to the outlet of the first water flow channel to flow out 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 channel, the thickness of the second adsorption layer is d2, the thickness of the first adsorption layer is d1, and d2>d1 is satisfied; and / or

[0013] On any cross section perpendicular to the second current-carrying plate and the second water passage, 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=0.5-0.99:1; and / or

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

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

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

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

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

[0020] During desalination, the cross-sectional area at the inlet of the first water passage 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 of ​​the inlet of the second water passage is A1', and the cross-sectional area of ​​the outlet is A2', satisfying A1': A2' = 1: 0.8-0.99.

[0022] A plurality of water-conducting protrusions are arranged in the flow channel.

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

[0024] Multiple electrode adsorption modules are stacked and connected up and down. In adjacent electrode adsorption modules, the inlet of the second water channel in the upper electrode adsorption module is connected to the outlet of the first water 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 electrosorption system comprises a raw water pipeline, a clean water pipeline, a concentrated water pipeline and a plurality of the above-mentioned electrosorption devices, wherein the raw water pipeline is connected to the inlet of the second water passage in the bottom layer of each electrosorption device through a first valve and is connected to the outlet of the first water passage in the top layer of each electrosorption device through a fourth valve, the clean water pipeline is connected to the outlet of the first water passage in the top layer of each electrosorption device through a second valve, and the concentrated water pipeline is connected to the inlet of the second water passage in the bottom layer of each electrosorption device through a third valve.

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

[0027] The electric adsorption device of the present invention has a salt concentration of raw water that gradually decreases as desalination proceeds, and the thickness of each electrode adsorption layer gradually decreases along the water flow direction of the desalination process, so that the adsorption of the head and tail of each electrode adsorption layer is more uniform, the consistency of the adsorption process of the head and tail of the electrode adsorption layer is improved, the asymmetric aging of the head and tail of each electrode adsorption layer is reduced, the service life of the electrode adsorption layer is extended, and the desalination efficiency is improved; the third current-carrying plate is arranged between the first current-carrying plate and the second current-carrying plate to form two groups of adsorption layers and two water flow channels, and the structure is simple and compact; the electric adsorption device can be regenerated by reverse flow of raw water and reversal of the positive and negative poles of the power supply to restore the adsorption capacity of the electrode, and the regeneration process is simple.

[0028] The electric adsorption system of the present invention can realize different working modes by controlling the on and off of different valves, and has strong applicability; multiple electric adsorption devices can be connected in parallel to synchronously desalinate and regenerate, and can treat large-flow raw water with high treatment efficiency; multiple parallel electric adsorption devices can be divided into two groups to perform desalination and regeneration respectively, so that at least one group of electric adsorption devices is always performing desalination, and the working continuity is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the electric adsorption device during desalination according to the first embodiment of the present invention.

[0030] Figure 2 It is a schematic diagram of the structure of the electric adsorption device during regeneration according to the first embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the structure of the electric adsorption device during desalination according to the second embodiment of the present invention.

[0032] Figure 4 It is a schematic diagram of the structure of the electric adsorption device during regeneration according to the second embodiment of the present invention.

[0033] Figure 5 It is a structural schematic diagram of the electric adsorption system of Example 3 of the present invention.

[0034] Figure 6 It is a schematic structural diagram of two electric adsorption devices of the electric adsorption system of Example 3 of the present invention during synchronous desalination.

[0035] Figure 7 It is a schematic structural diagram of the synchronous regeneration of two electric adsorption devices of the electric adsorption system of the third embodiment of the present invention.

[0036] Figure 8 It is a schematic diagram of the structure of two electric adsorption devices of the electric adsorption system of Example 3 of the present invention during alternate desalination and regeneration.

[0037] Fig. 9 This is another structural schematic diagram of the two electric adsorption devices of the electric adsorption system of Example 3 of the present invention when they are alternately desalting and regenerating.

[0038] Fig.10 This is a SEM image of the head of the activated carbon electrode adsorption layer after the existing CDI device was cycled 5000 times.

[0039] Fig.11 This is a SEM image of the tail of the activated carbon electrode adsorption layer after the existing CDI device was cycled 5000 times.

[0040] The numbers in the figure represent: 1. current-carrying plate; 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-guiding 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 DESCRIPTION

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

[0042] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are 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 understood as a limitation on the present invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, 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 The first embodiment of the electric adsorption device of the present invention is shown. The electric adsorption device of this embodiment includes at least one electric adsorption module. The electrode adsorption module includes an electrode adsorption layer 3, a flow channel 2 and a current-carrying plate 1.

[0047] The current-carrying plate member 1 comprises a first current-carrying plate 11 and a second current-carrying plate 12 arranged in parallel, and a third current-carrying plate 13 arranged 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 supply electrode, the third current-carrying plate 13 is connected to a second power supply electrode, and the first power supply electrode and the second power supply 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, wherein 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 arranged at intervals to form a first water flow channel 21, and 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 connected to the inlet of the first water flow channel 21 to form a flow channel 2. Raw water flows from the inlet of the second water flow channel 22 to the outlet of the first water flow channel 21 to flow out 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 are gradually reduced along the water flow direction of the desalination process.

[0051] The electric adsorption device of this embodiment, when desalting, Figure 1 As shown, the first current-carrying plate 1 and the second current-carrying plate 12 are respectively connected to the first power supply electrode, and the third current-carrying plate 13 is connected to the second power supply electrode. 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 causes the ions in the raw water to be adsorbed to the surface of the electrode adsorption layer 3 with opposite charge or the double electric layer region formed by the electrode / water interface. The raw water flows in from the inlet of the second water-passing channel 22, passes through the second water-passing channel 22 and the first water-passing channel 21 in sequence, and the raw water after desalination forms clear water, which flows out from the outlet of the first water-passing channel 21; when the desalination efficiency is reduced to less than 30%, the electrode adsorption layer 3 needs to be regenerated. During the regeneration, as shown in FIG. Figure 2As shown, the positive and negative leads of the power supply are reversed to change the direction of the current, that is, the first current-carrying plate 1 and the second current-carrying plate 12 are respectively connected to the second power supply electrode, and the third current-carrying plate 13 is connected to the first power supply electrode. Due to the repulsive force of the electric field, the ions on the electrode adsorption layer 3 are excluded and enriched in the raw water, and the raw water flows in the reverse direction, that is, the raw water flows in from the outlet of the first water flow channel 21, passes through the first water flow channel 21 and the second water flow channel 22 in sequence, and the raw water after regeneration forms concentrated water, which flows out from the inlet of the second water flow channel 22, thereby restoring the adsorption capacity of the device. In the electric adsorption device of the present embodiment, since the salt concentration of the raw water gradually decreases with the desalination process, the thickness of each electrode adsorption layer 3 gradually decreases along the water flow direction of the desalination process, so that the adsorption of the head and tail of each electrode adsorption layer 3 is more uniform, the consistency of the adsorption process of the head and tail of the electrode adsorption layer 3 is improved, the asymmetric aging of the head and tail of each electrode adsorption layer 3 is reduced, the service life of the electrode adsorption layer 3 is extended and the desalination efficiency is improved; the third current-carrying plate 13 is arranged between the first current-carrying plate 1 and the second current-carrying plate 12 to form two groups of adsorption layers and two water flow channels, and the structure is simple and compact; the electric adsorption device can be regenerated by the reverse flow of raw water and the reversal of the positive and negative poles of the power supply to restore the adsorption capacity of the electrode, and the regeneration process is simple.

[0052] The first adsorption layer 31 and the second adsorption layer 32 form a group of adsorption layers, and the third adsorption layer 33 and the fourth adsorption layer 34 form another group of adsorption layers. The first power supply pole is the negative pole of the power supply, and the second power supply pole is the positive pole of the power supply. Of course, in other embodiments, the first power supply pole can also be the positive pole and the second power supply pole 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, and the first current carrier plate 1 and the second current carrier plate 12 are graphite current carrier plates.

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

[0055] Preferably, in this embodiment, the outlet of the second water flow channel 22 is located on the same side as the inlet of the first water flow channel 21. The ports on the same side of the second water flow channel 22 and the first water flow channel 21 are connected to 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 flows from the outlet of the second water flow channel 22 to the inlet of the first water flow channel 21, flowing in a serpentine shape, so that the flow path is longer and the layout is compact under the same device volume.

[0056] Furthermore, in this embodiment, the electrode adsorption layer 3 is also covered with a separator 5. The separator 5 (such as an ion exchange membrane or a porous membrane, etc.) can allow a specific type of ions to pass through, while blocking other types of ions, so that the separator 5 can facilitate the electrode adsorption layer 3 to separate and enrich the target ions during the electrode adsorption process.

[0057] Furthermore, in the present embodiment, on any cross section perpendicular to the first current-carrying plate 11 and the first water 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 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, so that under the action of gravity, even if the water flow and ions are more likely to contact the lower electrode and the contact with the upper electrode is insufficient, the upper and lower electrode adsorption layers 3 are aged evenly due to the different thicknesses of the upper and lower electrode adsorption layers 3 of each group of adsorption layers, thereby improving the consistency of the life of the upper and lower electrode adsorption layers 3 in each group of adsorption layers, reducing overall performance limitations, and saving materials; the gradual change in the thickness of the electrode adsorption layer 3 at the head and tail, combined with the different thicknesses of the upper and lower electrode adsorption layers 3, achieves uniform loading of the electrode adsorption layer 3 in the entire desalination process, further extending the life of the electrode adsorption layer 3.

[0058] Furthermore, in this embodiment, d1:d2=0.5-0.99:1; and d3:d4=0.5-0.99:1. 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 prolonging the overall life of the electrode adsorption layer 3.

[0059] When other conditions are the same, such as initial seawater salinity: 35000mg / L; working voltage: 1.3V; water flow rate: 1m 3 / h; Electrode adsorption layer 3 material: activated carbon; Experimental temperature: 25℃, the influence of different adsorption layer thickness ratios on the overall life of the electrode adsorption layer 3 is as follows: When d1:d2 and d3:d4 are in the range of 0.5-0.99, the desalination efficiency of the electric adsorption device reaches the best, and the average desalination rate is about 95%; within this range, the energy consumption of the electric adsorption device is low, and the energy consumption per cubic meter of seawater treated is about 0.5kWh / m 3; The lifespan of the upper and lower electrode adsorption layers 3 in each group of adsorption layers is highly consistent, 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, the adsorption capacity of the upper electrode adsorption layer 3 will be insufficient, thereby reducing the overall desalination efficiency, and the desalination rate may drop below 80%; insufficient thickness of the upper electrode adsorption layer 3 will lead to increased resistance during the electrical adsorption process, and excessive load on the lower electrode adsorption layer 3 will result in a higher voltage required to maintain the adsorption effect during the electrical adsorption process, thereby increasing energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to 0.7kWh / m 3 The above; the insufficient thickness of the upper electrode adsorption layer 3 will lead to its 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, 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 the lower electrode adsorption layer 3, the lower electrode adsorption layer 3 will be overloaded, thereby reducing the overall desalination efficiency, and the desalination rate may drop below 85%; the overload of the lower electrode adsorption layer 3 will require a higher voltage to maintain the adsorption effect during the electrical adsorption process, thereby increasing energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to 0.6kWh / m 3 As mentioned above; excessive load on the lower electrode adsorption layer 3 will lead to accelerated aging rate, while the life of the upper electrode adsorption layer 3 is relatively long, which will also lead to inconsistent overall life of the electrode adsorption layer 3, 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 the present 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 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 channel 21 is s2, satisfying s2:s1=0.5~0.99:1; 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 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 channel 22 is s2', satisfying s2':s1'=0.5~0.99:1.

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

[0062] When other conditions are the same, such as the initial seawater salinity: 35000mg / L; the working voltage of the electric adsorption device: 1.3V; the water flow rate: 1m 3 / h;; Electrode adsorption layer 3 material: activated carbon; Experimental temperature: 25℃. For example, the ratio of the sum of the thickness of the electrode adsorption layer 3 at the channel inlet and outlet affects the overall life of the electrode adsorption layer 3 as follows: When s2:s1 and s2′:s1′ are in the range of 0.5 to 0.99, the desalination efficiency of the electric adsorption device reaches the best, and the average desalination rate is about 95%; The energy consumption of the electric adsorption device is low, and the energy consumption per cubic meter of seawater treated is about 0.5kWh / m 3 ; The service life of the adsorption layer is relatively 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 is significantly reduced, the adsorption capacity of the electrode adsorption layer 3 at the outlet will decrease, thereby reducing the desalination efficiency. Experimental data show that in this case, the desalination rate may drop below 80%; the reduction in the thickness of the electrode adsorption layer 3 at the outlet will increase the resistance in the electrosorption process, thereby increasing energy consumption. The energy consumption per cubic meter of seawater treatment may increase to 0.7kWh / m 3 The above; the aging rates of the electrode adsorption layer 3 at the inlet and outlet are inconsistent, and the thickness of the electrode adsorption layer 3 at the outlet is too low, which makes the structure easy to deform, and the average service life may drop to less than 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 remains almost unchanged or increases, the adsorption capacity of the electrode adsorption layer 3 at the inlet is reduced and the adsorption efficiency of the electrode adsorption layer 3 at the outlet is reduced, which 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 electrosorption process, thereby increasing energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to 0.6kWh / m 3 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 be reduced to less than 700 hours.

[0063] Furthermore, in the present embodiment, the third current-carrying plate 13 is arranged obliquely relative to the first current-carrying plate 11 or the second current-carrying plate 12; the cross-sectional areas of the first water channel 21 and the second water channel 22 are gradually reduced along the water flow direction of the desalination process. (It should be noted that during desalination, the cross-sectional areas of the inlet of the first water channel 21 and the outlet of the second water channel 22 are not equal. In the present embodiment, during desalination, the cross-sectional area of ​​the inlet of the first water channel 21 is approximately the same as the cross-sectional area of ​​the inlet of the second water channel 22). Since the salt concentration of the raw water will gradually decrease with the desalination process, the water volume decreases. By gradually reducing the cross-sectional areas of the first water channel 21 and the second water 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 the adsorption efficiency is thereby improved.

[0064] Furthermore, in the present embodiment, the reduction rate of the cross-sectional area of ​​the first water channel 21 and the second water channel 22 matches the reduction rate of the water volume during the desalination process. The cross-sectional area of ​​the first water channel 21 and the second water channel 22 decreases in proportion to the water volume during the desalination process, further promoting the uniform distribution of the water flow, thereby improving the desalination efficiency. For example, adding 10g of sodium sulfate to 100mL of water will cause the volume to expand to about 104mL. 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 separator 5 can be achieved, local overload can be reduced, and the service life of the equipment can be extended.

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

[0066] When other conditions are the same, such as initial seawater salinity: 35000mg / L; working voltage of the electrosorption device: 1.3V; water flow rate: 1m 3 / h; adsorption layer 3 material: activated carbon; experimental temperature: 25℃, for example, the ratio of the cross-sectional area at the channel inlet and outlet affects the overall life of the electrode adsorption layer 3 as follows: when A2:A1 and A2′:A1′ are in the range of 0.8 to 0.99, the desalination efficiency of the electrosorption device reaches the best, and the average desalination rate is about 95%; the energy consumption of the electrosorption device is low, and the energy consumption per cubic meter of seawater treatment is about 0.5kWh / m3; the structural stability of the electrode adsorption layer 3 and the separator 5 is 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, the water flow velocity will increase, and 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 faster water flow velocity will increase the resistance in the electrosorption process, thereby increasing the energy consumption, and the energy consumption per cubic meter of seawater treatment may increase to 0.6kWh / m 3 The above; the pressure at the inlet and outlet is uneven, which causes the adsorption material of the electrode adsorption 3 and the separator 5 to undergo structural deformation, such as compression, deformation or rupture, and the load of the electrode adsorption layer 3 and the separator 5 is uneven, further aggravating 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, the water flow rate will be slower, which may lead to a decrease in the mass transfer efficiency during the electrosorption process, and also reduce the desalination efficiency. The desalination rate may drop below 85%; too slow a water flow rate will result in a higher voltage being required to maintain the adsorption effect during the electrosorption process, thereby increasing energy consumption. The energy consumption per cubic meter of seawater treatment may increase to 0.6kWh / m 3 above.

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

[0068] Furthermore, in this embodiment, the central axis of the water-guiding protrusion 4 and the water flow direction of the flow channel 2 have an angle α, and α is between 10° and 70°. An appropriate angle α can prevent the water flow from being too gentle or too turbulent, ensure that the water flow is evenly distributed in the flow channel 2, and improve 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 separator 5 is small, the contact efficiency between the 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 separator 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 separator 5, resulting in structural deformation and aging, and the average service life of the electrode adsorption layer and the separator 5 may be reduced to less than 700 hours.

[0069] Specifically, the water-guiding protrusion 4 is at least one of a circular, elliptical, diamond-shaped, rectangular, conical, and spindle-shaped. When the water-guiding protrusion 4 is circular, the angle α does not exist. In this embodiment, it is a spindle-shaped.

[0070] The desalination performance test of the electric adsorption device of this embodiment is as follows: the first current-carrying plate 11, the second current-carrying plate 12 and the third current-carrying plate 13 are all 30×30 cm 2 The graphite plate, the electrode adsorption layer 3 is composed of a porous activated carbon material, the thickness of the first adsorption layer 31 and the third adsorption layer 33 at the inlet to the outlet of the water flow channel is reduced from 0.5 cm to 0.3 cm, the thickness of the second adsorption layer 32 and the fourth adsorption layer 34 at the inlet to the outlet of the water flow channel is reduced from 0.8 cm to 0.4 cm, and the cross-sectional area of ​​the first water flow channel 21 and the second water flow channel 22 at the inlet to the outlet is reduced from 30 cm to 10 cm. 2 Down to 29cm 2 , the electrode adsorption layers 3 are separated by anion and cation exchange membranes. When the raw water uses a NaCl solution with a solution concentration of 1g / L and a flow rate of 150mL / min, a conductivity meter is used to monitor the conductivity of the inlet and outlet water. Under the constant voltage mode of 1.2V, the salt adsorption capacity of the electric adsorption device of this embodiment remains at 31.8mg / g after 20 cycles, and the desalination rate remains above 85%; while the traditional horizontal flow channel structure with each electrode adsorption layer 3 having a thickness of 0.5cm has a salt adsorption capacity of 25.1mg / g after 20 cycles, and the desalination rate is 74%. When the raw water uses a NaCl solution with a solution concentration of 2g / L, the salt adsorption capacity of the electric adsorption device of this embodiment remains at 39.5mg / g after 20 cycles, and the desalination rate remains above 89%; while the traditional horizontal flow channel structure with each electrode adsorption layer 3 having a thickness of 0.5cm has a salt adsorption capacity of 28.1mg / g after 20 cycles, and the desalination rate is 77%. Compared with the traditional horizontal flow channel structure, the electric adsorption device of this embodiment has higher desalination performance and is conducive to maintaining a longer electrode life.

[0071] Embodiment 2:

[0072] Figure 3 and Figure 4 A second embodiment of the electric adsorption device of the present invention is shown. The structure of the electric adsorption device of this embodiment is basically the same as that of the first embodiment, and the differences include: in this embodiment, two electrode adsorption modules are provided, and the two electrode adsorption modules are stacked and connected up and down, and in adjacent electrode adsorption modules, the inlet of the second water channel 22 in the upper electrode adsorption module is connected to the outlet of the first water channel 21 in the lower electrode adsorption module, and the second current-carrying plate 12 in the upper electrode adsorption module is the first current-carrying plate 11 in the lower electrode adsorption module.

[0073] The electric adsorption device of this embodiment connects the inlet of the second water passage 22 of the upper electrode adsorption module with the outlet of the first water passage 21 of the lower electrode adsorption module to realize the series combination of the two electrode adsorption modules. Figure 3 As shown, raw water flows in from the inlet of the second water passage 22 in the lower electrode adsorption module, passes through the second water passage 22 and the first water passage 21 in the lower electrode adsorption module, and the second water passage 22 and the first water passage 21 in the upper electrode adsorption module in sequence, and the raw water after desalination is formed into clean water, which flows out from the outlet of the first water passage 21 in the upper electrode adsorption module. The rest is similar to the electric adsorption device of embodiment 1; during regeneration, as Figure 4 As shown, the regeneration process is the same and will not be described again. The electric adsorption device of this embodiment can realize the series combination of multiple electrode adsorption modules by connecting the inlet of the second water channel 22 in the upper electrode adsorption module with the outlet of the first water channel 21 in the lower electrode adsorption module. The structure is simple and reliable; the multiple electrode adsorption modules combined in series can make the flow path of the water flow longer, improve the processing capacity, and can adapt to the adsorption scenarios of raw water with higher concentration and larger processing volume, and have 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 needs to meet the water treatment requirements in different application scenarios, and have strong applicability.

[0074] Of course, in other embodiments, a greater number of electrode adsorption modules may be combined in series to extend the length of the water passage, thereby providing greater adaptability.

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

[0076] Embodiment three:

[0077] Figure 5 and Fig. 9An embodiment of the electrosorption system of the present invention is shown. The electrosorption system of this embodiment includes a raw water pipeline 61, a clean water pipeline 62, a concentrated water pipeline 63 and two electrosorption devices of the second embodiment. The raw water pipeline 61 is connected to the inlet of the second water channel 22 in the bottom layer of each electrosorption device through the first valve 71, and is connected to the outlet of the first water channel 21 in the top layer of each electrosorption device through the fourth valve 74. The clean water pipeline 62 is connected to the outlet of the first water channel 21 in the top layer of each electrosorption device through the second valve 72. The concentrated water pipeline 63 is connected to the inlet of the second water channel 22 in the bottom layer of each electrosorption device through the third valve 73.

[0078] The electric adsorption system of this embodiment can realize different working modes by controlling the on and off of different valves, as shown below.

[0079] Two electrosorption devices simultaneously desalinate and regenerate: During desalination, e.g. Figure 5 and Figure 6 As shown, the two first valves 71 and the two second valves 72 are opened, and the third valve 73 and the fourth valve 74 are closed. The raw water in the raw water pipeline 61 flows in from the inlet of the second water flow channel 22 at the bottom of the two electric adsorption devices respectively. The raw water is desalinated by the electric adsorption device to form clean water, which flows out from the clean water pipeline 62 through the outlet of the first water flow channel 21 at the top of the electric adsorption device, thereby realizing the parallel synchronous desalination of the two electric adsorption devices. During regeneration, as shown in FIG. Figure 7 As shown, the two third valves 73 and the two fourth valves 74 are opened, and the first valve 71 and the second valve 72 are closed. The raw water in the raw water pipe 61 flows in from the outlet of the topmost first water channel 21 in the two electric adsorption devices respectively. The raw water is regenerated by the electric adsorption device to form concentrated water, which flows out from the concentrated water pipe 63 through the inlet of the bottommost second water channel 22 in the electric adsorption device, thereby realizing the parallel synchronous regeneration of the two electric adsorption devices.

[0080] Two electrosorption devices are used to desalinate and regenerate alternately: when the first electrosorption device is desalting and the second electrosorption device is regenerating, Figure 8 As shown, the first valve 71 and the two second valves 72 of the first electric adsorption device are opened, the third valve 73 and the fourth valve 74 are closed, the raw water in the raw water pipeline 61 is desalted by the first electric adsorption device to form clean water, and flows out from the clean water pipeline 62, the third valve 73 and the fourth valve 74 of the second electric adsorption device are opened, the first valve 71 and the second valve 72 are closed, the raw water in the raw water pipeline 61 is regenerated by the second electric adsorption device to form concentrated water, and flows out from the concentrated water pipeline 63; Fig. 9As shown, when the first electric adsorption device is regenerated and the second electric adsorption device is desalting, the third valve 73 and the fourth valve 74 of the first electric adsorption device are opened, and the first valve 71 and the second valve 72 are closed. The raw water in the raw water pipeline 61 is regenerated by the first electric adsorption device to form concentrated water, which flows out from the concentrated water pipeline 63. The first valve 71 and the two second valves 72 of the second electric adsorption device are opened, and the third valve 73 and the fourth valve 74 are closed. The raw water in the raw water pipeline 61 is desalted by the second electric adsorption device to form clean water, which flows out from the clean water pipeline 62.

[0081] The electric adsorption system of this embodiment can realize different working modes by controlling the on and off of different valves, and has strong applicability; multiple electric adsorption devices can be connected in parallel for synchronous desalination and regeneration, and can treat a large flow of raw water with high treatment efficiency; multiple parallel electric adsorption devices can be divided into two groups for desalination and regeneration respectively, so that there is always at least one group of electric adsorption devices performing desalination, and the working continuity is high.

[0082] Of course, in other embodiments, the electrosorption system may also include a larger number of electrosorption devices, which can simultaneously process a larger flow of raw water with higher processing efficiency and greater adaptability.

[0083] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An electrosorption device, comprising at least one electrosorption module, characterized in that: The electrode adsorption module comprises an electrode adsorption layer (3), a flow channel (2) and a current-carrying plate (1). The current-carrying plate member (1) comprises a first current-carrying plate (11) and a second current-carrying plate (12) arranged in parallel, and a third current-carrying plate (13) arranged 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) being connected to a first power supply electrode respectively, the third current-carrying plate (13) being connected to a second power supply electrode, and the first power supply electrode and the second power supply electrode have opposite polarities; The electrode adsorption layer (3) comprises a first adsorption layer (31), a second adsorption layer (32), a third adsorption layer (33) and a fourth adsorption layer (34), wherein 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 connected to the inlet of the first water flow channel (21) to form a flow channel (2); raw water flows from the inlet of the second water flow channel (22) to the outlet of the first water flow channel (21) to be desalinated; 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.

2. The electric adsorption device according to claim 1, characterized in that: 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, the thickness of the first adsorption layer (31) is d1, and d2>d1 is satisfied; 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 electric adsorption device according to claim 2, characterized in that: d1:d2=0.5-0.99:1; and / or d3:d4=0.5~0.99:

1.

4. The electric adsorption device according to claim 2, characterized in that: The sum of the thicknesses of the first adsorption layer (31) and the second adsorption layer (32) at the inlet of the first water passage (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 passage (21) is s2, satisfying s2:s1=0.5-0.99:1; 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'=0.5-0.99:

1.

5. The electric adsorption device according to claim 1, characterized in that: The third current-carrying plate (13) is arranged obliquely relative to the first current-carrying plate (11) or the second current-carrying plate (12); The cross-sectional areas of the first water passage (21) and / or the second water passage (22) gradually decrease along the water flow direction of the desalination process.

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

99.

7. The electric adsorption device according to claim 1, characterized in that: A plurality of water-conducting protrusions (4) are provided in the flow channel (2).

8. The electric adsorption device according to claim 7, characterized in that: The central axis of the water-conducting protrusion (4) and the water flow direction of the flow channel (2) form an angle α, and α is between 10° and 70°.

9. The electrosorption device according to any one of claims 1 to 8, characterized in that: A plurality of the electrode adsorption modules are stacked and connected up and down, and in adjacent electrode adsorption modules, the inlet of the second water passage (22) in the upper electrode adsorption module is connected to the outlet of the first water passage (21) in the lower electrode adsorption module, and the second current-carrying plate (12) in the upper electrode adsorption module is the first current-carrying plate (11) in the lower electrode adsorption module.

10. An electrosorption system, characterized in that: It comprises a raw water pipeline (61), a clean water pipeline (62), a concentrated water pipeline (63) and a plurality of electric adsorption devices described in any one of claims 1 to 9, wherein the raw water pipeline (61) is connected to the inlet of the second water passage (22) in the bottom layer of each electric adsorption device through a first valve (71), and is connected to the outlet of the first water passage (21) in the top layer of each electric adsorption device through a fourth valve (74); the clean water pipeline (62) is connected to the outlet of the first water passage (21) in the top layer of each electric adsorption device through a second valve (72); and the concentrated water pipeline (63) is connected to the inlet of the second water passage (22) in the bottom layer of each electric adsorption device through a third valve (73).

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