Fluidized electrode desalination device, system and application

Abstract

The application provides a fluidized electrode desalination device, system and application, which comprises an anode end plate, an anode current collector, a first cation exchange membrane, a concentration chamber partition plate, an anion exchange membrane, a dilution chamber partition plate, a second cation exchange membrane, a cathode current collector and a cathode end plate which are sequentially arranged, at least one of the anode current collector and the cathode current collector is a metal folded mesh current collector, the metal folded mesh current collector is a continuous folded structure and comprises a plurality of folded units which are sequentially connected along a first direction. Compared with a traditional graphite plate current collector, the metal folded mesh current collector has the characteristics of light weight, high mechanical strength and large effective contact area, and is combined with a dispersible water distribution tank design, which is beneficial to improving the uniformity of the electrode slurry flow process, strengthening the effective collision of the electrode particles and the metal folded mesh current collector, and improving the charge transfer efficiency in the electrode slurry.

Description

Technical Field

[0001] This invention belongs to the field of fluidized electrode capacitive deionization technology, and particularly relates to a fluidized electrode desalination device, system and application based on a metal folded mesh current collector. Background Technology

[0002] Fluidized electrode capacitive deionization (FCDI) is a novel water desalination technology with broad application prospects in industrial wastewater treatment, seawater desalination, and salt lake resource extraction. Based on the directional migration of ions driven by a DC electric field and the capacitance characteristics of the "double layer" on the surface of carbon electrode particles, it achieves efficient removal of ions from water. Furthermore, utilizing the rheological properties of the fluidized electrode, it enables a continuous and dynamic desalination process, demonstrating significant industrial application potential. Compared to traditional deionization technologies such as electrodialysis, reverse osmosis, and ion exchange, FCDI technology offers advantages such as low energy consumption, high water yield, and low operating costs.

[0003] Currently, the industrial application of FCDI is mainly limited by the expansion of the device's effectiveness to improve processing efficiency. The design of the current collector in an FCDI device is one of the keys to enhancing desalination efficiency. Most existing current collector designs are based on graphite-etched channels. Graphite current collectors are brittle and fragile, and their high processing cost significantly limits the large-scale application of FCDI technology. Furthermore, traditional planar metal mesh current collectors have insufficient effective contact area with the fluidized electrode during operation, limiting charge transfer efficiency and ultimately leading to insufficient desalination performance.

[0004] Existing titanium mesh plates are perforated mesh structures, which, compared to woven mesh, have a smoother surface and thus offer poorer dispersion of electrode slurry flow. While porous metal materials such as foamed titanium and foamed nickel have high porosity, their random and irregular pore distribution easily creates significant resistance to electrode slurry flow, leading to clogging over long-term operation. Archimedes' spiral (mosquito coil-shaped), double Fermat spiral, and hexagonal honeycomb channels are all graphite plate collectors. Although they offer better dispersion of electrode slurry flow and alleviate the problem of particulate carbon accumulation and clogging compared to traditional serpentine or racetrack-shaped channels, these circular channel plates have insufficient utilization of the ion exchange membrane area. Furthermore, graphite plates are brittle and fragile, complex channel processing is costly, and large-scale scaling is difficult, limiting their practical application.

[0005] In view of this, the present invention provides a fluidized electrode desalination device and system based on a metal folded mesh current collector. Summary of the Invention

[0006] The main objective of this invention is to provide a fluidized electrode desalination device, system, and application to solve the technical problems of traditional graphite plate electrodes being brittle and difficult to scale up, and planar metal mesh electrodes having limited charge transfer efficiency.

[0007] To achieve the above objectives, the present invention provides a fluidized electrode desalination device, comprising an anode end plate, an anode current collector, a first cation exchange membrane, a concentration chamber partition, an anion exchange membrane, a desalination chamber partition, a second cation exchange membrane, a cathode current collector, and a cathode end plate arranged sequentially. At least one of the anode current collector and the cathode current collector is a metal folded mesh current collector, which has a continuously folded structure and includes multiple folded units connected sequentially along a first direction.

[0008] Furthermore, the metal folded mesh current collector has a mesh count of 30 to 120, a thickness of 1 to 2 mm, and a corrugation interval of 1 to 2.5 mm.

[0009] Furthermore, a groove is provided on the working surface of the anode end plate and / or the cathode end plate, the center line of the groove coincides with the center line of the end plate with the groove, and the metal folded mesh current collector is disposed in the groove.

[0010] Furthermore, the metal folded mesh current collector is placed at an angle of 0 to 90° in the groove.

[0011] Preferably, the metal folded mesh collector is placed at an angle of 45° in the groove.

[0012] Furthermore, the depth of the groove is 1 to 3 mm.

[0013] Furthermore, a dispersive water distribution trough is provided at the bottom of the groove, the depth of which is 1-3 mm; and at least two water flow channels are provided at the top of the dispersive water distribution trough, the width of which is 1-2 mm.

[0014] Furthermore, the lower ends of both the anode and cathode end plates are provided with a fresh water inlet, a concentrated water inlet, and an electrode slurry inlet, and the upper ends of both the anode and cathode end plates are provided with a fresh water outlet, a concentrated water outlet, and an electrode slurry outlet.

[0015] Furthermore, the thickness of both the concentration chamber partition and the desalination chamber partition is 0.5–2.5 mm; Both the concentration chamber partition and the desalination chamber partition have square through-hole areas with plastic mesh structures at their geometric centers. The bottom of the partition of the concentration chamber has a concentrated liquid flow channel, which is connected to the concentrated water inlet of the anode plate through a concentrated liquid pipe; the bottom of the partition of the desalination chamber has a desalination liquid flow channel, which is connected to the fresh water inlet of the cathode plate through a desalination liquid pipe.

[0016] The present invention also provides a fluidized electrode desalination system, comprising an anode end plate, an anode current collector, a first cation exchange membrane, a concentration chamber partition, an anion exchange membrane, a desalination chamber partition, a second cation exchange membrane, a cathode current collector, a cathode end plate, a desalination liquid transfer pump, a concentration liquid transfer pump, an electrode slurry transfer pump, an electrode slurry, and a power supply; The positive terminal of the power supply is connected to the anode current collector, and the negative terminal of the power supply is connected to the cathode current collector. The power supply is a DC power supply.

[0017] Furthermore, the desalination liquid delivery pump is installed on the desalination liquid pipeline, the concentrate delivery pump is installed on the concentrate pipeline, and the electrode slurry delivery pump is installed on the electrode slurry pipeline.

[0018] Furthermore, the electrode slurry comprises activated carbon and an electrolyte solution, wherein the activated carbon accounts for 5-25% of the mass of the electrode slurry, and the electrolyte solution accounts for 75-95% of the mass of the electrode slurry.

[0019] The fluidized electrode desalination device or fluidized electrode desalination system provided by this invention can be applied to water treatment desalination.

[0020] The technical effects of this invention are as follows: 1. Compared with traditional graphite plate current collectors, the metal folded (corrugated) mesh current collector of the present invention has the characteristics of being lightweight, having high mechanical strength and a large effective contact area. Combined with the design of a dispersive water distribution tank, it is beneficial to improve the uniformity of the electrode slurry flow process, enhance the effective collision between electrode particles and the metal folded mesh current collector, and improve the charge transfer efficiency in the electrode slurry.

[0021] 2. This invention overcomes the shortcomings of traditional graphite electrodes, such as high processing difficulty and brittleness. It also effectively solves the problem of insufficient effective collision between planar metal mesh and electrode particles, which leads to limited charge transfer efficiency. This is beneficial to improving the desalination performance of fluidized electrodes, reducing the difficulty of industrial application, and has greater practical application prospects.

[0022] 3. The metal folded mesh current collector of the present invention has a three-dimensional structure, which greatly increases the effective contact area between the current collector and the electrode slurry compared with the planar structure of titanium mesh plate and woven mesh, which is conducive to enhancing the charge transfer efficiency. The metal folded mesh current collector has high mechanical strength, which facilitates the later equipment maintenance. The folded structure is simple to process and easy to scale up. It has the advantage of being lightweight compared with graphite plate current collectors.

[0023] 4. The metal folded mesh current collector of the present invention is placed at a certain angle in the groove of the end plate, intersecting with the slurry flow direction, which improves the dispersion of the electrode slurry velocity field, facilitates high-frequency collisions between electrode particles and mesh wires, thereby enhancing the electron transfer process to carbon electrode particles and improving desalination efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the fluidized electrode desalination device according to an embodiment of the present invention; Figure 2 This is a front view of a male or female end plate with a groove provided in an embodiment of the present invention. Figure 3 This is a top view of the metal folded mesh current collector according to an embodiment of the present invention; Figure 4 This is a side view of a metal folded mesh current collector according to an embodiment of the present invention, wherein D is the thickness of the metal folded mesh current collector and L is the corrugation spacing of the metal folded mesh current collector; Figure 5 The graphs show the conductivity variations of stainless steel folded mesh current collectors with different mesh counts in Embodiment 1 of the present invention, where (a) is the conductivity variation graph of the desalination liquid and (b) is the conductivity variation graph of the concentrate. Figure 6 The diagram shows the conductivity variation of the stainless steel folded mesh current collector at different placement angles in Embodiment 2 of the present invention, where (a) is the conductivity variation of the desalination liquid and (b) is the conductivity variation of the concentrate. Figure 7 This is a graph showing the change in the conductivity of the desalination liquid based on titanium metal folded mesh current collectors with different mesh sizes in Embodiment 3 of the present invention; Figure 8 This is a graph showing the desalination rate variation of titanium metal folded mesh current collectors with different mesh sizes in Embodiment 3 of the present invention; Figure 9 This is a graph showing the changes in electrochemical performance of titanium metal folded mesh current collectors with different mesh sizes in Example 3 of the present invention; Figure 10 The diagram shows the conductivity variation of the cathode and anode plates with different groove depths in Embodiment 4 of the present invention. (a) is the conductivity variation of the desalination liquid, and (b) is the conductivity variation of the concentrate.

[0026] Reference numerals: 1. Fastening nut; 2. Fastening bolt; 3. Anode end plate; 4. Anode current collector; 5. First cation exchange membrane; 6. Concentration chamber partition; 7. Anion exchange membrane; 8. Desalination chamber partition; 9. Second cation exchange membrane; 10. Cathode current collector; 11. Cathode end plate. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0030] like Figure 1 As shown, the fluidized bed electrode desalination device provided by the present invention includes an anode end plate 3, an anode current collector 4, a first cation exchange membrane 5, a concentration chamber partition 6, an anion exchange membrane 7, a desalination chamber partition 8, a second cation exchange membrane 9, a cathode current collector 10, and a cathode end plate 11 arranged sequentially. Except for the anode current collector 4 and the cathode current collector 10, the edges of the other components of the device are provided with through holes for installing fastening bolts 2, and the device is fixedly connected by fastening nuts 1. The desalination chamber partition 8, together with the adjacent anion exchange membrane 7 and the second cation exchange membrane 9, forms a desalination chamber, and the concentration chamber partition 6, together with the adjacent first cation exchange membrane 5 and anion exchange membrane 7, forms a concentrate chamber.

[0031] In this invention, at least one of the anode current collector 4 and the cathode current collector 10 is a metal folded mesh current collector (e.g., Figure 3As shown), the metal folded mesh current collector (i.e., the metal folded mesh) is a continuous folded structure, comprising multiple folded units connected sequentially along a first direction. Specifically, the continuous folded structure of the present invention is as follows: adjacent folded units are connected by a common fold line; the main outline of the folded unit is triangular and has a wave crest protruding in a direction away from the common fold line. This folded structure has good continuity, good stability, and low manufacturing difficulty. If a rectangular structure is used, the processing is relatively difficult and deformation is easy to occur; wherein, the top of the wave crest is constructed as a vertex structure, and the vertex structure is configured as either a sharp vertex or an arc-shaped transition portion to form a sawtooth or wave-shaped three-dimensional outline in the folded or unfolded state.

[0032] like Figure 4 As shown, D represents the thickness of the metal folded mesh current collector, and L represents the corrugation spacing of the metal folded mesh current collector. In this invention, the mesh count of the metal folded mesh current collector is 30–120 mesh, the thickness is 1–2 mm, and the corrugation spacing is 1–2.5 mm. This ensures that the metal folded mesh current collector is easy to process, the electrode slurry flows smoothly, and carbon particle deposition is less likely to occur. If the mesh count of the metal folded mesh current collector is less than 30 mesh, the wires are too thick, making it impossible to process the folded structure. If the mesh count is too high, the mesh size is too small. An excessively small mesh size greatly increases the flow resistance of the electrode slurry in the metal folded mesh current collector, easily leading to clogging problems. The thickness of the metal folded mesh current collector depends on the corrugation spacing. An excessively large spacing will significantly increase the overall thickness of the metal folded mesh current collector, increasing the depth of the slurry flow area and slowing down the slurry flow rate, making carbon particle deposition more likely. If the thickness of the metal folded mesh current collector exceeds 3 mm, the desalination performance will be significantly reduced.

[0033] like Figure 2 As shown, in the embodiments of the present invention, grooves with a depth of 1 to 3 mm are provided on the working surfaces of the anode end plate 3 and / or the cathode end plate 11. That is: when the anode current collector 4 is a metal folded mesh current collector, the groove is only provided on the working surface of the anode end plate 3 (there is no groove on the working surface of the cathode end plate 11), and the metal folded mesh current collector is placed in the groove, and the cathode current collector 10 is conventionally configured (such as a graphite current collector); when the cathode current collector 10 is a metal folded mesh current collector, the groove is only provided on the working surface of the cathode end plate 11 (there is no groove on the working surface of the anode end plate 3), and the metal folded mesh current collector is placed in the groove, and the anode current collector 4 is conventionally configured (such as a graphite current collector); when both the anode current collector 4 and the cathode current collector 10 are metal folded mesh current collectors, grooves are provided on the working surfaces of both the anode end plate 3 and the cathode end plate 11, and the metal folded mesh current collectors are respectively placed in the grooves of the anode end plate 3 and the cathode end plate 11. Among them, the working surface of the anode end plate 3 refers to the side that contacts the anode current collector 4; the working surface of the cathode end plate 11 refers to the side that contacts the cathode current collector 10.

[0034] In a specific embodiment of the present invention, the center line of the groove coincides with the center line of the anode plate 3 or cathode plate 11 on which the groove is provided. That is, when the working surface of the anode plate 3 (or cathode plate 11) is provided with a groove, the center line of the groove coincides with the center line of the anode plate 3 (or cathode plate 11); when both the working surfaces of the anode plate 3 and the cathode plate 11 are provided with grooves, the center lines of the two grooves coincide with the center lines of their respective end plates. If they do not coincide, the metal folded mesh collector cannot correspond to the freshwater chamber and the concentration chamber, affecting the desalination efficiency.

[0035] In a specific embodiment of the present invention, a dispersive water distribution trough is provided at the bottom of the groove, the depth of the dispersive water distribution trough is 1 to 3 mm, and multiple water flow channels are provided at the top of the dispersive water distribution trough, the width of the water flow channels is 1 to 2 mm, so as to distribute the initial flow rate of the electrode slurry and enable the slurry to be evenly dispersed into the groove.

[0036] In this invention, the metal folded mesh current collector is placed in the groove of the working surface of the anode end plate 3 and / or the cathode end plate 11, and the placement angle of the metal folded mesh current collector in the groove is 0 to 90°. This ensures that the metal folded mesh current collector intersects with the slurry flow direction, improves the dispersion of the electrode slurry velocity field, facilitates high-frequency collisions between electrode particles and mesh wires, thereby strengthening the electron transfer process to carbon electrode particles and improving desalination efficiency.

[0037] It is worth noting that the placement angle of the metal folded mesh current collector in the groove of the present invention refers to the angle between the corrugation direction of the metal folded mesh current collector and the flow direction of the fluidized electrode slurry. That is, the corrugation is placed horizontally, vertically, or at a 45° angle. The corrugation has a certain disturbance effect on the flow of the slurry, which can enhance the effective collision between the electrode particles in the slurry and the metal folded mesh, and help to strengthen charge transfer.

[0038] In this invention, the lower ends of both the anode plate 3 and the cathode plate 11 are provided with a fresh water inlet, a concentrated water inlet, and an electrode slurry inlet, while the upper ends of both the anode plate 3 and the cathode plate 11 are provided with a fresh water outlet, a concentrated water outlet, and an electrode slurry outlet. Each inlet is connected to a corresponding delivery pump via a pipeline, and each outlet is connected to a corresponding storage tank via a pipeline.

[0039] In a specific embodiment of the present invention, both the concentration chamber partition 6 and the desalination chamber partition 8 have square through-hole areas with a plastic mesh structure at their geometric centers. This allows for more uniform flow of the desalination liquid or concentrate. The mesh size of the plastic mesh structure is generally less than 10 mesh, and the square through-hole areas are generally rectangular, maximizing the utilization of the membrane area. In this specific embodiment of the present invention, the mesh size of the plastic mesh structure is less than 10 mesh. The square through-hole areas in the concentration chamber partition 6 are used for uniform distribution of the concentrate; the square through-hole areas in the desalination chamber partition 8 are used for uniform distribution of the desalination liquid. The thickness of both the concentration chamber partition 6 and the desalination chamber partition 8 is 0.5–2.5 mm.

[0040] A concentrated liquid flow channel is provided at the bottom of the concentration chamber partition 6, and the concentrated liquid flow channel is connected to the concentrated water inlet of the anode plate 3 through a concentrated liquid pipe; a desalination liquid flow channel is provided at the bottom of the desalination chamber partition 8, and the desalination liquid flow channel is connected to the fresh water inlet of the cathode plate 11 through a desalination liquid pipe.

[0041] like Figure 1 As shown, the fluidized bed electrode desalination system provided by the present invention includes an anode end plate 3, an anode current collector 4, a first cation exchange membrane 5, a concentration chamber partition 6, an anion exchange membrane 7, a desalination chamber partition 8, a second cation exchange membrane 9, a cathode current collector 10, a cathode end plate 11, a desalination liquid transfer pump, a concentrate transfer pump, an electrode slurry transfer pump, electrode slurry, and a power supply. At least one of the anode current collector 4 and the cathode current collector 10 is a metal folded mesh current collector, and grooves are provided on the working surfaces of the anode end plate 3 and / or the cathode end plate 11, with the metal folded mesh current collector placed within the grooves. Preferably, both the anode current collector 4 and the cathode current collector 10 of the present invention are metal folded mesh current collectors, that is, grooves are provided on the working surfaces of both the anode end plate 3 and the cathode end plate 11, with the metal folded mesh current collector placed within the grooves.

[0042] In a specific embodiment of the present invention, the positive terminal of the power supply is connected to the anode current collector 4 (if the anode current collector 4 is a metal folded mesh current collector, then the positive terminal of the power supply is connected to the metal folded mesh current collector on the anode end plate 3), and the negative terminal of the power supply is connected to the cathode current collector 10 (if the cathode current collector 10 is a metal folded mesh current collector, then the negative terminal of the power supply is connected to the metal folded mesh current collector on the cathode end plate 11), and the power supply is a DC power supply.

[0043] In a specific embodiment of the present invention, a desalination liquid transfer pump is installed on a desalination liquid pipeline, which is connected to a desalination liquid storage tank. The outlet of the desalination liquid transfer pump is connected to the lower freshwater inlet of the cathode end plate 11 via the same pipeline, and the upper freshwater outlet of the cathode end plate 11 is connected to the desalination liquid storage tank via a pipeline, forming a desalination liquid circulation path. A concentrate transfer pump is installed on a concentrate pipeline, which is connected to a concentrate storage tank. The outlet of the concentrate transfer pump is connected to the lower concentrated water inlet of the anode end plate 3 via the same pipeline, and the upper concentrated water outlet of the cathode end plate 11 is connected to the desalination liquid storage tank via a pipeline, forming a desalination liquid circulation path. The electrode slurry transfer pump operates similarly, forming its own circulation loop.

[0044] In this invention, the electrode slurry includes activated carbon and an electrolyte solution, wherein the activated carbon accounts for 5-25% of the mass of the electrode slurry, and the electrolyte solution accounts for 75-95% of the mass of the electrode slurry.

[0045] The specific operating steps of the fluidized electrode desalination system of the present invention for treating wastewater are as follows: (1) Place the prepared desalination solution, concentrated solution and electrode slurry into the corresponding storage tanks and start stirring; place the conductivity meter probes into the desalination solution storage tank and the concentrated solution storage tank respectively to detect and record the conductivity changes.

[0046] (2) Connect the storage tank, the transfer pump, and the inlet of the FCDI device (i.e., the fluidized electrode desalination device of the present invention) in sequence using the pump pipe. The outlet of the FCDI device is connected to the corresponding storage tank by the pump pipe. Turn on the transfer pump. After each solution forms a circulating flow, record the conductivity of the desalination solution and the concentrate as the initial value.

[0047] (3) Apply voltage to the FCDI device in constant voltage electric field mode through DC power supply, and the desalination process begins. The voltage and current curves are automatically recorded by software.

[0048] (4) After running for a certain period of time, turn off the power and record the conductivity of the desalination solution and the concentrate as the final conductivity value.

[0049] The fluidized electrode desalination device and system of the present invention will be described below with reference to specific embodiments.

[0050] Example 1 The desalination process of wastewater using a fluidized bed electrode desalination device based on stainless steel folded mesh current collectors is as follows: Stainless steel folded mesh current collectors (the stainless steel folded mesh in the groove of the anode end plate 3 is the anode current collector 4, and the stainless steel folded mesh in the groove of the cathode end plate 11 is the cathode current collector 10) are placed in the grooves of both the anode end plate 3 and the cathode end plate 11. The thickness of the stainless steel folded mesh current collector is 2 mm, and the corrugation interval is 2.5 mm, forming the flow area for the FCDI electrode slurry. The experiment is conducted according to the above operating procedure. During the process, driven by a DC electric field, cations in the desalination solution pass through the second cation exchange membrane 9 on one side of the cathode current collector 10 and enter the cathode electrode slurry. Anions in the desalination solution pass through the middle anion exchange membrane 7 and enter the concentrate. Simultaneously, cations in the anode electrode slurry pass through the first cation exchange membrane 5 on one side of the anode current collector 4 and enter the concentrate, maintaining charge balance in the concentrate and achieving synergistic desalination-concentration processes.

[0051] Different mesh sizes (40 mesh, 60 mesh, 80 mesh, 100 mesh) of stainless steel folded (corrugated) mesh current collectors were used to test the desalination performance of the stainless steel folded mesh current collectors. The stainless steel folded mesh current collectors were placed at a 90° angle. A fluidized bed electrode slurry was prepared using 2000-mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field was a constant voltage electric field with an operating voltage of 1.2V and a running time of 180min. Both the desalination solution and the concentrate were 500mg / L KClO4 solutions.

[0052] like Figure 5 The figure shows the conductivity variation of stainless steel folded mesh collectors under different mesh sizes. (a) shows the conductivity variation of the desalination solution based on 40-mesh, 60-mesh, 80-mesh, and 100-mesh stainless steel folded mesh collectors; (b) shows the conductivity variation of the concentrate based on 40-mesh, 60-mesh, 80-mesh, and 100-mesh stainless steel folded mesh collectors. The mesh size of the stainless steel folded mesh collector has a significant impact on desalination performance. The 60-mesh stainless steel folded mesh collector showed good performance, with good deep purification capability and a desalination rate of 98.4%, while the desalination rates of the 40-mesh, 80-mesh, and 100-mesh stainless steel folded mesh collectors were 95.3%, 95.9%, and 93.1%, respectively.

[0053] Example 2 Compared to Example 1, this example tests the desalination performance of the stainless steel folded (corrugated) mesh current collector at different placement angles (0°, 45°, 90°). The stainless steel folded (corrugated) mesh has a mesh size of 60. A fluidized bed electrode slurry is prepared using 2000-mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field is set as a constant voltage electric field, the operating voltage is 1.2V, and the running time is 180min. Both the desalination solution and the concentrate are 500mg / L KClO4 solutions.

[0054] like Figure 6 The figure shows the conductivity variation of the stainless steel folded mesh current collector at different placement angles. (a) shows the conductivity variation of the desalination solution when the placement angle of the stainless steel folded mesh current collector is 0°, 45°, and 90°; (b) shows the conductivity variation of the concentrate when the placement angle of the stainless steel folded mesh current collector is 0°, 45°, and 90°. The placement angle of the stainless steel folded mesh current collector in the groove affects the desalination performance. The best desalination performance is achieved at a placement angle of 45°, with a desalination rate of 97.3%. The desalination rates are 95.8% and 91.3% at placement angles of 0° and 90°, respectively.

[0055] Example 3 Compared with Example 1, this example uses titanium metal folded (corrugated) mesh current collectors with different mesh sizes (40 mesh, 60 mesh, 80 mesh) to test the desalination performance of the titanium metal folded mesh current collectors. The titanium metal folded mesh current collectors are placed at an angle of 45°. Fluidized electrode slurry is prepared using 2000 mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field is set as a constant voltage electric field, the working voltage is 1.2V, the running time is 180min, and both the desalination solution and the concentrate are 500mg / L KClO4 solutions.

[0056] like Figure 7 The figure shows the variation of desalination liquid conductivity based on 40-mesh, 60-mesh, and 80-mesh titanium folded mesh current collectors; as shown... Figure 8 The figure shows the variation of desalination rate (SR) and average desalination rate (ASRR) based on 40-mesh, 60-mesh, and 80-mesh titanium folded mesh current collectors; as shown. Figure 9 The figure shows the changes in charge efficiency (CE) and molar energy consumption (Em) of titanium folded mesh current collectors with 40-mesh, 60-mesh, and 80-mesh meshes. For titanium folded mesh current collectors, the desalination performance is similar when the mesh number is 40-80. The desalination rates of 40, 60, and 80-mesh titanium folded mesh current collectors are 99.5%, 99.3%, and 99.4%, respectively. Within this mesh number range, a deep purification process can be achieved.

[0057] Example 4 Compared with Example 1, this example uses cathode plate 11 and anode plate 3 with different groove depths (2mm, 2.5mm, 4mm). A 40-mesh titanium folded (corrugated) mesh current collector is placed in each groove. The desalination performance is tested. The titanium metal folded mesh current collector is placed at an angle of 45°. A fluidized electrode slurry is prepared using 2000-mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field is set as a constant voltage electric field, the working voltage is 1.2V, the running time is 180min, and both the desalination solution and the concentrate are 500 mg / L KClO4 solutions.

[0058] like Figure 10 As shown, the conductivity variations of the cathode end plate 11 and anode end plate 3 are based on different groove depths. (a) shows the conductivity variations of the desalinated liquid for cathode end plates 11 and anode end plates 3 with groove depths of 2mm, 2.5mm, and 4mm; (b) shows the conductivity variations of the concentrate for cathode end plates 11 and anode end plates 3 with groove depths of 2mm, 2.5mm, and 4mm. Experimental data show that the groove depth has a significant impact on the desalination performance of the collector. When the depth is 2mm and 2.5mm, the desalination performance is similar, at 98.6% and 97.9%, respectively. When the groove depth is increased to 4mm, the desalination rate is 75.1%.

[0059] Comparative Example 1 Compared with Example 1, this comparative example uses 100, 120, and 150 mesh titanium folded mesh current collectors to test the desalination performance of the titanium folded mesh current collectors. The titanium folded mesh current collectors are placed at an angle of 45°. A fluidized electrode slurry is prepared using 2000 mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field is set as a constant voltage electric field, the working voltage is 1.2V, the running time is 120min, and the desalination solution and the concentrate are 2000mg / L NaCl solutions.

[0060] Experimental results show that when using 100-mesh and 120-mesh titanium folded mesh current collectors, the desalination rate reaches over 62%, while when using a 150-mesh titanium folded mesh current collector, the desalination rate drops to 51%, indicating a significant decrease in desalination performance. This suggests that excessively high mesh counts are detrimental to the desalination process, and the small mesh size of high-mesh titanium folded meshes increases the resistance to the flow of electrode slurry between the mesh openings.

[0061] Comparative Example 2 Compared with Example 1, this comparative example uses a 50-mesh titanium folded mesh current collector and a conventional serpentine flow channel current collector to test desalination performance. The titanium folded mesh current collector is placed at an angle of 45°. A fluidized electrode slurry is prepared using 2000-mesh supercapacitor activated carbon, with an activated carbon mass fraction of 10% and a sodium chloride solution mass fraction of 90%. The DC electric field is set as a constant voltage electric field with a working voltage of 1.2V and a running time of 120min. The desalination solution and the concentrate are both 2000mg / L NaCl solutions.

[0062] Experimental results show that the desalination rate of the 50-mesh titanium folded mesh current collector is 82%, while the desalination rate of the conventional serpentine flow channel graphite current collector is 74% under the same conditions. This proves that the desalination performance of the titanium metal folded mesh current collector is better than that of the serpentine flow channel graphite current collector.

[0063] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A fluidized bed electrode desalination device, characterized in that, The device includes, in sequence, an anode end plate, an anode current collector, a first cation exchange membrane, a concentration chamber partition, an anion exchange membrane, a desalination chamber partition, a second cation exchange membrane, a cathode current collector, and a cathode end plate. At least one of the anode current collector and the cathode current collector is a metal folded mesh current collector. The metal folded mesh current collector has a continuous folded structure and includes multiple folded units connected in sequence along a first direction. The continuous folding structure is such that adjacent folding units are connected by a common fold line; The main outline of the folding unit is triangular and has a peak that protrudes in the direction away from the common fold line. The top of the peak is a vertex structure, which is configured as either a sharp vertex or an arc transition section to form a serrated or wavy three-dimensional outline in the folded or unfolded state. The metal folded mesh current collector has a mesh count of 30-120, a thickness of 1-2 mm, and a corrugation interval of 1-2.5 mm. The working surfaces of the anode and / or cathode end plates are provided with grooves, the center line of the grooves coincides with the center line of the end plate with the grooves, and the metal folded mesh current collector is disposed in the grooves; The metal folded mesh current collector is placed at an angle of 0 to 90° in the groove.

2. The fluidized bed electrode desalination device according to claim 1, characterized in that, The metal folded mesh current collector is placed at an angle of 45° in the groove.

3. The fluidized bed electrode desalination device according to claim 1, characterized in that, The depth of the groove is 1 to 3 mm.

4. The fluidized bed electrode desalination device according to claim 1, characterized in that, A dispersing water distribution trough is provided at the bottom of the groove, and the depth of the dispersing water distribution trough is 1-3mm; The top of the dispersive water distribution tank is provided with at least two water flow channels, the width of which is 1 to 2 mm.

5. The fluidized bed electrode desalination apparatus according to any one of claims 1-4, characterized in that, The lower ends of both the anode and cathode end plates are provided with fresh water inlet, concentrated water inlet and electrode slurry inlet, and the upper ends of both the anode and cathode end plates are provided with fresh water outlet, concentrated water outlet and electrode slurry outlet. The thickness of both the concentration chamber partition and the desalination chamber partition is 0.5–2.5 mm. Both the concentration chamber partition and the desalination chamber partition have square through-hole areas with plastic mesh structures at their geometric centers. The bottom of the partition of the concentration chamber has a concentrated liquid flow channel, which is connected to the concentrated water inlet of the anode plate through a concentrated liquid pipe; the bottom of the partition of the desalination chamber has a desalination liquid flow channel, which is connected to the fresh water inlet of the cathode plate through a desalination liquid pipe.

6. A fluidized bed electrode desalination system, characterized in that, The fluidized electrode desalination device according to any one of claims 1-5 further includes a desalination liquid transfer pump, a concentrate transfer pump, an electrode slurry transfer pump, an electrode slurry, and a power supply; The positive terminal of the power supply is connected to the anode current collector, and the negative terminal of the power supply is connected to the cathode current collector. The power supply is a DC power supply. The electrode slurry comprises activated carbon and an electrolyte solution, wherein the activated carbon accounts for 5-25% of the mass of the electrode slurry, and the electrolyte solution accounts for 75-95% of the mass of the electrode slurry.

7. The application of a fluidized electrode desalination device as described in any one of claims 1-5 or a fluidized electrode desalination system as described in claim 6 in water treatment desalination.

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