Electrical ion concentrator

Abstract

To provide an electric ion concentrator capable of recovering ions of the same polarity separately through the outlets.SOLUTION: There is provided an electric ion concentrator including: a shell 2 having an inlet at one end and a plurality of outlets at the other end; four or more electrodes disposed within the shell 2 so as to extend from one end to the other end; and a conductive material filled in the shell, in which as the electrodes, a plurality of pairs of electrodes 5a to 5d are arranged so as to sandwich a center point of the shell in a cross section perpendicular to a longitudinal direction of the shell.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric ion concentrator for concentrating ions in water. One aspect of the present invention relates to an electric ion concentrator for concentrating and recovering specific ions from water in which multiple ions coexist. [Background technology]

[0002] Continuous electrodeionization devices are widely used as devices for concentrating ions in water. A continuous electrodeionization device is configured with a concentration compartment and a water-to-be-treated compartment (demineralized compartment) formed by alternately arranging multiple anion-exchange membranes and cation-exchange membranes between electrodes (anodes and cathodes). The water-to-be-treated compartment is filled with an ion exchanger, such as a mixed ion-exchange resin of anion-exchange resin and cation-exchange resin. Water containing ions is passed through the water-to-be-treated compartment (demineralized compartment), and a voltage is applied between the electrodes to separate the water into treated water with a low ion concentration and concentrated water with a high ion concentration (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 4-72567 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-350991 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional electrodeionization devices, the movement of ions is limited to one dimension (the direction connecting the anode and cathode). Therefore, ions of the same polarity move in the same direction regardless of their type, making it impossible to distinguish and recover ion species of the same polarity.

[0005] An object of the present invention is to provide an electric ion concentrator that can separate and recover ions even if they have the same polarity. [Means for solving the problem]

[0006] The gist of the electrical ion concentrator of the present invention is as follows.

[0007] [1] A shell having an inlet at one end and a plurality of outlets at the other end; four or more electrodes disposed within the shell and extending from the one end to the other end; a conductive material filled in the shell; An electrical ion concentrator having: The electrodes are arranged in pairs across the center of the shell in a cross section perpendicular to the longitudinal direction of the shell.

[0008] [2] The electrical ion concentrator of [1], wherein the electrodes are arranged at equal intervals in a circumferential direction around the center point of the shell.

[0009] [3] The electric ion concentrator according to [2], wherein a voltage of the same polarity is applied to a pair of electrodes on either side of the central point, and voltages of opposite polarity are applied to adjacent electrodes in the circumferential direction.

[0010] [4] The electric ion concentrator according to any one of [1] to [3], wherein the outlet is provided at the center of the other end face and at the periphery of the other end face.

[0011] [5] The electric ion concentrator according to any one of [1] to [3], wherein a plurality of the outlets are provided in a straight line passing through the center of the other end face.

[0012] [6] The electrical ion concentrator according to any one of [1] to [3], wherein the conductive substance is an ion exchange resin, an inorganic ion exchanger, or a metal-organic framework.

[0013] [7] The electric ion concentrator according to any one of [1] to [3], wherein the voltage is one of a DC voltage, an AC voltage, or a DC and an AC voltage, and the voltage can be changed over any time period. [Effects of the Invention]

[0014] In the present invention, four or more electrodes are installed in a point-symmetrical manner inside a shell filled with a conductive material, and the water to be treated flows from one end of the shell to the other end.

[0015] A DC voltage and an AC voltage are applied so that the paired electrodes have the same polarity. Furthermore, voltages of different polarities are applied to adjacent electrodes in the circumferential direction. Then, while the ions in the water to be treated flow in the water flow direction, they move in a plane perpendicular to the water flow direction due to the electrostatic attraction caused by the applied voltage. This causes them to gather at a specific location on the other end surface of the shell. By adjusting the applied voltage according to the ion species, specific ions gather at a specific two-dimensional location, flow out of the shell through an outlet located at that location, and are separated from other ions.

[0016] According to the present invention, even ions of the same polarity can be separated and recovered. According to the present invention, even ions that are difficult to remove can be separated, and the load on the downstream system can be reduced.

[0017] The device of the present invention can also be used to selectively recover valuable materials present in trace amounts in water.

[0018] The device of the present invention does not use an ion exchange membrane, and is therefore low cost and easy to assemble. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a front view of an electric ion concentrator according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 1 is a cross-sectional perspective view of a portion of the shell of an electrical ion concentrator. [Figure 5]FIG. 10 is a cross-sectional view of an electrical ion concentrator according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments will be described with reference to the drawings. Figures 1 to 4 show an electric ion concentrator according to a first embodiment.

[0021] 1 to 3, the electrical ion concentrator 1 has four electrodes 5a to 5d arranged inside a shell 2. In this embodiment, the shell 2 is cylindrical, but it may also be a polygonal prism. The polygonal shape is preferably one with three or more sides, particularly one with four or more sides, and is preferably one with four to eight sides.

[0022] The shell 2 has a cylindrical portion 2a, one end surface 2b, and the other end surface 2c. In this embodiment, the one end surface 2b and the other end surface 2c are formed of flat plates, but they may also be tapered or curved.

[0023] An inlet 3 for water to be treated is provided on one end face 2b in the longitudinal direction (axial direction of the cylinder) of the shell 2, and multiple (five in this embodiment) outlets 4a-4e are provided on the other end face 2c. Outlet 4a is located in the center of the other end face 2c, and outlets 4b-4e are located on the periphery of the other end face 2c. Outlets 4b-4e are arranged at equal intervals in the circumferential direction of the shell 2, and in this embodiment, are arranged at 90° intervals in the circumferential direction. The diameter of each of outlets 4a-4e is preferably 5-30% of the diameter of the cylinder portion 2a, and particularly preferably about 10-20%.

[0024] 4 is a cross-sectional perspective view of the other end surface 2c side of the shell 2, with the electrodes omitted, and shows the outlets 4a to 4e in a see-through state.

[0025] Electrodes 5a to 5d extend from one end surface 2b to the other end surface 2c. Electrodes 5a to 5d are arranged at equal circumferential positions along the cylindrical portion 2a of the shell 2. Electrode 5b is arranged between the outlets 4b and 4c, electrode 5c is arranged between the outlets 4c and 4d, electrode 5d is arranged between the outlets 4d and 4e, and electrode 5a is arranged between the outlets 4e and 4b.

[0026] The shell 2 is made of a non-conductive material, such as a non-conductive synthetic resin. Both ends of the electrodes 5a to 5d penetrate one end surface 2b and the other end surface 2c of the shell 2, and are connected to a current-carrying cable (not shown) via an attachment (not shown).

[0027] An electrically conductive material is filled inside the shell 2. Examples of the electrically conductive material include an ion exchange resin, an inorganic ion exchanger, and a metal-organic framework. The ion exchange resin may be a cation exchange resin, an anion exchange resin, or a mixed resin that is a mixture of both.

[0028] In the electric ion concentrator 1 configured as above, water to be treated is introduced into the shell 2 from the inlet 3, and a voltage is applied between the electrodes 5a to 5d. The voltage may be a DC voltage or an AC voltage.

[0029] A voltage of the same polarity is applied to electrodes 5a and 5c, which are paired across the axis of the shell 2, and a voltage of the same polarity is applied to electrodes 5b and 5d. The polarities of adjacent electrodes in the circumferential direction are opposite. For example, electrodes 5a and 5c are positive electrodes, and electrodes 5b and 5d are negative electrodes.

[0030] The water to be treated is preferably water containing two or more types of ions such as lithium, sodium, potassium, cesium, strontium, chromium, manganese, iron, cobalt, nickel, copper, silver, gold, palladium, platinum, ruthenium, rhodium, iridium, or sulfate, selenate, etc.

[0031] As the water flows from one end face 2b to the other end face 2c, the ions in the water move in a direction perpendicular to the longitudinal direction of the electrodes due to electrostatic attraction in response to the potential gradient between the electrodes, and gather at a specific position on the other end face 2c. As a result, water containing a large amount of the ions flows out from an outlet (one of 4a to 4e) located at that specific position. Water with a low concentration of the ions flows out from the other outlets.

[0032] In this way, it is possible to separate specific ions from other ions.

[0033] In the present invention, the applied voltage is changed depending on the ion species to be collected.

[0034] The migration speed of ions due to the application of a voltage differs depending on the ion species, so it is possible to guide only specific ions to a desired outlet by applying a desired voltage.

[0035] The length L of the shell 2 in the water flow direction from one end face 2b to the other end face 2c is preferably 0.4 m or more and 1.5 m or less. The ratio L / D of the length L to the diameter D of the shell 2 is preferably about 1 to 10. The amount of water flow is preferably 10 / h or more and 1000 / h or less in terms of space velocity (SV).

[0036] The ion concentration of the water passing through the shell 2 varies depending on the position within the shell 2. For this reason, for example, as in the second embodiment shown in Fig. 5, multiple outlets may be provided in a straight line passing through the center of the other end face 2c. By providing outlets 4 in a row from near the center of the other end face 2c, where the ion concentration distribution is high, to the periphery of the other end face, where the ion concentration distribution is low, the passing water can be easily separated into treated water with a low ion concentration and concentrated water with a high ion concentration.

[0037] Fig. 5 is a cross-sectional perspective view of the same part as Fig. 2. Other configurations in Fig. 5 are the same as those in Fig. 2, and the same reference numerals denote the same parts.

[0038] The above-described embodiment is an example of the present invention, and the present invention may have other configurations.

[0039] In FIGS. 1 to 5, the inlet is on the upper side and the outlet is on the lower side, but they may be reversed, or may be oriented sideways or obliquely.

[0040] The electrode may have a shape other than a cylinder, for example, a long plate shape. In the case of a long plate shape, the cross section in the direction perpendicular to the longitudinal direction may be a straight line (i.e., a flat electrode), or may be any shape such as an L-shape, a U-shape, or an E-shape.

[0041] The electrodes may be partially covered with an insulating material.

[0042] The number of electrode pairs is not limited to two pairs as shown in the figure, and may be three pairs or more, but is preferably about two to four pairs.

[0043] The number of outlets may be other than that shown in the drawing, and may be about 3 to 20, especially 3 to 9. [Explanation of symbols]

[0044] 1. Electrical ion concentrator 2 shells 3 Inlet 4,4a~4e Outlet 5a~5d electrode

Claims

1. a shell having an inlet at one end and a plurality of outlets at the other end; four or more electrodes disposed within the shell and extending from the one end to the other end; a conductive material filled in the shell; An electrical ion concentrator having: The electrodes are arranged in pairs across the center of the shell in a cross section perpendicular to the longitudinal direction of the shell.

2. 2. The electrical ion concentrator of claim 1, wherein the electrodes are arranged at equal intervals in a circumferential direction around a center point of the shell.

3. 3. The electrical ion concentrator according to claim 2, wherein voltages of the same polarity are applied to the pair of electrodes sandwiching the center point, and voltages of opposite polarities are applied to the electrodes adjacent to each other in the circumferential direction.

4. 4. The electric ion concentrator according to claim 1, wherein the outlet is provided at the center of the other end surface and at the periphery of the other end surface.

5. 4. The electric ion concentrator according to claim 1, wherein a plurality of said outlets are provided in a straight line passing through the center of said other end face.

6. The electrical ion concentrator according to any one of claims 1 to 3, wherein the conductive material is an ion exchange resin, an inorganic ion exchanger, or a metal organic framework.

7. 4. The electrical ion concentrator according to claim 1, wherein the voltage is one of a DC voltage, an AC voltage, or a combination of a DC voltage and an AC voltage, and the voltage can be changed over any time period.

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