CN111763952A - Desalination method and device for preparing ultra-high-purity hypochlorous acid aqueous solution by using salt as raw material - Google Patents

Abstract

The invention discloses a desalination method and a device for producing an ultra-high-purity hypochlorous acid aqueous solution by taking salt as a raw material, wherein the main technical scheme is that the salt is taken as the raw material, the step of electrolyzing chlorine-containing electrolyte and the desalination step of removing ionic impurities are continuously carried out in a single tank body, the raw material can be continuously fed in, and the high-purity hypochlorous acid aqueous solution after reaction is continuously harvested so as to realize continuous production, thereby improving the production efficiency and purity of the hypochlorous acid aqueous solution and reducing the production cost.

Description

Desalination method and device for preparing ultra-high-purity hypochlorous acid aqueous solution by using salt as raw material

Technical Field

The present invention relates to a desalination method and apparatus for producing an ultra-high purity hypochlorous acid aqueous solution using common salt as a raw material.

Background

Hypochlorous acid water is a disinfectant which is used most worldwide, and is widely used for disinfecting food, food containers and packaging materials. Recently, new coronavirus (such as COVID-19) epidemic situation occurs, which not only causes the shortage of alcohol disinfection products in the market, but also shows the importance of hypochlorous acid water in environmental cleaning and disinfection.

Hypochlorous acid is a weak acid which is substantially in the form of molecules (HClO) at a pH of 3 to 6 in an aqueous solution, and is mostly dissociated into hypochlorite ions (ClO) at a pH of 9 or more^-) Whereas, when the pH is 3 or less, toxic chlorine gas is easily generated. It is generally believed that molecular form hypochlorous acid is the main substance responsible for the disinfection. In terms of bactericidal power, hypochlorous acid molecules have a sterilizing power about 80 to 100 times that of hypochlorite ions, and mainly destroy the protein molecular structure of pathogens by oxidation, thereby killing bacteria and inhibiting the activity of viruses.

Hypochlorous acid water is generally prepared by electrolysis of aqueous solutions of alkali metal chloride salts or alkaline earth metal chloride salts: for example, hypochlorous acid can be obtained at the anode of the electrolysis electrode by electrolyzing an aqueous solution of sodium chloride and potassium chloride. The hypochlorite aqueous solution obtained by the electrolysis method is alkalescent, and acidic active ingredients such as hydrochloric acid, phosphoric acid, citric acid and the like are usually added to reduce the pH value so as to enhance the disinfection capability of the hypochlorite aqueous solution. However, the metal salt ions remaining from electrolysis may cause hypochlorous acid to be reduced rapidly and lose its cleaning and disinfecting abilities, resulting in a shortened commercial life of hypochlorous acid water. Therefore, it has been proposed to improve the quality of hypochlorous acid water by removing metal salt ions from the hypochlorite water solution.

Taiwan patent I427189 discloses a method for producing hypochlorous acid sterilized water, which comprises introducing hypochlorous acid aqueous solution generated by electrolysis through cation exchange resin, so that metal ions in the electrolyzed water are replaced by hydrogen ions in the cation exchange resin to adjust pH to 5.5-6.5. The solution of Japanese patent laid-open No. 2009-274950 is to pass a hypochlorite solution through a hydrogen-type cation exchange resin and a hydroxide-type anion exchange resin in this order to obtain a molecular-state hypochlorous acid solution. The taiwan patent I631072 is characterized in that a sodium hypochlorite solution is introduced into a weakly acidic ion exchange resin column to make the pH of the hypochlorous acid aqueous solution between 3.5 and 7.5. Japanese patent laid-open No. 2019202907 discloses that weakly acidic ion exchange resin pellets are added to a hypochlorite solution and stirred to trap metal ions in the resin, and then the ion exchange resin is separated to improve the shelf life of the aqueous hypochlorite solution.

The above patent documents all use ion exchange resins to remove ionic impurities from hypochlorite solutions, and all of them disclose methods in which an electrolytic reaction is performed in an electrolytic cell, and the prepared hypochlorite solution is introduced into another vessel containing ion exchange resins to perform a desalting treatment, and the lengthy manufacturing process is time-consuming and inefficient.

Accordingly, there is still a high need in the related art for a method and an apparatus for producing an aqueous hypochlorous acid solution with higher efficiency and higher purity.

Disclosure of Invention

In view of the above problems of the background art, the present inventors have made extensive studies to satisfy the above industrial demands, and as a result, have obtained a method and an apparatus for desalting for producing an ultra-high purity hypochlorous acid aqueous solution using common salt as a raw material according to the present invention. The main technical scheme of the invention is that the step of electrolyzing the chlorine-containing electrolyte and the step of desalting for removing ionic impurities are continuously carried out in a single tank body, so that continuous production can be realized, the manufacturing efficiency of the hypochlorous acid aqueous solution can be improved, and the production cost can be reduced.

The technical scheme of the invention is as follows:

a desalination method for producing an ultra-high purity hypochlorous acid aqueous solution from common salt, comprising the steps of:

(1) flowing an aqueous solution of a chlorine-containing electrolyte in a tank extending in a longitudinal direction toward the longitudinal direction thereof;

(2) electrolysis: electrolyzing the chlorine-containing electrolyte aqueous solution to obtain a crude solution containing hypochlorite;

(3) separation of ionic components: an electric field is applied in a transverse direction substantially perpendicular to the longitudinal direction to attract and thereby remove ionic components in the crude solution containing hypochlorite to obtain an aqueous hypochlorite solution.

Preferably, the electrolysis step of step (2) is followed by an activation step comprising adding an acidic activating component to the above crude solution containing hypochlorite to adjust the pH of the crude solution to weak acidity.

Preferably, it comprises a step of adjusting between the electrolysis step and the activation step, which comprises adding a neutral adjusting liquid to the crude solution and adjusting the pH value of the crude solution to 6-8.

Preferably, the method comprises a step of subjecting the hypochlorous acid aqueous solution obtained in the step (3) to an ion exchange treatment after the step of removing ionic components in the step (3) to remove residual ionic components in the hypochlorous acid aqueous solution.

The ultra-high purity hypochlorous acid aqueous solution after desalination prepared by the invention has super strong bactericidal capability, can be used for preparing eye cleaning and maintenance products such as eye drops, eye washing agents, eye sprays, ointments, gels and the like, and can also be used for preparing disinfection and sterilization products such as gynecological disinfectant.

The invention also provides a desalination device for preparing the ultra-high-purity hypochlorous acid aqueous solution by using the table salt as the raw material, which comprises 1 tank body extending along a longitudinal direction, wherein one end of the tank body is provided with 1 inlet for inputting the chlorine-containing electrolyte aqueous solution, the other end of the tank body is provided with 1 outlet for outputting the prepared hypochlorous acid aqueous solution, and the outlet is in fluid communication with the inlet so as to enable the chlorine-containing electrolyte aqueous solution to flow from the inlet to the outlet along the longitudinal direction;

the tank body is provided with 1 group of electrolysis electrodes near the inlet, the electrolysis electrodes comprise an anode and a cathode and are suitable for electrolyzing aqueous solution containing chlorine electrolyte to generate crude solution containing hypochlorite;

the tank is provided with 1 set of deionizing electrodes near the outlet, the deionizing electrodes comprise an anode and a cathode, and the deionizing electrodes are suitable for applying an electric field in a transverse direction which is substantially vertical to the longitudinal direction so as to attract and remove ionic components in the crude solution, thereby obtaining the hypochlorous acid aqueous solution.

Preferably, the electrolysis electrode is made of a conductive porous material to allow ionic components in the crude solution to be adsorbed on the surface of the electrolysis electrode.

Preferably, the cell body is provided with an ionic membrane parallel to the longitudinal direction adjacent the inlet to divide the cell body into an anode compartment adjacent the electrolysis electrode anode and a cathode compartment adjacent the set of electrolysis electrode cathodes, the downstream ends of the anode compartment and the cathode compartment being closed by a porous block.

Preferably, the housing is provided with an anion membrane parallel to the longitudinal direction adjacent to the deionization electrode anode and a cation membrane parallel to the longitudinal direction adjacent to the deionization electrode cathode, whereby the aqueous hypochlorous acid solution is harvested in a central region between the anion membrane and the cation membrane.

Preferably, the tank body comprises an inner channel nested within the tank body, one end of the inner channel being in fluid communication with the central zone for harvesting the aqueous hypochlorous acid solution; the ion exchange resin is contained in the inner channel, and after the hypochlorous acid aqueous solution enters the inner channel, the hypochlorous acid aqueous solution is subjected to ion exchange treatment by the ion exchange resin to remove residual ion components, and the hypochlorous acid aqueous solution is discharged from the other end of the inner channel.

By adopting the technical scheme, the beneficial effects are as follows:

the present invention uses a salt solution as a raw material, continuously electrolyzes, adjusts the pH value and desalts the chlorine-containing electrolyte aqueous solution in a single tank, continuously feeds the raw material, and continuously harvests the high-purity hypochlorous acid aqueous solution after the reaction, thereby realizing continuous production, and thus improving the production efficiency and purity of the hypochlorous acid aqueous solution and reducing the production cost.

Drawings

FIG. 1 is a schematic flow chart showing the steps of a method for producing an aqueous hypochlorous acid solution according to a first preferred embodiment of the present invention;

FIG. 2 is a schematic structural view of an apparatus for producing an aqueous hypochlorous acid solution according to a first preferred embodiment of the present invention;

FIG. 3 is a schematic structural view of an apparatus for producing an aqueous hypochlorous acid solution according to a second preferred embodiment of the present invention;

FIG. 4 is a schematic structural view of an apparatus for producing an aqueous hypochlorous acid solution according to a third preferred embodiment of the present invention;

FIG. 5 is a schematic structural view of an apparatus for producing an aqueous hypochlorous acid solution according to a fourth preferred embodiment of the present invention;

in the figure: 1-a groove body; 2-the longitudinal direction; 3-an inlet; 4-an outlet; 5-an electrolysis electrode; 6-activating liquid inlet; 7-transverse direction; 8-a deionization electrode; 9-ion diaphragm; 10-an anode chamber; 11-a cathode chamber; 12-a porous block; 13-anionic membrane; 14-a cationic membrane; 15-an acidic solution; 16-alkaline solution; 17-the central region; 18-a pipeline; 19-a pipeline; 20-an inner channel; 21-ion exchange resin; 22-activating solution inlet.

Detailed Description

Unless otherwise indicated, the following terms used in the present specification and claims have the definitions given below. It is noted that the use of the singular terms "a" and "an" in this specification and in various claims is intended to cover one or more than one of the recited items, such as at least one, at least two, or at least three, and not to imply that there is only a single recited item. In addition, the open-ended terms such as "include" and "have" used in each claim of the present application indicate combinations of components or elements described in the claim, and do not exclude other components or elements not specified in the claim. It should also be noted that the term "or" is generally also inclusive of "and/or" in a sense unless the content clearly dictates otherwise. The terms "about" and "substantially" as used in the specification and claims are intended to modify any slight variations that do not materially alter the spirit of the invention.

The invention provides a method and an apparatus for continuously producing an ultra-high purity hypochlorous acid aqueous solution from common salt, which are suitable for rapidly producing a high-purity molecular hypochlorous acid aqueous solution substantially free of salts. In the preferred embodiment shown in FIG. 1, the method comprises: A. feeding in; B. electrolyzing; C. activating; D. desalting; E. harvesting, and the like, all in a single tank.

In the preferred embodiment shown in fig. 2, the housing 1 extends in a longitudinal direction 2, with an inlet 3 and an outlet 4 at opposite ends. The housing 1 is made of a rigid material that does not substantially chemically react with other components of the aqueous hypochlorous acid solution manufacturing process, including, but not limited to, metal (e.g., stainless steel), glass, quartz, ceramic, inflexible plastic (e.g., acrylic plastic), and the like. The manufacturing process of the tank body 1 is familiar to those skilled in the relevant art, and can be adjusted according to different materials. For example, when the tank body 1 is made of a metal material, it can be manufactured by a conventional metal processing process such as stamping, rolling, turning, press molding, forging, etc.

In the feeding step a, an aqueous solution of chlorine-containing electrolyte is fed from the inlet 3, and the inlet 3 is in fluid communication with the outlet 4, so that the aqueous solution of chlorine-containing electrolyte can flow in the tank 1 along the longitudinal direction 2 from the inlet 3 towards the outlet 4, and a chemical reaction takes place during the flow. As used herein, the term "chlorine-containing electrolyte" refers to a chemical species that, in an aqueous solution, can substantially completely dissociate free chlorine ions (Cl-) and their counter cations, including chlorine-containing water-soluble salts, acids, and bases. Thus, the term "aqueous solution of a chlorine-containing electrolyte" as used herein encompasses supersaturated, saturated or unsaturated aqueous solutions of the aforementioned chlorine-containing electrolyte, including, but not limited to, aqueous solutions of alkali metal chloride salts, such as sodium chloride and potassium chloride; an aqueous solution of an alkaline earth metal chloride salt; and chlorous acids such as hydrochloric acid. In a preferred embodiment, the "aqueous solution of chlorine-containing electrolyte" includes an aqueous solution containing sodium chloride or potassium chloride, and particularly an aqueous solution containing sodium chloride, such as a salt solution prepared from refined or crude salt, or brine obtained by precipitation and solarization of natural seawater or seawater taken from the ocean, or industrially reclaimed water rich in sodium chloride or potassium chloride. In a preferred embodiment, the "aqueous solution of chlorine-containing electrolyte" comprises a saturated aqueous solution of sodium chloride or potassium chloride. For the purpose of illustration, an aqueous solution containing sodium chloride is hereinafter used as a specific example of the aqueous solution containing the chlorine-containing electrolyte.

In the electrolysis step B, the chlorine-containing electrolyte aqueous solution fed into the tank 1 is subjected to electrolysis. The term "electrolysis" as used herein means the application of external electrical energy to cause redox reactions of ions in an aqueous solution. Taking an aqueous solution containing sodium chloride as an example, the main electrolytic reaction formula is as follows:

2NaCl+2H₂O→2NaOH+Cl2+H2↑

2NaOH+Cl₂→NaCl+NaClO+H₂O

thus obtaining a product containing Na⁺、ClO^-、Cl^-A crude solution of the plasma component. In the preferred embodiment shown in figure 2, a set of electrolysis electrodes 5 having an anode and a cathode suitable for the electrolysis of aqueous chlorine-containing electrolyte is provided adjacent the inlet 3 of the vessel 1. Materials suitable for use as electrolytic electrodes are well known in the art. For example, the anode of the electrolysis electrode 5 may include, but is not limited to, a graphite electrode, a platinum electrode, and a titanium-based ruthenium iridium electrode, and the cathode of the electrolysis electrode 5 may include, but is not limited to, a stainless steel electrode, a titanium electrode, and a graphite electrode.

The crude hypochlorite solution is weakly alkaline (pH 8-10). At this pH, hypochlorous acid is mostly in the form of hypochlorite ions (ClO-), and its disinfecting effect is far less than that of molecular hypochlorous acid (HClO). Thus, the process preferably comprises a selective activation step C which comprises adding an acidic activating component to the crude solution containing hypochlorite to lower the pH of the crude solution and thereby increase the proportion of molecular hypochlorous acid. The pH of the crude solution is preferably adjusted to be weakly acidic, for example to a pH in the range of 5.5-6.5. The acidic activating component suitable for use in the present invention includes, but is not limited to, hydrochloric acid, acetic acid and phosphoric acid, and it is preferable to previously adjust the acidic activating component to an aqueous solution having an appropriate concentration, for example, an aqueous solution having a concentration in the range of 1 to 3% (v/v), and then inject the aqueous solution into the crude solution. The chemical reaction formula of the activation step C is as follows:

NaClO+HCl→HClO+NaCl

in the preferred embodiment shown in FIG. 2, the housing 1 may be formed with an activating solution inlet 6 adapted to introduce the acidic activating component into the crude hypochlorite-containing solution to mix the two. Preferably, the activating liquid inlet 6 is disposed downstream of the electrolysis electrode 5 along the longitudinal direction 2.

In a preferred embodiment of the process, an optional tempering step is included prior to the activation step C for tempering the crude solution to an appropriate concentration and pH prior to activation, more preferably to a substantially neutral pH, for example a pH in the range of pH 7-9, and/or a concentration in the range of 50-2000 ppm. In a preferred embodiment, the blending step comprises adding a neutral blending liquid to the crude solution, wherein the neutral blending liquid includes, but is not limited to, pure water and deionized water. In terms of the structural arrangement, a solution inlet (not shown) adapted to introduce the neutral solution into the crude solution containing hypochlorite may be formed in the tank body 1. Preferably, the conditioning liquid inlet is arranged downstream of the electrolysis electrode 5 and upstream of the activating liquid inlet 6 along the longitudinal direction 2.

In the preferred embodiment shown in FIG. 2, the desalting step D uses a so-called "Capacitive Deionization" technique (CDI) comprising applying an electric field in a lateral direction 7 substantially perpendicular to the longitudinal direction 2. The molecular form of hypochlorous acid is not charged and continues to flow along the longitudinal direction 2, but various charged particles in the crude solution are deviated from the longitudinal direction 2 by the attraction of the charged electric field and adsorbed on the surface of the deionizing electrode 8, whereby Na is separated and removed from the crude solution⁺、ClO^-、Cl^-Plasma components and other charged impurities. Suitable electrode materials are well known in the art and may be made of conductive porous materials, having good conductivity and large specific surface area to facilitate the adsorption of large amounts of charged particles. In the preferred embodiment shown in figure 2, a set of deionization electrodes 8 having an anode and a cathode, which may include but are not limited to porous activated carbon electrodes, nickel foam electrodes and porous titanium-based ruthenium iridium electrodes, is provided near the outlet 4 of the tank 1. Since the electric field applied in the desalting step D has a relatively low operating voltage, usually in the range of 0.8V to 1.2V, the voltage applied in the desalting step D is relatively lowThe components in the crude solution are not subject to electrolytic reaction. It does not need to apply high temperature or high pressure, thus compared with traditional desalination technologies such as distillation, reverse osmosis and the like, the method has the advantages of low energy consumption, low pollution, low cost and the like. Moreover, compared with ion exchange resin, the regeneration of the deionization electrode does not need to use any acid, alkali and salt solution, and adsorbed substances can be released only by changing the direction of an electric field, so that the deionization electrode also has the advantage of reducing pollutants.

The present invention improves the efficiency of producing a hypochlorous acid aqueous solution by continuously performing an electrolysis step and a desalting step in a single tank. From the structural configuration, the device can be divided into a front section and a rear section, wherein the front section is an electrolysis section defined by the electrolysis electrode 5, and the rear section is a desalination section defined by the deionization electrode 8. The front and rear sections are in constant fluid communication without a flow control device such as a valve for blocking the continuous flow of fluid in the tank 1 along the longitudinal direction 2, thereby continuously subjecting the fed aqueous solution of chlorine-containing electrolyte to electrolysis and desalination. The molecular hypochlorous acid aqueous solution with high purity generated by the method and the device can be harvested at the outlet 4 of the tank body 1.

FIG. 3 shows an apparatus for producing an aqueous hypochlorous acid solution according to a second preferred embodiment of the present invention, which basically has the structural arrangement of the first preferred embodiment of the present invention, with the main difference that the electrolysis step B in the first preferred embodiment involves a non-diaphragm type electrolysis reaction, while the electrolysis step B in the second preferred embodiment employs a diaphragm type electrolysis reaction. In the second preferred embodiment, a set of electrolysis electrodes 5 is also provided close to the inlet 3, but in addition an ionic membrane 9 is provided close to the inlet 3, parallel to the longitudinal direction 2, so as to separate the electrolysis region into an anode chamber 10 close to the anode of the electrolysis electrode 5 and a cathode chamber 11 close to the cathode of the electrolysis electrode 5, the downstream ends of which are closed by a porous block 12. Ionic membranes 9 suitable for use in the present invention are well known in the art. Preferably, the ion membrane 9 is a strong acid type ion exchange membrane, such as a perfluorosulfonic acid membrane (perfluorosulfonic acid membrane). A chlorine-containing electrolyte solution and pure/deionized water are introduced into the anode chamber 10 and the cathode, respectively, via the inlet 3In the chamber 11. The anode compartment 10 is electrolyzed to produce chlorine gas and the cathode compartment 11 is electrolyzed to produce OH-. Na + moves to the cathode chamber 11 through the ion diaphragm and reacts with OH^-The reaction produces sodium hydroxide. The chlorine gas leaving the anode compartment 10 is mixed with the sodium hydroxide leaving the cathode compartment 11 in the porous block 12 to produce a crude solution containing hypochlorite. The material of the porous block 12 may include, but is not limited to, titanium mesh, zeolites, and porous alumina.

FIG. 4 shows an apparatus for producing an aqueous hypochlorous acid solution according to a third preferred embodiment of the present invention, which basically has the structural configuration of the first preferred embodiment of the present invention, except that the desalting step D of the third preferred embodiment uses the so-called "Electro-Deionization" technique (EDI). A set of deionization electrodes 8 is also arranged near the outlet 4 of the tank 1 in order to apply an electric field in a transverse direction 7 substantially perpendicular to the longitudinal direction 2, so that the various charged particles in the crude solution are attracted by the electric field to move away from the longitudinal direction 2 towards the transverse direction 7. Preferably, the anode of the deionization electrode 8 may include, but is not limited to, a titanium-based ruthenium iridium electrode, a graphite electrode, and a platinum electrode, and the cathode of the deionization electrode 8 may include, but is not limited to, a stainless steel electrode, a titanium electrode, and a graphite electrode. In addition, an anion membrane 13 parallel to the longitudinal direction 2 is provided at the anode near the deionization electrode 8, and a cation membrane 14 parallel to the longitudinal direction 2 is provided at the cathode near the deionization electrode 8. Suitable anionic and cationic membranes for EDI are well known in the art. Preferably, the anion membrane 13 is a quaternary amine type anion membrane, and the cation membrane 14 is a sulfonic acid type cation membrane. With this structure, anions such as ClO-, Cl-, etc. in the crude solution are attracted by the anode to pass through the anion membrane 13 to form the acidic solution 15 near the anode, while cations such as Na + etc. in the crude solution are attracted by the cathode to pass through the cation membrane 14 to form the alkaline solution 16 near the cathode. Molecular hypochlorous acid, which is not charged and continues to flow in the longitudinal direction 2, generates a high-purity hypochlorous acid aqueous solution in the central region 17 between the anionic membrane 13 and the cationic membrane 14, and can be harvested at the outlet 4 communicating with the central region 17. In this specific example, the charged particles are not adsorbed to the surface of the deionization electrode 8. The resulting acidic and alkaline liquors 15, 16 may be recycled and returned to the inlet 3 via lines 18,19 respectively and mixed with fresh aqueous chlorine-containing electrolyte and fed to the tank 1 for treatment.

FIG. 5 shows an apparatus for producing an aqueous hypochlorous acid solution according to a fourth preferred embodiment of the present invention, which basically has the structural configuration of the third preferred embodiment of the present invention, but further includes an inner channel 20 fitted inside the tank body 1 along the longitudinal direction 2. One end of the inner channel 20 serves as an outlet 4 of the housing 1, which is in fluid communication with the central region 17 for harvesting the primarily desalinated hypochlorous acid aqueous solution. The inner channel 20 contains an ion exchange resin 21, preferably a combination of acidic and basic ion exchange resins, or an acidic-basic mixed ion resin. For example, the acidic ion exchange resin may be a sulfonic acid type resin and the basic ion exchange resin may be a quaternary amine type resin. The hypochlorous acid aqueous solution entering the inner channel 20 is subjected to a secondary desalting process, which comprises subjecting the hypochlorous acid aqueous solution to an ion exchange treatment, wherein a basic ion exchange resin is used to adsorb anions such as ClO-, Cl-, etc., and an acidic ion exchange resin is used to adsorb cations such as Na +, etc., and finally, a molecular hypochlorous acid aqueous solution having a high purity and substantially no salts is obtained at the other end of the inner channel 20. It should be noted that, compared to the conventional apparatus for desalting with only ion exchange resin, the fourth preferred embodiment of the present invention firstly uses EDI technology to perform the first desalting, and then uses ion exchange resin 21 to perform the second desalting, which not only effectively increases the purity of the hypochlorous acid aqueous solution, but also prolongs the service life of ion exchange resin 21. Therefore, the fourth preferred embodiment of the present invention is very suitable for feeding seawater, brine or industrial recycled water, in addition to the salt water. In one embodiment, a further activating solution inlet 22 is provided near one end of the inner channel 20, i.e. near the outlet 4 of the housing 1, adapted to add an acidic activating component to the primarily desalinated aqueous hypochlorous acid solution to ensure that the pH of the aqueous hypochlorous acid solution is weakly acidic, e.g. in the range of pH 5.5-6.5.

The above-mentioned manufacturing method and apparatus can be performed manually or automatically, preferably by automatic control. In the embodiment where the above-mentioned manufacturing method and apparatus are operated in an automatic manner, it is preferable to set the parameter conditions of the process through a computer interface and to monitor the data such as the feeding rate of the chlorine-containing electrolyte aqueous solution, the acidic activating component and the concentration of the hypochlorous acid aqueous solution in real time through a detector to ensure the manufacturing quality. Automation can be achieved by subjecting the apparatus to the control of a programmed microprocessor.

Although the present invention has been described with reference to the above preferred embodiments, it is to be understood that the preferred embodiments are given by way of example only and are not intended to limit the scope of the present invention, and that various changes and modifications apparent to those skilled in the relevant art may be made without departing from the scope of the present invention.

Claims (9)

1. A desalination method for producing an ultra-high purity hypochlorous acid aqueous solution from common salt, comprising the steps of:

(1) flowing an aqueous solution of a chlorine-containing electrolyte in a tank extending in a longitudinal direction toward the longitudinal direction thereof;

(2) electrolysis: electrolyzing the chlorine-containing electrolyte aqueous solution to obtain a crude solution containing hypochlorite;

(3) separation of ionic components: an electric field is applied in a transverse direction substantially perpendicular to the longitudinal direction to attract and thereby remove ionic components in the crude solution containing hypochlorite to obtain an aqueous hypochlorite solution.

2. The desalination method of claim 1, wherein the electrolysis step of step (2) is followed by an activation step comprising adding an acidic activating component to the crude hypochlorite solution to adjust the pH of the crude solution to a weak acidity.

3. The desalination method of claim 2, comprising a step of adjusting pH of the crude solution to 6-8 by adding a neutral solution to the crude solution between the electrolysis step and the activation step.

4. The desalination method of claim 3, comprising a step of removing residual ionic components in the hypochlorous acid aqueous solution by subjecting the hypochlorous acid aqueous solution obtained in step (3) to an ion exchange treatment after the step of removing ionic components in step (3).

5. A desalination apparatus for producing ultra-high purity hypochlorous acid aqueous solution from common salt, comprising 1 tank (1) extending in a longitudinal direction (2), wherein one end of the tank (1) is provided with 1 inlet (3) for feeding chlorine-containing electrolyte aqueous solution, and the other end of the tank (1) is provided with 1 outlet (4) for discharging the prepared hypochlorous acid aqueous solution, wherein the outlet (4) is in fluid communication with the inlet (3) so as to enable the chlorine-containing electrolyte aqueous solution to flow in the longitudinal direction (2) from the inlet (3) towards the outlet (4);

the tank body (1) is provided with 1 group of electrolysis electrodes (5) near the inlet (3), the electrolysis electrodes (5) comprise an anode and a cathode, and the electrolysis electrodes are suitable for electrolyzing aqueous solution of chlorine-containing electrolyte to generate crude solution containing hypochlorite;

the tank (1) is provided with 1 set of deionizing electrodes (8) near the outlet (4), said deionizing electrodes (8) comprising an anode and a cathode adapted to apply an electric field in a transverse direction (7) substantially perpendicular to the longitudinal direction (2) to attract and thereby remove ionic components from the crude solution to obtain an aqueous hypochlorous acid solution.

6. The desalination apparatus for producing an ultra-high purity hypochlorous acid aqueous solution using salt as a raw material according to claim 5, wherein the electrolysis electrode (5) is made of a conductive porous material to allow ionic components in the crude solution to be adsorbed on the surface of the electrolysis electrode (5).

7. The desalination apparatus for producing an ultra-high purity hypochlorous acid aqueous solution from table salt as claimed in claim 5, wherein the tank (1) is provided with an ion membrane (9) parallel to the longitudinal direction (2) near the inlet (3) to divide the tank (1) into an anode compartment (10) near the anode of the electrolysis electrode (5) and a cathode compartment (11) near the cathode of the group of electrolysis electrodes (5), and the downstream ends of the anode compartment (10) and the cathode compartment (11) are closed by a porous block (12).

8. The desalination apparatus for producing ultra-high purity hypochlorous acid solution from table salt as claimed in claim 5, wherein the tank (1) is provided with an anionic membrane (13) parallel to the longitudinal direction (2) near the anode of the deionizing electrode (8), and a cationic membrane (14) parallel to the longitudinal direction (2) at the cathode of the deionizing electrode (8), so that hypochlorous acid solution is harvested in a central region (17) between the anionic membrane (13) and the cationic membrane (14).

9. The desalination apparatus for producing ultra-high purity hypochlorous acid aqueous solution from table salt as claimed in claim 8, wherein the tank (1) comprises an inner channel (20) nested in the tank, one end of the inner channel (20) being in fluid communication with the central region (17) for harvesting hypochlorous acid aqueous solution; the ion exchange resin (21) is arranged in the inner channel (20), and after the hypochlorous acid aqueous solution enters the inner channel (20), the hypochlorous acid aqueous solution is subjected to ion exchange treatment by the ion exchange resin (21) to remove residual ion components, and is discharged from the other end of the inner channel (20).

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