A device and method for preparing hypochlorous acid water

Abstract

The present invention relates to a device and method for preparing hypochlorous acid water, and belongs to the technical field of water electrolysis. The device comprises a container, a cathode electrode, an anode electrode and a DC power supply. The bottom of the container is provided with a contracted opening, the outer wall of the opening is provided with a screw cap connected by a thread, the anode electrode and the cathode electrode are arranged in the opening and arranged in an upper and lower position, and the screw cap is provided with an interface that can electrically connect the electrode with the DC power supply; an opening connected to the external atmosphere is provided on the end surface of the screw cap, the cathode electrode is close to the opening and has a channel, and a resistance member that forms resistance to the solution flowing outward through the opening is provided at the opening; the wall shell of the container has a deformation amount that can increase the volume of the container during electrolysis; the resistance member is used to make the solution have a first state in which it is prevented from being discharged outward by the resistance member and a second state in which it can be discharged outward through the resistance member. The device can stably prepare slightly acidic hypochlorous acid water with a pH value of 5.5 to 6.5.

Description

Technical Field

[0001] The invention relates to a device for preparing hypochlorous acid water and a method for preparing hypochlorous acid water, belonging to the technical field of water electrolysis. Background Art

[0002] Hypochlorous acid water is a chlorine-containing disinfectant, and its effective bactericidal ingredient is hypochlorous acid (HClO). The pH of hypochlorous acid water has a great influence on the concentration of hypochlorous acid in the water. When the pH value is in the range of 5.5 to 6.5, the concentration of hypochlorous acid tends to be the largest, and the bactericidal effect of hypochlorous acid water is greatly enhanced; the more alkaline the pH value is, the more hypochlorous acid in the hypochlorous acid water is converted into the state of hypochlorite ions (OCl-), and the bactericidal power decreases (according to relevant tests, the bactericidal power of hypochlorite ions is only about 1 / 80 of that of hypochlorous acid); if the pH value of hypochlorous acid water is more acidic, more chlorine gas is generated in the water, and the concentration of hypochlorous acid also decreases. (The above relationship is shown in Figure 1 )

[0003] There are many methods for producing hypochlorous acid water. The known standard method is to produce it by electrolyzing 2% to 6% dilute hydrochloric acid water (generally diluted with pure water) in a one-chamber type, i.e., non-diaphragm electrolytic cell at a DC voltage of about 2V. Chlorine gas and H+ are generated at the anode. H+ dissolves in water to make the water acidic. Chlorine gas reacts with water to generate hydrochloric acid and hypochlorous acid (HClO), so that the effective chlorine concentration in the water reaches 10 to 30 mg / L; hydrogen gas is generated at the cathode.

[0004] Since hydrochloric acid is expensive and is a highly toxic and dangerous substance that is restricted for purchase and difficult to obtain, it cannot be widely used. Currently, table salt (sodium chloride) is commonly used to replace hydrochloric acid.

[0005] The typical method for producing hypochlorous acid water is to use sodium chloride as the electrolytic solution, and the two-chamber or three-chamber diaphragm electrolysis is used. Taking the two-chamber electrolytic cell as an example, the raw water (salt water) is sent to the anode chamber (or sent to the cathode chamber at the same time), the water output from the anode chamber is acidic electrolyzed water and the water output from the cathode chamber is alkaline electrolyzed water, the alkaline water produced by the cathode chamber is mixed with the acidic electrolyzed water produced by the anode chamber in a certain proportion, and the pH of the acidic electrolyzed water produced by the anode chamber is increased, and finally slightly acidic hypochlorous acid water with a pH value of 5.5 to 6.5 is obtained.

[0006] Another method for producing hypochlorous acid water is to first electrolyze a sodium chloride aqueous solution without a diaphragm to obtain an alkaline sodium hypochlorite solution, and then add an acid solution (typically dilute hydrochloric acid, but also weak acids such as acetic acid and carbonic acid) to the sodium hypochlorite solution in proportion to gradually reduce the alkalinity of the sodium hypochlorite solution until it becomes neutral or slightly acidic hypochlorous acid water.

[0007] The key point of the existing device for producing hypochlorous acid water by electrolyzing salt water is the online monitoring of pH value, and some are also equipped with online monitoring of redox potential or effective chlorine. However, there are many factors affecting the above parameters, so that the control system (usually single parameter or multi-parameter closed-loop regulation) has a very complex structure, difficult process control, difficult to maintain stable characteristic parameters, poor safety and many other problems. Summary of the invention

[0008] The technical problem to be solved by the present invention is to simplify the structure and process of the existing hypochlorous acid water preparation device to achieve the preparation of hypochlorous acid water with stable and reliable process, simple device structure and high safety, so as to be suitable for promotion and popularization to households.

[0009] The present invention proposes a first technical solution to solve the above technical problems: a device for preparing hypochlorous acid water, comprising a container for containing a salt solution, a cathode electrode, an anode electrode and a DC power supply for supplying power to the electrodes to electrolyze the solution, the container is provided with a contracted inlet and outlet port, the outer wall of the port is provided with a screw cap connected by a thread, the cathode electrode and the anode electrode are arranged in the port, when the container is in a normal state with the port facing downward, the anode electrode is located above the cathode electrode, and the screw cap is provided with an interface that can electrically connect the electrode with the DC power supply; characterized in that: an opening connected to the atmosphere is provided on the end surface of the screw cap, the cathode electrode is close to the opening and a channel is left for the solution to pass through the opening, the wall shell of the container has a deformation amount that can increase the volume of the container during electrolysis, and a resistance member is provided at the opening to form a resistance pressure for the solution to flow outward through the opening; when the container is in the normal state, the resistance member is used to make the solution have a first state in which it is prevented from being discharged outward by the resistance member and a second state in which it is discharged outward through the resistance member.

[0010] The technical solution of the first aspect is further that when the solution is in the first state, there is no gas in the container before electrolysis and the gravity pressure of the solution - the resistance pressure ≤ atmospheric pressure, or there is gas in the container at the beginning of electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure ≤ atmospheric pressure; when the solution is in the second state: there is gas in the container during electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure > atmospheric pressure. The deformation amount and the resistance pressure are both set constant values. A partition with holes is also provided between the cathode and the anode. The cathode and the anode are made into a mesh plate with micropores, and the channel is composed of the holes on the cathode, the anode and the partition. An exhaust port and an exhaust valve are provided on the wall shell of the container. The screw cap is also connected to a waste liquid tank, and the waste liquid tank is provided with a normally open air hole connected to the atmosphere, a waste outlet and a waste valve. The resistance member is a microporous plate, a microporous membrane or a pressure reducing valve.

[0011] The present invention proposes a second technical solution to solve the above technical problem: a method for preparing hypochlorous acid water, applying the above first technical solution and performing the following steps:

[0012] 1) selecting a container with a set deformation amount and containing a saline solution, selecting a resistance member with a set resistance pressure, and arranging the resistance member at the opening of the screw cap;

[0013] 2) tightening the container and the screw cap, so that the electrode is docked with the interface of the screw cap, and then placing the container in the normal state;

[0014] 3) setting the electrolysis time according to the volume of the container, turning on the DC power supply to power the electrodes, and electrolyzing the solution in the container;

[0015] 4) During electrolysis, gas is generated in the container. When the wall shell of the container is deformed and the gas pressure formed by the gas in the container + the gravity pressure of the solution - the resistance pressure > atmospheric pressure, the opening is observed to discharge the solution outward;

[0016] 5) When the electrolysis time is reached, the DC power supply is turned off, the screw cap is unscrewed, and the electrolyzed solution is poured out from the opening.

[0017] The first change of the technical solution of the second aspect is that a partition with holes is set between the cathode and the anode, and an exhaust port and an exhaust valve are set on the wall shell of the container; in the step 4), the exhaust valve is adjusted so that the gas pressure formed by the gas in the container + the gravity pressure of the solution - the resistance pressure > atmospheric pressure.

[0018] A second variation of the technical solution of the second aspect is that a waste liquid tank is connected to the screw cap, and the waste liquid tank is provided with a normally open waste outlet and a waste outlet valve connected to the atmosphere and a bypass valve; in the step 4), the opening discharges the solution into the waste liquid tank; in the step 5), the bypass valve is opened, and the electrolyzed solution is discharged from the bypass valve.

[0019] The above-mentioned second technical solution is further:

[0020] In the step 2), when there is no gas in the container and the gravity pressure of the solution minus the resistance pressure ≤ atmospheric pressure, or in the step 3), when there is gas in the container at the start of electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution minus the resistance pressure ≤ atmospheric pressure, the solution is in a first state where it is prevented from being discharged outward by the resistance member;

[0021] In the step 4), during electrolysis, when there is gas in the container and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure > atmospheric pressure, the solution is in a second state of being discharged outward through the resistance member.

[0022] The beneficial effects of the present invention are:

[0023] 1. Compared with the existing hypochlorous acid water preparation process and device, the device of the present invention has a simple structure, a stable and reliable method, low requirements on components, and a very high cost performance, and is suitable for promotion and popularization to thousands of households.

[0024] 2. Based on the device of the present invention, the positive and negative electrodes are arranged in the mouth of the container and form an upper and lower position arrangement, and direct current is provided to the positive and negative electrodes through the interface of the screw cap. Since the negative electrode is close to the opening of the mouth of the container, when the electrode is energized to electrolyze the solution in the container, the heavy metal ions and alkali solution (NaOH) produced by the electrolysis of the solution near the negative electrode can be discharged from the container, thereby improving the quality and safety of hypochlorous acid water produced by electrolysis.

[0025] 3. The liquid container of the device of the present invention can be any specific elastic deformation product on the market, such as a mineral water bottle / barrel, etc. The corresponding resistance element and its resistance pressure constant can be configured according to the volume of the selected liquid container, which is very convenient.

[0026] 4. The device of the present invention can stably produce slightly acidic hypochlorous acid water with a pH value of 5.5 to 6.5. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following is a further description of a device for preparing hypochlorous acid water and a method for preparing hypochlorous acid water according to the present invention in conjunction with the accompanying drawings.

[0028] Figure 1 A graph showing the relationship between the residual ratio of hypochlorous acid water and the pH value of hypochlorous acid water in the background art.

[0029] Figure 2 The present invention is a schematic diagram of the structure of a device for preparing hypochlorous acid water according to the first embodiment.

[0030] Figure 3 This is a schematic diagram of the structure of a device for preparing hypochlorous acid water according to Example 2.

[0031] Figure 4 This is a schematic diagram of the structure of a device for preparing hypochlorous acid water in Example 3.

[0032] Figure 5 It is a schematic diagram of the structure of a device for preparing hypochlorous acid water according to Example 4.

[0033] Figure 6 yes Figure 5 A partial enlarged view of point I in the middle. DETAILED DESCRIPTION

[0034] Embodiment 1

[0035] This embodiment proposes a device for preparing hypochlorous acid water, such as Figure 1 As shown, it includes a container 1 for holding a salt-containing solution (salt is selected in this embodiment) and a DC power supply 6. When the container 1 is placed normally, a contracted port 2 for entering and exiting the solution is provided at the bottom, and the diameter of the port 2 is much smaller than the diameter of the container 1. A screw cap 3 connected by a thread is provided on the outer wall of the port 2, and a pair of anode electrodes 4 and cathode electrodes 5 arranged in upper and lower positions (i.e., the anode electrode 4 is on the top and the cathode electrode 5 is on the bottom) are provided in the port. The cathode electrode 2 and the anode electrode 5 can usually be made into a plate, a block or other shapes. The DC power supply 6 supplies power to the anode electrode 4 and the cathode electrode 5 to form electrolysis on the solution in the container 1. The screw cap 3 is provided with an interface that can electrically connect the electrodes (the anode electrode 4 and the cathode electrode 5) with the DC power supply 6. An opening 7 connected to the atmosphere is provided on the end surface of the screw cap 3, and the cathode electrode 5 is close to the opening 7 and has a passage for the solution in the container 1 to pass through the opening 7. A resistance member 8 is provided at the opening 7 to form a resistance pressure for the solution in the container 1 to flow outward through the opening 7. In this embodiment, the resistance member 8 is a metal microporous plate (metal mesh plate) with micropores, and the pore size of the micropores is between 10-100 microns. The surface tension of the metal mesh plate for water or saline solutions can form a resistance pressure on the solution in the container 1 passing through the resistance member 8. The resistance pressure is usually set to a constant based on the metal mesh plate and its micropores.

[0036] The wall of container 1 has a set deformation amount that can increase the volume of container 1 during electrolysis. Usually, container 1 is a container filled with solution similar to a commercially available mineral water bottle or mineral water barrel. Mineral water bottles or mineral water barrels are plastic products and can undergo a certain amount of deformation to increase their own volume. Therefore, the wall deformation amount of container 1 can be set to a constant, and the volume increase of container 1 can also be set to a constant.

[0037] The resistance member 8 is used to make the solution in the container 1 have a first state in which the solution is blocked by the resistance member 8 (i.e., cannot be discharged outward through the opening 7) and a second state in which the solution can be discharged outward through the opening 7 during electrolysis. The specific process of producing hypochlorous acid water by the hypochlorous acid water producing device of this embodiment is:

[0038] 1) Select a container with a set deformation amount and containing a saline solution (a mineral water barrel, salt can be added to a mineral water bottle or a mineral water barrel), select a resistance member 8 with a set constant resistance pressure and set the resistance 8 at the opening 7 of the screw cap 3.

[0039] 2) Tighten the mouth 2 of the container 1 and the screw cap 3, so that the positive electrode 4 and the negative electrode 5 in the mouth 2 are well connected with the interface of the screw cap 3, and then the container 1 is placed in a normal state. The normal state of this embodiment is as follows: Figure 1 The container 1 shown is in a vertical state, and the mouth 2 is at the bottom of the container 1; at this time, there is no gas in the container 1, and the brine cannot be discharged through the micropores at the metal mesh plate due to the resistance pressure formed by the surface tension of the liquid and the atmospheric pressure, that is, the gravity pressure Pweight of the solution in the container - the resistance pressure Presistance of the resistance member on the solution in the container 1 ≤ atmospheric pressure, that is, the resistance member 8 with this resistance pressure can satisfy the first state in which the solution in the container 1 cannot be discharged outward through the opening 7.

[0040] 3) The electrolysis time T is set according to the volume of the container 1, and the DC power supply 6 is turned on to supply power to the anode electrode 4 and the cathode electrode 5, and the salt solution (brine) in the container 1 is electrolyzed; the following electrochemical reactions occur during the electrolysis:

[0041] 2NaCl+2H2O+e→2NaOH+H2+Cl2+O2 (1)

[0042] 2H2O+e→2H2+O2 (2)

[0043] H2O+Cl2→HClO+HCl (3)

[0044] 2NaOH+Cl2=2NaClO+H2 (4);

[0045] Cl2↑ and O2↑ are generated on the anode 5 side, and H2↑ is generated on the cathode 2 side. The Cl2 generated on the anode 5 side dissolves in the salt water to react and generate hypochlorous acid HClO; a portion of Cl2 and O2 rise and gather in the upper space of the container 1 (the volume of this space = V1-V2) and gradually form a gas pressure Pgas when the salt water in the container 1 and its electrolytic solution. When the electrolysis starts, Pgas+Pheavy-Presistance≤atmospheric pressure, at this time, the solution in the container 1 is still in the first state where it is blocked by the resistance member 8 and cannot be discharged out through the opening 7.

[0046] 4) During electrolysis, gas (Cl2, O2, H2) is generated in container 1. When the wall shell of container 1 is deformed and the gas pressure formed by the gas in container 1 + the gravity pressure of the solution in container 1 - the resistance pressure of the resistance member 8 on the solution in container 1 (constant) is greater than the atmospheric pressure, the brine in container 1 generates a solution (containing the cathode side product NaOH) during electrolysis (especially at the cathode electrode 5) and is discharged outward through the micropores of the resistance member 4 (metal mesh) at the opening 7. At this time, the solution can be observed to be discharged outward from the opening 7.

[0047] 5) When the electrolysis time T is reached, the DC power supply 6 is turned off, the screw cap 3 is unscrewed, and the solution in the container 1 after electrolysis, which contains the anode side products hypochlorous acid HClO and sodium hypochlorite NaClO, is poured out from the opening 2, thereby obtaining the desired solution containing hypochlorous acid HClO.

[0048] In this embodiment, the volume of the container 1 excluding the mouth portion is basically the total amount of liquid that can be discharged. Therefore, even when the amount of liquid discharged exceeds this volume, the anode 5 is exposed from the liquid surface in the container 1. At this time, the electrolysis current drops to zero, and the electrolysis is automatically stopped to provide safety protection.

[0049] Embodiment 2

[0050] This embodiment is a variation of the first embodiment. Figure 2 As shown, in addition to being the same as Example 1, the differences are: (1) the cathode electrode 5 and the anode electrode 4 themselves are made into a mesh with micropores; (2) a partition plate 9 with micropores is also provided between the cathode electrode 5 and the anode electrode 4; (3) the channel through which the solution in the container 1 passes through the opening 7 is changed to be composed of the micropores of the anode electrode 4, the cathode electrode 5 and the partition plate 9; (4) an exhaust port and an exhaust valve 10 are provided on the wall shell of the container 1; (5) the resistance member 8 is replaced by a water-permeable microporous membrane instead of a metal mesh plate.

[0051] The method for preparing hypochlorous acid water in the hypochlorous acid preparation device of this embodiment is basically the same as that in the first embodiment, except that: in step 4), an adjustable exhaust valve is added to make the relationship between Pgas+Pweight-Presistance in the container 1 and the atmospheric pressure controllable, so as to achieve the controllable discharge of the NaOH-containing solution from the opening 7.

[0052] Embodiment 3

[0053] This embodiment is a variation of the second embodiment. Figure 3 As shown, in addition to being the same as Example 2, the differences are: (1) the resistance member 8 is replaced by a metal mesh plate with a pressure reducing valve 11, and the pressure reducing valve 11 is connected to a waste liquid tank 12 and a bypass valve 13, and the waste liquid tank 12 is provided with a waste outlet and a waste valve 14 that is normally open and connected to the atmosphere.

[0054] The method for preparing hypochlorous acid water in the hypochlorous acid preparation device of this embodiment is the same as that in the second embodiment except that:

[0055] 1. In step 4), the opening 7 discharges the solution outwardly into the waste liquid tank 12;

[0056] 2. In step 5), the bypass valve 13 is opened, and the solution containing hypochlorous acid HClO in the container 1 after electrolysis is discharged from the bypass valve 13.

[0057] Embodiment 4

[0058] This embodiment is a refinement of the third embodiment. Figure 4 and Figure 5 As shown, except for the same as the third embodiment, the difference is:

[0059] (1) Container 1 is a mineral water bottle (salt can be added);

[0060] (2) The waste liquid tank 12 is connected to the screw cap 3 by threads, and the waste valve 14 is replaced by a normally open air hole 15;

[0061] (3) The DC power source 6 is a battery and is directly built into the rotary cover 3;

[0062] (4)) The resistance member 8 is still made of a water-permeable microporous membrane;

[0063] (5) Remove the bypass valve 13.

[0064] The method for preparing hypochlorous acid water in the hypochlorous acid preparation device of this embodiment is the same as that in the third embodiment except that:

[0065] 1. In step 4) of preparing hypochlorous acid water, the waste liquid discharged into the waste liquid tank 12 is finally discharged by unscrewing the waste liquid tank 12;

[0066] 2. In step 5), the solution containing hypochlorous acid HClO is discharged by opening the screw cap 3.

[0067] The above are only several preferred embodiments of the present invention, but the present invention is not limited thereto. All equivalent replacements or equivalent changes of the concepts and technical solutions according to the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preparing hypochlorous acid water, comprising a container for containing a saline solution, a cathode electrode, an anode electrode and a DC power supply for supplying power to the electrodes to electrolyze the solution, the container being provided with a contracted inlet and outlet port, the diameter of the port being much smaller than the diameter of the container, the outer wall of the port being provided with a screw cap connected by a thread, the cathode electrode and the anode electrode being arranged in the port, the anode electrode being located above the cathode electrode when the container is in a normal state with the port facing downward, and the screw cap being provided with an interface for electrically connecting the electrode to the DC power supply; characterized in that An opening communicating with the atmosphere is provided on the end surface of the screw cap, the cathode electrode is close to the opening and has a passage for the solution to pass through the opening, the wall shell of the container has a deformation amount that can increase the volume of the container during electrolysis, and a resistance member that forms a resistance pressure for the solution to flow outward through the opening is provided at the opening; when the container is in the normal state, the resistance member is used to make the solution have a first state in which the solution is prevented from being discharged outward by the resistance member and a second state in which the solution is discharged outward through the resistance member.

2. The device for producing hypochlorous acid water according to claim 1, characterized in that: When the solution is in the first state, there is no gas in the container before electrolysis and the gravity pressure of the solution - the resistance pressure ≤ atmospheric pressure, or there is gas in the container at the beginning of electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure ≤ atmospheric pressure; when the solution is in the second state: there is gas in the container during electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure > atmospheric pressure.

3. The device for producing hypochlorous acid water according to claim 1, characterized in that: The deformation amount and the resistance pressure are both set constant values.

4. The device for producing hypochlorous acid water according to claim 1, characterized in that: A partition with holes is also provided between the cathode electrode and the anode electrode.

5. The device for producing hypochlorous acid water according to claim 4, characterized in that: The cathode electrode and the anode electrode are made into a mesh plate with micropores, and the channel is formed by the holes on the cathode electrode, the anode electrode and the separator.

6. The device for producing hypochlorous acid water according to claim 1, characterized in that: An exhaust port and an exhaust valve are arranged on the wall shell of the container.

7. The device for producing hypochlorous acid water according to claim 1, characterized in that: The screw cap is also connected to a waste liquid tank, and the waste liquid tank is provided with a normally open air hole connected to the atmosphere, a waste outlet and a waste valve.

8. The device for producing hypochlorous acid water according to claim 1, characterized in that: The resistance member is a microporous plate, a microporous membrane or a pressure reducing valve.

9. A method for preparing hypochlorous acid water, using the device for preparing hypochlorous acid water according to claim 1, characterized in that Perform the following steps: 1) selecting a container with a set deformation amount and containing a saline solution, selecting a resistance member with a set resistance pressure, and arranging the resistance member at the opening of the screw cap; 2) tightening the container and the screw cap, so that the electrode is docked with the interface of the screw cap, and then placing the container in the normal state; 3) setting the electrolysis time according to the volume of the container, turning on the DC power supply to power the electrodes, and electrolyzing the solution in the container; 4) During electrolysis, gas is generated in the container. When the wall shell of the container is deformed and the gas pressure formed by the gas in the container + the gravity pressure of the solution - the resistance pressure > atmospheric pressure, the opening is observed to discharge the solution outward; 5) When the electrolysis time is reached, the DC power supply is turned off, the screw cap is unscrewed, and the electrolyzed solution is poured out from the opening.

10. A method for producing hypochlorous acid water according to claim 9, characterized in that: A partition with holes is arranged between the cathode and the anode, and an exhaust port and an exhaust valve are arranged on the wall shell of the container; in the step 4), the exhaust valve is adjusted so that the gas pressure formed by the gas in the container + the gravity pressure of the solution - the resistance pressure > atmospheric pressure.

11. A method for producing hypochlorous acid water according to claim 9, characterized in that: A waste liquid tank is connected to the screw cap, and the waste liquid tank is provided with a normally open air hole connected to the atmosphere, a waste outlet and a waste outlet valve; in the step 4), the opening discharges the solution into the waste liquid tank; in the step 5), the bypass valve is opened, and the electrolyzed solution is discharged from the bypass valve.

12. A method for producing hypochlorous acid water according to claim 9, 10 or 11, characterized in that: In the step 2), when there is no gas in the container and the gravity pressure of the solution minus the resistance pressure ≤ atmospheric pressure, or in the step 3), when there is gas in the container at the start of electrolysis and the gas pressure formed by the gas + the gravity pressure of the solution minus the resistance pressure ≤ atmospheric pressure, the solution is in a first state where it is prevented from being discharged outward by the resistance member; In the step 4), during electrolysis, when there is gas in the container and the gas pressure formed by the gas + the gravity pressure of the solution - the resistance pressure > atmospheric pressure, the solution is in a second state of being discharged outward through the resistance member.

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