Method and Device for Preparing Slightly Acidic Electrolyzed Water with Controllable and Stable Concentration

Abstract

The disclosure provides a method and device for preparing slightly acidic electrolyzed water with a controllable and stable concentration. According to the method, a solution addition velocity of a first solution addition device is adjusted according to a difference between a detected voltage U.sub.detected and a control voltage U.sub.control in an electrolytic cell, so that the first solution addition device adds an electrolyte stock solution to the electrolytic cell in real time, thereby preparing the slightly acidic electrolyzed water with a controllable and stable concentration. The device includes an electrolyte stock solution storage, an electrolytic cell and a first mixer connected sequentially. A first solution addition device is connected in series between the electrolyte stock solution storage and the electrolytic cell. The disclosure overcomes the defects of uncontrollable and unstable concentration in the preparation of present slightly acidic electrolyzed water.

Claims

1. A method for preparing slightly acidic electrolyzed water with a controllable and stable concentration, wherein a solution addition velocity of a first solution addition device is adjusted according to a difference between a detected voltage U.sub.detected and a control voltage U.sub.control in an electrolytic cell, so that the first solution addition device adds an electrolyte stock solution to the electrolytic cell in real time, thereby preparing the slightly acidic electrolyzed water with a controllable and stable concentration.

2. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 1, specifically comprising the following steps: step S001, setting C.sub.effluent and carrying out electrolysis; wherein a suitable effluent concentration of slightly acidic electrolyzed water C.sub.effluent is set according to needs, and after the electrolytic cell is filled up with the electrolyte stock solution, a current I.sub.control and a voltage U.sub.control are applied to two ends of the electrolytic cell and electrolysis is started; step S002, calculating ?U; wherein the actual voltage U.sub.detected in the electrolytic cell is detected, and ?U is calculated according to ?U=U.sub.detected?U.sub.control; step S003, determining whether ?U is greater than 0; if so, the first solution addition device works; if not, the first solution addition device stops working; step S004, repeating steps S002-S003.

3. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 2, wherein in step S001, U.sub.control is determined according to U.sub.control=f (C.sub.effluent, T.sub.detected), wherein U.sub.control is directly proportional to C.sub.effluent and U.sub.control is inversely proportional to T.sub.detected.

4. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 3, wherein U.sub.control is calculated according to the following formula:
U=K.sub.1.Math.(C.sub.effluent?K.sub.2).Math.[1?K.sub.3.Math.(T.sub.detected?T.sub.calibrated)]+K.sub.4 wherein K.sub.1, K.sub.2, K.sub.3, K.sub.4 and T.sub.calibrated are all constants greater than 0.

5. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 2, wherein in step S001, U.sub.control is determined according to U.sub.control=f(C.sub.effluent), wherein U.sub.control is directly proportional to C.sub.effluent.

6. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 5, wherein U.sub.control is calculated according to the following formula:
U.sub.control=K.sub.1.Math.(C.sub.effluent?K.sub.2)+K.sub.4 wherein K.sub.1, K.sub.2 and K.sub.4 are all constants greater than 0.

7. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 4, wherein I.sub.control and the voltage U.sub.control are determined by the following steps: step A1, calculating I.sub.calibrated; wherein based on C.sub.effluent, I.sub.calibrated is calculated according to $I_{\mathrm{calibrated}}=\frac{\left(C_{\mathrm{effluent}}-K_2\right)}{K_5},$ wherein K.sub.5 is a constant greater than 0; step A2, calculating ?T; wherein an actual temperature T.sub.detected of the electrolyte solution in the electrolytic cell (2) is detected, preset T.sub.calibrated in the system is acquired, and ?T is calculated according to ?T=T.sub.detected?T.sub.calibrated; step A3, calculating I.sub.control and U.sub.control; wherein based on ?T, I.sub.control is calculated according to I.sub.control=I.sub.calibrated (1?K.sub.3.Math.?T); and then, U.sub.control is calculated according to U.sub.control=K.sub.6.Math.I.sub.control+K.sub.4, wherein K.sub.6 is a constant greater than 0.

8. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 6, wherein I.sub.control and the voltage U.sub.control are determined by the following steps: step A1, calculating I.sub.calibrated; wherein based on C.sub.effluent, I.sub.calibrated is calculated according to $I_{\mathrm{calibrated}}=\frac{\left(C_{\mathrm{effluent}}-K_2\right)}{K_5},$ wherein K.sub.5 is a constant greater than 0; step A2, calculating I.sub.control and U.sub.control; wherein based on I.sub.calibrated; I.sub.control is determined according to I.sub.control=I.sub.calibrated, and then, U.sub.control is calculated according to U.sub.control=K.sub.6.Math.I.sub.control+K.sub.4, wherein K.sub.6 is a constant greater than 0.

9. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 2, wherein in step S002, an actual current I.sub.detected and the actual voltage U.sub.detected in the electrolytic cell are detected at T.sub.1 intervals, and when I.sub.detected=I.sub.control, the corresponding U.sub.detected is acquired.

10. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 2, wherein in step S003, when ?U>0: based on ?U, V is calculated according to V=K.sub.7.Math.?U, wherein K.sub.7 is a constant greater than 0; and then, the first solution addition device adds the electrolyte stock solution to the electrolytic cell at a velocity V.

11. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 4, wherein T.sub.calibrated is any value of 20? C., 25? C. or 45? C.

12. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 2, wherein step S001 specifically comprises the following steps: step S0001, setting C.sub.effluent; wherein a user sets a suitable effluent concentration of slightly acidic electrolyzed water C.sub.effluent in a master control unit according to actual needs, wherein C.sub.effluent is 20-90 ppm; step S0002, carrying out initial solution addition; wherein the electrolyte stock solution in an electrolyte stock solution storage is added to the electrolytic cell by the first solution addition device, and when a detection liquid level of a liquid level detection unit is reached, the first solution addition device stops working; and the electrolyte stock solution is a dilute hydrochloric acid solution with a concentration of 6%-8%; step S0003, carrying out electrolysis by energization; wherein the current I.sub.control and the voltage U.sub.control are applied to the two ends of the electrolytic cell by a current and voltage control unit, and the electrolysis is started in the electrolytic cell.

13. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 1, wherein a rear end of the electrolytic cell is connected in series with a first mixer, water is introduced into the first mixer, and a flow velocity of the water is ?1 L/min.

14. The method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 1, wherein when the electrolytic cell is in a standby state, a current 100 mA and a voltage 1000 mV are applied into the electrolytic cell and held for 3 s at 1200 s intervals, so that after start-up, an accurate concentration of slightly acidic electrolyzed water is reached quickly.

15. A device for preparing slightly acidic electrolyzed water with a controllable and stable concentration, comprising: an electrolyte stock solution storage, an electrolytic cell and a first mixer connected sequentially, wherein a first solution addition device is connected in series between the electrolyte stock solution storage and the electrolytic cell, and the electrolytic cell is respectively connected with a current and voltage control unit and a current and voltage detection unit; and when in use, a solution addition velocity of the first solution addition device is adjusted according to a difference between a detected voltage U.sub.detected and a control voltage U.sub.control, so that the first solution addition device adds an electrolyte stock solution to the electrolytic cell in real time, thereby preparing the slightly acidic electrolyzed water with a controllable and stable concentration.

16. The device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 15, further comprising a master control unit; wherein the electrolytic cell is connected with a temperature detection unit configured to detect an electrolyte solution temperature and a liquid level detection unit configured to detect a liquid level, and the first solution addition device, the current and voltage control unit, the current and voltage detection unit, the temperature detection unit and the liquid level detection unit are all connected to the master control unit.

17. The device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 15, wherein a front end of the first mixer is connected with a flowmeter, a solenoid valve and a constant pressure valve are sequentially connected in series between the flowmeter and the first mixer, and water sequentially flows through the flowmeter, the solenoid valve and the constant pressure valve and enters the first mixer.

18. The device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 15, further comprising a neutralization solution storage, a second solution addition device and a second mixer sequentially connected in series, wherein the second mixer is connected in series at a rear end of the first mixer.

19. The device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to claim 18, wherein the first solution addition device and the second solution addition device are both peristaltic metering pumps.

Description

BRIEF DESCRIPTION OF FIGURES

[0039] FIG. 1 is a schematic flow diagram of a method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure;

[0040] FIG. 2 is a schematic flow diagram of determining I.sub.control and U.sub.control in the method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure;

[0041] FIG. 3 is another schematic flow diagram of determining I.sub.control and U.sub.control in the method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure;

[0042] FIG. 4 is a schematic flow diagram of step S001 in the method for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure;

[0043] FIG. 5 is a schematic structural diagram of a device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure;

[0044] FIG. 6 is a schematic structural diagram of a master control unit connected to detection units in the device for preparing slightly acidic electrolyzed water with a controllable and stable concentration according to the disclosure.

[0045] Corresponding component names of reference signs in the figures are: 1. electrolyte stock solution storage; 2. electrolytic cell; 3. first mixer; 4. first solution addition device; 5. current and voltage control unit; 6. current and voltage detection unit; 7. temperature detection unit; 8. liquid level detection unit; 9. master control unit; 10. flowmeter; 11. solenoid valve; 12. constant pressure valve; 13. neutralization solution storage; 14. second solution addition device; 15. second mixer.

DETAILED DESCRIPTION

[0046] Specific implementations of the disclosure will be further described in detail below with reference to the drawings and examples. The following examples are intended to illustrate the disclosure, but not to limit the scope of the disclosure.

Example I

[0047] Referring to FIG. 5 and FIG. 6, this example provides a device for preparing slightly acidic electrolyzed water with a controllable and stable concentration, including an electrolyte stock solution storage 1, an electrolytic cell 2 and a first mixer 3 connected sequentially. A first solution addition device 4 is connected in series between the electrolyte stock solution storage 1 and the electrolytic cell 2, and the first solution addition device 4 may be a peristaltic metering pump. The electrolytic cell 2 is respectively connected with a current and voltage control unit 5 and a current and voltage detection unit 6. The current and voltage control unit 5 is connected to the electrolytic cell 2 through an energized wire, and the current and voltage detection unit 6 is connected to the electrolytic cell 2 through a detection probe. The current and voltage control unit 5 is configured to control a current and a voltage across two ends of the electrolytic cell 2, and the current and voltage detection unit 6 is configured to detect the actual current and voltage in the electrolytic cell 2. When in use, a solution addition velocity of the first solution addition device 4 is adjusted according to a difference between a detected voltage U.sub.detected and a control voltage U.sub.control, so that the first solution addition device 4 adds an electrolyte stock solution to the electrolytic cell 2 in real time, thereby preparing the slightly acidic electrolyzed water with a controllable and stable concentration.

[0048] Referring to FIG. 6, the device for preparing slightly acidic electrolyzed water with a controllable and stable concentration further includes a master control unit 9, the electrolytic cell 2 is connected with a temperature detection unit 7 configured to detect an electrolyte solution temperature and a liquid level detection unit 8 configured to detect a liquid level, and the temperature detection unit 7 may be a temperature probe. The first solution addition device 4, the current and voltage control unit 5, the current and voltage detection unit 6, the temperature detection unit 7 and the liquid level detection unit 8 are all connected to the master control unit 9. By arranging the current and voltage control unit 5, the current and voltage detection unit 6, the temperature detection unit 7 and the liquid level detection unit 8 that cooperate with each other, the rotation speed of the peristaltic metering pump can be adjusted through detection data and control data, thereby ensuring the feasibility of the structure.

[0049] Referring to FIG. 5, a front end of the first mixer 3 is connected with a flowmeter 10. A solenoid valve 11 and a constant pressure valve 12 are sequentially connected in series between the flowmeter 10 and the first mixer 3, and water sequentially flows through the flowmeter 10, the solenoid valve 11 and the constant pressure valve 12 and enters the first mixer 3. By using the flowmeter 10, the constant pressure valve 12 and the solenoid valve 11, a flow velocity of the water can be effectively controlled.

[0050] Referring to FIG. 1, this example further provides a method for preparing slightly acidic electrolyzed water with a controllable and stable concentration based on the above device. A solution addition velocity of a first solution addition device 4 is adjusted according to a difference between a detected voltage U.sub.detected and a control voltage U.sub.control in an electrolytic cell 2, so that the first solution addition device 4 adds an electrolyte stock solution to the electrolytic cell 2 in real time, thereby preparing the slightly acidic electrolyzed water with a controllable and stable concentration.

[0051] The method specifically includes the following steps: [0052] step S001, setting C.sub.effluent and carrying out electrolysis; where a suitable effluent concentration of slightly acidic electrolyzed water C.sub.effluent is set according to needs, and after the electrolytic cell is filled up with the electrolyte stock solution, a current I.sub.control and a voltage U.sub.control are applied to two ends of the electrolytic cell 2 and electrolysis is started; [0053] step S002, calculating ?U; where the actual voltage U.sub.detected in the electrolytic cell 2 is detected, and ?U is calculated according to

?U=U.sub.detected?U.sub.control; [0054] step S003, determining whether ?U is greater than 0; [0055] if so, the first solution addition device 4 works; [0056] if not, the first solution addition device 4 stops working; [0057] step S004, repeating steps S002-S003.

[0058] In step S002, an actual current I.sub.detected and the actual voltage U.sub.detected in the electrolytic cell 2 are detected at T.sub.1 intervals at the same time, and when I.sub.detected=I.sub.control, U.sub.detected corresponding to I.sub.detected is acquired. T.sub.1=0.5 s. In a case that I.sub.detected=I.sub.control is not detected continuously for a certain period of time, if I.sub.detected?I.sub.control, the output of U.sub.control will automatically increase until it reaches the maximum value; and if I.sub.detected>I.sub.control, the output of U.sub.control will automatically decrease until it reaches the minimum value, the electrolytic cell is shut down for maintenance.

[0059] In step S003, when ?U>0:

[0060] based on ?U, V is calculated according to V=K.sub.7.Math.?U, and then, the first solution addition device 4 adds the electrolyte stock solution to the electrolytic cell 2 at a velocity V until a next velocity V sent by the master control unit 10 is received. K.sub.7 is a constant greater than 0, and K.sub.7 may be 90-110. The unit of ?U is V, and the voltage detection accuracy is 0.01V. The unit of V is r/min.

[0061] Further, a rear end of the electrolytic cell 2 is connected in series with a first mixer 3, water is introduced into the first mixer 3, the water may be tap water, a flow velocity of the water is ?1 L/min, and the flow velocity of the water may be 1.2 L/min. A distance between two electrodes of the electrolytic cell used is 2.7 mm, and an area of the electrode is 14400 mm.sup.2.

Example II

[0062] Referring to FIG. 1 and FIG. 2, a method for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by this example is different from Example I in that: in step S001, U.sub.control is determined according to U.sub.control=f(C.sub.effluent, T.sub.detected) where U.sub.control is directly proportional to C.sub.effluent, and U.sub.control is inversely proportional to T.sub.detected.

[0063] Specifically, U.sub.control is calculated according to the following formula:

U.sub.control=K.sub.1.Math.(C.sub.effluent?K.sub.2).Math.[1?K.sub.3.Math.(T.sub.detected?T.sub.calibrated)]+K.sub.4

where K.sub.1, K.sub.2, K.sub.3, K.sub.4 and T.sub.calibrated are all constants greater than 0, K.sub.1 may be 0.03-0.048, K.sub.2 may be 12.929-14.929, K.sub.3 may be 0-1, K.sub.4 may be 1.8328-3.8328, T.sub.calibrated may be any value of 20? C., 25? C. or 45? C.

[0064] Further, I.sub.control and the voltage U.sub.control are determined by the following steps: [0065] step A1, calculating I.sub.calibrated; where based on C.sub.effluent, I.sub.calibrated is calculated according to

[00003]$I_{\mathrm{calibrated}}=\frac{\left(C_{\mathrm{effluent}}-K_2\right)}{K_5},$ where K.sub.5 is a constant greater than 0, and K.sub.5 may be 14.746-16.746; [0066] step A2, calculating ?T; where an actual temperature T.sub.detected of the electrolyte solution in the electrolytic cell 2 is detected, preset T.sub.calibrated in the system is acquired, and ?T is calculated according to ?T=T.sub.detected?T.sub.calibrated; [0067] step A3, calculating I.sub.control and U.sub.control; where based on ?T, I.sub.control is calculated according to I.sub.control=I.sub.calibrated (1?K.sub.3.Math.?T); and then, U.sub.control is calculated according to U.sub.control=K.sub.6.Math.I.sub.control+K.sub.4, where K.sub.6 is a constant greater than 0, and K.sub.6 may be 0.5076-0.7076.

[0068] After the current I.sub.control and the voltage U.sub.control are applied to the two ends of the electrolytic cell 2, the current in the electrolytic cell 2 starts to slowly rise from 0 to I.sub.control and is then kept constant. As the electrolyte solution is electrolyzed at the constant current, the final electrolyte solution in the electrolytic cell contains a mixed solution of chlorine gas molecules, hypochlorous acid molecules, hypochlorite ions, chlorine ions, sodium ions and hydrogen ions, and the concentration of hydrochloric acid decreases. In order to maintain the constant current value, the master control unit gives a higher output voltage to the electrolytic cell, and at the same time, the master control unit detects the actual voltage value in the electrolytic cell through the current and voltage detection unit, and controls the rotation speed of the peristaltic pump according to the difference between the actual voltage and the actual control voltage. The voltage difference is greater, the higher the rotation speed of the first solution addition device is faster. In one aspect, the decrease of the electrolyte stock solution in the electrolytic cell is compensated, the electrolysis velocity is increased, and a larger amount of chlorine gas is generated. In another aspect, an addition velocity of the chlorine gas discharged from the electrolytic cell is increased. Therefore, the velocity of reaction between chlorine gas and water is increased from two aspects, so the concentration of the slightly acidic electrolyzed water will increase, thereby achieving the purpose of preparing the slightly acidic electrolyzed water with a controllable and stable concentration.

Example III

[0069] Referring to FIG. 1 and FIG. 3, a method for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by this example is different from Example I in that: in step S001, U.sub.control is determined according to U.sub.control=f(C.sub.effluent), where U.sub.control is directly proportional to C.sub.effluent.

[0070] Specifically, U.sub.control is calculated according to the following formula:

U.sub.control=K.sub.1.Math.(C.sub.effluent?K.sub.2)+K.sub.4 [0071] where K.sub.1, K.sub.2 and K.sub.4 are all constants greater than 0, K.sub.1 may be 0.03-0.048, K.sub.2 may be 12.929-14.929, and K.sub.4 may be 1.8328-3.8328.

[0072] Further, I.sub.control and the voltage U.sub.control are determined by the following steps: [0073] step A1, calculating I.sub.calibrated; where based on C.sub.effluent, I.sub.calibrated is calculated according to

[00004]$I_{\mathrm{calibrated}}=\frac{\left(C_{\mathrm{effluent}}-K_2\right)}{K_5},$ where K.sub.5 is a constant greater than 0, and K.sub.5 may be 14.746-16.746; [0074] step A2, calculating I.sub.control and U.sub.control; where based on I.sub.calibrated I.sub.control is determined according to I.sub.control=I.sub.calibrated, and then, U.sub.control is calculated according to U.sub.control=K.sub.6.Math.I.sub.control+K.sub.4, where K.sub.6 is a constant greater than 0, and K.sub.6 may be 0.5076-0.7076.

Example IV

[0075] Referring to FIG. 1 and FIG. 4, a method for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by this example is different from Example I in that: step S001 specifically includes the following steps: [0076] step S0001, setting C.sub.effluent; where a user sets a suitable effluent concentration of slightly acidic electrolyzed water C.sub.effluent in a master control unit 9 according to actual needs, where C.sub.effluent is 20-90 ppm; [0077] step S0002, carrying out initial solution addition; where the electrolyte stock solution in an electrolyte stock solution storage 1 is added to the electrolytic cell 2 by the first solution addition device 4, and when a detection liquid level of a liquid level detection unit 8 is reached, the first solution addition device 4 stops working; and the electrolyte stock solution is a dilute hydrochloric acid solution with a concentration of 6%-8%; [0078] step S0003, carrying out electrolysis by energization; where the current I.sub.control and the voltage U.sub.control are applied to the two ends of the electrolytic cell 2 by a current and voltage control unit 5, and the electrolysis is started in the electrolytic cell 2.

Example V

[0079] A method for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by this example is different from Example I in that: when the electrolytic cell is in a standby state, a current 100 mA and a voltage 1000 mV are applied into the electrolytic cell and held for 3 s at 1200 s intervals, so that after start-up, an accurate concentration of slightly acidic electrolyzed water can be reached quickly.

[0080] When the electrolytic cell 2 is in the standby state, since the electrolyte solution has not been energized for a long time, the chlorine gas dissolved in the electrolyte solution decreases slowly, and the electrolyte solution appears transparent. Therefore, very small current and voltage are maintained in the electrolytic cell at intervals, so that the concentration of the chlorine gas in the electrolyte solution is maintained but the chlorine gas is not discharged out to the mixer, and thus, the electrolyte solution appears yellowish-green. When the electrolytic cell 2 starts to prepare the slightly acidic electrolyzed water, since there is already a certain concentration of chlorine gas in the electrolyte solution, the accurate concentration of the slightly acidic electrolyzed water can be quickly reached.

Example VI

[0081] Referring to FIG. 5 and FIG. 6, a device for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by this example is different from Example I in that: the device for preparing slightly acidic electrolyzed water with a controllable and stable concentration further includes a neutralization solution storage 13, a second solution addition device 14 and a second mixer 15 sequentially connected in series. The second mixer 15 is connected in series at a rear end of the first mixer 3. The first solution addition device 4 and the second solution addition device 14 are both peristaltic metering pumps. By connecting the second mixer 15 in series to the rear end of the first mixer 3, the concentration of the slightly acidic electrolyzed water can be effectively neutralized, which is more convenient to use.

[0082] Tests have proved that the slightly acidic electrolyzed water with a controllable and stable concentration can be prepared by using any of the above examples. The results are shown in the following table:

TABLE-US-00001 C.sub.effluent L S C U.sub.calibrated I.sub.calibrated V.sub.water C.sub.final 20 2.7 14400 7.3% 3.15 0.51 1.2 21 31 2.7 14400 7.3% 3.51 1.10 1.2 33 39 2.7 14400 7.3% 3.83 1.62 1.2 42 49 2.7 14400 7.3% 4.22 2.27 1.2 51 53 2.7 14400 7.3% 4.37 2.52 1.2 53 62 2.7 14400 7.3% 4.72 3.11 1.2 61 68 2.7 14400 7.3% 4.96 3.49 1.2 68 72 2.7 14400 7.3% 5.11 3.75 1.2 72 80 2.7 14400 7.3% 5.42 4.27 1.2 80 90 2.7 14400 7.3% 5.82 4.92 1.2 91

[0083] C.sub.effluent is the concentration of the input slightly acidic electrolyzed water in ppm. L is the distance between the two electrodes in mm. S is the area of the electrode in mm.sup.2. C is the initial concentration of the hydrochloric acid in %. U.sub.calibrated is the calibrated voltage in V. I.sub.calibrated is the calibrated current in A. V.sub.water is the flow velocity of water in L/min. C.sub.final is the available chlorine concentration of the prepared slightly acidic electrolyzed water effluent in ppm.

[0084] It can be seen from the above table that the method and device for preparing slightly acidic electrolyzed water with a controllable and stable concentration provided by the disclosure can prepare slightly acidic electrolyzed water with a concentration of 20-90 ppm, which meets the national standard for slightly acidic electrolyzed water (40-80 ppm). Besides, the method and device can prepare slightly acidic electrolyzed water with a controllable and stable concentration. When the concentration of the slightly acidic electrolyzed water is stable and controllable, the slightly acidic electrolyzed water with different concentrations can be prepared according to one's own needs. The slightly acidic electrolyzed water with different concentrations has different functions, for example, washing, vegetable washing, dish washing and the like, so that the slightly acidic electrolyzed water has stronger functionality, wider application range and more application scenarios.

[0085] The disclosure provides the method and device for preparing slightly acidic electrolyzed water with a controllable and stable concentration. In the method, after the electrolyte stock solution in the electrolytic cell is electrolyzed, the concentration of the slightly acidic electrolyzed water becomes lower. Then, the solution addition velocity of the first solution addition device is adjusted based on the difference between the detected voltage and the control voltage in the electrolytic cell, so that the first solution addition device adds the electrolyte stock solution to the electrolytic cell in real time. The voltage difference is greater, the rotation speed of the first solution addition device is faster. In one aspect, the decrease of the electrolyte stock solution in the electrolytic cell is compensated, the electrolysis velocity is increased, and a larger amount of chlorine gas is generated. In another aspect, an addition velocity of the chlorine gas discharged from the electrolytic cell is increased. Therefore, the velocity of reaction between chlorine gas and water is increased from two aspects, so the concentration of the slightly acidic electrolyzed water will increase, thereby achieving the purpose of preparing the slightly acidic electrolyzed water with a controllable and stable concentration. The device is simple in structure, can prepare the slightly acidic electrolyzed water with a controllable and stable concentration through the cooperation of various components, and overcomes the defects of uncontrollable and unstable concentration and low effective power in the preparation of the present slightly acidic electrolyzed water.

[0086] The above description is only preferred implementations of the disclosure. It should be noted that those of ordinary skill in the art can also make several improvements and modifications without departing from the technical principles of the disclosure, and such improvements and modifications should also be considered as the protection scope of the disclosure.