Method and device for disinfectant production

Abstract

A method of producing disinfectants by diaphragm electrolysis of an aqueous solution of sodium chloride is disclosed. Such disinfectants are used in agriculture, public health care and medical institutions, public water supply systems and elsewhere. A method for producing disinfectants is disclosed which permits adjustment of the range of the pH value from 2.5 to 8.5 by using devices with various capacities ranging from 1 to 600 g active chlorine per hour, while decreasing the consumption of electric energy and sodium chloride for the production of 1 g of active chlorine, and reducing the consumption of fresh water for producing of waste catholyte. The disclosed method processes the concentrated aqueous solution of sodium chloride in anode and cathode compartments at a lower flow rate, using the flow of fresh water through the inner space of a tubular cathode for cooling the solution.

1 . A method for production of disinfectant, comprising following stages:
 converting an aqueous solution of sodium chloride into anolyte in an anode compartment of a diaphragm electrolyzer and into catolyte in a cathode compartment,   a flow of the solution moving in the anode and cathode compartments in one direction from bottom to top, obtaining disinfectants with a pH value in a range of 2.5 to 5.5 from the solution of sodium chloride arriving to the anode compartment immediately after a mixer of a sodium chloride concentrate and fresh water, disinfectants with a pH value in a range of 5.5 to 8.5 from the solution of sodium chloride arriving to the anode compartment after treatment in the cathode compartment;   changing the pH of disinfectant in the ranges of 2.5 to 5.5 and 5.5 to 8.5 by changing a ratio of flow rates in the anode and cathode compartments with the adjustment of a discharge of catholyte to an external environment;   discharging the disinfectant from the electrolyzer with a selected concentration of active chlorine;   wherein only the solution of sodium chloride is treated in the anode and cathode compartments, which has been prepared with a first part of the fresh water used in the production of the disinfectant, a second part of the fresh water being guided first inside the cathode compartment and then to a co-mixer of the electrolyzer, where the second part of the fresh water is mixed with the anolyte arriving from the anode compartment, resulting in a disinfectant with a concentration of active chlorine of up to 2 g/l and with a pH with a preset value in the range of 2.5 to 8.5.   
     
     
         2 . The method according to  claim 1 , wherein the flow rate of sodium chloride solution passing through the anode compartment is not less than 5 l/t per 1 dm 2  of an anode surface facing the cathode. 
     
     
         3 . The method according to  claim 1 , wherein the flow rate of sodium chloride solution passing through the cathode compartment is not less than 4 l/t. 
     
     
         4 . The method according to  claim 1 , wherein the concentration of sodium chloride in the solution passing through the anode compartment is up to 20 g/l. 
     
     
         5 . The method according to  claim 1 , wherein hydrogen is removed from the cathode compartment before the catolyte is guided to the anode compartment. 
     
     
         6 . A device for production of disinfectant, comprising:
 a cylindrical diaphragm electrolyzer with coaxially located electrodes, wherein an inner tubular hollow electrode functions as a cathode compartment and is covered on two sides with covers that contain openings for letting fresh water in and out of the cathode compartment,   wherein an external electrode functions as an anode compartment and further includes a co-mixer that has four openings; a first opening to let in fresh water, a second opening to discharge disinfectant, a third opening to remove hydrogen and catolyte and a fourth opening to discharge sodium chloride solution in the form of catolyte;   a mixing unit for mixing concentrate of sodium chloride and fresh water,   a first pipe for supplying fresh water to the mixing unit,   a tank for the concentrate of sodium chloride,   a first adjustment valve for adjustment of supplied concentrate of sodium chloride while mixing with fresh water,   a second pipe with a second adjustment valve for supplying the sodium chloride solution to an inlet of the cathode compartment of the electrolyzer,   a converter of electrical energy, wherein positive and negative poles of the converter are connected to the anode and cathode compartments, respectively;   a third pipe with a third adjustment valve to supply fresh water to the inlet of the hollow internal space of the cathode compartment,   a fourth pipe to supply fresh water from an outlet of the hollow internal space of the cathode compartment to an inlet of the co-mixer that is equipped with an injector, at an extension of the anode compartment located in the co-mixer of the electrolyzer;   fifth and sixth pipes with fourth and fifth valves, respectively, through which an inlet of the anode compartment is connected to the mixing unit of fresh water and concentrated sodium chloride, and to a lower outlet of the cathode compartment;   wherein the electrolyzer is also equipped with a thermal switch located on an external surface of the anode, and   wherein the converter of electrical energy has a protecting device for protecting a supply network against overload during switching on the device, a protecting device for protection against increase in consumed power, and a protecting device for protection against overcurrent up to a preset value.