On site portable electrolytic sodium hypochlorite generator

Abstract

The present invention describes an apparatus for the production on site of a solution of sodium hypochlorite. It is based on the electrolysis of a dilute solution of sodium chloride and operates in flow through mode. Its main use is the potabilization of drinking water. Other uses include the production of sterilizing solutions for washing, wound disinfection, etc. It can be powered by a solar photovoltaic module (PVM), and it is portable in order to be easily transported in remote areas or emergency situations where chemicals or electricity are not available. The flow through operation is based on a gas lifting mechanism, the gas being hydrogen generated during the electrolysis of the sodium chloride solution. Therefore no moving parts are employed for pumping the solution through the electrolytic cell.

1 . An apparatus for the production of sodium hypochlorite by means of the electrolysis of a diluted solution of sodium chloride in water, comprising an electrolytic cell, said electrolytic cell being composed with at least two metallic electrodes placed vertically face to face, parallel to each other, electrically insulated and supplied with a dc current, said electric cell having in its lower part a chamber where the solution to be electrolysed is fed through an inlet port, and in its upper part with a collecting chamber of the solution already electrolysed, said collecting chamber comprising an outlet port. 
     
     
         2 . Apparatus of  claim 1 , wherein said inlet is connected by means of a tube to the outlet of at least one auxiliary reservoir placed at a higher level with respect to said electrolytic cell said auxiliary reservoir being fed with the saline solution maintaining a constant level of said solution. 
     
     
         3 . Apparatus of  claim 1  wherein said outlet is connected by means of a vertical tube to the inlet of a vessel placed at a higher level with respect to said electrolytic cell, said tube protruding into said vessel up to a specified height, said vessel, used for he collection of the hypochlorite solution produced in the electrolytic cell, being open in its upper part for the release of hydrogen generated in said electrolytic cell. 
     
     
         4 . Apparatus of  claim 2  wherein at least one o said auxiliary reservoirs comprises in its upper part an aperture into which a cylindrical element for feeding the saline solution can be introduced from top down. 
     
     
         5 . Apparatus of  claim 4  wherein the upper end of said cylindrical element is part of a lid that can be screwed and unscrewed, forming a watertight connection, to the neck of at least one storage reservoir for the saline solution, said cylindrical element comprising a hole extending, coaxial to said element, from the upper end to a specified distance from other end, being open on the side of said element, through which air can pass, and another hole, parallel to said hole, extending between the two ends of said element, through which the saline solution flows out into said auxiliary reservoir. 
     
     
         6 . Apparatus of  claim 5  wherein said two holes in said cylindrical element determines the solution level inside said auxiliary reservoirs in such a manner that air enters through one hole into the main storage reservoir permitting the saline solution to flow out through the second hole into the auxiliary reservoir until the solution level reaches the bottom part of the hole through which air flows causing the interruption the air flow, and consequently the interruption of said saline solution flow into the auxiliary reservoir, therefore stabilising the liquid level. 
     
     
         7 . Apparatus of  claim 3  and  6  wherein the level of said saline solution in the auxiliary reservoir is at a level higher than the outlet of the electrolytic cell and at a level slightly lower than the upper end of said tube protruding into said vessel and connected to the electrolytic cell. 
     
     
         8 . Apparatus of  claim 3  wherein said vertical tube connected to the outlet of said electrolytic cell protrudes into said hypochlorite solution collection vessel to about three quarter of the height of said vessel, said tube being the conduit of the hypochlorite solution mixed with the hydrogen generated in the electrolytic cell, said hydrogen acting as a lift of the hypochlorite solution into said collecting vessel. 
     
     
         9 . Apparatus of  claim 8  wherein said hypochlorite collection vessel comprises an outlet on its bottom part connected to a flexible tube wherefrom the hypochlorite solution can be collected. 
     
     
         10 . Apparatus of  claim 1  wherein said metallic electrodes are made of titanium coated with noble metals oxides like ruthenium, iridium, lanthanum, titanium. 
     
     
         11 . Apparatus of  claim 1  wherein said electrodes are connected to a constant current power supply through a polarity reversal circuit controlled by a timer. 
     
     
         12 . Apparatus for the production of sodium hypochlorite as described and illustrated above.