Mesh electrode electrolysis apparatus and method for generating a sanitizing solution

Abstract

The present invention is an apparatus and method of employing an electrolysis cell assembly for producing simultaneously various diluted Hypochlorous Acid solutions and simultaneously a diluted Sodium Hydroxide solution for usage as cleaning and sanitation by electrolysis of an aqueous saline solution. The apparatus comprising a cylindrical three chamber electrolysis cell consisting of an inner chamber, a middle chamber and an outer chamber having two middle mesh-electrodes in the middle chamber wherein ion-selective exchange membranes are sealed around or on the inside of the middle mesh-electrodes to separate the middle chamber from the inner and outer chamber. The method allows production of different concentrations of Sodium Hydroxide and Hypochlorous Acid solutions isolating a Sodium Hydroxide solution having a negative redox potential ranging from −600 to −1200 mV and isolating a diluted Hypochlorous Acid solution having a positive redox potential ranging from +700 to +1200 mV.

We claim: 
     
         1 . An apparatus for generating a stabilized sanitizing solution comprising:
 an outer cylindrical electrode tube separated from two middle cylindrical mesh-electrodes by an outer cylindrical ion-selective exchange membrane; an inner cylindrical electrode tube separated from said two middle mesh-electrodes by an inner cylindrical ion-selective exchange membrane, said two middle cylindrical mesh-electrodes separated from the inner and outer electrode tubes by two ion-selective exchange membranes arranged coaxially one within the other to create an middle chamber having two mesh-electrodes; an inner chamber with an inner electrode tube and an outer chamber with an outer electrode tube; a pair of end pieces where a space between the inner cylindrical electrode-tube and the inner cylindrical ion-selective exchange membrane and a space between the outer cylindrical ion-selective exchange membrane and the outer electrode tube defines anode and cathode chambers, a space between said two ion-selective exchange membranes defines cathode or anode chambers and said two middle mesh-electrode functions as a cathode or anode and the inner and outer electrode tubes function as a anode or cathode; one of said end pieces having a lateral inlet through an outer wall thereof, said inlet being provided with a fitting for tangential feeding of the liquid to the inside of the end piece, and three pairs of ports for entrance or exit of fluid are situated in the upper and lower end piece each comprising an external fitting for attachment of a hose or pipe; wherein said first pair of ports at opposite ends of said assembly internally addresses a space between said outer electrode tube and said outer ion-selective membrane and said second pair of ports at opposite ends of said assembly internally addresses a space between said outer ion-selective membrane and said inner ion-selective membrane and said third pair of ports at opposite ends of said assembly internally addresses a space between said inner electrode tube and said inner ion-selective membrane, whereby a diluted brine solution is passed through the middle chamber of the electrolysis cell and distributing the electrolysis product of the middle chamber separately or successively to both the inner and outer chamber of the electrolysis cell.   
     
     
         2 . The apparatus according to  claim 1  wherein said outer mesh-electrode is constructed from titanium wire screen securable to an inside surface of said outer electrode tube, said outer electrode tube constructed from titanium to form a screen along the inside of the outer electrode tube, wherein the screen and the electrode tube may be coated with a mixed metal oxide coating for use as an anode. 
     
     
         3 . The apparatus according to  claim 1  wherein said an inner mesh-electrode is constructed from titanium wire screen securable to an outside surface of said inner electrode tube, said inner electrode tube constructed from titanium for form a screen along the outside of the inner electrode tube, wherein the screen and the electrode tube may be coated with a mixed metal oxide coating for use as an anode. 
     
     
         4 . The apparatus of  claim 1  wherein the two middle mesh-electrodes is constructed from titanium wire screen placed in a cylindrical shape, said middle mesh electrodes having a titanium bushing securable thereto, wherein the two cylindrical mesh-electrodes and bushings are coated with a mixed metal oxide for use as an anode. 
     
     
         5 . The apparatus according to  claim 1  wherein the anode and cathode, or both, comprise a titanium base activated with a mixed metal oxide coating structure consisting of a mixture of ruthenium, iridium, titanium, tantalum and rhodium. 
     
     
         6 . The apparatus according to  claim 1  wherein a connector is secured to an outside surface of the outer electrode tube for use in applying voltage on the outer electrode tube and on the outer mesh-electrode tacked on the inside of the outer electrode tube. 
     
     
         7 . The apparatus according to  claim 1  wherein a connector is secured to one of the tube edges of the inner electrode allowing for the application of voltage to the inner electrode tube and the inner mesh-electrode on the outside of the inner electrode tube. 
     
     
         8 . The apparatus according to  claim 1  wherein connector-bolts are threaded to the end piece of the electrolysis cell, said connector bolts having a length to make contact with a titanium bushing placed over the tube-ends of the mesh-electrodes whereby the connector-bolts make contact with the bushing on one tube-end of each middle mesh-electrode to apply a voltage on both middle mesh-electrodes. 
     
     
         9 . The apparatus according to  claim 1  wherein the middle mesh-electrodes function as a cathode and the inner and outer electrode-tubes functions as an anode. 
     
     
         10 . The apparatus according to  claim 1  wherein the middle mesh-electrodes function as an anode and the inner and outer electrode-tubes function as a cathode. 
     
     
         11 . The apparatus according to  claim 1  wherein the ion-selective membranes are construed from a polymer or a perfluorinated sheet and the inner ion-selective membrane is sealed inside the inner mesh-electrode and the outer ion-selective membrane is sealed around the outer mesh-electrode. 
     
     
         12 . The apparatus according to  claim 1  wherein said end piece is further defined as four stackable sections having complimentary topography with at least one seal between adjacent sections 
     
     
         13 . The apparatus according to  claim 1  wherein the end pieces are formed from Polyvinyl Chloride (PVC). 
     
     
         14 . The apparatus according to  claim 1  wherein the outer chamber comprises an inlet fitting connected to a tube that passes tangentially through a specific section of the lower end piece to communicate with the outer chamber through an aperture and wherein the inner chamber comprises an inlet fitting connected to a tube that passes tangentially through a specific section of the lower end piece to communicate with the inner chamber through an aperture and wherein a specific section of the lower end piece comprises an inlet fitting connected to a pipe that passes through the specific section of the lower end piece to communicate with the middle chamber through an aperture. 
     
     
         15 . The apparatus according to  claim 1  wherein the outer chamber comprises an outlet fitting connected to a tube that passes tangentially through a specific section of the upper end piece to communicate with the outer chamber through an aperture and wherein the inner chamber comprises an outlet fitting connected to a tube that passes tangentially through a specific section of the upper end piece to communicate with the inner chamber through an aperture and wherein a specific section of the upper end piece comprises an outlet fitting connected to a pipe that passes through the specific section of the upper end piece to communicate with the middle chamber through an aperture. 
     
     
         16 . The apparatus according to  claim 1  wherein ports address spaces through said end pieces or through said electrode tubes adjacent to the site of insertion of said electrode tubes into said end pieces. 
     
     
         17 . The apparatus according to  claim 1  wherein entrance ports direct fluid flow at an angle between 0 to 15 degrees relative to the plane of the seats of the end pieces. 
     
     
         18 . A method of generating a stabilized sanitizing solution comprising the steps of:
 preparing a diluted brine solution;   injecting a liquid through a three chamber cylindrical electrolysis cell in a predetermined flow pattern;   venting gases from said chambers;   isolating of a Sodium Hydroxide solution having a negative redox potential ranging from −600 to −1200 mV; and   isolating of a diluted Hypochlorous Acid solution having a positive redox potential ranging from +700 to +1200 mV.   
     
     
         19 . The method according to  claim 18  including the step of modifying the flow pattern to said chambers to change pH, free available chlorine content, redox-potential, osmolorarity and conductivity of the diluted Sodium Hydroxide solution. 
     
     
         20 . The method according to  claim 18  including the step of modifying the flow pattern to said chambers to change pH, free available chlorine content, redox-potential, osmolorarity and conductivity of the diluted Hypochlorous Acid solution. 
     
     
         21 . The method according to  claim 18  wherein said three chamber cylindrical electrolysis cell is further defined as a mesh based electrode electrolysis apparatus comprising an outer cylindrical electrode tube separated from two middle cylindrical mesh-electrodes by an outer cylindrical ion-selective exchange membrane; an inner cylindrical electrode tube separated from said two middle mesh-electrodes by an inner cylindrical ion-selective exchange membrane, said two middle cylindrical mesh-electrodes separated from the inner and outer electrode tubes by two ion-selective exchange membranes arranged coaxially one within the other to create an middle chamber having two mesh-electrodes; an inner chamber with an inner electrode tube and an outer chamber with an outer electrode tube; a pair of end pieces where a space between the inner cylindrical electrode-tube and the inner cylindrical ion-selective exchange membrane and a space between the outer cylindrical ion-selective exchange membrane and the outer electrode tube defines anode and cathode chambers, a space between said two ion-selective exchange membranes defines cathode or anode chambers and said two middle mesh-electrode functions as a cathode or anode and the inner and outer electrode tubes function as a anode or cathode; one of said end pieces having a lateral inlet through an outer wall thereof, said inlet being provided with a fitting for tangential feeding of the liquid to the inside of the end piece, and wherein three pairs of ports for entrance or exit of fluid are situated in the upper and lower end piece, each comprising an external fitting for attachment of a hose or pipe, said first pair of ports at opposite ends of said assembly internally addresses a space between said outer electrode tube and said outer ion-selective membrane and said second pair of ports at opposite ends of said assembly internally addresses a space between said outer ion-selective membrane and said inner ion-selective membrane and said third pair of ports at opposite ends of said assembly internally addresses a space between said inner electrode tube and said inner ion-selective membrane. 
     
     
         22 . The method according to  claim 21  wherein a diluted brine solution passes through the middle chamber and wherein the electrolysis product of the middle chamber is partly or in total separately or successively re-distributed to the inner and outer chamber of the cylindrical electrolysis cell. 
     
     
         23 . The method according to  claim 21  wherein the middle chamber functions preferably as cathode chamber and wherein the inner and outer chambers preferably function as anode chambers. 
     
     
         24 . The method according to  claim 21 , wherein the two middle mesh-electrodes preferably function as cathode and the inner and outer electrode tubes preferably function as anode. 
     
     
         25 . The method of  claim 18 , wherein the liquid is brine and the method further comprises, isolating a Sodium Hydroxide solution having a negative redox potential ranging from −600 to −1200 mV. 
     
     
         26 . The method of  claim 18 , wherein the liquid is brine and the method further comprises, isolating a diluted Hypochlorous Acid solution having a positive redox potential ranging from +700 to +1200 mV. 
     
     
         27 . The method of  claim 18 , wherein a portion of the liquid exiting the middle chamber is fed into the inner and outer chambers and another portion collected in a storage tank or drained. 
     
     
         28 . The method of  claim 18 , wherein a part of the diluted Sodium Hydroxide solution (NAOH) is fed separately or successively through the anode chambers to produce a more neutral pH Hypochlorous Acid solution (HOCL). 
     
     
         29 . The method of  claim 18 , wherein the pH of the sanitizing solution is regulated by re-directing a volume of Sodium Hydroxide (NAOH) exiting the cathode chamber through the anode chambers. 
     
     
         30 . The method of  claim 21 , wherein the electrolysis product of the middle chamber is supplied separately or successively to the inner chamber and outer chamber at a lower end piece of the electrolysis cell and cleaning solutions (NAOH) and sanitizing solutions (HOCL) are obtained from an upper end piece of the cell. 
     
     
         31 . The method of  claim 21 , wherein a spiral feed of a diluted brine solution is fed to the middle chamber and the electrolysis product of the middle chamber fed into the inner chamber and outer chamber using tangential inlet and outlet ports. 
     
     
         32 . The method of  claim 21 , wherein the current is a direct current is applied across the anodes and cathodes and wherein the middle mesh-electrodes are wired together and wherein the outer electrode-tube and inner electrode-tube are wired together and a voltage is applied across the two middle-mesh electrodes and the inner electrode tube plus outer electrode tubes. 
     
     
         33 . The method of  claim 21 , wherein pH, the free available chlorine content, conductivity and osmolality is regulated by altering the voltage, volume of the dilute brine solution passing through the middle, inner and outer chamber, brine concentration and whereas the current across the electrodes is at least 20 amps.