US20130146473A1

US20130146473A1 - Dual diaphragm electrolysis cell assembly and method for generating a cleaning solution without any salt residues and simultaneously generating a sanitizing solution having a predetermined level of available free chlorine and pH

Info

Publication number: US20130146473A1
Application number: US13/324,714
Authority: US
Inventors: Ralph A. Lambert; Michael van Schaik
Original assignee: AQUAOX LLC
Current assignee: AQUAOX Inc
Priority date: 2011-12-13
Filing date: 2011-12-13
Publication date: 2013-06-13
Also published as: CA2859367A1; JP2015500402A; WO2013090560A3; WO2013090560A2; EP2791393A2

Abstract

An Electrolysis cell assembly to produce diluted Sodium Hydroxide solutions (NAOH) and diluted Hypochlorous Acid (HOCL) solutions having cleaning and sanitizing properties. The electrolysis cell consists of two insulating end pieces for a cylindrical electrolysis cell comprising at least two cylindrical electrodes with two cylindrical diaphragms arranged co-axially between them. The method of producing different volumes and concentrations of diluted NAOH solutions and diluted HOCL solutions comprises recirculating an aqueous sodium chloride or potassium chloride solution into the middle chamber of the cylindrical electrolytic cell and feeding softened filtered water into the cathode chamber and into the anode chamber of the cylindrical electrolysis cell.

Description

FIELD OF THE INVENTION

The present invention relates to a cylindrical electrolysis cell assembly for producing simultaneously a diluted Sodium Hydroxide and diluted Hypochlorous Acid solution for usage as cleaning and sanitizing solutions by electrolysis of an aqueous saline solution. The method comprising a cathode chamber, an electrolyte chamber and an anode chamber separated by two cylindrical diaphragms to prevent presence of salt residues in the cleaning and sanitizing solutions and whereas pH and free available chlorine content of the sanitizing solution can be altered.

BACKGROUND OF THE INVENTION

Electrolysis cells are used for the production of cleaning and sanitizing solutions from brine. Also, electrolysis cells are used to produce a sanitizing solution to disinfect water or other media. Many types of electrolysis cells exist for these purposes. The basic feature of these cells is two concentrically disposed cylindrical electrodes with a diaphragm separating the space between the two electrodes to define anode and cathode compartments. An electrolyte, such as brine, is passed through the anode and cathode compartments, separately or successively. When brine is electrolyzed in this way, under suitable conditions, it can produce a cleaning and sanitizing solution of high strength and long shelf life, which is ecologically and human friendly.
Typically an electrolyte solution is passed through the anode and cathode chambers separately to produce a diluted Hypochlorous Acid solution as a sanitizing solution and a diluted Sodium Hydroxide solution as a cleaning solution. Alternatively, neutral sanitizing solutions can be produced when an electrolyte is passed through the anode and cathode chambers successively.
The diaphragm is either made of a permeable ceramic or an ion-exchange membrane. The diaphragm permits the diffusion of electrolytes between the anode and cathode but retard the migration of electrolysis products at the anode and cathode from diffusing to each other reverting back to starting material or undesired side products.
Acidic sanitizing solutions are generated by passing saline through an electrolytic cell comprising an anode chamber, a cathode chamber, and a separator. The result contains free available chlorine (FAC) in the form of a mixture of oxidizing species, predominantly Hypochlorous Acid (HOCl) and sodium hypochlorite, and is characterized by its pH, FAC content, and redox level. Such reactive species have a finite life and so, while the pH of the solution will usually stay constant over time, its biocide efficacy will decrease with age. Electrolysis cells either comprise cylindrical electrodes plus one cylindrical ceramic diaphragm or electrolysis cells comprise plate electrodes plus one ion permeable sheet of membrane as separator.
Usage of insoluble ion permeable membranes or ceramic diaphragms between the electrodes have been described for more than 100 years as, for example, that described in U.S. Pat. No. 590,826. U.S. Pat. No. 914,856 describes a cell which permits the flow of electrolyte solutions separately through the anode and cathode compartments using concentric cylindrical electrodes with an ion permeable diaphragm.
The three-chamber cell has the following merits. Reductive species such as dissolved hydrogen gas produced in the cathode chamber are likely to migrate into the anode chamber through the diaphragm when utilizing a two chamber cell, such as described in U.S. Pat. No. 7,374,645, U.S. Pat. No. 7,691,249 or in U.S. Pat. No. 7,828,942. However, the middle chamber in the three-chamber cell control the diffusion of reductive species from the cathode chamber to the anode chamber and then the more strongly oxidative anode water can be obtained.
In the cell shown in FIG. 1, the following electrolysis reactions take place.

At the Anode:

2H₂O→2H⁺+O₂+2e ⁻ [1]

At the Cathode:

2H++2e ⁻→H₂ [2]
These reactions increase the oxygen concentration in the anode solution and the hydrogen concentration in the cathode solution, while leaving the essential properties of electrolytic water unchanged. Further, migration of hydrogen ions formed on the anode toward the cathode is limited, and then the electrolysis reaction [3] takes place in addition to the reaction [1] and [2]:
H₂O+2e ⁻→½H₂+OH⁻ [3]
This reaction suggests that the pH of cathode water tends to shift to the alkaline region. Hydrogen ions formed in the anode chamber in the reaction [1] remain partly in that chamber. In the two-chamber cell shown in FIG. 1 the anode solution, therefore, is likely to be charged with the hydrogen ions, while the cathode water is charged with hydroxide ions. In other words, the charged water produced using electrolysis cell shown in FIG. 1 may not be suitable for the surface cleaning such as glass, mirrors, metals or treatment of semiconductors or resins.
In order to enhance the cleaning or surface treatment efficacy, anode water is required to be more oxidative and/or acidic and cathode water is required to be more reductive and/or alkaline. However, the electrolysis cell shown in FIG. 1 is difficult to produce the effective solutions.
The three-chamber cell shown in FIG. 2 is designed to solve the problem mentioned above, where the middle chamber added between the anode chamber and the cathode chamber. Using the three-chamber cell easily electrolysis softened water.
Another merit of a three chamber cell is the fact that no electrolyte is fed into the anode and cathode chamber. Although efficiency of two chamber electrolysis cells has been significantly improved, not all electrolytes that pass the cathode chamber are conversed into Sodium Hydroxide. Likewise, not all electrolytes that pass the anode chamber are conversed into Hypochlorous Acid and/or Hypochlorite Ion.
As a result, both the cleaning and sanitizing solutions generated in a two cell electrolysis cell contain salt residues. Presence of salt in both the cleaning and sanitizing solutions limit its usage for surface treatment, as salt is corrosive, streaks the surface, and leaves deposits on the surface. As a result, most cleaning and sanitizing procedures include an extra rinse with potable water.
This invention resolves the deposits of salt and thus allows for cleaning and sanitation of surfaces without additional rinsing.

SUMMARY OF THE INVENTION

The invention is directed to a cylindrical dual diaphragm electrolysis cell assembly comprising a cathode chamber, electrolyte chamber, and an anode chamber. The present invention provides an insulating end piece for a cylindrical electrolysis cell of the type comprising at least two cylindrical electrodes arranged coaxially one within the other with two cylindrical diaphragms arranged coaxially between them.
Softened filtered water passed through the cathode chamber functions as cleaning agent for all surfaces, fabrics, textiles, and carpets. Softened filtered water passed through the anode chamber functions as sanitizing agent for all hard surfaces.
Anodic electrolysis of softened water produces hydrogen ions, where no anion is present as counter ion, unlike acidic solutions prepared by adding acid such as hydrochloric acid or sulfuric acid. The anode water produced by electrolyzing softened water exhibits that the solution is charged. Moreover, the hydrogen ion by itself is an electron acceptor and so exhibits one of oxidizing species. So, the oxidation-reduction potential of anode water tends to shift to noble side. In other words, the redox sensor indicates a plus value. During cathodic electrolysis of softened water is reduced at the cathode. This occurs because water is more easily reduced than are sodium ions. Cathodic electrolysis alters the H+/OH− balance around the cathode making the solution more basic and the oxidation reduction potential of cathode becomes negative.
When the two-chamber cell depicted in FIG. 1 is used, the cathode water is not necessarily suitable for actual cleaning or a surface treatment without rinsing the surface with distilled, RO or tap water. The anode water is not necessarily suitable for sanitizing hard surfaces without rinsing the surface afterwards with distilled, RO or tap water. So improving the electrolysis cell is very important to apply to actual use.
More specifically, the important factors for producing effective cleaning and sanitizing agents are an apparent current density (current (A)/apparent area of whole electrode (cm.sup.2), a fluid velocity along the electrode surface, and a true current density (effective current density=current (A)/true area of the electrode (cm.sup.2)). As the fluid velocity increases, the hydrogen ions and other electrolytic species produced on the electrode surface migrate faster.
Various different sanitizing solutions can be produced in the electrolysis cells of the present invention, depending on the various flow patterns through the cell. For example, the softened water can be fed to the anode and cathode chambers and the electrolyzed solutions can then be collected from each of these chambers separately. Alternatively, the softened water can be fed through both the cathode and anode chambers successively. Other factors which can be used to vary the sanitizing solution include the voltage applied to the electrodes, the electrical power absorbed, the electrode coating and physical size of the electrode, the shape of the electrodes and distances between them and the spacing and material of the membrane. The membrane material is also an important feature since it affects the mobility of ions passing between the electrodes.
An objective of the invention is to provide a cylindrical electrolytic cell than can produce diluted Sodium Hydroxide and simultaneously diluted Hypochlorous Acid whereas the pH and the free chlorine content can be adjusted.
Another objective of the invention is to disclose a method and apparatus that can prevent the presence of salt residues in cleaning and sanitizing solutions whereas pH and free available chlorine content of the sanitizing solution can be altered.
Another objective of the invention is to improve cleanliness, as the cleaning solutions produced by the electrolytic cell are effective for cleaning all surfaces by removing fine particles or the like wherefrom and sanitizing solutions produced by the electrolytic cell are effective for sanitizing all hard surfaces by oxidation of micro-organism and viruses.
Yet another objective of the invention is to produce cleaning and sanitizing solutions that are also effective for cleaning and sanitizing resins or the like, in particular resins for beverage, dairy, and even medical devices.
Yet still another objective of the invention is to produce cleaning and sanitizing solutions wherein no special chemical remains after cleaning and sanitizing.
Other objectives and further advantages and benefits associated with this invention will be apparent to those skilled in the art from the description, examples and claims which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (prior art) is a view of a two chamber cylindrical electrolysis cell as described in e.g. in U.S. Pat. No. 7,374,645, U.S. Pat. No. 7,691,249, U.S. Pat. No. 7,828,942, or in U.S. Pat. No. 8,002,955.

FIG. 2 is a view of a three chamber cylindrical electrolysis cell assembly using two diaphragms to create a middle chamber whereas electrolyte is circulated.

FIG. 3 (prior art) is a view of a typical two chamber electrolysis cell assembly cut in a plane on the center axis between the port to one electrode compartment in one end cap and the port to the other electrode compartment in the other end cap.

FIG. 4 is a view of a three chamber electrolysis cell assembly cut in a plane on the center axis between the port to one electrode compartment in one end cap and the port to the other electrode compartment in the other end cap.

FIG. 5 (prior art) is a view of a one section end piece from the side into which the tubes of a two chamber electrolysis cell would be inserted.

FIG. 6 (prior art) is a view of a one section end plug with only the inserted tubes cut in a plane of the center axis.

FIG. 7 is a view of a multiple section end piece from the side into which the tubes of a three chamber electrolysis cell would be inserted.

FIG. 8 is a view of a multiple section end piece from the top of a three chamber electrolysis cell.

FIG. 9 (prior art) is a view of typical flow patterns in a two chamber electrolysis cell.

FIG. 10 is a view of typical flow patterns in a three chamber electrolysis cell.

FIG. 11 (prior art) is a view of alternative flow patterns in a two chamber electrolysis cell.

FIG. 12 is a view of alternative flow patterns in a three chamber electrolysis cell.

FIG. 13 is a view of the brine reservoir and peristaltic pump to circulate the electrolyte.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to the construction of an optimized cylindrical electrolysis cell that produces a cleaning solution and simultaneously a sanitizing solution. The diluted Sodium Hydroxide solution is more alkaline, contains no salt residues and, therefore, the solutions can be used to clean any surface without rinsing the surface afterwards with distilled, RO water or tap water. The diluted Hypochlorous Acid solution contains no salt residues and its free available chlorine content as well as pH can be adjusted. As a result, surfaces can be effectively sanitized using a sanitizing solution which pH and free available chlorine is ‘tailored’ to sanitize a certain surface taking into account chlorine consumption and in line with various sanitizing procedures as set by regulatory agencies such as the FDA, EPA, USDA and CDC. Certain surfaces require a more acidic sanitizer whereas other surfaces are damaged by the acid nature of the sanitizer. In these cases, a more neutral pH Hypochlorous Acid is preferred. Also, the absence of salt residues allows the use of the sanitizing solution on any surface without rinsing the surface with distilled, RO or tap water.
The three chamber electrolysis cell is illustrated in FIG. 2 and FIG. 4, where a cylindrical electrode [1] is positioned within a cylindrical diaphragm [2] which is positioned within a second cylindrical diaphragm [3], where the cylindrical diaphragm [3] is positioned within a second cylindrical electrode [4] by the use of two end pieces [99] which consist of a tube cap [6], port A cap [7], port B cap [8] and port C cap [9].
The design of the four sections of the end piece [99] permits the orientation and sealing of the entire assembly [100]. Tube cap [6] seals the outer electrode [4] with the end piece [99] using an O-ring [12]. The tube cap [6] is either glued or screwed on the outer electrode [4]. In case the tube cap [6] is screwed on the outer electrode [4], the outer electrode tube-ends have a male thread that fits a female thread manufactured in the tube cap [6].
Port A cap [7] features port A for direction of the flow of softened water through port A ending in fittings [17] into the chamber A defined by the spaces between the anode [4] and the diaphragm [3] and out of chamber A through port A ending in fittings [17] of the opposite port A cap [6].
Port B cap [8] features port B for direction of the flow of saturated brine through port B ending in fittings [17] into chamber B defined by the spaces between the diaphragm [2] and diaphragm [3] and out of chamber B through port B ending in fittings [17] of the opposite port B cap [8].
Port C cap [9] features port C for direction of the flow of softened water through port C ending in fittings [17] into chamber C defined by the spaces between the inner electrode [1] and the diaphragm [2] and out of chamber C through port C ending in fittings [17] of the opposite port C cap [9].
The four sections of end piece [99] are either glued on each other or compressed on each other using O-rings [13] to seal the section on each other.
The tube cap [6] is either glued or screwed on the outer electrode [4]. Port A cap [7] is either glued or pressed on the tube cap [6] whereas the tube cap [6] facilitated a groove for an O-ring [13] and whereas port A cap [7] is pressed on the tube cap [6]. Port B cap [8] is either glued or pressed on port A cap [7] whereas the port A cap [7] facilitated a groove for an O-ring [13] and whereas the Port B cap [8] is pressed on port A cap [7]. Port C cap [8] is either glued or pressed on port B cap [7] whereas port B cap [7] facilitated a groove for an O-ring [13] and whereas port C cap [8] is pressed on port B cap [7].
The tube cap [6], port A cap [7], port B cap [8] and port C cap [8] are bolted together using three stainless steel bolts [18], washers [19] and nuts [20]. In each section of the end piece [99], there are three holes [21] to facilitate the stainless steel bolts [18], washers [19] and nuts [20]. The seal between each section of the end piece [99] is achieved by compressing the sections of the end piece [99] onto each other, in a manner such that the compressive force can be applied slowly and smoothly without the introduction of torque such that a reliable seal is produced without damaging the ceramic diaphragms [2] and [3].
Either of the electrodes [1] and [4] can act as the anode with the other acting as the cathode. The choice can be made by considerations of the ease of manufacture or requirements of the nature of the electrolysis process to be performed which can favor the anode or cathode chamber preferentially being the outer chamber. These considerations include the desired spacing between the electrodes and the diaphragms, the desired space between diaphragm [2] and [3] and the relative volume requirements for the balance of flows of the electrolyte solution in chamber B and the softened water in chamber A and chamber C.
The inner electrode [1] and outer electrode [4] tubes are constructed of an electrically conductive material, preferably titanium.
The metal electrode tubes are coated with a mixed metal oxide on the face of the tube directed toward the diaphragms [2] and [3]. The metals of the two electrodes can be titanium or stainless steel. Both metals can be coated with a mixed metal oxide. The cathode can be an uncoated metal, but the anode has to be a mixed metal oxide coated metal. A preferred arrangement has the outside electrode tube [4] as the anode internally coated with a mixed metal oxide and the inner electrode tube [1] as the cathode and not coated.
The outer electrode [4] is shown in FIG. 2 with an electrical connector [10] welded to the outside of the outer electrode [4] tube. The inner electrode [1] has an electrical connector [11] on its end that is part of the inner electrode [1] and extends out of the outside of the upper end piece [99]. Although not necessary for the function of the assembly, the outside of the outer electrode [4] is insulated by a rubber sleeve [5] that is heat-shrinked over the outer electrode [4] and cut to length. Another option is to glue an insulating sheath [5] or tube on the outside of the outer electrode [4].
The anode and cathode are separated by two diaphragms [2] and [3]. Preferably, these diaphragms are made of alumina, zirconium containing ceramic. The thickness of the diaphragm can vary over a broad range depending on the application the electrolysis cell assembly [100] is to be used, the diaphragms [2] and [3] are relatively fragile and a wall thickness of 1.5 to 2 mm is preferred for most applications.
The relative diameter of the outer electrode [4], inner electrode [1], diaphragms [2] and [3] can vary within the single requirement that outer electrode [4] must be of greater diameter than diaphragm [3], the diameter of diaphragm [3] greater than diaphragm [2] and the diameter of diaphragm [3] greater than the inner electrode tube [4]. The actual diameters can vary depending upon the desired features of the electrolysis cell assembly [100]. To this end the diameters can be varied to optimize the rate of electrolysis, rate of flow through the cell assembly, and other needs of the system to which the assembly will be used. Likewise, the relative length of the electrodes [1] and [4] and diaphragms [2] and [3] can vary within the single requirement of this embodiment that the outer electrode tube [4] must be shorter than diaphragm [3], diaphragm [3] shorter than diaphragm [2] and diaphragm [2] shorter than inner electrode [1]. The lengths of the electrodes [1] and [4] and the length of the diaphragms [2] and [3] can be determined by factors such as ease of construction and geometries to optimize the performance of the electrolysis cell assembly in the system in which it is to perform.
The upper and lower end pieces [99] are interchangeable and constructed of an insulating material, preferably Polyvinyl Chloride. Each end piece [99] consist of four sections, the tube cap [6], Port A cap [7], Port B cap [8] and port C cap [9].
The four sections of the end piece [99] can be formed by molding or machining. Ports [17] are for introduction or exit of softened water to chamber A and to chamber C. Port [17] is for the introduction and exit of electrolyte to chamber B. All sections of the end piece [99] consist of three or more holes to accept three or more stainless steel bolts [18], washers [19] and nuts [20] by which the four sections of the end piece [99] are compressed together.
Three sections [6], [7] and [9] of the end piece [99] have a groove to facilitate O-ring [13] to form the seals between the end piece sections. When the tube cap [6] is screwed on the outer electrode [4] and stainless steel bolts [18], washers [19] and nuts [20] are used, then the three bolts provide the structural integrity of the assembly [100]. If the tube cap [6] is glued on the outer electrode [4], then the three sections of the end piece [99] are also glued together.
Two holes [22] with female thread are made in the tube cap [6] at both opposite sides. This allows mounting the assembly [100] on a plate or bracket. This plate or bracket may be a plastic or stainless steel as long as the metal is insulated from one or both of the electrodes. A preferred fabrication of a mounting plate or bracket is a machined sheet of Polyvinyl Chloride, which is commercially available as PVC.
One critical feature of the end piece [99] is that the inside diameter of all sections of the end piece [99] closely match the outside diameters of the four tubes [1], [2], [3] and [4] so that when using glue as a sealant, a good seal can be achieved. When screwing the tube cap [6] on the outer electrode [4] and when the other sections of the end piece [99] are compressed on each other, it is important that the O-rings [12], [14], [15] and [16] form a good seal between the tubes [1], [2], [3] and [4] and the four end caps [6], [7], [8] and [9] as well form a good seal between the four sections themselves using O-ring [13]. The relatively fragile diaphragms [2] and [3] require the use of O-rings [14] and [15] to form the seal such that whilst assembling, the diaphragms do not break. It is necessary that, upon assembly, the length of the cell assembly [100] is defined by the length imposed by the outer electrode tube [4]. The diaphragms [2] and [3] must be long enough to seal at both ends by O-rings [14] and [15] even if one end of the diaphragms [2] and [3] is resting on Port B cap [8] and Port C cap [9].
A second critical feature of the end caps [99] is the presence of three ports. Port A begins at fitting [17] on an outside surface of Port A [7] permits the flow of softened water through chamber A defined by the inside of the outer electrode tube [4] and the outside of diaphragm [3] as illustrated in FIG. 2 and FIG. 4. Port C begins at fitting [17] on an outside surface of Port C cap [9] and permits the flow of softened water through chamber C defined by the inside of diaphragm [2] and the outside of inner electrode [1] as illustrated in FIG. 2 and FIG. 4. Port B begins at the fitting [17] on an outside surface of port B cap [8] and permits the flow of an electrolyte solution through chamber B defined by the inside of diaphragm [3] and the outside diaphragm [2], as illustrated in FIG. 2 and FIG. 3. The outside of port A, port B and port C is a fitting [17] which accepts a tube for introduction or exit of a fluid to the cell assembly [100].
These fittings [17] can be a compression fitting, as is illustrated in FIG. 2 and FIG. 4, or it can be a hose barb or some other coupling which is appropriate for the system within which the electrolysis cell assembly [100] is to function. The orientation of the portsis necessarily to promote a tight spiral flow around the inner electrode tube [1], diaphragm [2] and [3] between the spaces in chamber A, chamber B and chamber C.
The end pieces [99] can have other configurations as long as the configuration permits for the sealing of the assembly where the compressive force is imposed upon the outer electrode [4] and no significant compressive force is imposed on the diaphragms [2] and [3]. The different types of end pieces [99] can be combined in any combination as long as the appropriate lengths of tubing are chosen and as long as the sections of the end piece [99] can be sealed together by compression or by using glue. While the preferred end piece [99] has been illustrated and described, it will be clear that the invention is not so limited. Modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as described in the claims.
Another critical feature of this invention is the construction of the brine reservoir [98] and the usage of a pump [23] to circulate an electrolyte from the brine reservoir [98] through chamber B to the brine reservoir [98] as shown in FIG. 13. The brine reservoir [98] is preferably manufactured from a transparent plastic tube [24] and two end pieces [25] and [26] made of Polyvinyl Chloride, which is commercially available as PVC. The transparent tube [24] is glued between end piece [25] and end piece [26]. End piece [25] has a male thread that allows screwing a cap [27] on top of end piece [25]. End piece [25] has also a port [28] whereas through fitting [17] a tube can be connected for the exit of the electrolyte to chamber B. End piece [26] has a port [29] on the bottom of end piece [26] whereas through fitting [17] a tube can be connected for the inlet of softened water. End piece [26] has another port [30] on the bottom of end piece [26] with valve [31]. Opening valve [31] allows drainage of the electrolyte from the brine reservoir [98]. Ports [29] and [30] have been constructed in such a way that the aperture of ports [29] and [30] is located above the brine fill line. This feature is important for two reasons. Firstly, when granular salt is added to the brine container [98] by opening cap [26], no salt can enter into ports [29] and [30] as the apertures are located at the side of these elevated ports [29] and [30]. Secondly, when opening valve [31], only the electrolyte is drained and the brine reservoir [98] remains filled with granular salt that is collected at the bottom of the brine reservoir [98] on top of end piece [26]. End piece [26] has a third port [32] on the bottom of end piece [26] whereas through a fitting [17] a tube can be connected for the inlet of electrolyte from the pump [23]. Port [32] has been constructed in such a way that the aperture of port [31] is located under the brine fill line. This feature is important for two reasons. Firstly, when granular salt is added to the brine container [98] by opening cap [27], no salt can enter into port [31] as the inlet is located at the side of the port [31]. Secondly, the electrolyte from the pump is circulated through a brine layer that saturates the electrolyte. The electrolyte is circulated through pump [23] which is preferably a peristaltic pump with a variable pump-speed and which has two fittings [17] to connect a tube from the brine reservoir [98] to the pump [23] and from the pump [23] to the cell assembly [100]. The brine concentration can be adjusted by adding granular salt and softened water into the brine reservoir [98]. The electrolyte is preferably made by adding granular sodium chloride into the brine reservoir [98] by opening cap [27]. Besides granular sodium chloride, granular potassium chloride can be used. The electrolyte is preferably a saturated aqueous brine solution. Saturation of the electrolyte is ensured by circulating the electrolyte through the brine reservoir [98] that is filled with a certain minimum amount of brine. The electrolyte is circulated from the bottom of the brine reservoir [98] through a layer of salt that is at the bottom of the brine reservoir [98].
This three chamber cylindrical electrolysis cell can be used with different flow patterns allowing changing the volume of the cleaning and sanitizing solution, as well the pH and free available chlorine content. A typical flow pattern permits approximately 30 to 70% of the softened water to pass the anode chamber and approximately 70 to 30% of the softened water to pass the cathode chamber. The volume of softened water that passes the anode chamber or cathode chamber can be restricted by closing a valve which is mounted in the outlet tube of the anode chamber and the volume of softened water that passes the cathode chamber can be restricted by closing a valve that is mounted in the outlet tube of the cathode chamber. An alternative flow pattern is a flow pattern whereas 100% of the softened water is passed through either the cathode chamber or anode chamber. Approximately 70 to 100% of the electrolyzed solution that either exits the cathode chamber or anode chamber is re-directed to the inlet of either the anode chamber or the cathode chamber whereas 0 to 30% of the electrolyzed liquid is collected in a Sodium Hydroxide storage container or drained as useful by-product. This alternative flow pattern whereas 70 to 100% of the electrolyzed solution is collected in a Hypochlorous Acid storage container is preferred when there is no or little usage of the by-product and whereas the volume of the main-product is maximized. A preferred alternative flow pattern is to pass softened water first through the cathode chamber, wherein the outlet tube is a tee mounted to allow approximately 20% of the diluted sodium hydroxide to flow to a storage tank and where approximately 80% of the diluted sodium hydroxide is re-entered in the anode chamber. The result of this preferred alternative flow pattern is that approximately 80% of the softened water has undergone cathodic electrolysis followed by anodic electrolysis to generate a neutral pH sanitizing solution. Re-entering more diluted Sodium Hydroxide into the anode chamber will increase the pH of the diluted Hypochlorous Acid and re-entering less diluted Sodium Hydroxide will reduce the pH of the diluted Hypochlorous Acid. The volume of the diluted Sodium Hydroxide that enters the anode chamber is regulated by a valve that is mounted in the outlet tube of the cathode chamber between the tee and the Sodium Hydroxide storage container.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims

We claim:

1. A method of making electrolyzed liquids utilizing an electrolysis cell comprising an outer cylindrical electrode separated from an inner cylindrical electrode by two cylindrical diaphragms arranged coaxially one within the other to create a cathode chamber, a middle chamber and an anode chamber; providing a pair of end pieces where the space between the inner tubular electrode and the membrane and the space between the membrane and the outer tubular electrode defines anode and cathode chambers; where the space between the diaphragms defines the electrolyte chamber and where one of the electrodes functions as an anode and the other electrode functions as a cathode; providing a saturated brine solution to the middle chamber of the electrolysis cell and providing softened water to the anode and cathode chamber applying a current across the electrodes, wherein each end piece provides a sealing engagement between the four sections of the end piece and each of the cylindrical electrodes and the two cylindrical diaphragms, wherein the end piece has 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, wherein said first pair of ports at opposite ends of said assembly internally addresses a space between said outer electrode tube and said outer diaphragm and said second pair of ports at opposite ends of said assembly internally addresses a space between said outer diaphragm and said inner diaphragm and said third pair of ports at opposite ends of said assembly internally addresses a space between said inner electrode tube and said inner diaphragm.

2. The method of claim 1, wherein the two diaphragms are a cylindrical ceramic membrane or a cylindrical polymer ion exchange membrane.

3. The method according to claim 1, wherein the anode and cathode, or both, comprise a titanium base activated with a mixed metal oxide coating structure comprising ruthenium, iridium, titanium, tantalum, rhodium and mixtures thereof.

4. The assembly of claim 1, wherein said end piece comprises four stackable sections of complimentary topography with at least one seal forming feature at every interface between adjacent sections wherein said seal forming feature is a sealant or compressible ridge, a gasket, or an O-ring.

5. The assembly of claim 4, wherein the end pieces comprise Polyvinyl Chloride (PVC), said gaskets and O-rings comprised of Ethylene Propylene (EPDM), Nitrile (BUNA-N), Fluorocarbon (FKM any) or combination of a plastic and a rubber.

6. The method of claim 1, wherein an electrolyte is circulated through the middle chamber is a sodium chloride solution or a potassium chloride solution.

7. The method of claim 1, where the electrolyte is saturated by circulating the electrolyte through an intermediate chamber lined with sodium chloride or potassium chloride and where the intermediate chamber can be opened to fill the reservoir with granular sodium chloride or granular potassium chloride and whereas the intermediate chamber is an external brine reservoir and not part of the cylindrical electrolysis cell.

8. The method of claim 7, whereas the electrolyte is circulated between the middle chamber and the brine reservoir using a variable speed peristaltic pump and where said pump being in communication with the reservoir through a main feed line made from a flexible and resilient material and to the middle chamber.

9. The method of claim 7, whereas the intermediate chamber is pressurized with softened water and whereas the electrolyte in intermediate chamber can be drained by opening a valve.

10. The method of claim 1, wherein the liquid is brine and the method further comprises, isolating an alkaline cleaning liquid having a negative redox potential ranging from 600 to 1200 mV.

11. The method of claim 1, wherein the liquid is brine and the method further comprises, isolating an acidic sanitizing solution having a positive redox potential ranging from 600 to 1200 mV.

12. The method of claim 1, wherein a portion of the liquid exiting the cathode chamber is fed into the anode chamber and another portion collected in a storage tank or drained.

13. The method of claim 1, wherein a part of the diluted Sodium Hydroxide solution (NAOH) is fed successively through the anode chamber to produce a more neutral pH Hypochlorous Acid solution (HOCL).

14. The method of claim 13, wherein the pH of the sanitizing solution is regulated by re-directing a volume of Sodium Hydroxide (NAOH) through the anode chamber.

15. The method of claim 1, wherein softened water is supplied to both the anode chamber and cathode 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.

16. The method of claim 1, wherein a spiral feed of the softened water is fed to the anode and cathode chamber using tangential inlet and outlet ports and a spiral fed of electrolyte is fed into the middle chamber using tangential inlet and outlet ports.

17. The method of claim 1, wherein the current is a direct current is applied across the electrodes.

18. The method of claim 1, wherein the free available chlorine content is regulated by altering the voltage, volume of softened water through the anode chamber and cathode chamber, brine concentration and whereas the current across the electrodes is at least 20 amps.

19. The assembly of claim 1, wherein the cathode 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 cathode chamber through an aperture and wherein the anode 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 cathode chamber through an aperture

20. The assembly of claim 19, 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.

21. The assembly of claim 1, wherein the cathode chamber comprises an outlet fitting connected to an tube that passes tangentially through a specific section of the upper end piece to communicate with the cathode chamber through an aperture and wherein the anode 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 cathode chamber through an aperture.

22. The assembly of claim 21, wherein a specific section of the upper end piece comprises an outlet fitting connected to a pipe that passes through a specific section of the upper end piece to communicate with the middle chamber through an aperture.

23. The assembly of claim 1, wherein said ports address said spaces through said end pieces or through said electrode tubes adjacent to the site of insertion of said electrode tubes into said end pieces.

24. The assembly of claim 1, wherein said entrance ports direct the flow of said fluid at an angle of 0 to 15 degrees relative to the plane of said seats of said end pieces.

25. The method of claim 1, where the generated diluted Sodium Hydroxide as cleaning solution is suitable for cleaning all surfaces, including textiles, fabrics and carpets.

26. The method of claim 1, where the generated diluted Hypochlorous Acid as sanitizing solution is suitable for sanitizing all hard surfaces including glass, mirrors, plastics, wood, ceramic, granite, metals and laminate.

27. The method of claim 1, where the generated cleaning and sanitizing solution contains no salt residues due to the fact that the electrolyte is circulated in the middle chamber and no electrolyte is fed into the cathode chamber and no electrolyte is fed into the anode chamber.

28. The method of claim 27, wherein the absence of salt residue means that no residue will appear on surfaces including fabrics that are cleaned and sanitized with the generated diluted Sodium Hydroxide and diluted Hypochlorous Acid solutions.