Method and apparatus for generating, applying and neutralizing an electrochemically activated liquid

FIELD OF THE DISCLOSURE

0001The present disclosure relates to cleaning and/or sanitizing systems, and more particularly but not limited to systems that generate a working liquid having cleaning and/or sanitizing properties.

BACKGROUND OF THE DISCLOSURE

0002A wide variety of systems are in use today for cleaning or disinfecting residential, industrial, commercial, hospital, food processing, and restaurant facilities, such as surfaces and other substrates, and for cleaning or disinfecting various items, such as food products or other articles.

0003For example, hard floor surface scrubbing machines are widely used to clean the floors of industrial and commercial buildings. They range in size from a small model, which is controlled by an operator walking behind it, to a large model, which is controlled by an operator riding on the machine. Such machines in general are wheeled vehicles with suitable operator controls. Their bodies contain power and drive elements, a solution tank to hold a cleaning liquid, and a recovery tank to hold soiled solution recovered from the floor being scrubbed. A scrub head, which contains one or more scrubbing brushes and associated drive elements are attached to the vehicle and may be located in front of, under or behind it. A solution distribution system dispenses cleaning liquid from the solution tank to the floor in the vicinity of the scrubbing brush or brushes.

0004Soft floor cleaning machines can be implemented as small mobile machines that are handled by an operator or can be implemented in a truck-mounted system having a cleaning wand connected to the truck. The truck carries a cleaning liquid solution tank, a wastewater recovery tank and a powerful vacuum extractor.

0005Typical cleaning liquids used in hard and soft floor cleaning systems include water and a chemically based detergent. The detergent typically includes a solvent, a builder, and a surfactant. While these detergents increase cleaning effectiveness for a variety of different soil types, such as dirt and oils, these detergents also have a tendency to leave unwanted residue on the cleaned surface. Such residue can adversely affect the appearance of the surface and the tendency of the surface to re-soil and, depending on the detergent, can potentially cause adverse health or environment effects. Similar disadvantages apply to cleaning systems for other types of surfaces and items.

0006<patcit id="pcit0001" dnum="US2004112763A"><text>US 2004/112763</text></patcit> relates to a method for treating the surface of a processed copper article such as a patterned copper electrode in a printed-wiring board, by using an electrolyzed acidic water. In particular, electrolyzed acidic water and electrolyzed alkaline water are stored in separate tanks, wherein the treatment with the stored electrolyzed acidic water and a treatment with the stored electrolyzed alkaline water or a washing treatment with water is carried out sequentially after the treatment with the electrolyzed acidic water.

0007<patcit id="pcit0002" dnum="US20020023847A"><text>US 2002/0023847</text></patcit> relates to a system for cleansing using an alkaline solution formed in an electrolysis chamber. An anode section of the electrolysis chamber produces an acidic solution containing acidic water and HOCl, which as antibacterial properties. A cathode section of the electrolysis chamber produces an alkaline solution containing alkaline water and NaOH, which has reducing or cleansing properties. The alkaline water and NaOH is then collected in alkaline solution tank. Acidic water and HOCl is collected in acidic solution tank. In addition, a mixture of acidic solution and alkaline solution is collected in electrolyzed hypochrolite tank. Pumps and spigots can then spray the stored liquids from the alkaline solution tank, the hypochrolite solution tank, and the acidic solution tank onto objects to cleanse and disinfect the objects.

0008Improved cleaning systems are desired for reducing the use of typical detergents and/or reducing the residue left on the surface after cleaning while maintaining desired cleaning and/or disinfecting properties.

SUMMARY

0009The invention is defined by the features of the independent claims. Preferred embodiments of the invention are exemplified in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

0010<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> illustrates an example of a functional generator, which can be used to electrochemically activate a liquid to be treated for use in cleaning, such as water, onboard or off-board a hard and/or soft floor cleaner according to an embodiment of the disclosure.</li><li><figref idref="f0001">FIG. 2</figref> illustrates a functional generator according to another embodiment of the disclosure.</li><li><figref idref="f0002">FIG. 3</figref> illustrates an apparatus having a sparging device located downstream of a functional generator, according to an embodiment of the disclosure.</li><li><figref idref="f0002">FIG. 4</figref> illustrates an apparatus having a sparging device located upstream of a functional generator, according to an embodiment of the disclosure.</li><li><figref idref="f0002">FIG. 5</figref> illustrates an apparatus having an electrolysis cell type sparging device located upstream of a functional generator, according to an embodiment of the disclosure.</li><li><figref idref="f0002">FIG. 6</figref> illustrates an apparatus having sparging devices located upstream and downstream of a functional generator, according to an embodiment of the disclosure.</li><li><figref idref="f0003">FIG. 7</figref> illustrates an electrolysis cell type sparging device, according to an embodiment of the disclosure.</li><li><figref idref="f0004">FIGS. 8A and 8B</figref> together illustrate a housing containing a sparging device and a functional generator according to an embodiment of the disclosure.</li><li><figref idref="f0005">FIG. 9</figref> is a perspective view of the sparging device shown in <figref idref="f0004">FIG. 8B</figref>.</li><li><figref idref="f0006">FIG. 10A</figref> is a side elevation view of a mobile hard floor surface cleaner in accordance with one or more exemplary embodiments of the disclosure.</li><li><figref idref="f0007">FIG. 10B</figref> is a perspective view of the mobile hard floor surface cleaner shown in <figref idref="f0006">FIG. 10A</figref> with its lid in a closed state.</li><li><figref idref="f0008">FIG. 10C</figref> is a perspective view of the mobile hard floor surface cleaner shown in <figref idref="f0006">FIG. 10A</figref> with its lid in an open state.</li><li><figref idref="f0009">FIG. 11</figref> is a block diagram illustrating a liquid distribution flow path of the cleaner shown in <figref idref="f0006 f0008">FIGS. 10A-10C</figref> in greater detail according to an embodiment of the disclosure.</li><li><figref idref="f0010">FIG. 12</figref> is a block diagram of a floor cleaner that is configurable with multiple types of cleaning tools and extractors to accommodate different cleaning operations while using the same overall cleaner.</li><li><figref idref="f0011">FIG. 13</figref> is a block diagram, which illustrates the cleaner shown in <figref idref="f0010">FIG. 12</figref> in a mode adapted to clean soft floors, according to an embodiment of the disclosure.</li><li><figref idref="f0012">FIG. 14</figref> is a block diagram, which illustrates the cleaner shown in <figref idref="f0010">FIG. 12</figref> in a mode adapted to deeply clean soft floors, according to an embodiment of the disclosure.</li><li><figref idref="f0013">FIG. 15</figref> is a block diagram, which illustrates the cleaner shown in <figref idref="f0002">FIG. 5</figref> in a mode adapted to clean hard floors, according to an embodiment of the disclosure.</li><li><figref idref="f0014">FIG. 16</figref> is a perspective view of a soft floor cleaner (e.g. carpet extractor), according to an embodiment of the disclosure.</li><li><figref idref="f0015">FIG. 17</figref> is a perspective view of an all-surface cleaner, according to an embodiment of the disclosure.</li><li><figref idref="f0016">FIG. 18</figref> is a diagram illustrating a truck-mounted system according to a further embodiment of the disclosure.</li><li><figref idref="f0016">FIG. 19</figref> is a simplified block diagram, which illustrates a cleaner having an EA water distribution system with an odorous compound source according to a further embodiment of the disclosure.</li><li><figref idref="f0016">FIG. 20</figref> is a simplified block diagram of a cleaning liquid generator that mounted to a platform according to another embodiment.</li><li><figref idref="f0017">FIG. 21</figref> is a block diagram of a system, which includes an indicator representing an operating state of a functional generator.</li></ul>

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

0011In one exemplary embodiment of the disclosure, a method and apparatus are provided, which use sparged liquid, an electrochemically activated (EA) anolyte and/or catholyte liquid, or a liquid that is both sparged and an electrochemically activated anolyte and/or catholyte liquid as the sole or primary cleaning liquid to substantially or completely eliminate the use of conventional surfactants/detergents during cleaning or disinfecting.

1. Surfactants Used in Traditional Cleaning Liquids

0012Conventional cleaning liquids generally include water and a chemical surfactant. As used herein, the term "surfactants" or "surface-active agents" refer to amphiphilic compounds that facilitate adsorption at surfaces or interfaces as well as aggregation at certain concentrations and temperatures. The chemical make up of a surfactant adheres to a particular molecular structure. The molecule is made up of at least two components, one that is water-soluble (hydrophilic), and the other water insoluble (hydrophobic). In oil, the components are lipophilic and lipophobic respectively. The two are balanced to achieve desired properties for the surfactant.

0013With a cleaning apparatus that includes a mechanical scrubber, such as a mobile hard floor cleaner for example, one benefit of including surfactants has been the ability to efficiently aerate the liquid to be used in cleaning into a foam, apply the foamed cleaning liquid to the hard floor surface, work the foamed cleaning liquid with the scrub brushes, and substantially deaerate the foamed cleaning liquid prior to recovery of the soiled solution. In operation, dearation of the aerated cleaning liquid is rapidly achieved via brush contact. As a result, relatively little foam is transferred into the recovery tank.

0014There are basically four types of surfactants, for example - (1) anionic surfactants that dissociate into a negatively charged ion (anion) and a positively charged ion (cation) in an aqueous environment, wherein the anion becomes the carrier of the surface-active properties, (2) cationic surfactants that also dissociate into an anion and a cation, wherein the cation becomes the carrier of the surface-active properties, (3) non-ionic surfactants that are surface-active substances, which do not dissociate into ions in an aqueous environment, and (4) amphoteric surfactants that contain both a positive and a negative charge in the same surfactant molecule when present in an aqueous environment and can have anionic or cationic properties depending on the composition and conditions, such as pH value of the aqueous environment.

0015In general, two main tasks of the surface-active agents for cleaning include (1) reducing the surface tension of water to get wetting properties and releasing soil from surfaces, and (2) dispersing solid particles and pigment. There are many variables that come into play when it comes to producing effective cleaning surfactants and detergents. Generally, important parameters are time, temperature, aerated or non-aerated systems, concentration, soil and mechanical treatment.

2. EA Liquids and Sparging

0016It has been discovered that electrochemically activated (EA) water and other EA liquids can be used with conventional cleaning systems instead of or in addition to chemical surfactant-based liquids to clean surfaces such as hard and/or soft floors. The following discussion uses EA "water" as an example of a primary cleaning liquid. However, any other suitable EA liquid or solution can be used in other embodiments.

0017As used herein, the term "electrochemically activated liquid" or "EA liquid" refers, for example, to water with elevated reactivity that contains (1) reactive species, and/or (2) meta-stable (activated) ions and free radicals formed after exposure to electrochemical energy in the form of a substantial voltage potential or current under non-equilibrium conditions. The term "activated" means, for example, the electrochemical or eletrophysical state or condition of having excessive inner potential energy that is attained after exposure to thermodynamically non-equilibrium conditions for a period of time. Meta-stable ions and free radicals relax in time by undergoing a gradual transition from a meta-stable state to a state of thermo-dynamic equilibrium.

0018As used herein, the term "electrochemical activation" refers, for example, to the process in which substances in a meta-stable state are produced during electrochemical exposure of liquid containing ions and molecules of dissolved substances to an area of special charge close to an electrode surface under non-equilibrium charge transfer conditions.

0019In the case of EA water production, the initial liquid source used to form EA water can include, for example, (1) regular, untreated tap water or other water that is commonly available, (2) pure water to which one or more electrolytes have been added, (3) chemically treated tap water, and (4) other aqueous solutions containing a suitable concentration of electrolytes. In one embodiment, one or more electrolytes are added to pure water (or other aqueous solution) to attain an electrolyte concentration that is greater than zero and does not exceed 0.1 moles per liter. In a further embodiment, the electrolyte concentration that is greater than zero and does not exceed 1.0 moles per liter. Other concentrations inside or outside of this range can be used in other embodiments. Examples of suitable electrolytes include chloride salt, nitrate salt, carbonate salt or any other salt that is soluble in water (or other liquid being electrochemically activated). Chloride salts include, for example, sodium chloride (such as pure NaCl), potassium chloride, magnesium chloride, calcium chloride or the like. The term "electrolyte" means any substance that dissociates into two or more ions when dissolved in water or any substance that will conduct an electric current when in solution.

0020EA water has enhanced cleaning power and sanitation capability when compared to non-EA water. EA water also differs from regular or untreated water at the molecular level and electron level.

0021It has further been discovered that a sparging device can be used to add fine gas bubbles to the EA water (or other liquid to be sparged) to create a cleaning liquid that is delivered to the surface or item to be cleaned and utilized in the cleaning process. The liquid can be sparged, for example, before or after the liquid is electrochemically activated into an anolyte and a catholyte. The resulting cleaning liquid facilitates an efficient wetting of the floor surface. If a reactive gas is used, such as oxygen, the oxygen gas bubbles can further improve the wetting properties of the liquid by reducing the surface tension of the liquid and can be reactive to further enhance the cleaning and/or sanitizing properties of the liquid.

0022If the liquid to be treated for use in cleaning is sparged, for example by mechanical and/or electrical methods, before being electrochemically activated, the elevated oxygen (or other gas) levels produced by sparging can assist in the electrochemical activation process to create super oxygenated EA liquid for enhanced cleaning or sanitizing power. The super oxygenated EA water contains high levels of oxygen and is electrochemically activated due to the presence of a diverse range of meta-stable ions and reactive free radicals. The end result is an electrochemically activated foam, froth or reactive gas with enhanced cleaning and/or sanitizing power.

3. Functional Generator to Produce EA Liquid

0023<figref idref="f0001">FIG. 1</figref> illustrates an example of a functional generator (reactor) 10, which can be used to generate EA liquid. The terms "functional generator" and "reactor" are interchangeable herein. Functional generator 10 includes one or more electrochemical activation (EA) cells 12, which receive feed water (or other liquid to be treated for use in cleaning) from a liquid source 14 through feed lines 16, 17 and 18. Liquid source 14 can include a tank or other solution reservoir or can include a fitting or other inlet for receiving a liquid from an external source. In an embodiment, the feed water includes an aqueous composition, such as regular tap water, containing no more than 1.0 moles per liter salt. In another embodiment, the aqueous composition contains no more than 0.1 moles per liter salt. An aqueous composition containing more than 1.0 moles per liter salt can be used in further embodiments.

0024The term regular "tap water" means any water that is commonly available for home or commercial use, from public works, storage, wells, etc. Regular tap water typically contains salt at a concentration of less than 0.1 moles per liter. Deionized water or water in which the ionic content is negligible is less preferable since ions aid in the electrochemical activation of water. As discussed above, liquid compositions other than or in addition to regular tap water can be used as the liquid to be treated for use in cleaning and/or sanitizing and electrochemically activated for enhanced cleaning and/or sanitizing power.

0025Each EA cell 12 electrochemically activates the feed water by at least partially utilizing electrolysis and produces EA water in the form of an acidic anolyte composition 20 and a basic catholyte composition 22. The terms "acidic anolyte", "EA anolyte", "EA oxidized water" and "anolyte composition" are used interchangeably within the detailed description. Similarly the terms "basic catholyte", "EA reduced water," "EA catholyte" and "catholyte composition" are used interchangeably within the detailed description.

0026In one embodiment, each EA cell 12 has one or more anode chambers 24 and one or more cathode chambers 26 (only one shown), which are separated by an ion exchange membrane 27, such as a cation or anion exchange membrane. One or more anode electrodes 30 and cathode electrodes 32 (one of each electrode shown) are disposed in each anode chamber 24 and each cathode chamber 26, respectively. The anode and cathode electrodes 30, 32 can be made from any suitable material, such as titanium or titanium coated with a precious metal, such as platinum, or any other suitable electrode material. The electrodes and respective chambers can have any suitable shape and construction. For example, the electrodes can be flat plates, coaxial plates, rods, or a combination thereof. Each electrode can have, for example, a solid construction or can have one or more apertures, such as a metallic mesh. In addition, multiple cells 12 can be coupled in series or in parallel with one another, for example.

0027The electrodes 30, 32 are electrically connected to opposite terminals of a conventional power supply (not shown). Ion exchange membrane 27 is located between electrodes 30 and 32. The power supply can provide a constant DC output voltage, a pulsed or otherwise modulated DC output voltage, or a pulsed or otherwise modulated AC output voltage to the anode and cathode electrodes. The power supply can have any suitable output voltage level, current level, duty cycle or waveform.

0028For example in one embodiment, the power supply applies the voltage supplied to the plates at a relative steady state. The power supply includes a DC/DC converter that uses a pulse-width modulation (PWM) control scheme to control voltage and current output. The DC/DC converter uses approximately a 15 kHz pulse to produce the desired voltage to the anode and cathode in the range of 5V to 25V, such as a voltage of 15V with a power up to about 120-150 Watts. The duty cycle is dependent on desired voltage and current output. For example, the duty cycle of the DC/DC converter can be 90%. As explained in more detail below, the power supply can be configured, if desired, to alternate between a relative steady state voltage for 5 seconds at one polarity and then a relative steady state voltage for 5 seconds at the opposite polarity.

0029Other types of power supplies can also be used, which can be pulsed or not pulsed and at other voltage and power ranges. The parameters are application-specific.

0030Feed water is supplied from source 14 to both anode chamber 24 and cathode chamber 26 via feed water supply line 16, which can be branched into anode supply line or manifold 17 and cathode supply line or manifold 18. The anode supply line 17 supplies the feed water to each anode chamber 24, and the cathode supply line 18 supplies the feed water to each cathode chamber.

0031In the case of a cation exchange membrane, upon application of a DC voltage potential across anode 30 and cathode 32, such as a voltage in a range of about 5 Volts (V) to about 25V, cations originally present in the anode chamber 24 move across the ion-exchange membrane 27 towards cathode 32 while anions in anode chamber 24 move towards anode 30. Similarly, cations present in the cathode chamber 26 move towards cathode 32. However, anions present in cathode chamber 26 are not able to pass through the cation-exchange membrane, and therefore remain confined within cathode chamber 26.

0032In addition, water molecules in contact with anode 30 are electrochemically oxidized to oxygen (O₂) and hydrogen ions (H⁺) in the anode chamber 24 while water molecules in contact with the cathode 32 are electrochemically reduced to hydrogen gas (H₂) and hydroxyl ions (OH^-) in the cathode chamber 26. The hydrogen ions in the anode chamber 24 are allowed to pass through the cation-exchange membrane 27 into the cathode chamber 26 where the hydrogen ions are reduced to hydrogen gas while the oxygen gas in the anode chamber 24 oxygenates the feed water to form the anolyte 20. Furthermore, since regular tap water typically includes sodium chloride and/or other chlorides, the anode 30 oxidizes the chlorides present to form chlorine gas. As a result, a substantial amount of chlorine is produced and the pH of the anolyte composition 20 becomes increasingly acidic over time.

0033As noted, water molecules in contact with the cathode 32 are electrochemically reduced to hydrogen gas and hydroxyl ions (OH^-) while cations in the anode chamber 24 pass through the cation-exchange membrane 27 into the cathode 32 when the voltage potential is applied. These cations are available to ionically associate with the hydroxyl ions produced at the cathode 32, while hydrogen gas typically bubbles to the surface and escapes the cathode chamber 26, as noted by arrow 34. As a result, a substantial amount of hydroxyl ions accumulates over time in the cathode chamber 26 and reacts with cations to form basic hydroxides. In addition, the hydroxides remain confined to the cathode chamber 26 since the cation-exchange membrane does not allow the negatively charged hydroxyl ions pass through the cation-exchange membrane. Consequently, a substantial amount of hydroxides is produced in the cathode chamber 26, and the pH of the catholyte composition 22 becomes increasingly alkaline over time.

0034Since hydrogen gas 34 readily escapes from the cathode chamber 26, the electrochemical reactions of the functional generator 10 never reach equilibrium. As a result, the non-equilibrium conditions of the electrolysis process in the functional generator 10 allow concentration of reactive species and the formation of metastable ions and radicals in the anode chamber 24 and cathode chamber 26 chamber.

0035The electrochemical activation process typically occurs by either electron withdrawal (at anode 30) or electron introduction (at cathode 32), which leads to alteration of physiochemical (including structural, energetic and catalytic) properties of the feed water. It is believed that the feed water (anolyte or catholyte) gets activated in the immediate proximity of the electrode surface where the electric field intensity can reach a very high level. This area can be referred to as an electric double layer (EDL).

0036Alternatively, for example, an aqueous composition containing deionized water and up to 0.1 moles per liter salt, such as 0.1 moles per liter sodium chloride, can be introduced into the anode and cathode chambers 24 and 26. The sodium chloride fully dissociates into positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl^-). The sodium and chloride ions become hydrated by water molecules. Positively charged sodium ions present in the water move towards cathode 32 while negative chloride ions move towards anode 30.

0037Water is oxidized to oxygen gas and hydrogen ions at anode 30 and reduced to hydroxyl ions and hydrogen gas at cathode 32. Sodium ions located near or on the surface of the cathode 32 are therefore capable of ionically associating with the negatively charged hydroxyl ions to form sodium hydroxide. As a result, cathode chamber 26 contains water and hydroxides, which cause an increase in the pH, and the water becomes increasingly alkaline over time.

0038Similarly, chloride ions present in anode chamber 24 become electrochemically oxidized to chlorine gas. Hydrogen ions or other cations present in anode chamber 32 are transferred through cation-exchange membrane 27. As a result, anode chamber 24 contains chlorine and oxygen gas that cause a decrease in pH over time.

0039As mentioned, hydrogen gas readily escapes from aqueous compositions; hence, the electrochemical reactions do not reach equilibrium. As a result, the non-equilibrium condition of the electrolysis process in the functional generator 10 continues to allow concentration of reactive species and the formation of metastable ions and radicals in the anode chamber 24 and cathode chamber 26.

0040In another embodiment, one or both of electrodes 30 and 32 can be coated with silver. Alternatively, for example, additional electrodes can be added to chamber 12, which are coated or embedded with silver. The silver slowly dissolves during use, thereby releasing silver ions; such as silver nano-ions, into the anolyte and/or catholyte. The silver ions can help increase the sanitizing properties of the produced EA liquid.

4. Ion Exchange Membrane

0041As mentioned above, the ion exchange membrane 27 can include a cation exchange membrane or an anion exchange membrane. In the case of a cation exchange membrane, the membrane may be in the form of a single-layer membrane derived from one perfluoroionomer resin, for example. Alternatively, for example, the cation-exchange membrane 27 may be in the form of a two-layer membrane derived from the same or two different perfluoroionomer resins, for example. Other materials can also be used having various numbers of layers. In addition, membranes are usually reinforced by a porous structure or body that is made of polytetrafluoroethylene (PTFE), for example, to provide sufficient mechanical strength.

0042Cation-exchange membranes include anion-exchange groups (-SO₃^- or - COO^-), for example, which are covalently bound to the polymer skeleton. During operation, ionic salts disassociate in water into cations or anions. The cations are referred to as counter ions while anions are referred to as co-ions of the cation-exchange membrane.

0043Under an electrical potential gradient existing in electrochemical cell, Na⁺ and H⁺ ions clustering with water molecules are transported through the membrane toward the negative charged cathode and co-ions (Cl^- and OH^*) are transported toward positively charged anode.

0044Even though cation-exchange membranes selectively transmit Na⁺, other cations and water molecules but suppress diffusion of Cl^- and OH^- ions, some hydroxyl anions are still able to migrate through the cation-exchange membrane. The main net result is an enrichment of Cl^- ions in anode chamber 24 and Na⁺ (and to a lesser degree H⁺) ions in cathode chamber 26, and extremely low diffusion of Cl^- anions from anolyte 20 to catholyte 22 and OH^- anions from catholyte 22 to anolyte 20. In one embodiment, to limit or prevent hydroxyl ion migration, the side of the perfluorosulfonic acid membrane contacting the catholyte 22 can be covered by a layer of perfluorocarbohylyc acid polymer.

0045The charge of bonded ions in the cation-exchange membrane is balanced by equivalent charges of counter ions in the form of H⁺, Li⁺, Na⁺, K⁺, and the like. Cation-exchange membranes typically work when sufficiently hydrated. When a polymer is placed in water, the polymer swells, becomes pliable and allows ions to move freely under the action of a voltage potential or by diffusion. As a result, it is believed the cation-exchange membrane behaves like an ion conductor in an electric field and can transmit cations with high selectivity.

0046It is also believed the hydrogen (R-SO₃H) and sodium (R-SO₃Na) forms of strong acid resins are highly dissociated and the exchangeable Na⁺ and H⁺ are readily available for exchange over the entire pH range. Hence, exchange capacity and therefore process efficiency is not pH dependent. However, it is believed hydrogen (R-COOH) and sodium (R-COONa) forms of weak carboxylic acids the dissociation is not high and is very pH dependent. Consequently, the exchange capacity of weak carboxylic acids is strongly pH dependent as is the process efficiency when such membranes are employed.

0047The operation of cation-exchange membranes is also a function of (1) ionic conductivity or the total transport of cations through the membrane, (2) ion current density, (3) ion transport number or the current carried by a specific ion relative to the total current applied, (4) molecular weight of the backbone polymer, (5) porosity of the membrane, (6) equivalent weight or weight of dry polymer in grams containing one mole of sulfonic acid group, (7) ion exchange capacity or total number of chemical equivalent of sulfonic acid groups available for exchange per unit weight or unit volume of polymer resin, (8) hydration or percent water adsorbed by the polymer and/or (9) water transport.

0048Examples of suitable cation-exchange membranes that can be used in functional generator 10 include Nafion membranes from DuPont, USA, Flemion membranes from Asahi Glass Co., Japan, Aciplex membranes from Asahi Chemical Industries Co., Japan and Dow membranes from Dow Chemical, USA. An example of a suitable functional generator includes the Emco Tech "JP102" cell found within the JP2000 ALKABLUE LX, which is available from Emco Tech Co., LTD, of Yeupdong, Goyang-City, Kyungki-Do, South Korea. This particular cell has a DC range of 27 Volts, a pH range of about 10 to about 5.0, a cell size of 62 mm by 109mm by 0.5 mm, and five electrode plates. Other types of functional generators can also be used, which can have various different specifications.

5. Properties of the EA Water Output

0049Electrochemical activation within functional generator 10 produces EA water that can be used for cleaning and/or sanitizing. The EA water is produced in the form of an acidic anolyte 20 and a basic catholyte 22 at the outputs of anode chamber 24 and cathode chamber 26, respectively.

A. Anolyte

0050Anolyte 20 is acidic in nature and contains very strong oxidants in the form of active chlorine (Cl₂), for example. In one embodiment, anolyte 20 has a pH of about 2.0 to about 4.0, but can have a pH outside of that range in other embodiments, such as in a range of about 2.5 to 6. In one embodiment, anolyte 20 has an oxidation-reduction potential (ORP) of about +600mV to about +1200mV, or can be in other ranges such as +100mV to +1200mV, +400mV to +900 mV, or +400 mV to +700mV, for example. Other values of pH, oxidation-reduction potential and chlorine concentration can be used in other embodiments. Intensity of oxidation-reduction reactions depends on electron activity in aqueous solutions, which is characterized by the oxidation-reduction potential (ORP) value. The higher the ORP value, the more "acid" the medium, and the more it is capable of oxidating molecules. The lower ORP value, the higher its reducing, anti-oxidant, ability. As a result of electrochemical exposure of water near the anode, its oxidation-reduction potential increases, and it acquires oxidant characteristics.

0051Anolyte 20 can be used wherever there is a desire to disinfect or sterilize. Anolyte 20 can be used to kill bacteria since water having this range of oxidation-reduction potential changes the environment in which microbes, viruses, germs and other biological life forms can thrive and attracts electrons from the environment and microbes. As a result, the environment and microbes are oxidized. Therefore, EA anolyte water can be used as a disinfectant and sanitizer during operation of a surface cleaner in one or more embodiments. However, care should be taken on surfaces having a potential for corrosion.

0052Anolyte 20 may also contain many meta-stable ionic and reactive free radical molecules produced at the anode 30 during electrochemical activation of water. These molecules can include: O₃, O₂, H₂O₂, Cl₂, ClO₂, HClO, HCl, HClO₃, O₂, H₂O₂, O₃, H⁺, H₃O⁺, OH^-' ClO^-, HO^-, H₂O^-, O₂^*, O^-, ClO^-, and Cl^- free radicals and other excited molecules.

0053Molecular chlorine can also react to form hypochlorous acid and other ions of OCl^- ions. These ions of OCl^- can further oxidize and become chloric acid ions (ClO₃^-) and perchloric acid ion (HClO₄^-). Chlorine dioxide may also be obtained by oxidation of sodium chloride and hydrochloric acid. Furthermore, many other pH-dependent reactions result in a wide variety of very meta-stable and/or reactive chlorine containing molecules, ions and free radicals. In addition to the sanitizing properties, the chlorine ions in the mildly acidic anolyte solution 20 can react with metal oxides in scale deposits on the surface being cleaned, which assist in removing the scale deposits.

B. Catholyte

0054As a result of electrochemical exposure of water near the cathode, its oxidation-reduction potential decreases, and it acquires anti-oxidant characteristics. Catholyte 22 is strongly basic, and the pH of the catholyte solution ranges from about 8 to about 12, or from 9 to about 12 in one or more embodiments. However, the catholyte can have pH values outside of this range in other embodiments. In one embodiment, catholyte 22 has an ORP of about - 600mV to about -1000mV, or the ORP can be in other ranges such as -150mV to -1000mV, -150mV to -700mV, or -300mV to -700mV. Catholyte 22 can be used for flocculation of heavy metals, coagulation, washing, and extraction. In addition, catholyte 22 can be used to wash wounds (instead of using iodine) and wherever there is a need to increase pH levels of water. Catholyte 22 may also include reactive hydrogen peroxide (H₂O₂), sodium and other hydroxides, meta-stable ions, and/or free radicals.

0055Water molecules cluster typically together at 12-14 molecules per cluster around ions, for example. This is sometimes known as "Surface Tension". Normal tap water includes a network of icosahedral water clusters. These large water conglomerates are too large to easily penetrate different organic and inorganic materials and biological objects, which can be a time-consuming and energy consuming process. The degradation of large water clusters into smaller clusters can make water more active and more valuable for practical applications. When the functional generator electrochemically activates water, the covalent hydrogen bonds between hydrogen and oxygen is broken resulting in the clusters of H₂O being reduced to below 10 molecules per cluster, such as between 5 and 6 molecules per cluster. The resulting EA water therefore has a distribution of water cluster sizes that has a greater number of smaller-sized clusters. The EA water is therefore much "wetter" has more wetting ability, more permeable, and more soluble. Because EA water is wetter has more wetting ability than typical water, it can hydrate six to ten times (for example) faster than non-EA water and will act as a transport mechanism for lifting and separating debris from the surface being cleaned more readily than non-EA water.

0056More specifically, EA water in the form of the basic catholyte composition has the capacity to mimic anionic, cationic, nonionic and amphoteric surfactants. Catholyte 22 has a surfactant mimicking effect since the catholyte 22 can have a high pH and is packed with a very large quantity of negative ions after electrochemical activation. In one embodiment, catholyte 22 is highly alkaline with a pH of 9 or greater, for example in the range of about 10 to about 12, but can have other pH values outside of this range in other embodiments. Water molecule clusters typically surround ions when in solution. During electrochemical activation, electrons and ions furiously move about within water molecule clusters and bombard each other until the water molecule cluster becomes very small. Consequently, these smaller water molecule clusters are able to penetrate cracks and crevices between dirt and objects, and are able to lift dirt more effectively than ordinary non-EA water.

0057Catholyte 22 is able to enhance dispersion in a manner similar to that observed when using commonly known surfactants. These effects are observed since catholyte 22 contains negative ions that envelope any molecules of objects and dirt. Enveloping or surrounding molecules of objects and dirt with negative charges creates a negative potential that causes molecules of objects and dirt to repel each other and remain separate.

0058These properties also improve solvation and removal of grease, acidic soils, and carbonaceous oils. This is because catholyte 22 surrounds grease molecules with negative charges that can be lifted off separately after being surrounded by negative ions. In addition, surrounding grease molecules with negative charges helps to reduce the overall size of grease molecules, and therefore catholyte 22 causes grease molecules to become smaller.

0059Furthermore, surrounding grease molecules with negative charges effectively saponifies the grease molecules and helps emulsify or stabilize hydrophobic grease molecules in water. When a fatty or grease like substance is surrounded by negative charges from catholyte 22, catholyte transforms grease into a synthetic liquid soap. As a result, oily or greasy stains become soluble and can be removed by catholyte 22 without addition of surfactant/detergent chemistry as part of the cleaning liquid. However, a surfactant/detergent can be added to the liquid to be treated for use in cleaning before or after activation, if desired, in other embodiments.

0060Catholyte 22 therefore has strong cleaning capacity. Catholyte 22 can be used as a cleaning solution with a high level of cleaning power, is safe and does not pollute the environment. Catholyte 22 is safe to the environment since reduced water reduces matter and does not oxidize matter. Oxidization causes some materials to rust, degrade, age and become dirty. Catholyte 22 avoids rusting, degradation, premature aging and dirtying.

0061The EA water (catholyte and anolyte) produced from functional generator 10 therefore has cleaning power and bacteria-killing power. As a result, a cleaning apparatus, such as a mobile or immobile hard and/or soft floor cleaner, can use EA water to clean floors and other off-floor surfaces of industrial, commercial and residential buildings, for example. The cleaner can use the EA water without the addition of surface-active ingredients, such as a surfactant or detergent to aid in the cleaning of hard and/or soft surfaces.

0062Also, the EA water produced by functional generator 10 has a solvating power that is very effective in forcing oils into a solution that can be extracted from the surface. In contrast to detergents that tend to keep oils in suspension, EA water allows oils to recombine after extraction when the water loses its activated properties and neutralizes. When used with a cleaning apparatus that has a soiled-liquid recovery function, this characteristic of the EA water allows oils to be separated from the extracted, soiled water more efficiently. This may reduce the expenses associated with disposing of the soiled wastewater recovered from the surface or item being cleaned.

0063As described in more detail below, the anolyte and catholyte can be separately applied to and extracted from the surface or item being cleaned or can be applied together. The anolyte and catholyte can be applied through separate distribution systems. In one example, if a particular one of the anolyte and catholyte is not used, it can be routed from the output of functional generator to a buffer or reservoir for later use or can be routed to a waste or recovery tank. The terms tank, buffer, and reservoir are interchangeable.

C. Blended Anolyte and Catholyte

0064It has been found that the anolyte and catholyte can be blended on the surface or item being cleaned while still retaining beneficial cleaning and sanitizing properties. Although the anolyte and catholyte are blended, they are initially not in equilibrium and therefore temporarily retain their enhanced cleaning and sanitizing properties.

0065Also for a typical mobile surface cleaner or for an extractor type of cleaner, the residence time of the liquid on the surface being cleaned before extraction is relatively short, such as between 2-3 seconds for a typical mobile surface cleaner.

6. Varying Production Concentrations and Volumes of Anolyte and Catholyte

0066The anolyte and catholyte can be generated or applied in different ratios to one another through modifications to the structure of the functional generator 10, the flow rates through the generator and/or the distribution system.

0067For example, the functional generator can be configured to produce a greater volume of catholyte than anolyte if the primary function of the EA water is cleaning. Alternatively, for example, the functional generator can be configured to produce a greater volume of anolyte than catholyte if the primary function of the EA water is sanitizing. Also, the concentrations of reactive species in each can be varied.

0068<figref idref="f0001">FIG. 2</figref> illustrates a schematic diagram of a functional generator 40 according to an embodiment having a 3:2 ratio of cathode plates 41 to anode plates 42 for producing a greater volume of catholyte than anolyte. Each cathode plate 41 is separated from anode plate 42 by a respective ion exchange membrane 43. Thus, there are three cathode chambers for two anode chambers. This configuration produces roughly 60% catholyte through output 44 to 40% anolyte through output 45. In another embodiment, each cell includes three cathode chambers and one anode chamber, each being separated by a respective membrane, similar to the embodiment shown in <figref idref="f0001">FIG. 2</figref>. Other ratios can also be used.

0069With multiple anode and cathode chambers, the ratios can be further modified by electrically enabling and disabling selected electrode plates. Enabling and disabling can be achieved with suitable switches in the power supply lines to the electrodes, which can be controlled automatically by a control circuit, manually by an operator or a combination of both. In the example shown in <figref idref="f0001">FIG. 2</figref>, a 1:1 ratio can be achieved by disabling one of the cathodes 41 and cutting flow to that chamber. A 2:3 ratio of cathode plates to anode plates can be achieved in this example by simply reversing the polarity of the electrical potential applied to plates 41 and 42. Thus, each plate 41 becomes an anode plate, while each plate 42 becomes a cathode plate. The polarity of the applied voltage can also be reversed periodically or at other times to self-clean the anode and cathode plates and therefore extend their life. Therefore, the terms "anode" and "cathode" and the terms "anolyte" and "catholyte" as used in the description and claims are respectively interchangeable.

0070Alternatively or in addition, flow to selected chambers can be mechanically enabled, disabled or reduced through flow restriction devices 46, which can be positioned at the input end or output end of functional generator 40. Flow restriction devices can include any device that is adapted to restrict flow, such as a valve or pump.

0071The concentration of reactive species, change in pH or reduction potential in each chamber can be adjusted by adjusting the flow through that chamber. With a higher flow rate in a particular chamber, the feed water has a shorter residence time in the chamber and thus less time to generate reactive species or change pH or reduction potential.

0072Functional generator 40 can also have multiple cells in parallel with one another, which can be selectively enabled and disabled as desired.

0073In another embodiment one or more of the cathode plates can have a different surface area than a respective anode plate to alter the concentration of active water produced in one chamber relative to another.

0074In another embodiment of the disclosure, catholyte output 44 and anolyte output 45 are combined in the flow path at the output of functional generator 40.

7. Sparging

0075As mentioned above, it has been found that sparging the liquid to be treated for use in cleaning downstream or upstream of the functional generator can enhance the cleaning or sanitizing properties of the resulting liquid. Alternatively, for example, a sparging device can be used by itself, with no functional generator, in any apparatus, such as but not limited to those disclosed herein. In one embodiment, the term "sparging" means to disperse a gas in a liquid or to disperse a liquid in a gas by any appropriate method as will be appreciated by those of ordinary skill in the art. The terms "sparged EA liquid" and "sparged EA water" refers to EA liquid or EA water that has been sparged upstream and/or downstream of the functional generator that electrochemically activates the liquid or water.<figref idref="f0002">FIG. 3</figref> illustrates an apparatus having a sparging device 50 located downstream of functional generator 10. Sparging device 50 sparges or infuses anolyte EA liquid 20 and catholyte EA liquid 22 with a gas to form sparged anolyte EA liquid 51 and sparged catholyte EA liquid 52. A single, combined sparging device or separate devices can be used to sparge each of the flow streams. Alternatively, for example, sparging device 50 is coupled to sparge only one or the other of the anolyte EA liquid 20 and the catholyte EA liquid 22. Also, multiple sparging devices can be coupled together in series for in parallel with one another, for example.

0076In one embodiment, sparging device 50 disperses fine gas bubbles to the EA liquid to create a froth that is delivered to the surface or item to be cleaned. Suitable gases include air, oxygen, nitrogen, ammonia, carbon dioxide and other gases. In the cases of air and oxygen, the resulting sparged EA liquid becomes highly oxygenated. The increase in oxygenation further facilitates an efficient wetting of the surface or item being cleaned and can enhance chemical reactions that facilitate cleaning or sanitizing.

0077Sparging device 50 may include a variety of froth generation devices, including but not limited to devices that operate on a mechanical basis, devices that operate on an electrochemical basis, such as by electrolysis, and devices that operate on a chemical basis, or a combinations thereof. Mechanical sparging devices can be adapted to disperse a gas in the liquid or disperse the liquid in a gas. Examples include pressurized or non-pressurized gas delivery systems, pressurized or non-pressurized liquid delivery systems, agitation systems, sprayers, and bubblers. In one embodiment, a pressurized gas is introduced into the flow path of the liquid being treated for use in cleaning and then dispersed in the liquid by a suitable mixing member, such as a diffusion medium that is capable of producing froth by shearing action, gas entrainment or a combination of both. In another embodiment, a Venturi tube can be used to introduce a gas into the liquid flow path, for example.

0078If sparging device 50 is placed upstream of functional generator 10, such as in the embodiment shown in <figref idref="f0002">FIG. 4</figref>, the gas can also assist in the electrochemical activation process to enhance the cleaning or sanitizing power of the resulting EA liquid. The sparged liquid 53 from sparging device can be supplied to the anode chamber, the cathode chamber or both the anode and cathode chambers of functional generator 10, while regular tap water (or other liquid) can be supplied to any chamber not receiving the sparged liquid.

0079If the sparged gas includes air or oxygen, the elevated oxygen levels during electrochemical activation can create super oxygenated EA water. The increased levels of oxygen increase efficiency of the electrochemical activation process. Also, during the electrochemical activation process, the sparged water may have a distribution of water cluster sizes that has a greater number of smaller clusters having lower numbers of water molecules per cluster. These smaller clusters may increase efficiency in transport and separation through the ion exchange membrane of the functional generator. The super oxygenated EA water becomes electrochemically activated, resulting in an electrochemically activated foam, froth, and/or reactive gas with enhanced cleaning or sanitizing power.

0080In the embodiment shown in <figref idref="f0002">FIG. 5</figref>, sparging device 50 includes one or more electrolysis cells that operate on an electrochemical basis to accomplish sparging. The electrolysis cells can be positioned upstream or downstream of the functional generator 10. In <figref idref="f0002">FIG. 5</figref>, an electrolysis cell 50 is upstream of functional generator 10. The electrolysis cell has one or more anodes and one or more cathodes similar to the functional generators shown in <figref idref="f0001">FIGS. 1 and 2</figref>. However in one embodiment, the electrolysis cell has no ion exchange membrane.

0081In addition, sparging device 50 can be positioned along the flow path from liquid source 14 (shown in <figref idref="f0001">FIGS. 1 and 2</figref>) or inside of the liquid source 14, such as in a source tank carried by a mobile floor surface cleaner.

0082Regular tap water typically contains 8 to 40 mg/L of oxygen. Oxygen levels can be boosted by electrolysis. Electrolysis of the feed water from the water source (or of the EA water from functional generator 10) can introduce oxygen gas and hydrogen peroxide into the water. The oxygen and other gas bubbles not only further improve the wetting properties of the water by reducing the surface tension of the water, these gas bubbles can also be reactive to further enhance the cleaning and/or sanitizing properties of the water. The oxygenated water 54 produced by electrolysis may also contain hydrogen peroxide, which is a strong oxidizer and can further boost the sanitizing properties of the water.

0083Sparging may result in the introduction of "micro-bubbles" or "nano-bubbles". Micro-bubbles and nano-bubbles have a size that is generally too small to break the surface tension of the liquid. As a result these bubbles remain suspended indefinitely in the liquid. Indefinite suspension of bubbles allows for increased concentration of bubbles, and ultimately, super-saturation of water with the gas bubbles.

0084<figref idref="f0002">FIG. 6</figref> is a diagram illustrating an embodiment similar to that of <figref idref="f0002">FIG. 5</figref>, but further including a second electrolysis cell (or other device to accomplish sparging) 50 downstream of functional generator 10 for additional electrolysis and oxygen generation to produce a reactive froth with superior cleaning or sanitizing capacity. In one embodiment, the super-oxygenated anolyte and catholyte outputs from functional generator 10, represented by arrows 51 and 52, are passed through the second electrolysis cell 50, separately through two separate chambers. In another embodiment, one of the outputs, such as the super-oxygenated anolyte output, is passed through the second cell 50 while the other output, such as super-oxygenated catholyte output, bypasses the second cell 50, as shown by arrow 55. By electrochemically activating water prior to electrolysis by the additional cell 50, less electrical resistance may be encountered during the electrolysis process used to sparge the liquid. In addition, more effective retention of the nano-bubbles in the final reactive froth may be attained.

0085In a further embodiment, a tank can be filled from a previously-sealed container of EA liquid or can be filled from a nearby stationary or mobile "filling station", which carries a functional generator for electrochemically activating a liquid and then loading the tank through a hose or other temporary attachment to the cleaner. After loading the EA water, the EA water is delivered to a sparging device before delivery to the surface or item to be cleaned or sanitized.

0086In yet a further embodiment, a tank can be filled from a previously-sealed container of sparged liquid or can be filled from a nearby stationary or mobile "filling station", which carries a sparging device for sparging a liquid and then loading the tank through a hose or other temporary attachment to the cleaner. After loading the sparged liquid, the liquid is delivered to a functional generator for electrochemical activation before delivery to the surface or item to be cleaned or sanitized. In one example, a sparged liquid is contained in a container having a suitable internal pressure to maintain the sparged state of the liquid until delivery or use. The container can be emptied into a tank carried by the cleaning device and/or can be configured to be connected directly into the flow path of the device, either upstream or downstream of the functional generator.

8. Electrolysis Cell

0087<figref idref="f0003">FIG. 7</figref> is a block diagram of an electrolysis cell 50 that can be used as a sparging device according to one embodiment of the present disclosure. Cell 50 includes a reaction chamber 56, an anode 57 and a cathode 58. Chamber 56 can be defined by the walls of cell 50, by the walls of a container or conduit in which electrodes 57 and 58 are placed, or by the electrodes themselves, for example. Anode 57 and cathode 58 may be made from any suitable material or a combination of materials, such as titanium or titanium coated with a precious metal, such as platinum. Anode 57 and cathode 58 are connected to a conventional electrical power supply (not shown). In one embodiment, electrolytic cell 50 includes its own container that defines chamber 56 and is located in the flow path of the liquid to be treated in the cleaning apparatus. In another embodiment, electrolysis cell 50 includes anode 57 and cathode 58 but no container. In these embodiments, the reaction chamber 56 may be defined by a container or conduit section in which the electrodes are placed.

0088In another example, the anode and cathode electrodes can be placed inside liquid tank 14, shown in <figref idref="f0001">FIGS. 1 and 2</figref>.

0089In a further example, the anode and cathode electrodes can be placed inside or along a section of conduit positioned along the liquid flow path of the cleaning apparatus.

0090Electrolysis cell 50 and its electrodes can have any physical shape and construction. For example, the electrodes can be flat plates, coaxial plates, rods, or a combination thereof. Each electrode can have a solid construction or can have one or more apertures, such as a metallic mesh.

0091During operation liquid is supplied by a source 14, such as tank 14 in <figref idref="f0001">FIGS 1 and 2</figref> and/or functional generator 10, and is introduced into electrolysis chamber 56 of electrolysis cell 50. In the embodiment shown in <figref idref="f0003">FIG. 7</figref>, electrolysis cell 50 does not include an ion exchange membrane that separates reaction products at anode 57 from reaction products at cathode 58. In the example in which tap water is used as the liquid to be treated for use in cleaning, after introducing the water into chamber 56 and applying a voltage potential between anode 57 and cathode 58, water molecules in contact with or near anode 57 are electrochemically oxidized to oxygen (O₂) and hydrogen ions (H⁺) while water molecules in contact or near cathode 58 are electrochemically reduced to hydrogen gas (H₂) and hydroxyl ions (OH^-). The reaction products from both electrodes are able to mix and form an oxygenated fluid 59 having a neutral pH and an ORP in the range of about 500 mV to about 800 mV since there is no physical barrier separating the reaction products from each other. Hydrogen gas 60 typically bubbles to the surface of the fluid surrounding the cathode 58 and escapes into the atmosphere air while oxygen gas remains suspended in water for longer periods of time since oxygen gas is much denser than hydrogen gas. As a result, fluid 59 becomes supersaturated with oxygen and has a strong ORP. If electrolysis cell 50 is placed upstream of the functional generator, the super-oxygenated, strong ORP, and reduced cluster size properties of the incoming fluid can greatly assist the electrochemical activation process within the functional generator.

0092Alternatively, for example, anode 57 can be separated from cathode 58 by using a dielectric barrier such as a non-permeable membrane (not shown) disposed between the anode and cathode.

9. Sparging Enhances Blended Anolyte and Catholyte EA Water

0093It has also been found that sparging upstream and/or downstream of the functional generator can also enhance and help retain the cleaning and/or sanitizing properties of the water.

0094A simple experiment was performed in which various types of EA water were placed in an open container and a drop of oil was placed on the water surface to measure the oil dispersion properties of each EA water type. Non-sparged anolyte EA water showed no oil dispersing properties. Non-sparged and sparged catholyte EA water showed 100% oil dispersing properties, wherein the oil was dispersed over 100% of the water surface. Non-sparged anolyte and catholyte EA water, when combined, showed 100% oil dispersion. Sparged anolyte EA water showed 50% oil dispersing properties, wherein the oil was dispersed over 50% of the water surface, as compared to 0% for the non-sparged anolyte EA water. The sparged anolyte and catholyte EA water, when combined, showed 100% oil dispersion.

0095The 50% increase in oil dispersion properties for the sparged anolyte suggests that the blended EA water has increased oil dispersion capability, which should enhance the cleaning/sanitization properties and should lengthen the time before the blended EA water neutralizes due to the increased activity in the water. Alternatively, for example, the liquid can be passed more quickly through the functional generator while retaining substantially the same cleaning/sanitizing power.

10. Example Housing For Combined Sparging Device and Functional Generator

0096<figref idref="f0004">FIGS. 8A and 8B</figref> together illustrate a housing formed by clamshell halves 62A and 62B, which together form a generally water-tight housing containing control electronics 64, functional generator 10 and sparging device 50. Housing 62 provides a convenient, compact housing for both functional generator 10 and sparging device 50 and their related control electronics 64. However, these devices can be mounted separately in other embodiments.

0097Control electronics 64 includes a printed circuit board containing electronic devices for powering and controlling the operation of functional generator 10 and sparging device 50. Housing half 62A includes an access port 65, which provides access to one or more electrical test points, and a cable 66, which provides wire connections for powering control electronics 64 and devices 10 and 50 and for controlling further elements, such as one or more pumps or valves, outside of housing 62. Housing half 62A can further include a cover plate 67 for providing a heat sink for control electronics 64. Plate 67 can further include a plurality of fins for providing additional cooling, and can also be modified to support a cooling fan, if desired. In other embodiments, a cooling fan can be provided in, on or near any other location of housing 62.

0098In one example, control circuit 64 includes a power supply having an output that is coupled in parallel with functional generator 10 and sparging device 50 and which limits the power delivered to the two devices to 150 Watts, for example. Control circuit 64 also includes an H-bridge that is capable of selectively reversing the polarity of the voltage applied to functional generator 10 and sparging device 50 as a function of a control signal generated by the control circuit. For example, control circuit 64 can be configured to alternate polarity in a predetermined pattern, such as every 5 seconds. Frequent reversals of polarity can provide a self-cleaning function to the electrodes, which can reduce scaling or build-up of deposits on the electrode surfaces and can extend the life of the electrodes.

0099In the example shown in <figref idref="f0004">FIG. 8B</figref> and similar to the example shown in <figref idref="f0002">FIG. 4</figref>, sparging device 50 is coupled upstream of functional generator 10. The arrows in <figref idref="f0004">FIG. 8B</figref> illustrate the flow path of liquid from an inlet 70 to an outlet 71. Sparging device 50 and functional generator 10 are coupled together, between inlet 70 and outlet 71 by various sections of tubing 72.

0100<figref idref="f0004">FIG. 8B</figref> illustrates an example of functional generator 10, which is implemented by modifying a commercially available cell, namely a JP102 cell from Emco Tech Co., LTD. Functional generator cell 10 has a housing that contains the electrode plates (e.g., as shown in <figref idref="f0001">FIG. 2</figref>) and has two inlets 73 and two outlets 74 and 75. One or both inlets 73 can be coupled to the sparging device 50. If one inlet is not used, that inlet can be capped closed. The output liquid produced by the anode and cathode chambers within generator 10 are supplied through separate ports to a chamber 76.

0101In the example shown in <figref idref="f0004">FIG. 8B</figref>, sparging device 50 has a tubular shape. <figref idref="f0005">FIG. 9A</figref> illustrates sparging device 50 in greater detail according to one illustrative example, wherein portions of device 50 are cut away for illustration purposes. In this example, sparging device 50 is an electrolysis cell having a tubular outer electrode 80 and a tubular inner electrode 82, which are separated by a suitable gap, such as 0.020 inches. Other gap sizes can also be used. In one example, outer electrode 80 has a solid plate construction, inner electrode 82 has a wire mesh construction, and the two electrodes are separated by a tubular dielectric mesh 84. For example, outer electrode 80 can include a titanium plate spattered with platinum, and inner electrode 82 can include a mesh of #304 stainless steel having a 1/16-inch grid. Other materials, electrode shapes and dimensions. In this example, the mesh construction of elements 82 and 84 enhances liquid flow within the gap between the two electrodes. This liquid flow is conductive and completes an electrical circuit between the two electrodes. Electrolysis cell 50 can have any suitable dimensions. In one example, cell 50 can have a length of about 4 inches long and an outer diameter of about 3/4 inch. The length and diameter can be selected to control the treatment time and the quantity of nanobubbles or microbubbles generated per unit volume of the liquid. Alternatively, for example, both electrodes can be tubular meshes, if the cell is housed in an outer lumen that contains the liquid. In a further example, the inner electrode includes a bare wire that is coaxial with the outer electrode. Numerous variations can be utilized.

0102Cell 50 can be coupled at any suitable location along the liquid flow path, such as by splicing the cell between two pieces of conduit such that the liquid flows through the cell, in the direction of the arrows shown in <figref idref="f0004">FIG. 8B</figref>. Any method of attachment can be used, such as through plastic quick-connect fittings 86.

0103<figref idref="f0005">FIG. 9B</figref> illustrates sparging device 50 according to another embodiment of the disclosure. In one example shown in <figref idref="f0005">FIG. 9B</figref>, sparging device 50 includes a commercially available oxygenator 90, which is mounted within a container 91 having an inlet 92 and an outlet 93. For example, oxygenator 90 can include the OXYGENATOR Bait Keeper available from Aqua Innovation, Inc. of Bloomington, MN, which is described in more detail in <patcit id="pcit0003" dnum="US6689262B"><text>Senkiw U.S. Patent No. 6,689,262</text></patcit>. Oxygenator 90 has a pair of externally-exposed electrodes 94 formed by a planar, circular wire mesh and a planar, circular plate that are parallel to one another and separated by a small gap to form a reaction chamber. Container 91 can be positioned at any suitable location along the liquid flow path.

11. Example of a Hard and/or Soft Floor Cleaning System

0104The various functional generators and sparging devices discussed above can be implemented in a variety of different types of cleaning or sanitizing systems. For example, they can be implemented on an onboard (or off-board) mobile (or immobile) surface cleaner, such as a mobile hard floor surface cleaner, a mobile soft floor surface cleaner or a mobile surface cleaner that is adapted to clean both hard and soft floors or other surfaces, for example.

0105<figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref> illustrate a mobile hard floor surface cleaner 100 in accordance with one or more exemplary embodiments of the present disclosure. <figref idref="f0006">FIG. 10A</figref> is a side elevation view of cleaner 100. <figref idref="f0007">FIG. 10B</figref> is a perspective view of cleaner 100 having its lid in a closed position, and <figref idref="f0008">FIG. 10C</figref> is a perspective view of cleaner 100 having its lid in an open position.

0106In one example, cleaner 100 is substantially similar to the Tennant T5 Scrubber-Dryer as shown and described in the T5 Operator Manual Rev. 02, dated September 9, 2006, and the T5 Parts Manual Rev. 02, dated November 11, 2006, for example, which has been modified to include a sparging device and a functional generator, such as but not limited to those shown in <figref idref="f0004">FIGS. 8A and 8B</figref> or any of the other embodiments shown or described herein and/or combinations thereof.

0107In this example, cleaner 100 is a walk-behind cleaner used to clean hard floor surfaces, such as concrete, tile, vinyl, terrazzo, etc. Alternatively, for example, cleaner 100 can be configured as a ride-on, attachable, or towed-behind cleaner for performing a scrubbing operation as described herein. In a further example, cleaner 100 can be adapted to clean soft floors, such as carpet, or both hard and soft floors in further embodiments. Cleaner 100 may include electrical motors powered through an on-board power source, such as batteries, or through an electrical cord. Alternatively, for example, an internal combustion engine system could be used either alone, or in combination with, the electric motors.

0108Cleaner 100 generally includes a base 102 and a lid 104, which is attached along one side of the base 102 by hinges (not shown) so that lid 104 can be pivoted up to provide access to the interior of base 102. Base 102 includes a tank 106 for containing a liquid or a primary cleaning and/or sanitizing liquid component (such as regular tap water) to be treated and applied to the floor surface during cleaning/sanitizing operations. Alternatively, for example, the liquid can be treated onboard or offboard cleaner 100 prior to containment in tank 106. Tank 106 can have any suitable shape within base 102, and can have compartments that at least partially surround other components carried by base 102.

0109Base 102 carries a motorized scrub head 110, which includes one or more scrubbing members 112, shrouds 114, and a scrubbing member drive 116. Scrubbing member 112 may include one or more brushes, such as bristle brushes, pad scrubbers, microfibers, or other hard (or soft) floor surface scrubbing elements. Drive 116 includes one or more electric motors to rotate the scrubbing member 112. Scrubbing members 112 may include a disc-type scrub brush rotating about a generally vertical axis of rotation relative to the floor surface, as shown in <figref idref="f0006 f0007 f0008">FIGS 10A-10C</figref>. Alternatively, for example, scrubbing members 112 may include one or more cylindrical-type scrub brushes rotating about a generally horizontal axis of rotation relative to the hard floor surface. Drive 116 may also oscillate scrubbing members 112. Scrub head 110 may be attached to cleaner 100 such that scrub head 110 can be moved between a lowered cleaning position and a raised traveling position. Alternatively, for example, cleaner 100 can include no scrub head 110 or scrub brushes.

0110Base 102 further includes a machine frame 117, which supports source tank 106 on wheels 118 and castors 119. Wheels 118 are driven by a motor and transaxle assembly, shown at 120. The rear of the frame carries a linkage 121 to which a fluid recovery device 122 is attached. In the embodiment of <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>, the fluid recovery device 122 includes a vacuum squeegee 124 that is in vacuum communication with an inlet chamber in recovery tank 108 through a hose 126. The bottom of source tank 106 includes a drain 130, which is coupled to a drain hose 132 for emptying source tank 106. Similarly, the bottom of recovery tank 108 includes a drain 133, which is coupled to a drain hose 134 for emptying recovery tank 108. Alternatively, for example, one or both of the source tank and recovery tank and related systems can be housed in or carried by a separate apparatus.

0111In a further exemplary embodiment, the fluid recovery device includes a non-vacuumized mechanical device for lifting the soiled solution away from the floor surface and conveying the soiled solution toward a collection tank or receptacle. The non-vacuumized mechanical device can include, for example, a plurality of wiping media such as pliable material elements, which are rotated into contact with the floor surface to engage and lift the soiled solution from the floor surface.

0112In a further embodiment, cleaner 100 is equipped without a scrub head, wherein the liquid is dispensed to floor 125 for cleaning or sanitizing without a scrubbing action. Subsequently, fluid recovery device 122 recovers at least part of the dispensed liquid from the floor.

0113In another embodiment, cleaner 100 includes a wand sprayer and extractor or other attachment (not shown) that can be used to clean off-floor surfaces.

0114Cleaner 100 can further include a battery compartment 140 in which batteries 142 reside. Batteries 142 provide power to drive motors 116, vacuum fan or pump 144, and other electrical components of cleaner 100. Vacuum fan 144 is mounted in the lid 104. A control unit 146 mounted on the rear of the body of cleaner 100 includes steering control handles 148 and operating controls and gages for cleaner 100.

0115Liquid tank 106 is filled with a liquid to be treated for cleaning and/or sanitizing use, such as regular tap water. In one embodiment, the liquid is free of any surfactant, detergent or other cleaning chemical. Cleaner 100 further includes an output fluid flow path 160, which includes a pump 164, a sparging device 161 and a functional generator 162. Tank 106, sparging device 161, functional generator 162 and pump 164 can be positioned anywhere on cleaner 100. In one embodiment, sparging device 161 and functional generator 162 are similar to those shown in <figref idref="f0004">FIGS. 8A and 8B</figref> and are mounted within a housing 150 that is carried within base 102. Pump 164 is mounted beneath source tank 106 and pumps water from tank 106 along flow path 160, through sparging device 161 and functional generator 162 to the vicinity of scrub head 110 an ultimately to floor 125, wherein recovery device 122 recovers the soiled liquid and returns it to recovery tank 108. The arrows in <figref idref="f0006">FIG. 10A</figref> illustrate the direction of liquid flow from tank 106, through flow path 160, to floor 125 and then from recovery device 122 to recovery tank 128. Alternatively, for example, a second sparging device 163 (shown in <figref idref="f0009">FIG. 11</figref>) can be positioned downstream of functional generator 162. Similarly, pump 164 can be positioned downstream or upstream of any of the components along flow path 160. Alternatively, for example, pump 164 can be removed and the flow path 160 configured such that water passes along flow path 160 by the operation of gravity. Any suitable type or model of pump can be used. For example, pump 164 can include a SHURflo SLV10-AB41 diaphragm pump (available from SHURflo, LLC of Cypress California) having an open flow capacity of 1.0 gallons/minute (gpm). In this example, a pump having a small open flow capacity can be used since the flow path 160 in this example has little or no back pressure. When enabled, pump 164 can be controlled to pump at any suitable rate, such as at any rate greater than zero gpm and up to 1.0 gpm. For example the rate can be set to a predetermined rate or an adjustable rate within the range of 0.1 gpm to 1.0 gpm, or within the range of 0.15 gpm to 0.75 gpm. Larger rates can be achieved with larger pumps, if desired.

0116In one embodiment of the disclosure, the control unit 146 is configured to operate pump 164, sparging device 161 and functional generator 162 in an "on demand" fashion. Pump 164 is in an "off" state and sparging device 161 and functional generator 162 are de-energized when cleaner 100 is at rest and not moving relative to the floor being cleaned. Control unit 146 switches pump 164 to an "on" state and energizes sparging device 161 and functional generator 162 when cleaner 100 travels in a forward direction relative to the floor, as indicated by arrow 165. In the "on" state, pump 164 pumps water from tank 106 through flow path 160 to the vicinity of scrub head 110. Thus, sparging device 161 and functional generator 162 generate and deliver EA water "on demand".

0117As the water passes along flow path 160, sparging device 161 and functional generator 162 temporarily restructure the water by injecting nanobubbles into the water so that it becomes highly oxygenated and by electrochemically activating the water and separating the activated water into a catholyte output stream and an anolyte output stream. The functional generator changes the oxidation reduction potential (ORP) of the catholyte and anolyte output streams. As discussed above, normal tap water is made of large conglomerates of unstructured water molecules, which are too large to move efficiently without a surfactant to break the water's surface tension. The catholyte output stream becomes highly alkaline with a pH of about 11, for example, and is structured with smaller clusters of water molecules, which penetrate at a much faster rate when used for cleaning purposes. The alkaline water is abundant with electrons and is called reducing water. It has the capacity to penetrate dirt molecules and clean surfaces, mimicking a surfactant-based cleaning solution. The anolyte output stream becomes highly acidic, with a pH of about 3, for example. The resulting acidic water lacks electrons and is called oxidizing water. As such, the acidic water has the capacity to reduce bacteria and other harmful organisms by depriving them of electrons.

0118Alternatively, for example, one or more tanks 106 can be filled with sparged water, non-sparged EA water (catholyte and/or anolyte), or sparged EA water, which is then dispensed by cleaner 100. For example, tank 106 can be filled from a previously-sealed container of EA water or can be filled from a nearby stationary or mobile "filling station", which carries a functional generator for electrochemically activating water and then loading the tank 106 through a hose or other temporary attachment to cleaner 100. An additive, if needed, can be added to the pre-electrochemically activated water to maintain the electrochemically activated state. In the case in which tank 106 is filled with sparged non-EA water, cleaner 100 can include a functional generator to electrochemically activate the water prior to dispensing the water. In the case in which tank 106 is filled with non-sparged EA water, cleaner 100 can dispense the non-sparged EA water without further treatment or can include a sparging device to sparge the water prior to dispensing the water. If tank 106 is filled with sparged EA water, cleaner 100 can dispense the liquid with or without further treatment by an onboard functional generator and/or an onboard sparging device. Alternatively, for example, an additional sparging device can be implemented onboard the cleaner to sparge the EA water prior to distribution.

0119As described in more detail below, flow path 160 can remain separate along the entire length of flow path 160. The separate flow streams can be routed to separate liquid dispensers. Pump 164 can represent a single pump or multiple pumps for multiple flow paths.

0120In an embodiment in which cleaner 100 is configured to selectively dispense one or both the anolyte or catholyte EA water outputs, cleaner 100 can also include one or more waste water flow paths from functional generator 162 for routing unused catholyte or anolyte EA water from housing 150 to recovery tank 108 or a separate waste water tank. A flow path can also be provided for routing unused catholyte or anolyte to a buffer or reservoir (not shown in <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>) for later use by cleaner 100. For example if cleaner 100 is operated in a cleaning only mode, the anolyte EA water produced by functional generator 162 is not needed and can be routed to recovery tank 108 or to a buffer or separate storage tank for later use, such as in a disinfecting operating mode.

0121If cleaner 100 is operated in a disinfecting only mode, the catholyte EA water produced by functional generator is not needed and can be routed to recovery tank 108 or to a buffer or separate storage tank for later use, such as in a cleaning operating mode. In a cleaning and disinfecting operating mode, both the catholyte EA water and the anolyte EA water are routed along flow path 160 to be applied to the floor either simultaneously or sequentially. The catholyte EA water can be applied to the floor surface to clean the floor surface and then removed prior to application of the anolyte EA water to the same floor surface for disinfecting purposes. The catholyte and anolyte EA water can also be applied in a reverse order. Alternatively, for example, cleaner 100 can be configured to apply intermittently catholyte EA water for a short period of time followed by application of anolyte EA water, or vice versa. The various operating modes that control whether catholyte and/or anolyte EA water are applied and at what times, concentrations, flow rates and proportions (such as those described with reference to <figref idref="f0001">FIG. 2</figref>) can be controlled by the operator through control unit 146.

0122In a further embodiment, cleaner 100 can be modified to include two separate cleaning heads, one for dispensing and recovering anolyte EA water and one for dispensing and recovering catholyte EA water. For example, each head would include its own liquid dispenser, scrub head and squeegee. One can follow the other along the travel path of the cleaner. For example, the leading head can be used for cleaning, while the trailing head can be used for sanitizing.

0123It has been found that when the two liquids streams containing the anolyte EA water and the catholyte EA water are applied to the surface being cleaned at the same time through separate output streams, the two liquids, although blended or combined on the surface, retain their individual enhanced cleaning and sanitizing properties during a typical resident time on the surface. For example, as cleaner 100 advances at a typical rate across the surface being cleaned, the residence time on the surface between distribution to the surface and then recovery by vacuum squeegee 124 is relatively short, such as about three seconds.

0124After recovery, the nanobubbles begin to diminish and the alkaline and acidic liquids begin to neutralize. Once neutralized, the electrochemical properties, including the pH, of the recovered, blended liquid, reverts to those of regular tap water.

0125Sparging device 161 and functional generator 162 can be powered by batteries 142 or by one or more separate power supplies that are powered by or independent of batteries 142 and adapted to provide the electrodes with the desired voltage and current levels in a desired waveform. In one example, sparging device 161 and functional generator 162 are electrically coupled in parallel with one another and powered by batteries 142 through a control circuit such as that shown in <figref idref="f0004">FIG. 8A</figref>, which intermittently reverses the polarity applied to the devices.

0126The liquid distribution path of cleaner 100 can also include, if desired, one or more filters for removing selected components or chemicals from the feed water or the produced EA water to reduce residue left on the surface being cleaned. The path can also include an ultraviolet (UV) radiation generator for UV-treating the liquid to reduce viruses and bacteria in the liquid.

0127<figref idref="f0009">FIG. 11</figref> is a block diagram illustrating the liquid distribution flow path 160 of cleaner 100 in greater detail according to an embodiment of the disclosure. For simplicity, the wastewater flow path to recovery tank 108 and other components of cleaner 100 are not illustrated in <figref idref="f0009">FIG. 11</figref>. The elements in flow path 160 can be rearranged upstream or downstream relative to one another in other embodiments. Also, the particular elements along flow path 160 may vary greatly from one embodiment to the next, depending upon the particular application and platform being implemented. Some elements may be removed, while others can be added. For example, in one embodiment, sparging device 161 may be eliminated, while in another embodiment, functional generator 162 may be eliminated. The elements shown in dashed lines are not present in the example shown in <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>, but may be included in other embodiments. The embodiment shown in <figref idref="f0009">FIG. 11</figref> is merely exemplary.

0128The liquid or feed water in tank 106 is coupled to the input of functional generator 162 through conduit sections 170, 171, pump 164 and sparging device 161. Pump 164 can include any suitable type of pump, such as a diaphragm pump. Other types of pumps can also be used.

0129As discussed above, an additive or boosting compound, such as an electrolyte (e.g., sodium chloride) or other compound, can be added to the feed water at any desired concentration and at any desired location along the flow path upstream of functional generator 162. For example, the additive can be added to the water within tank 106. In a further example, an additive flow-through device 173 can be coupled in-line with the flow path, such as downstream (or upstream) of pump 164 for inserting the additive into the feed water. However, such an additive is not required for many cleaning applications and types of liquid, such as regular tap water. In some applications an additive can be used to further boost the respective pH values of the anolyte and catholyte outputs of the functional generator even further away from a neutral pH, if desired.

0130Sparging device 161 can be located anywhere along the flow path between liquid source 106 and functional generator 162, or anywhere downstream of functional generator 162. In one embodiment, sparging device includes an electrolysis cell, such as that shown in <figref idref="f0005">FIGS. 9A or 9B</figref> for sparging the liquid by electrolysis. However, other types of sparging devices can also be used, such as those discussed above.

0131In applications in which an additional detergent is desired, cleaner 100 can be modified to further include a source 180 of a cleaning agent, which is supplied to the input of functional generator through conduit sections 181, 182 and pump 183 (all shown in dashed lines). Alternatively, for example, pump 183 can supply the cleaning agent to one or more of the flow paths 160 downstream of functional generator 162 or to the flow path upstream of pump 164, for example. Mixing member 184 mixes the supplied cleaning agent with the feed water from liquid source 106.

0132The flow of cleaning agent is generated substantially independently of the volume of cleaning agent in supply 180. A check valve (not shown) can be installed in line with conduit section 170 to prevent the back flow of cleaning agent and primary cleaning liquid component to tank 106 when fluid mixing member 184 is upstream of pump 164. Pump 183 can include any suitable pump, such as a solenoid pump. An example of a suitable solenoid pump is pump number ET200BRHP sold through Farmington Engineering of Madison, CT and manufactured by CEME. Another suitable pump is the SV 653 metering pump manufactured by Valcor Scientific. Other types of pumps can also be used for pump.

0133A controller 186 (shown in dashed lines) controls the operations of pump 183 through a control signal 187. One suitable controller is part number QRS2211C (either 24V of 36V) sold by Infitec Inc. or Syracuse, NY. In accordance with one embodiment, signal 187 is a pulsed signal that provides power relative to ground (not shown) and controls the duration over which the pump drives the cleaning agent through conduit 182. For example, control signal 187 can turn pump 183 on for 0.1 seconds and off for 2.75 seconds to produce a low volume output flow of concentrated cleaning agent. Other on/off times can also be used. In addition, pumps 164 and 183 can be eliminated and the liquid and cleaning agent can be fed by another mechanism, such as gravity. In the example shown in <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>, cleaner 100 does not include elements 180, 183, 184 and 186 since no additional cleaning agent is used.

0134Functional generator 162 has a catholyte EA water output 190 and an anolyte EA water output 192. Flow path 160 includes a separate flow path 160A and 160B (shown in dashed lines) for each output 190 and 192. The relative flows through the individual or combined flow paths can be controlled through one or more valves or other flow control devices 195 placed along the paths.

0135Buffers or reservoirs 196 can be placed along paths 160, 160A and/or 160B to collect any catholyte or anolyte produced by functional generator 162 but not immediately delivered to fluid dispenser 194. For example, reservoirs 196 can include a burp valve, which allows the reservoir to fill, then once filled, empty into the respective flow path for use. Other types of reservoirs and valve or baffle systems can also be used. The two reservoirs 196 can be controlled to open or empty alternately, simultaneously, or on any other interval or control signal. A separate storage tank can also be used, for example, in embodiments in which the output flow rate of the dispenser exceeds the rate at which one or more of the elements in the flow path can treat the liquid to be dispensed effectively.

0136In accordance with another embodiment of the disclosure, one or more flow restriction members 198 can be placed in line with flow paths 160, 160A and/or 160B to regulate the flow of liquid if desired or needed for a particular configuration. For example, a pressure drop across flow restriction members 198 can restrict the flow of fluid to provide the desired volume flow rate. For example, a flow restriction member 198 can include a metering orifice or orifice plate that provides a desired output flow, such as of 0.2 GPM, for example, when the pressure of outlet of pump 164 is at approx. 40 psi. Other flow rates greater than or less than 0.2 GPM can also be used.

0137If a supply of cleaning agent is used, the volume flow rate of cleaning agent can be limited by pump 183 to approximately 10 cubic centimeters or less per minute, for example. Examples of elements and methods for controlling the volume flow rates of the liquid and the cleaning agent are described in more detail in <patcit id="pcit0004" dnum="US7051399B"><text>U.S. Patent No. 7,051,399</text></patcit>. However, these elements and methods are not required in one or more embodiments of the present disclosure.

0138In addition to or in replace of sparging device 161, cleaner 100 can further include one or more sparging devices 163 along combined flow path 160 or along one or both the separate flow paths 160A and 160B, downstream of functional generator 162. Sparging devices 163 can be located anywhere along flow paths 160, 160A and 160B between functional generator 162 and fluid dispenser 194. In one embodiment, sparging devices 163 include an electrolysis cell, such as that shown in <figref idref="f0005">FIGS. 9A or 9B</figref> for sparging the liquid by electrolysis. However, other types of sparging devices can also be used.

0139Flow paths 160, 160A and/or 160B can further include pressure relief valves 202 and check valves 204, which can be located at any suitable position along any flow path in cleaner 100. Check valves 204 can help to limit leakage of liquid when cleaner 100 is not in use.

0140Fluid dispenser 194 can include any suitable distribution elements for the particular application in which cleaner 100 is used. For example in one embodiment, fluid dispenser 194 directs the liquid to the hard floor surface or to another component of cleaner 100, such as a scrub head. In the case in which the scrub head has multiple brushes, fluid dispenser 194 can include a T-coupling, for example, can be used to route separate output streams to each brush, if desired. The liquid can be dispensed in any suitable manner, such as by spraying or dripping.

0141In embodiments in which the anolyte and catholyte are applied separately from one another, fluid dispenser 194 can have separate outputs, one for each type of liquid. The terms fluid dispenser and liquid dispenser can include, for example, a single dispensing element or multiple dispensing elements whether or not those elements are connected together.

0142It has also been found that the fine gas bubbles, such as nanobubbles, produced by any one of the sparging devices 161 and 163 can further delay neutralization of the anolyte EA water and the catholyte EA water when the two liquids are applied to the surface being cleaned at the same time and blended together. This benefit can exist whether the sparging device is upstream of functional generator 162, downstream of functional generator 162, in one or both of the downstream flow paths 160A and 160B or any combination of these locations.

0143It has been found that when the two liquids streams containing the anolyte EA water and the catholyte EA water are applied to the surface being cleaned at the same time, the two liquids, although blended on the surface, retain their individual enhanced cleaning and sanitizing properties during a typical resident time on the surface. For example, when cleaner 100 advances at a typical rate across the surface being cleaned, the residence time on the surface between distribution to the surface and then recovery by vacuum squeegee 124 (shown in <figref idref="f0006">FIG. 10A</figref>) is relatively short, such as about 2-3 seconds. During this time, the distinct electrochemical activation properties of the two types of liquid do not neutralize until after the liquid has been recovered from the surface. This allows the advantageous properties of each liquid to be utilized during a common cleaning operation.

0144After recovery, the nanobubbles begin to diminish and the alkaline and acidic liquids begin to neutralize. Once neutralized, the electrochemical properties, including the pH, of the recovered, blended liquid reverts to those of regular tap water.

0145Also, it has been found that the oxidation-reduction potential and other electrochemically activated properties of the blended EA water (or other EA liquid) neutralize relatively quickly in the recovery tank after recovery. This allows the recovered liquid to be disposed of almost immediately after a cleaning operation has been completed without having to wait or store the recovered liquid in a temporary disposal tank until the liquid neutralizes.

0146Cleaner 100 is simply one example of a surface cleaner with which one or more embodiments can be used. Other types of cleaners having a variety of other configurations and elements can be used in alternative embodiments of the present disclosure, such as those discussed below.

0147In a further embodiment, the liquid can be converted into an anolyte EA liquid and a catholyte EA liquid off board cleaner 100. In this embodiment, cleaner 100 can be modified to include an anolyte source tank and a catholyte source tank for receiving the anolyte EA liquid and catholyte EA liquid generated by an off-board functional generator. Functional generator 162 can therefore be eliminated on cleaner 100. The outputs from the anolyte liquid tank and the catholyte liquid tank can be or maintained as separate output flows as described above. Cleaner 100 can include one or more sparging devices such as those shown in <figref idref="f0009">FIG. 11</figref>, if desired, to sparge the combined or separate output flows.

12. Quick Neutralization of Anolyte and Catholyte Outputs

0148A further aspect of the present disclosure is directed to a method in which a liquid, such as water, having a relatively neutral pH between pH6 and pH8, such as pH7, and a relatively neutral ORP between ±50mV, such as 0mV, is passed through a functional generator to produce an anolyte EA output and a catholyte EA output. The anolyte and catholyte EA outputs have pHs outside of the range between pH6 and pH8 and have ORPs outside the range of ±50mV. For example, the anolyte EA output has a pH of about 2.5 to 6 and an ORP in a range of +100mV to +1200mV, +400mV to +900 mV, or +400 mV to +700mV. The catholyte EA output has a pH of about 8-12 and an ORP in a range of about -150mV to -1000mV, -150mV to -700mV, or -300mV to -700mV, for example.

0149The anolyte and catholyte EA outputs are applied to a surface for a residence time and then recovered from the surface and placed in a recovery tank. In one embodiment, the anolyte and catholyte EA outputs are applied to the surface within 5 seconds of the time at which the liquids are produced by the functional generator, and can be applied to the surface in a smaller time range, such as within 3 seconds of production. In one embodiment, the residence time on the surface is greater than zero seconds and less than 5 seconds, such as between 1-5 seconds, or between 2-3 seconds.

0150The anolyte and catholyte EA outputs can be blended on the surface or blended in the recovery tank. For example, the anolyte and catholyte EA outputs can be applied to the surface simultaneously as a single, blended liquid or as separate liquids or can be applied and recovered sequentially, either overlapping or non-overlapping on the surface.

0151Once recovered, the blended anolyte and catholyte EA outputs within the recovery tank quickly neutralize substantially to the original pH and ORP of the source liquid (e.g., those of normal tap water). In one example, the blended anolyte and catholyte EA outputs within the recovery tank quickly neutralize substantially to a pH between pH6 and pH8 and an ORP between ±50mV within a time window of less than 1 minute (such as within 30 seconds) from the time the anolyte and catholyte EA outputs are produced by the functional generator.

0152Thereafter, the recovered liquid can be disposed in any suitable manner. This method can be performed with cleaner 100 or any other apparatus, such as but not limited to those disclosed herein.

13. Example of a Combined Hard and Soft Floor Cleaner

0153<figref idref="f0010">FIG. 12</figref> is a block diagram of a floor cleaner 300 that is configurable with multiple types of cleaning tools and extractors to accommodate different cleaning operations while using the same overall cleaner.

0154Cleaner 300 can be configured in a soil transfer cleaning mode for performing a soil transfer cleaning operation on a soft floor surface, a deep extraction mode for performing a deep extraction cleaning operation, and a hard floor scrubbing mode for scrubbing a hard floor surface. In each of these modes, cleaner 300 removes liquid waste and debris with a fluid recovery system. However, all such components are not required in all embodiments of <figref idref="f0010">FIG. 12</figref>. The particular selection of components is provided as an example only.

0155Cleaner 300 can be configured for use by an operator that walks behind or rides on cleaner 300 or can be configured as a tow-behind cleaner, attached on to another device, be held by hand, or carried on a person, etc. Cleaner 300 may be powered through an on-board power source, such as batteries or an internal combustion engine, or powered though an electrical cord.

0156Floor cleaner 300 generally includes a mobile body 306, a motorized cleaning head 308, a liquid dispenser 310, one or more vacuums 312, at least one vacuum extractor tool 314, a vacuum squeegee 316 and a waste recovery tank 317.

0157The mobile body 306 is supported on drive wheels 318 and castor wheels 320 for travel over surface 302. In one embodiment, the drive wheels are driven by a motor 322.

0158Cleaner 300 has a liquid distribution path similar to one or more of the embodiments discussed with respect to <figref idref="f0004">FIGS. 8</figref> and <figref idref="f0005">9</figref>. Liquid dispenser 310 receives liquid, such as anolyte EA water, catholyte EA water, anolyte and catholyte EA water depending on the configuration, from a functional generator 324 and one or more sparging devices 325 and 326, as described above with respect to <figref idref="f0005">FIG. 9</figref>, for example. Alternatively, for example, cleaner 300 can include functional generator 324 without a sparging device or can include a sparging device without a functional generator. Dispenser 310 dispenses the liquid directly to floor 302 or to a component of cleaning head 308 through one or more nozzles or openings.

0159Cleaning head 308 includes a cleaning tool 328 and one or more motors 330 for driving rotation of the cleaning tool 328 about an axis that is either parallel or perpendicular to the surface 302, for example. The rotating cleaning tool 328 engages the surface 302 to perform a hard or soft floor cleaning operation, as indicated by arrow 331. Cleaning tool 328 may include one or more brushes, such as bristle brushes, pad scrubbers, microfibers, or other hard or soft floor surface scrubbing elements.

0160In accordance with one example, cleaner 300 includes a cleaning head lift, which lowers the cleaning head 308 for floor cleaning operations and raises the cleaning head 308 when not in use, such as during transport of the cleaner 300.

0161One embodiment of the cleaning head 308 is configured for use with multiple types of cleaning tools 328 in order to accommodate different cleaning operations while using the same motors 330, for example. Thus, the cleaning head 308 can be equipped with a soft floor cleaning tool 328 or a hard floor cleaning tool 328. Alternatively, for example, the cleaner 300 is configurable with separate soft and hard floor cleaning heads 308.

0162In a further embodiment, cleaner 300 can include a cleaning wand (not shown) in addition to or in place of cleaning head 308. The cleaning wand can include a first hose coupled to dispenser 310 for dispensing the EA water and a second hose coupled to the vacuum 312 for extracting soiled EA water from surface 302.

0163In the embodiment shown in <figref idref="f0010">FIG. 12</figref>, one or more vacuums 312 are used in combination with at least one vacuum extractor tool 314 to remove liquid and solid waste (i.e., soiled cleaning liquid) from cleaning tool 328 and/or surface 302. One vacuum 312 also operates with squeegee 316 to remove waste from surface 102. The waste is then deposited in one or more waste recovery tanks 317 or another location. In one embodiment, a single vacuum 312 is selectively coupled to squeegee 316 and extractor tool 314 using a vacuum path selector 332. In another embodiment, cleaner 300 includes separate vacuums 312 for vacuum squeegee 316 and extractor tool 314. One or more lifts may be provided to lift and lower each tool 314 and 316 out of and into operation.

0164In one embodiment, extractor tool 314 is used for removing liquid and solid debris from soft surfaces, whereas squeegee 316 is used for removing liquid and solid debris from hard surfaces. Other types of liquid and debris recovery tools and methods can also be used for use on hard surfaces, soft floor surfaces or both.

0165<figref idref="f0011">FIG. 13</figref> is a diagram, which shows cleaning tool 328 in greater detail. In the embodiment shown in <figref idref="f0011">FIG. 13</figref>, cleaning tool 328 includes one or more soil transfer rolls 340 for cleaning soft floors, and extractor tool 314 includes a roll extractor tool 342. The rolls are rotated by operation of one or more motors 330 (<figref idref="f0010">FIG. 12</figref>) and wipe the surface 302, which transfers soil from the surface onto soil transfer rolls 340. The rotation of rolls 340 in the directions indicated by the arrows results in portions of the soil transfer rolls being wetted with the cleaning liquid, extracted by roll extractors 340, and wiped against surface 302. For example as the rolls 340 are revolved, they engage the soft floor (e.g., carpet fibers) 302 and cause soil to be transferred from the carpet fibers to the rolls 340. Rolls 340 are further rotated and sprayed again with cleaning liquid by a nozzle 346. Subsequently, the surfaces of rolls 340 are vacuum extracted to remove the soiled cleaning liquid from the rolls, which is conveyed into recovery tank 317. Another embodiment of extractor tool 314 is in the form of a surface extractor tool 348 that is configured to remove liquid and solid waste from surface 302.

0166<figref idref="f0012">FIG. 14</figref> illustrates cleaning tool 328 in a deep extraction cleaning mode of operation, in which the cleaner 300 functions similarly to known carpet extractors, except that the cleaning liquid includes EA water and/or sparged water as discussed above. If necessary, soil transfer rolls 340 are replaced with the extractor brushes 350, the cleaning head 308 and the surface extractor 344 are moved to their operating positions, and the vacuum squeegee 316 is moved to the raised position. The liquid dispenser 310 discharges cleaning liquid to surface 302 through nozzle(s) 352 or uses nozzle(s) 354 to direct liquid onto both the surface 302 and the leading extractor brush 350. Extractor brushes 350 are driven via the motor(s) 330 to engage the floor surface 302. As the cleaner 300 progresses across the floor surface 302, surface extractor 344 engages the wetted portion of the surface to remove the soiled liquid from the surface. Also, roll extractor tools 342 remove soiled liquid and debris from brushes 350.

0167<figref idref="f0013">FIG. 15</figref> illustrates cleaning tool 328 in a hard floor scrubbing mode of operation. Initially, a hard floor scrub brush 360 is installed in a reconfigurable cleaning head 308, or a separate hard floor cleaning head 308 having the scrub brush 360 is attached to the mobile body 306 (<figref idref="f0010">FIG. 12</figref>). Also, the cleaning head 308 and the vacuum squeegee 316 are moved to their operating positions and the surface extractor tool 344 is moved to the raised position. Next the liquid dispenser 310 wets surface 302 with liquid by discharging the liquid through nozzle 352 and/or wets the surface 302 and scrub brush 360 by discharging liquid 230 through tubing 362 that is internal or external to scrub brush 360. Motor 330 rotates scrub brush 360 as it engages the wetted surface 302. As the cleaner 300 moves in the forward direction, the soiled liquid is collected by squeegee 316 and directed toward waste recovery tank 317.

0168In a further embodiment, cleaner 300 is constructed similar to a commercially-available multi-mode cleaner from Tennant Company of Minneapolis, Minnesota under the trademark READY SPACE®, but is modified to eliminate the traditional detergent supply system and replace it with a sparging device and/or a functional generator similar to one or more of the embodiments described herein. One embodiment of the READY SPACE® cleaner is described in more detail in <patcit id="pcit0005" dnum="US6735812B"><text>U.S. Patent No. 6,735,812</text></patcit>, for example.

14. Example of a Carpet Extractor System

0169<figref idref="f0014">FIG. 16</figref> is a perspective view of a carpet extractor machine 370, which has a vacuum pick-up head 371 used to extract at least a part of soiled liquid from carpet and other soft floors. Extractor 370 further includes a pair of wheels 372 and a control handle 373. During operation, an operator pulls extractor 370 rearwards in the direction of arrow 373 as the extractor dispenses a liquid to the floor being cleaned and/or one or more motorized cleaning tools 375. Cleaning tools 375 can include any known soft floor cleaning tool, such as brushs, rollers, bristles, etc. Additional details of extractor 370 are disclosed in <patcit id="pcit0006" dnum="US7059013B"><text>U.S. Patent Nos. 7,059,013</text></patcit> and <patcit id="pcit0007" dnum="US4956891A"><text>4,956,891</text></patcit>. Any of the vacuum pick-up heads disclosed therein, for example, can be used in extractor 370. In an exemplary embodiment, extractor 370 can exclude cleaning tool 375 and just dispense the liquid to the floor then extract the soiled liquid from the floor.

0170Extractor 370 is modified to include a liquid distribution system with a sparging device and/or a functional generator, such as but not limited to that disclosed in <figref idref="f0009">FIG. 11</figref> or any of the other embodiments disclosed herein. Extractor 370 can be constructed to deliver and then extract one or more of the following liquids, for example, to and from the floor being cleaned: anolyte EA water, catholyte EA water, sparged anolyte EA water, sparged catholyte EA water and sparged water. Liquid other than or in addition to water can also be used.

15. Example of an All Surface (e.g., Bathroom) Cleaner

0171<figref idref="f0015">FIG. 17</figref> is a perspective view of an all surface cleaning assembly 380, which is described in more detail in <patcit id="pcit0008" dnum="US6425958B"><text>U.S. Patent No. 6,425,958</text></patcit>. The cleaning assembly 380 is modified to include a liquid distribution path with one or more sparging devices and/or one or more functional generators such as but not limited to those shown in <figref idref="f0009">FIG. 11</figref>, for example, or any of the other embodiments disclosed herein.

0172Cleaning assembly 380 can be constructed to deliver and optionally recover one or more of the following liquids, for example, to and from the floor being cleaned: anolyte EA water, catholyte EA water, sparged anolyte EA water, sparged catholyte EA water and sparged water. Liquid other than or in addition to water can also be used.

0173Cleaning assembly 380 can be used to clean hard surfaces in restrooms or any other room having at least one hard surface, for example. Cleaning assembly 380 includes the cleaning device and the accessories used with the cleaning device for cleaning the surfaces, as described in <patcit id="pcit0009" dnum="US6425958B"><text>U.S. Patent No. 6,425,958</text></patcit>. Cleaning assembly 380 includes a housing 381, a handle 382, wheels 383, a drain hose 384 and various accessories. The accessories can include a floor brush 385 having a telescoping and extending handle 386, a first piece 387A and a second piece 387B of a two piece double bend wand, and various additional accessories not shown in <figref idref="f0015">FIG. 17</figref>, including a vacuum hose, a blower hose, a sprayer hose, a blower hose nozzle, a spray gun, a squeegee floor tool attachment, a gulper tool, and a tank fill hose (which can be coupled to ports on assembly 380). The assembly has a housing that carries a tank or removable liquid container and a recovery tank or removable recovery liquid container. The cleaning assembly 380 is used to clean surfaces by spraying the cleaning liquid through a sprayer hose and onto the surfaces. The blower hose is then used to blow dry the surfaces and to blow the fluid on the surfaces in a predetermined direction. The vacuum hose is used to suction the fluid off of the surfaces and into the recovery tank within cleaning device 380, thereby cleaning the surfaces. The vacuum hose, blower hose, sprayer hose and other accessories used with cleaning assembly 380 can be carried with the cleaning device 380 for easy transportation.

0174In some embodiments, the output flow may be very high, such as with a sprayer. If the output flow rate of a particular tool or apparatus exceeds the rate at which the functional generator or sparging device is capable of effectively treating the liquid to be sprayed, the apparatus can be configured to include one or more output reservoirs for containing the produced anolyte and catholyte separately until needed. Once primed with output liquid, the output reservoirs can provide a buffer that can supply a higher output flow rate.

16. Example of a Truck-Mounted Cleaning System

0175<figref idref="f0016">FIG. 18</figref> is a diagram illustrating a truck-mounted system 400 according to a further embodiment of the disclosure. A cleaning system, with one or more of the components of the embodiments discussed herein, such as those shown in <figref idref="f0009">FIG. 11</figref>, is mounted within truck 402. Using the reference numbers shown in <figref idref="f0009">FIG. 11</figref>, truck 402 carries a source tank 106 for containing liquid, such as regular tap water, an onboard functional generator 162 and one or more sparging devices 161 and/or 163 for electrochemically activating and sparging the water. Alternatively, for example, the sparging device(s) and/or the functional generator can be eliminated. The liquid distribution system includes one or more hoses 404, which pass the electrochemically activated water (e.g., sparged anolyte EA water and/or sparged catholyte EA water) to a cleaning wand 406, which dispenses the water onto the surface being cleaned. Cleaning wand 406 can further include an extractor, which is coupled by a hose 408 to a vacuum source that is also carried by truck 402. As the operator passes the cleaning end of wand 406 over the surface to be cleaned, the wand dispenses the EA water onto the surface while the extractor recovers soiled water and debris from the surface.

0176In a further embodiment, a wand similar to wand 406 can be implemented on any of the cleaners shown or discussed with reference to any of the figures herein, with or without additional cleaning or extraction tools or recovery systems.

17. Odorant

0177<figref idref="f0016">FIG. 19</figref> is a simplified block diagram, which illustrates a mobile or immobile cleaner 500 having an EA water distribution system according to a further embodiment, which could be implemented in any of the embodiments discussed herein. In one embodiment, the distribution system includes a source of liquid 502, a sparging device 503, a functional generator 504, a sparging device 504 and a fluid dispenser 506. In addition, cleaning system 500 includes a source of an odorous compound 508, which can be drawn into the liquid flow path by a dispersion pump 510 either upstream or downstream of functional generator 504. Other apparatus and methods can also be used to disperse the odorous compound in the liquid. For example, the odorous compound can be formed in the shape of a long lasting puck that can be placed in the flow path and dissolves slowly. Also, one or more of the sparging device 503, functional generator 504 or sparging device 505 can be eliminated in other embodiments.

0178The odorous compound adds an aroma or odor to the liquid affects, stimulates, or is perceived by the sense of smell of the user. For example, such an aroma could include a readily selectable scent that could be perceived by the user to indicate that the surface is clean. The scent could be "fresh", "sharp" or "citrus", for example. Other scents can also be used for other effects, such as for aroma therapy or for matching a situation in which the processed floor or surface is used. For example, a tropical scent can be used to match a tropical decor. The user of the cleaner can choose an appropriate scent for the situation.

0179However, it has been found that one or more of the cleaning devices disclosed herein already provide a naturally "clean" scent without the use of an extra odorous compound 508 due to the meta-stable reactive species that may be produced by the functional generator, such as chlorine.

18. Cleaning Liquid Generator

0180<figref idref="f0016">FIG. 20</figref> is a simplified block diagram of a cleaning liquid generator 600 that is mounted to a platform 601 according to an exemplary embodiment. Platform 601 can be configured to be mounted or placed in a facility on a floor, a wall, a bench or other surface, held by hand, carried by an operator or vehicle, attached on to another device, be held by hand, or carried on a person, etc. For example, platform 601 can be carried by a cleaning or maintenance trolley or mop bucket. Platform 601 includes an inlet 602 for receiving a liquid, such as tap water, from a source. Alternatively, for example, platform 601 can include a tank for holding a supply of liquid to be treated. Platform 601 further includes a sparging device 603, a functional generator 604 and a further sparging device 605. In an embodiment, platform 601 includes only one of the sparging devices 603 or 605. In a further embodiment, both sparging devices 603 and 605 are eliminated. The output of sparging device 605 (or functional generator 604, is coupled to an outlet 606. Platform 601 can also include any of the other devices or components such as but not limited to those disclosed herein.

0181The flow paths from the output of functional generator 604 can be configured to dispense anolyte EA liquid only, catholyte EA liquid only, both anolyte EA liquid and catholyte EA liquid. Unused anolyte or catholyte can be directed to a waste tank on platform 601 or to a drain outlet, for example. In embodiments in which both anolyte and catholyte EA are dispensed through outlet 606, the outlet can have separate ports, as discussed with reference to <figref idref="f0009">FIG. 11</figref>. Further, any of the embodiments herein can include a storage tank for containing the produced liquid at the output of the dispenser. Also, one or more of the sparging device 603, functional generator 604 or sparging device 605 can be eliminated in other embodiments.

0182In a further embodiment, platform can be incorporated into or on a spray bottle, such as a hand-triggered spray bottle, wherein the spray bottle contains a liquid to be sprayed on a surface and the functional generator converts the liquid to an anolyte EA liquid and a catholyte EA liquid prior to dispensing the converted liquid as an output spray. The anolyte and catholyte EA liquids can be dispensed as separate spray outputs. With a small and intermittent output flow rate provided the spray bottle, the functional generator can have a small package and be powered by batteries carried by the package or spray bottle, for example.

19. Oxidation-Reduction Potential Indicator

0183Another aspect of the disclosure relates to a method and apparatus for providing a user with a humanly-perceptible indication of the oxidation-reduction potential of EA liquid, such as but not limited to the EA liquid generated or used in any of the embodiments discussed herein. For example, the mobile hard and/or soft floor surface cleaners discussed with respect to <figref idref="f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015">FIGS. 10-17</figref> can be modified to include an onboard functional generator and a visual or audible indicator of the output liquid's oxidation-reduction potential. Similarly, any of the apparatus shown or described with reference to any of the other figures can be modified to further include such an indicator.

0184The indicator can include a measurement instrument having an analog or digital scale, an indicator light, a dial or a sound output, or can include a change in a perceptible property of the liquid such as its color. For example, a dye can be injected into the liquid based on an output of a measurement instrument or the color change can be triggered by a chemical response of an additive within the liquid to the oxidation-reduction potential of the liquid. For example certain metal ions can change the water color as a function of the water's oxidation-reduction potential.

0185In a further embodiment, the indicator provides a machine-readable analog or digital output as a function of the oxidation-reduction potential. The apparatus can include electrical hardware and software for providing a respective output signal of any type, for monitoring the oxidation-reduction potential, and/or for storing a history of the oxidation-reduction potential and any other desired indicators that reflect an operating state or condition of the apparatus. In one embodiment, the apparatus monitors the amount of EA water being used, the status of the apparatus, and the oxidation-reduction potential of the output liquid. If the oxidation-reduction potential is not within a desired range or if another error condition occurs on the apparatus, this event can be logged on the apparatus and reported to the user of the machine or transmitted to local or remote maintenance personnel through a suitable output and transmission media. For example, a local monitoring system can receive the transmission and send a corresponding report to maintenance personnel through an email message. Other maintenance events can also be logged and reported for triggering automatic maintenance steps.

0186Also, EA liquid usage can be automatically logged on the apparatus and transmitted to a local or remote monitoring system for billing purposes.

0187In a further embodiment, the apparatus can monitor, log and/or report the status and functioning states of the sparging devices through any of the above methods. The apparatus can measure, log and report time of operation for purposes of scheduling certain maintenance procedures at predetermined intervals. For example, in embodiments in which one or more of the electrodes in the functional generator or sparging devices emit ions, such as silver ions, a measure of the total time of use since the electrode was installed can be used to schedule replacement before the end of the electrode's useful life or to notify the user through an indicator.

20. Visual Indicator Representing Operation of Functional Generator

0188Another aspect of the disclosure relates to a method and apparatus for providing a user with a humanly-perceptible indication of the electrical operation of the functional generator or the sparger. The level of power consumed by the function generator (and/or sparger) can be used to determine whether the functional generator is operating correctly and therefore whether the liquid (EA anolyte and/or EA catholyte) produced by the generator is electrochemically activated to a sufficient level. Power consumption below a reasonable level can reflect various potential problems such as use of ultra-pure feed water or feed water having a generally low electrolyte content (e.g., low sodium/mineral content) such that the water does not conduct a sufficient level of electrical current within the functional generator. The current consumption can therefore also indicate high or low levels of oxidation-reduction potential, for example.

0189For example, the mobile hard and/or soft floor surface cleaners discussed with respect to <figref idref="f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015">FIGS. 10-17</figref> can be modified to include an onboard functional generator and a visual, audible or tactile indicator that is representative of the power consumed by the functional generator. Similarly, any of the apparatus shown or described with reference to any of the other figures can further include such an indicator.

0190<figref idref="f0017">FIG. 21</figref> is a block diagram of a system 700 having an indicator according to an embodiment of the disclosure, which can be incorporated into any of the embodiments disclosed herein, for example. System 700 includes power supply 702, functional generator (and/or sparger) 704, control electronics 706, cooling fan 708, current sensor, 710, logic circuit 712 and indicator 714. For simplicity, the liquid inputs and outputs of functional generator 704 are not shown in <figref idref="f0017">FIG. 21</figref>. All elements of system 700 can be powered by the same power supply 702 or by two or more separate power supplies, for example.

0191Control electronics 706 are coupled to control the operating state of functional generator 704 based on the present operating mode of system 700 and user control inputs, such as those received from control unit 146 of cleaner 100 shown in <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>. Control electronics 706 can correspond to the control electronics 64 in the embodiment shown in <figref idref="f0004">FIG. 8A</figref>, for example. Cooling fan 708 can be provided to cool control electronics 706 and can be attached to a housing containing functional generator 704 and control electronics 706, for example.

0192The power consumed by functional generator 710 can be monitored through current sensor 710, which can be coupled in electrical series with functional generator 704 and power supply 702. Current sensor 710 provides an analog or digital output 716 that is representative of the current flowing through the functional generator. Logic circuit 712 compares output 716 to predetermined threshold current levels or ranges and then operates indicator 714 as a function of the comparison. The threshold current levels or ranges can be selected to represent predetermined power consumption levels, for example.

0193Indicator 714 can include an indicator light, a dial, a sound output, a tactile output, a measurement instrument having an analog or digital scale, or any other perceptible output. In one embodiment, shown in more detail below with respect to FIG. 22, fan 708 is a lighted fan comprising one or more colored lights (e.g., LEDs) that are electrically coupled in parallel with the fan motor, as shown in <figref idref="f0017">FIG. 21</figref>. When operated by logic circuit 712 through switch 718, the lights function as indicator lights representative of the operating state of functional generator 704. However, the indicator lights can be operated by logic circuit 712 independently of the fan motor in other embodiments.

0194In one illustrative embodiment, logic circuit 712 operates the indicator lights 714 as a function of the current level sensed by current sensor 710. For example, logic circuit 712 can turn off (or alternatively, turn on) the indicator lights as a function of whether the current level sensed is above or below a threshold level. In one embodiment, logic circuit 712 operates the indicator lights in a steady "on" state when the sensed current level is above the threshold level, and cycles the indicator lights between the "on" state and an "off" state at a selected frequency to indicate a problem when the sensed current level is below the threshold level. Multiple threshold levels and frequencies can be used in other embodiments. Also, indicator 714 can include a plurality of separately-controlled indicators, such as a plurality of lights, each indicating operation within a predefined range. Alternatively or in addition, logic circuit can be configured to alter the illumination level of one or more indicator lights as a function of the sensed current level relative to one or more thresholds or ranges, for example.

0195In the embodiment shown in <figref idref="f0008">FIG. 10C</figref>, the top of housing 150 includes a cooling fan 708 for cooling the control electronics of the functional generator and sparger. In this embodiment, the cooling fan included a Mad Dog MD-80MM-4LED-F type 80mm color fan, which includes four blue LED lights to illuminate the fan assembly when the fan is powered and the fan blades are spinning at approximately 2000 RPM. This type of fan is typically used for gaming computer systems for cooling and illumination of a clear computer case that houses the computer hardware. Other types of lighted fans can be used in other embodiments.

0196In embodiment shown in <figref idref="f0008">FIG. 10C</figref>, the fan motor and LEDs are electrically coupled in parallel with one another as shown in <figref idref="f0017">FIG. 21</figref>. The fan motor and LEDs are therefore turned on and off together under the control of logic circuit 712. However, the fan motor and the LEDs can be controlled independently as mentioned above. The lighted fan provides a simple means of visually indicating the health of the functional generator. To the user, the steady glow of the indicator light provides assurance that the water being applied to the surface being cleaned is in fact electrochemically activated.

0197<figref idref="f0007">FIG. 10B</figref> illustrates cleaner 100 with the lid 104 of the cleaner is closed on top of base 102. Due to the placement of the functional generator near a gap between lid 104 and base 102, the steady glow of the cooling fan LEDs, represented by arrows 720, is visible in an area along the side of the cleaner, during normal operation. However, the indicator light can be positioned at any other location, either with the fan motor or remote from the fan motor.

0198In another embodiment, indicator 714 can be located at any location on the device in which system 700 is incorporated. For example, indicator 714 can include one or more a light emitting diodes attached to the user control panel of cleaner 100 shown in <figref idref="f0006 f0008">FIGS. 10A-10C</figref>. Alternatively, for example, indicator 714 can be located within or on a housing of cleaner 100.

0199In a further embodiment, logic circuit 712 can store a history of the current level or consumed power and any other desired indicators that reflect an operating state or condition of the apparatus. In one embodiment, if the consumed power is not within a desired range or if another error condition occurs on the apparatus, this event can be logged on the apparatus and reported to the user of the machine or transmitted to local or remote maintenance personnel through a suitable output and transmission media. For example, a local monitoring system can receive the transmission and send a corresponding report to maintenance personnel through an email message. Other maintenance events can also be logged and reported for triggering automatic maintenance steps.

0200In yet another embodiment, the indicator includes a tactile indicator, such as a vibrator, which vibrates and element of the cleaner when the power consumed by the functional generator is outside a desired range or below some threshold. For example, in the embodiment shown in <figref idref="f0006 f0007 f0008">FIGS. 10A-10C</figref>, the tactile indicator can vibrate control handle 148 or wheels 118 or 119. In an embodiment that includes a seat for the operator, the tactile indicator can selectively vibrate the seat upon an error condition.

21. Output Liquid

0201In an exemplary embodiment, a sparged reaction product is provided, which is produced at least in part from water being in contact with an anode and a cathode, the anode and cathode being separated by a membrane that permits one-way transport across the membrane of selected ions generated by the cathode or anode.

0202For example, the reaction product may include tap water or may consist essentially of water. Other fluids can also be used. The reaction product can include a combination of an anolyte and a catholyte, as discussed above. The catholyte may be characterized by a stochiometric excess of hydroxide ions, for example.

0203In a further exemplary embodiment, a reaction product is provided, which is produced from a combination of water being in contact with an anode and water being in contact with a cathode, the anode and cathode being separated by a membrane that permits one-way transport across the membrane of selected ions generated by the cathode or anode.

0204For example, the membrane permits one-way transport of hydroxide ions towards the cathode, the hydrogen ions having been generated by the anode, and wherein the membrane permits transport across the membrane of ions generated by the cathode towards the anode. The reaction product can include, for example, an anolyte produced by the anode and a catholyte produced by the cathode, wherein the catholyte is characterized by a stochiometric excess of hydroxide ions.

0205The fluid can include tap water or can consist essentially of water. Other fluids can also be used.

22. Conclusion

0206With no added surfactant or detergent, one or more embodiments provide a cleaning system that is purely non-chemical and has the ability to use typical tap water that has been electrochemically activated as the primary or sole liquid while providing effective cleaning and/or sanitizing properties. However, surfactants or detergents can be added if desired. Also, the addition of sparging upstream and/or downstream of the functional generator can further enhance the cleaning or sanitizing properties of the output liquid and production efficiency. The system can therefore provide an effective environmental solution for cleaning residential, industrial, commercial, hospital, food processing, and restaurant facilities and more. The cleaning system can be mobile or immobile.

0207Also, when tap water has been electrochemically activated as the sole cleaning liquid when used in a cleaning and/or sanitizing system, no de-foaming chamber would be required in the recovery tank of a hard or soft floor scrubbing machine.

0208The term "coupled" as used in the specification and claims can include a direct connection or a connection through one or more intermediate elements.