WO2008051746A2

WO2008051746A2 - Ozone laundering system and method

Info

Publication number: WO2008051746A2
Application number: PCT/US2007/081387
Authority: WO
Inventors: James Anthony Konides; Mark Edward Moore
Original assignee: Progressive Laundry, Llc
Priority date: 2006-10-23
Filing date: 2007-10-15
Publication date: 2008-05-02
Also published as: US20080092601A1; WO2008051746A3

Abstract

An open-loop ozone washing system for safely washing with high levels of ozone is shown and described, hi one embodiment, the system includes at least one washer having a drain in fluid communication with a sewer. The system also includes an ozone source, which is preferably an ozone generator. The system also includes an off-gas control system operably connected to at least one washer. Using such a configuration, the washer can safely wash with a liquid wash bath having about 2 ppm to about 20 ppm ozone. The present invention also includes kits and methods for converting traditional washing machines to open-loop ozone washing machines.

Description

OZONE LAUNDERING SYSTEM AND METHOD

Background

This application claims the benefit of the filing date of U.S. Provisional

Application Serial No. 60/853,535 filed October 23, 2006.

(1) Field

The present invention relates generally to ozone laundering machines and methods, and more particularly to open- loop ozone laundering machines and methods. Additionally, the present invention relates to kits for converting traditional washing machines to open-loop ozone laundering machines configured to launder with high concentrations of ozone.

(2) Related Art

Ozone is created when oxygen comes in contact with either ultraviolet light or electricity. The ultraviolet light or electricity breaks some of the oxygen molecules, each consisting of a pair of single oxygen atoms, into numerous single oxygen atoms. These single oxygen atoms reform into ozone (O₃) molecules. The use of ozone to assist in the laundering of articles is known in both closed- loop recycle systems and open-loop systems.

Closed-loop recycle laundry systems are systems that recycle the water after a cycle of the wash process. For example, water is supplied from a municipal water source to a storage tank where it is ozonated with ozone generated by an ozone generator. A washing or laundry machine is then filled with the ozonated water at the start of the wash process. During a drain cycle of the wash process, the wash bath is drained from the laundry machine, filtered, and then returned to the storage tank, thus creating the closed- loop recycle laundry system. After the wash process has completed its final drain cycle, the treated waste water can be returned to the storage tank or diverted to the sewer.

Open-loop laundry systems, on the other hand, drain and divert the laundry waste water to a sewer after each wash cycle and after each rinse cycle of the wash process.

Open-loop and closed-loop recycle systems also use different concentrations of ozone in the wash cycle. With closed-loop recycle systems, higher ozone concentrations (e.g., over 2 ppm) may be feasible because ozone off-gas is trapped within the system and re-circulated to a storage tank. See, for example, United States Patent No. 5,493,743, the entire contents of which are hereby incorporated by reference. With both open-loop and closed-loop systems, and particularly with open-loop systems, off-gassing ozone into the environment is cause for concern. With open-loop systems the ozone concentration of the wash bath is conservatively calculated so that all or most ozone is consumed by oxidative chemistry during the wash cycle (see, for example, United States Patent. No. 5,960,649, col. 8). Applicants incorporate the entire contents of United States Patent. No. 5,960,649 by reference. Using an open-loop strategy with a conventional washing machine, high levels of ozone cannot be safely used and open-loop systems commonly supplement ozone with large amounts of detergents and/or alkalis and bleaches.

Despite the existence of both open-loop and closed-loop recycle ozone systems, a large percentage of commercial washing is still being performed with traditional (non- ozone) washing machines. These types of machines use even larger amounts of chemicals, e.g., detergents and bleach, and require even more rinse water to adequately remove chemical traces from the laundered items.

Traditional machines come in a variety of configurations and may be, for example, commercial front load washers, side load washers, top load washers and tunnel washers. Figure 1 shows one example of a prior art traditional washing machine 2.

Washing machine 2 may be considered a front load washing machine, but it may also be representative of other types of traditional machines, e.g., those mentioned above. Machine 2 includes a door 4 through which clothes (not shown) are placed into machine 2 or the wash tub of machine 2. During a wash cycle, water from water source 6 is used to fill the machine through water intake 8, and chemicals from chemical feed box 10 are injected into the machine. The chemicals can include detergent/alkali or bleach. In some embodiments of the traditional machines chemicals may be added manually. Depending on the make and model of the machine, it may have both a cold water intake and a hot water intake to facilitate the addition of cold and hot water. Other machines may rely on a single water intake, e.g. for cold water, and an internal heater to heat water as desired.

During or after the wash cycle, the wash bath (water in the machine plus the additives) is drained from drain 12 into sewer 14. In the event that drain 12 becomes clogged, an overflow 16 may be used to allow fluid and/or pressure release. Machines, e.g., machine 2, commonly have vent 20 configured to prevent buildup of pressure within the machine and to accommodate draining.

Traditional washing machines, especially commercial machines, are expensive. Consumers, particularly commercial organizations, e.g., hospitals or hotels that purchase commercial machines in multiple unit quantities, may be reluctant to replace operational traditional machines with high cost ozone washing systems simply to reduce water or chemical consumption.

Thus, what is needed is a conversion kit and method that is useful for converting traditional washing machines to ozone machines. Additionally, what is needed is a way to allow traditional machines to achieve equal or superior levels of cleanliness with lower water consumption and little or no chemical consumption. The present invention is not, however, limited to conversion kits and methods of conversion. In many embodiments, the present invention will include machines manufactured as open-loop ozone machines capable of achieving the benefits of the present invention. For many, these embodiments of the present invention may be preferable.

Summary

In one embodiment, the present invention includes a method of converting traditional washing machines to ozone washing machines, and in particular to open-loop ozone washing machines. The method includes sealing the traditional machine, connecting an ozone source to the machine, connecting an off-gas control system to the machine, and regulating the addition of ozone to the machine.

In another embodiment, the method of conversion includes sealing the traditional machine. Sealing includes connecting a gas-trap to the drain line of the machine, plumbing the machine's vent to the drain line upstream of the gas-trap, plumbing the machines overflow line to the drain line upstream of the gas-trap, and installing a check valve downstream from the vacuum breaker body of the machine. In this embodiment, connecting an ozone source to the machine includes connecting an ozone generator having a venturi, such that the ozone generator is configured to dissolve ozone into water as it is being added to the machine. Connecting the ozone source also includes connecting at least one solenoid valve in between the water source and the washing machine. The present embodiment also includes connecting an off-gas control system to the washing machine, which includes connecting an ozone destruct, including a catalyst and an exhaust, to the vent. This embodiment also includes modifying a chemical feed box to inject an ozone reducing agent at the desired time during the wash cycle. Another embodiment of the present invention includes a kit for converting traditional washing machines into ozone machines. In this embodiment, the kit includes an off-gas control system configured to connect to a traditional washing machine. The kit also includes an ozone generator configured to connect to a traditional washing machine. The kit may optionally include an oxygen concentrator configured to concentrate oxygen for the ozone generator. The kit also includes instructions for the conversion. Instructions can include instructions for modifying a chemical injection portion of the washing machine to operate as an ozone-kill injection system configured to inject a reducing agent into the machine at the end of the wash cycle. Instructions may also instruct on the conversion and/or interfacing of other components.

In another embodiment, the present invention also includes an open-loop ozone washing system. The system includes at least one washer having a drain, which is preferably in fluid communication with a sewer, an ozone source, and an off-gas control system operably attached to the at least one washer. Preferably, the washer is configured to safely wash with a liquid wash bath having about 1 ppm to about 20 ppm ozone, more preferably about 2 ppm to about 10 ppm. Embodiments of the invention are also inclusive of machines that are operated with higher or lower concentrations of ozone. In another embodiment, the open-loop ozone laundry system includes at least one washer in fluid communication with a water intake and a drain. The washer also has a door configured to be sealed during operation to reduce ozone escape. An indirect ozone source is configured to dissolve ozone into water traveling through the water intake. An off-gas control system is operably attached to at least one washer. The off-gas control system includes an ozone destruct having a catalyst. A liquid wash bath is located in at least one washer. The liquid wash bath has about 2 ppm to about 10 ppm ozone. In preferred embodiments, the liquid wash bath consists essentially of water, ozone, and any laundry added to the bath (prior to the addition of reducing agent by an ozone-kill injection system). Using the present invention, adequate washing can be achieved without the addition of bleach, alkali, detergent, etc., and potentially harmful off-gassing is controlled.

The above summary was intended to summarize certain embodiments of the present invention. Methods, apparatuses, and kits of the present invention will be set forth in more detail in the figures and detailed description below. It should be apparent, however, that neither the summary nor the detailed description is intended to limit the present invention, the scope of which should be properly determined by the appended claims. Brief Description of the Drawings

Figure 1 shows a representation of a traditional washing machine. Figure 2 shows one embodiment of an ozone washing machine of the present invention.

Figure 3 shows another embodiment of an ozone washing machine according to the present invention.

Figure 4 shows a close-up view of a gas-trap of the present invention. Figure 5 is a flow chart representation of logic used to operate certain embodiments of the present invention.

Figure 6 shows a graphical approximation of the relationship between pH, ozone concentration, and relative whiteness of laundered items.

Description of the Preferred Embodiments

In the following description, like reference characters designate like or corresponding parts throughout the several views. Also in the following description, it is to be understood that such terms as "forward," "rearward," "left," "right," "upwardly," "downwardly," and the like are words of convenience and are not to be construed as limiting terms.

Figure 1, discussed above, shows one type of traditional washing machine. Figure 2 shows the traditional machine of Figure 1 that has been converted according to the present invention to create an open-loop ozone washing system 40.

The conversion includes sealing traditional machine 2. As discussed above, traditional machines are not concerned with preventing the escape of excess or potentially harmful off-gas into the washroom environment. They commonly contain drains, vents, overflow drains, chemical feed boxes, etc., that could allow undesirable amounts of off- gas exposure or the undesirable release of ozonated water.

Sealing will preferably include inserting a gas-trap 42 (discussed in more detail below) downstream of drain 12. Sealing may also include sealing an overflow drain 16 of machine 2. Overflow drains, e.g., drain 16, are commonly used in traditional machines, especially commercial grade machines, to allow excess pressure, fluid or soap to be released during the washing cycle if, for example, the drain becomes clogged.

Applicants prefer to seal overflow drain 16 by plumbing it through line 17 into drain line 12a upstream of gas-trap 42.

Sealing may also include sealing chemical feed box 10, for example, by covering it with a sealable plate or cover, for example, that is configured to allow the addition of chemicals as needed and prevent off-gas escape. In preferred embodiments, chemical feed box 10 will be configured to serve as an ozone-kill injection system, such as those discussed below, and thus should be sealed in such a manner that allows for the injection of a reducing agent. In such embodiments, it may also be necessary to configure the feed box, which is normally configured to inject chemicals at the beginning or middle of a wash cycle, so that it injects chemicals at the desired time, for example, at the end of the wash cycle. Such a modification may be made by modifying the existing logic used by the machine or by adding new logic. Sealing may also include sealing vacuum breaker body 18 positioned upstream of water intake 8. Vacuum breaker box 18 functions to prevent wash bath liquid from being pulled back into water supply 6. Breaker box 18 may be insufficient however to prevent off-gas escape. Sealing is preferably achieved by installing check valve 18a to prevent ozone off-gas from traveling to breaker body 18. Sealing may also include sealing the vent 20 of machine 2. As mentioned above, vent 20 prevents pressure build-up in the washer and accommodate draining, and is normally open into the wash room environment. If the washer contained ozone off- gas, that gas would be released directly into the wash room environment. In one embodiment, applicants seal by plumbing vent 20 to off-gas control 50. hi a preferred embodiment, applicant plumb vent 20 to tee 22 with line 22a. Upper line 22b off tee 22 connects to off-gas control system 50. Off-gas control system 50 preferably includes ozone destruct 52, e.g., the TERMINATOR series from Ozotech Inc., or D412 from Pacific Ozone, others may prefer to construct their own. Ozone destruct 52 preferably includes a catalyst (not shown), which converts ozone back to oxygen. hi many embodiments, it may also be preferable to include an exhaust fan 54 as part of the off-gas system, for pulling off-gas to the off-gas control system. Additionally, it may be desirable to have line 22c off tee 22 connect to drain line 12a in between drain 12 and gas-trap 42 to control off-gas coming from drained liquid.

The present invention also includes connecting an ozone source 44 for adding ozonated water to machine 2. The ozone source may be an indirect ozone source or a direct ozone source. As used herein, a direct ozone source is a source that has been ozonated by bubbling ozone into the water supply, for example, either inside or outside of the washer. An indirect ozone source is a source that has been ozonated by dissolving ozone, e.g., with a venturi, into the water supply. Preferably, ozone source 44 is an ozone generator, such as the ECG Series, provided by Pacific Ozone, which has been configured to use venturi 44a to dissolve ozone into water coming from water source 6 as it is being fed into machine 2 through line 9. Flow-specific Venturis may be preferred to optimize the injection and dissolution of ozone. For example, venturi 44a may be configured to dissolve ozone into a high flow rate and venturi 44b may be configured to dissolve ozone into a low flow rate. In such embodiments, it may also be desirable to use an oxygen concentrator 45 (e.g., AERO 590 by Glenn Medical, or the ONYX by Airsep) in communication with ozone generator 44. Applicants believe that such a configuration may allow for more efficient ozone generation. Methods of the present invention maybe achieved by feeding ozonated water into water intake 8 of machine 2, e.g., a cold or hot water intake. Others may feed ozonated water into a drain or a new opening designed for feeding ozonated water, etc.

Applicants prefer to connect at least one solenoid valve, e.g. 46a or 46b, in between water source 6 and machine 2 for regulating the flow of ozonated water into machine 2. In preferred embodiments, methods of the present invention include connecting a first solenoid valve 46a for regulating or allowing a high flow rate of water, and connecting a second solenoid valve 46b for regulating or allowing a low flow rate of water. Because ozone from ozone generator 44 is injected into water traveling in line 9, solenoid valves also regulate the flow of ozonated water. For example, high flow valve 46a may be used to regulate a high flow having liquid flow rate of about 5 to about 70 gal/min and including an ozone level of about 2 to about 20 ppm, and low flow valve 46b may be used to regulate a low flow ozone source having a liquid flow rate of about 2 to about 20 gal/min and an ozone level of about 2 to about 20 ppm. Using such a configuration, high flow valve 46a can be used to add ozonated water during a fill cycle until a desired water level is reached, and low flow valve 46b can be used to add ozonated water to machine 2 to maintain or to optimize ozone levels during operation. Flow rates are preferably adjusted based on the size or capacity of the washing machine, and may be based on the table below. Ozone concentration may vary depending on the soil level or wash cycle selected. For example, the table below provides an example of preferred flow rates and ozone concentrations depending on washing machine capacity and soil level.

Applicants have provided the above table to teach preferred embodiments, and it should not be used to limit the scope of the invention.

Applicants prefer to feed ozone from ozone generator 44 into the water supply downstream of solenoid valves at points 44a and 44b. Others however may prefer to feed upstream of solenoid valves, and such embodiments would also be considered within the scope of the present invention. It may also be desirable in some embodiments, to using a single venturi in inject ozone after line 9 has merged downstream of the pair of solenoid valves. Further, applicants prefer to feed ozone at a constant rate to the water supply which allow ozone concentration to be regulated by adjusting water flow. Ozone may also be fed to the water supply at a variable rate, which could be adjusted by, for example, a programmable logic controller (PLC).

In other embodiments, e.g., pay-per-use embodiments or multiple washer embodiments, it may be desirable to maintain reservoirs of ozonated water for filling, hi these tvnes of embodiments, or other embodiments, others may prefer a direct ozone source or a single gas-trap for multiple machines, or a single off-gas control for multiple machines, or any combination thereof. For example, reservoirs may include a first reservoir having a first ozone concentration and a second reservoir having a second ozone concentration. All such embodiments are considered to be within the scope of the present invention.

The method of the current embodiment also includes regulating the addition of ozone to machine 2. In most embodiments, regulating is achieved primarily through the control of ozone generator 44, or water source 6, or solenoids, e.g., 46a or 46b, or any such combination. For example, regulating may include the installing external logic devices to control ozone generators, water sources or solenoids. External logic sources are also considered to be inclusive of timing devices. Alternatively or additionally, regulating may include interfacing existing controls or logic of machine 2 with any parts of the ozone system. For example, logic for regulating the addition of hot and cold water to the traditional machine may be used to control the addition of ozonated water through the high flow or low flow solenoids.

Other embodiments of the present invention include open-loop ozone systems that are manufactured as open-loop ozone machines rather than converted from traditional machines. Figure 3 shows a rear view of one embodiment of an open- loop ozone laundry system 100. System 100 includes at least one washer 102 (rear view shown) having a drain 104 in fluid communication with a sewer 106. Fluid communication is established, at least in part, by drain line 108. Washer 102 is also in fluid communication with water source 110, which preferably includes hot water source 110a and cold water source 110b. As shown, hot water source 110a connects to hot water intake 112a through water line 114a, and cold water source 1 10b connects to cold water intake 112b through water line 114b. Both the hot water intake 112a and the cold water intake 112b feed to tub fill 116 through lines 120a and 120b, respectively. Tub fill 116 feeds the wash tub (not visible, located within washer 102) configured to hold the wash bath and any laundry contained in the wash bath. Those of ordinary skill in the art will recognize that the opposite side or front of the washer includes a door, similar to the door shown in Figure 2 that is configured to be sealed during operation to reduce ozone escape. Applicants prefer to use a silicone seal, preferably a hard silicone seal, to configure the door in such a way. System 100 also includes ozone source 122. Li the embodiment depicted, ozone source is considered to be an ozone generator 122 similar, for example, to those described above. It may also be inclusive of an oxygen concentrator, similar to those mentioned above. In this embodiment, it is preferable to have ozone generator 122 attached to, or integral with, washer 102. Ozone generator 122 ozonates water traveling through water feed line 124, which is in fluid communication with water intake 112b. Water feed line 124 can be opened and closed, e.g. through solenoid valve 123 to allow or prevent water flow. Applicants prefer to locate additional solenoid valves, e.g. 126a or 126b, along line 124 to provide variable levels of ozonation. In preferred embodiments, line 124 is split into lines 124a and 124b. Line 124a includes a first solenoid valve 126a to allow and regulate a high water flow rate (e.g., 5 to 70 gal/min). Line 124b includes a second solenoid valve 126b to allow and regulate a low water flow rate (e.g., about 2 to 20 gal/min). With a 60 pound machine for example, the high flow rate may be about 5 to about 15 or 20 gal/min and the low flow rate may be about 2 to about 4 gal/min. Line 124a and line 124b also each include a venturi 130a and 130b in ozone communication with ozone generator 122. Ozone generator 122 injects ozone indirectly into water traveling through lines 124a or 124b through venturi 130a or 130b. Venturi 130a maybe configured for its respective high flow rate, and venturi 130b may be configured for its respective low flow rate.

For example, during a fill cycle, solenoid valve 126a is opened to allow a high flow of water to travel to tub fill 116. As water travels through line 124a, venturi 130a injects and dissolves ozone into the passing water stream. This ozonated water fills the wash quickly with water having a first level of ozonation, for example, of about 2 ppm (may vary according to table above). After the fill cycle, ozone levels can be increased and maintained by opening solenoid valve 126b, which allows water to flow at a much slower rate. As water travels through line 124b, venturi 130b injects and dissolves ozone into the water stream where it is dissolved in larger concentrations due to the slow water flow, (see for example, ozone concentrations in the above table). This ozonated water can be used to bring the wash bath to, or maintain it at, desired or high ozone concentrations. Rather than use two Venturis as shown, some may prefer to use a single venturi injecting along line 124c, and such embodiments are considered to be within the scope of the present invention.

While applicants prefer injecting ozone into either water line at a constant rate, others may prefer to adjust the rate of ozone being injected, for example, with a

Programmable Logic Controller (PLC). Others may prefer other embodiments. For example, some may prefer to use a single water line and adjust the flow rate of water flowing within that single line to achieve similar results. In other embodiments, it may be desirable, rather than using an ozone generator, to add ozonated water that has previously been ozonated, for example, water that has been ozonated in an external ozonation tank. For example, ozone source 122 may be considered a reservoir having ozonated water. Such embodiments may be ideal, for example, in large washing facilities using multiple machines. In other embodiments, it may be desirable to have a first reservoir having a first ozone concentration optimized for one type of laundry and a second reservoir having a second ozone concentration optimized for a second type of laundry. All such embodiments are considered to be within the scope of the present invention.

In preferred embodiments, gas-trap 132 is located in between drain 104, which is in fluid communication with the wash tub, and sewer 106. The gas-trap is described in more detail in Figure 4.

System 100 includes an off- gas control system 140 operably attached to washer 102, which is configured to allow washer 102 to safely wash with a liquid wash bath having about 2 ppm to about 10 ppm, or about 2 ppm to about 15 ppm of ozone, or more. Off-gas control system includes ozone destruct 146, which preferably includes a catalyst for converting ozone to oxygen. Ozone destruct 146 connects vent 142 through upper branch 144a of tee 144. Off-gas from the drained liquid may also be sent to ozone destruct 146 through lower line 144b of tee 144, which connects upstream of gas-trap 132 or to gas-trap 132. Ozone off-gas may be allowed to reach ozone destruct 146 passively, however, applicants prefer to include exhaust fan 150 in fluid communication with ozone destruct 146 and vent 142 to assist in actively pulling ozone off-gas to ozone destruct 146.

System 100 also includes an ozone-kill injection system 152. Ozone-kill injection system includes a reservoir 154 for holding a reducing agent, and an injector 156 for injecting the reducing agent. Preferably, the injection system is configured to inject the reducing agent into the wash bath at a desired time, which is preferably prior to opening the washer door. Using such a system, the high levels of ozone in the wash bath can quickly be diminished and thus reduce off-gas exposure. As shown, injector 156 injects the reducing agent into injection orifice 160, which is in fluid communication with the wash bath. In many embodiments, it may also be desirable to aerosolize or inject by misting to reduce ozone off-gas within the washer. Others may prefer to inject in other ways, for example by injecting into tub fill 116. Combining various methods of injecting is also considered to be within the scope of the present invention. The preferred reducing agent is hydrogen peroxide, which may be injected in amounts ranging from less than a milliliter to several milliliters, depending on, for example, the concentration of ozone and the volume of the water bath. Applicants prefer this method because it provides quick and reliable reduction of off-gas. Others, however, may prefer to inject water or some other fluid in an attempt to dilute rather than reduce the ozone. If such a technique is used, ozone levels will preferably be reduced to below about lppm. Such embodiments are also considered to be inclusive of the present invention. Using the present invention, the liquid wash bath located within the washer can safely have and utilize ozone concentrations greater than about 2 ppm ozone when washing. In preferred embodiments, the liquid wash bath has an ozone concentration of about 2 ppm to about 15 ppm or higher, but in many embodiments, applicant believes an ozone concentration of about 3ppm to about 5ppm will be suitable. Using such concentrations of ozone, detergents, alkali, bleaches, etc., will not be necessary. For example, for most standard uses, the liquid wash bath will consist essentially of water and ozone and laundry during washing, prior to the addition of any reducing agent. In certain applications, however, e.g., very heavily soiled clothes, it may be desirable to include detergent, etc., or to use hot water from a hot water feed. Such embodiments are also considered to be within the scope of the present invention.

The system of the present invention may also include an ozone sensor 160 for measuring ozone concentration. As shown, sensor 160 is located on feed line 124 in between ozone generator and tub feed 116. Others may prefer either single or multiple sensors at a variety of locations. For example, sensors may also be located in a single or plurality of baths, drains, etc., or any combination thereof. All such embodiments are considered to be within the scope of the present invention.

Those of ordinary skill in the art will recognize that the components shown on the rear of machine 102 may be either internal or external or have portions that are both. Figure 4 shows one embodiment of a gas-trap 170 of the present invention, which may be considered similar to the gas-traps previously discussed. In this embodiment, the gas-trap is a j-trap. J-trap 170 connects at one end 172 to washer 174. The opposite end of j-trap 170 includes bend 176, which is disconnected from and positioned over drain pan 178. Fluid draining from bend 176 flows into drain pan 178 having drain pan-drain 180, which flows to sewer 182. Drain pan 178 allows any bubbles contained in the drained wash bath to dissipate prior to draining down pan-drain 180. Inputs plumbed from the vent and overflow drain (not visible, but discussed above) may be plumbed up stream of portion 176 of j-trap or along portion 184, and may be used for fluid delivery to the gas-trap and/or gas removal to the ozone destruct. Portion 176a of the j -trap is raised relative to portion 176b in a manner that allows liquid to drain and that allows liquid to pool in portion 176c to prevent ozone gas from escaping. Others may prefer other gas- traps, such as p-traps or loops for example, which could be similarly configured to prevent ozone gas from escaping.

Figure 5 shows one example of logic that could be used to operate machines of the present invention, and should not be construed as limiting the scope of the present invention. Block 200 represents selecting the desired wash load. Wash load type may be selected based on the type, size, or cleanliness of load. In some embodiments, for example, coin operated embodiments, payment block 202 may precede block 200. After load selection, wash cycle counter is initialized 204 and high flow fill 206 begins filling the wash tub with ozonated water having a first concentration. The high flow fill may be exclusively or partially ozonated water. For example, in some embodiments, logic may direct the cold or hot water input to allow water to flow to the wash bath as well. During the high flow fill, water level within the wash tub is monitored 210. In embodiments using a powered off-gas control, e.g., one having a fan, it is also desirable to activate the off-gas control.

Once the desired water level is reached within the wash tub, a wash cycle is started 212 and a low flow fill 214, preferably at a second higher ozone concentration begins. Low flow 214 can be used to bring the ozone concentration up to the desired level or maintain ozone concentrations at the desired levels during wash cycle 212. After the wash cycle, the wash tub is drained and the wash cycle counter is incremented 216. A wash cycle determination is made 220. After the first wash cycle, the high flow fill 206 is initiated and the cycle progresses as described above. After the second wash cycle, the ozone-kill injection system is activated 222. The ozone-kill injection system may also be activated by the opening of the washer door. Logic may additionally include a rinse cycle, e.g., of cold water. Figure 6 shows a graphical approximation made by the applicants of the relationship between pH, ozone concentration, and relative whiteness of laundered items. Relative whiteness is based on a scale of 1-5 with 5 being the whitest. Applicants have found that at pHs above about 7, in particular, those created by the addition of detergents, relative whiteness of laundered items diminishes with ozone washing. Using open-loop washers of the present invention, ozone concentrations of about 5 ppm can be used with out the addition of detergents to launder an item to superior relative whiteness.

Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. The novel features are pointed out in the appended claims. The disclosure, however, is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts, within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the general claims are expressed.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein, and every number between the end points. For example, a stated range of "1 to 10" should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g. 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10, as well as all ranges beginning and ending within the end points, e.g. 2 to 9, 3 to 8, 3 to 9, 4 to 7, and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 contained within the range. Additionally, any reference referred to as being "incorporated herein" is to be understood as being incorporated in its entirety. It is further noted that, as used in this specification, the singular forms "a," "an," and "the" include plural referents unless expressly and unequivocally limited to one referent.

Claims

What is claimed is:

1. An open- loop ozone laundry system comprising: at least one washer having a drain; an ozone source; and an off-gas control system operably connected to said at least one washer, wherein said washer is configured to safely wash with a liquid wash bath having about 2 ppm to about 15 ppm ozone.

2. The system of Claim 1, including a gas-trap located downstream of said drain.

3. The system of Claim 2, wherein said gas-trap is connected at its upstream end to said drain and is disconnected from and positioned above a drain pan.

4. The system of Claim 2, wherein said gas-trap is a j-trap.

5. The system of Claim 1, wherein said off-gas control system includes a vent.

6. The system of Claim 5, wherein said off-gas control system includes an exhaust fan.

7. The system of Claim 1, wherein said off-gas control system includes an ozone destruct.

8. The system of Claim 7, wherein said ozone destruct includes a catalyst.

9. The system of Claim 1, wherein said ozone source includes an ozone generator.

10. The system of Claim 1, wherein said ozone source is an indirect ozone source.

11. The system of Claim 10, wherein said indirect ozone source includes a venturi for dissolving ozone.

12. The system of Claim 1, wherein said ozone source is configured to dissolve ozone into water as water is being added to said at least one washer.

13. The system of Claim 1, further including an ozone sensor.

14. The system of Claim 13, wherein said ozone sensor is operably positioned in between said ozone generator and a wash tub of said washer.

15. The system of Claim 1, wherein said ozone source includes a first reservoir having a first ozone concentration optimized for one type of laundry and as a second reservoir having a second ozone concentration optimized for a second type of laundry.

16. The system of Claim 1, further including an ozone-kill injection system.

17. The system of Claim 16, wherein said ozone-kill injection system is configured to inject an ozone reducing agent into said at least one wash bath prior to opening said door of said washer.

18. The system of Claim 16, wherein said ozone-kill injection system further includes a supply of reducing agent.

19. The system of Claim 18, wherein said supply of reducing agent includes a supply of hydrogen peroxide.

20. The system of Claim 1, further including a liquid wash bath located in said at least one washer, said wash bath having greater than about 2 ppm ozone.

21. The system of Claim 20, wherein said liquid wash bath has an ozone concentration of about 2 ppm to about 15 ppm.

22. The system of Claim 21, wherein said liquid wash bath has an ozone concentration of about 5 ppm.

23. The system of Claim 20, wherein said liquid wash bath consists essentially of water, ozone, and laundry prior to the addition of a reducing agent.

24. An open-loop ozone laundry system comprising: at least one washer in fluid communication with a water intake, and having a door configured to be sealed during operation to reduce ozone escape; an indirect ozone source configured to dissolve ozone into water traveling through said water intake; an off-gas control system including an ozone destruct having a catalyst operably attached to said at least one washer; an ozone-kill injection system configured to inject a reducing agent into said washer as desired; and a liquid wash bath located in said at least one washer, said wash bath having about 2 ppm to about 15 ppm ozone, and consisting essentially of water, ozone and laundry prior to the addition of a reducing agent by said ozone-kill injection system.

25. A method of converting traditional washing machines in fluid communication with a drain line to open loop ozone laundry machines, said method comprising the steps of: sealing said traditional machine; connecting an ozone source for adding ozonated water to said machine; connecting an off-gas control system to said washing machine; and regulating said addition of ozone to said machine.

26. The method of Claim 25, wherein said sealing includes connecting a gas-trap to said drain line.

27. The method of Claim 25, wherein said sealing includes sealing said vent.

28. The method of Claim 27, wherein said sealing said vent includes plumbing said vent to said drain line up stream of said gas-trap.

29. The method of Claim 25, wherein said sealing includes sealing an overflow line.

30. The method of Claim 29, wherein said sealing an overflow drain includes plumbing said overflow drain into said drain line upstream of said gas-trap.

31. The method of Claim 25, wherein said sealing includes sealing a chemical feed box.

32. The method of Claim 25, wherein said sealing includes sealing a vacuum breaker body.

33. The method of Claim 32, wherein said sealing includes installing a check valve downstream of said vacuum breaker body.

34. The method of Claim 25, wherein connecting includes connecting an ozone source to a water intake of said machine.

35. The method of Claim 34, wherein said ozone source is in communication with a venturi configured to dissolve ozone into water as it is being feed into said machine.

36. The method of Claim 25, wherein said connecting includes connecting at least one solenoid valve in between said water source and said machine.

37. The method of Claim 25, wherein said connecting includes connecting a first solenoid valve for regulating a high flow ozone source, and connecting a second solenoid valve for regulating a low flow ozone source.

38. The method of Claim 37, wherein said high flow ozone source includes, depending on machine capacity and soil content, a liquid flow rate of about 5 to about 90 gal/min, and includes an ozone level of about 2 to about 20 ppm, and wherein said low flow ozone source rate includes a liquid flow rate of about 2 to about 20 gal/min and a includes an ozone level of about 2 to about 20 ppm.

39. The method of Claim 38, wherein said high flow rate is used to add said ozonated water until a desired water level is reached, and wherein said low flow rate is used to add ozonated water to said machine to increase ozone concentration within the wash bath.

40. The method of Claim 25, wherein said connecting an off-gas control system includes teeing said off-gas control system to said drain line upstream of said gas-trap.

41. The method of Claim 25, wherein said off-gas control system includes an ozone destruct.

42. The method of Claim 25, wherein said ozone destruct includes a catalyst.

43. The method of Claim 25, wherein said off-gas control system includes an exhaust fan for pulling off-gas to said off-gas control system.

44. The method of Claim 25, wherein said regulating includes external logic.

45. The method of Claim 25, wherein said regulating includes interfacing existing controls of said machine with said ozone system.

46. The method of Claim 25, further including modifying a chemical feed box to inject an ozone reducing agent at the desired time during the wash cycle.

47. A method of converting traditional washing machines to open loop ozone laundry machines, said method comprising the steps of: sealing said traditional machine, wherein said sealing includes connecting a gas-trap to said drain line, plumbing a vent to said drain line upstream of said gas-trap, plumbing an overflow line to said drain line upstream of said gas-trap, and installing a check valve down stream of a vacuum breaker body; connecting an ozone source for adding ozonated water to said machine, wherein said connecting includes connecting an ozone generator having a venturi to a fluid intake of said machine, wherein said generator is configured to dissolve ozone into water as it is being added into said machine; connecting at least one solenoid valve in between said ozone generator; connecting an off-gas control system to said washing machine, wherein said connecting includes teeing an ozone destruct including a catalyst and an exhaust to said drain line up stream of said gas-trap and downstream of said vent plumbed to said drain line; and modifying a chemical feed box to inject an ozone reducing agent at the desired time during the wash cycle.

48. A conversion kit for converting traditional washing machines to open-loop ozone laundry machines, said kit comprising: an off-gas control system configured to connect to a traditional washing machine; an ozone generator configured to connect to a traditional washing machine; and instructions for modifying a chemical injection portion of said washing machine to an ozone-kill injection system configured to inject a reducing agent at the end of the wash cycle.