Controlling Water Levels and Detergent Concentration in a Wash Cycle

This is a continuation application of U.S. Ser. No. 18/153,539, filed Jan. 12, 2023, which is a divisional application of U.S. Ser. No. 16/778,684 filed Jan. 31, 2020, now U.S. Pat. No. 11,572,652, issued Feb. 7, 2023, which claims priority under 35 U.S.C. § 119 to U.S. Provisional Application Ser. No. 62/799,496 filed Jan. 31, 2019, entitled OPTIMIZATION OF WATER LEVELS AND DETERGENT CONCENTRATION IN A WASH CYCLE. This application claims priority to and incorporates the entire contents of the applications by reference including, without limitation, the specification, claims, and abstract, as well as any figures, tables, or drawings thereof.

The application relates to methods of controlling the various phases, and in particular the soak phase, in a wash cycle of a wash machine allowing for the use of less water and lower quantities of more concentrated detergent compositions which are customized to the types of soil to be removed.

Commercial, institutional and industrial (CII) laundry facilities clean large quantities of textiles made from many materials and used in many different applications. On premises laundries (OPLs) and other industrial laundries thus use vast amounts of water at varying degrees of efficiency. Water and wastewater disposal represent significant costs for many businesses and can account for more than 50% of total operating costs at a typical commercial laundry. Thus, decreasing water usage and reusing wastewater presents an appealing avenue for improving cost efficiency of CII laundries. However, water efficiency and wastewater reuse technologies and methods cannot sacrifice cleaning performance.

CII laundries regularly deal with textiles containing a high quantity and great diversity of soils, such as vacuum soils, food soils, oily soils, bacterial, viral and other microbial contaminants, industrial and food grease, makeup soils, waxy soils, and others. Both the quantity and diversity of these soils make CII laundry soil removal a challenge. Low water machines, washer-extractor machines, and current water recycle systems often provide inefficient and/or incomplete removal of soils. Currently available machines designed to use less water often do not provide enough free water to solubilize soils and carry them away from textiles. On the other hand, to allow solubilization of these soils, some laundry machines use a lot of water. This negatively impacts the cleaning of chemistry sensitive laundry stains due to the reduced chemistry concentration in a higher volume of water. Overall today's processes not only result in greater water and wastewater costs, but also increase the wear on the textiles, causing them to wear out faster, resulting in an increase in costs related to textile repair and replacement.

In some traditional cleaning systems or methods, the washing process comprises a pre-wash or pre-soak where the textiles are wetted, and a pre-soak composition is added. The wash phase follows the pre-soak phase; a detergent composition is added to the wash tank to facilitate soil removal. In some cases, a bleach phase follows the wash phase in order to remove oxidizable stains and whiten the textiles. Next, the rinsing phase removes all suspended soils. In some cases, a laundry sour is added in a souring or finishing phase to neutralize any residual alkalinity from the detergent composition. In many cases a fabric softener or other finishing chemical like a starch is also added in the finishing step. Finally, the extraction phase removes as much water from the wash tank and textiles as possible. In some cases, a wash cycle may have two rinse and extraction phases, i.e. a rinse cycle, an intermediate-extract cycle, a final rinse cycle, and a final extraction cycle. After the wash cycle is complete, the resulting wastewater is typically removed and discarded.

Traditional CII wash machines and CII wash machines with reuse systems do not effectively manage and reduce water and wastewater usage. Traditional systems simply use high quantities of water and do not manage wastewater. Existing water recycle systems fail to effectively minimize the quantity of wastewater produced and often recycle reuse water which is too heavily soiled to facilitate soil removal in a new wash cycle. The effectiveness of water recycling depends heavily on the scale of the application, the chemical and physical properties of the recycled water (based on the nature of the cleaning chemistry and soils), and the logistical requirements of the operation. Total water recycle systems in practice can reduce water usage by up to 70% by capturing, treating, and reusing all of the wash water and rinse water. However, mere water recapture does not indicate that a water reuse system is effective. Existing water reuse and recirculation systems struggle to make reuse water usable for a variety of reasons. First, total recycle systems often get fouled with heavy soils, thus requiring frequent manual cleaning operations and a large amount of downtime which takes personnel time and effort as well as prevents the operation from using recycled water during the manual cleaning operation. Second, when reuse water is stored in a reservoir tank, it is usually idle for a period of time. This idleness creates ideal conditions for microbial growth. Further, as the water sits idle in a reservoir tank, it cools in temperature to the point where it no longer provides effective soil removal. The cooled water must be reheated or have water temperature maintained through heating components; both heating options are costly.

Furthermore, the lower quantities of water used in each wash cycle often creates a challenge for detergent composition distribution. Lower water levels used in water-efficient or water reuse systems can result in poor distribution and diffusion of detergent composition. Further, industrial soils such as makeup, blood, and greasy soils, are especially difficult to remove using a reuse water system, even where water levels would be otherwise appropriate to remove soil from articles soiled with an average level of soils.

As a result, there is a need to develop improved water reuse systems, particularly systems using the rinse water of a wash cycle. Such rinse water reuse systems could save a high percentage of total water used in washing machines and require significantly less costly filtration systems to render the water readily usable.

There is also a need to develop water recirculation systems which enable effective contact between water and linens with smaller volumes of water in the wash tank.

Existing water reuse systems use a captured water reservoir tank to deliver water to only the wash step of a washing machines cycle. This delivery of water by using a pump is faster than delivering water from the building tap pipes but is only saves a small amount of cycle time because it only speeds up the wash step filling process. There is a pressing need to save as much time and labor as possible in laundry room operations so there is a need to speed up not only the wash step filling process, but to speed up the filling process of all steps in the laundry machines cycle.

There is also a need to develop methods and compositions for sufficiently distributing and diffusing detergent compositions in a wash machine and further preventing the redeposition of soils onto textiles in a low water wash environment. There is also a need to clean with recirculated and reuse water that uses customized detergent compositions and rely on water cleaning methods which do not require the use of expensive filtration systems.

Finally, there is a need to solve the aforementioned problems without substantially increasing installation and/or operating costs for industrial wash facilities. Also, to make a major impact throughout the industry, all the systems should ideally be retrofitted in existing machines as the turnover of laundry equipment is very slow. As such, there is a need to develop water reuse systems which do not take up more space than the footprint of the original wash machine, and there is a need to develop water reuse, water distribution, and wash phase systems that can be easily incorporated into a new machine or retrofitted onto an existing machine.

Therefore, it is a principal object, feature, and/or advantage of the present application to provide an apparatus, method, and/or system that overcomes the deficiencies in the art.

It is a further object, feature, and/or advantage of the present application to provide a water reuse system that enables the cleaning and capture of water from any phase of the wash process other than the highly soiled wash phase for reuse as wash water in a subsequent wash cycle.

It is another object, feature, and/or advantage of the present application to provide a customized detergent composition and methods of use thereof which demonstrate soil removal efficacy on stubborn industrial and hospitality soils in a wash machine equipped with a water reuse system, and wherein detergent composition is customized according to the types of soils to be removed.

It is another objective of the present application to show that the new wash method works by controlling both the detergent composition concentration and the water levels used during a wash cycle and works preferably by controlling the water level and detergent concentrations to provide improved cleaning performance.

It is a further objective feature, and/or advantage of the present application to provide a water reuse system for use in conjunction with customized detergent compositions that extracts, recirculates and sprays rinse water in the wash tank of the wash machine.

The water reuse system generally comprises a small water reservoir tank equipped with a pump, which is capable of returning rinse water back into the wash tank. In an embodiment, the reservoir tank is narrow, e.g. tall and not wide, having one dimension that can be set up against a machine or wall without blocking the walking space surrounding the wash machine. In a further embodiment, the width of the reservoir tank is 16 inches or less. The reservoir tank may contain several features to prevent contamination and microbial growth in the reuse water. For example, the reservoir tank may be equipped with an auto-dump feature, a conical base which flushes debris, an antimicrobial detergent composition, a scum/debris skimming device, a filter/strainer and/or a lint screen, among others. In an embodiment, the reservoir tank is placed to the side of the wash machine, underneath the wash machine, on top of the wash machine, or above the wash machine. Additionally, a support framework or other suitable mounting device may be used to support the reservoir tank on, under or around the tank. The size of the reservoir tank is proportionate to the size of the wash tank of the wash machines incorporated in the system.

The rinse water reuse system generally also comprises tubing and connectors placing the wash tank and reservoir tank in fluid communication. In an embodiment, the tubing and connectors connect one reservoir tank to a plurality of wash machines. In a further embodiment, the tubing and connectors connect a plurality of reservoir tanks to one wash machine. Like the reservoir tank, the tubing and connectors when taken together should not expand the footprint of the original wash machine.

The system may optionally comprise a water recirculation kit which delivers wash water and/or rinse water through the window of the wash door and directly onto the linens in the wash tank via a system of nozzles. In an embodiment, the nozzle system comprises a hollow body having a central bore and a valve positioned in the central bore. The nozzle is in fluid communication with a pump and a wash tank such that the nozzle recirculates water from the pump to the wash tank, propelled by the pump. In an embodiment, the nozzle has a slit or other aperture on the tip of the nozzle through which a fluid may pass. In a further embodiment, the nozzle has a plurality of slits or other apertures allowing the passage of a fluid. In a still further embodiment, the plurality of slits is positioned radially around the center point on the nozzle tip. In a still further embodiment, the radially positioned slits are arranged in a 180° arc on the nozzle tip. In an embodiment, the valve positioned in the central bore is a shut-off valve, and preferably a quarter-turn stop valve.

In addition to the nozzle system, the water recirculation kit may further comprise a replacement window. The replacement window may provide a substitute for the window in the wash door of an original, unmodified wash machine. In an embodiment, the replacement window has an aperture in the center of the window; the aperture may be located anywhere in the window. In a preferred embodiment, the aperture is located generally in the center of the window. The aperture of the replacement window may be used to connect the nozzle system directly to the wash tank. In an embodiment, the space between the replacement window and the nozzle system is sealed by a sealant or is tight such that it does not allowance the passage of fluid between the aperture and nozzle system. In an embodiment, the replacement window is made of polycarbonate with a polyethylene covering.

In addition to the nozzle system and replacement window, the water recirculation kit may further comprise a pump. In an embodiment, the pump is a centrifugal pump. In a preferred embodiment, the pump is Laing Thermotech E5-NSHNNN3 W-14, having a voltage of 100 to 230 VAC, and 1/25 HP. The flow of the pump should be sufficient to dispense the recirculated water, including a detergent composition and soil from the wash cycle. The flow of the pump may range between about 2 gpm and about 10 gpm, preferably between about 2 gpm and about 8 gpm, and more preferably between about 4 gpm and 6 gpm.

The recirculation kit may further comprise tubing, and connectors for connecting the tubing to the nozzle system, the tubing to the pump, etc. The tubing and connectors should be configured so as to prevent the buildup of lint inside the tubing and connectors. In an embodiment, the tubing and connectors have smooth inner walls. In a further embodiment, the tubing and connectors are configured such that when applied, i.e. when connecting, for example, the pump to the nozzle system, the tubing and connectors do so at angles less than 90°, preferably 45° or less. In other words, the connectors are not 90° connectors, and the tubing is not oriented such that fluid must pass at a 90° angle. The tubing and connectors may comprise a sump connector kit for connecting the pump to the wash machine sump.

In addition to the aforementioned components, the wash machines having reuse and/or recirculation systems of the present application may further comprise a variety of energy-saving features. It may have heating elements along with thermocouples, thermostats and relays. The aforementioned systems may further comprise insulation which insulates the wash tank and/or the reservoir tank(s) to maintain water temperature, particularly for the water in the reservoir tank which will be returned back to the wash tank.

The wash machines having reuse and/or recirculation systems of the present application may be used to deliver reuse and/or recirculated water to the wash tank. The method of recirculating water from a wash machine tank may comprise introducing a supply of water to a wash machine tank, wherein the wash machine tank contains one or more soiled articles, subsequently adding a detergent composition to the wash machine tank and washing the one or more soiled articles in the wash machine tank. Next the method may comprise delivering the supply of water from the wash machine sump to at least one filter, delivering the supply of water to a pump, and delivering the supply of water back to the wash machine tank via the spray nozzle. The method of reusing rinse water may comprise the steps of washing one or more soiled articles by running the wash phase as normal, and then running the rinse phase, wherein the rinse water is extracted from the wash tank, transferred to one or more reservoir tanks, and then returned to the wash tank in a subsequent wash phase.

According to this method, the detergent composition may be added to the wash machine tank through a dispenser that is in fluid communication with the wash machine tank. Further, the detergent composition may be provided as a solid or liquid concentrate and subsequently diluted to form a use solution that is added to the wash machine tank. In a further embodiment, the use solution is added to the wash machine tank for a predetermined amount of time such that the solution is added at a desired, predetermined concentration.

According to another aspect of the application, a dispensing system for dispensing a detergent composition is provided in connection with the water reuse system. The detergent composition may be provided in concentrate or liquid and may be mixed with a diluting product. The detergent composition may be provided as a solid or a liquid, either of which may be subsequently diluted with a diluent. The dispensing system includes a dispenser including a dispenser outlet, a product container containing the detergent composition, an unprimed product line connecting the product container and the dispenser, and optionally a diluter line operatively connected to the product line to combine the detergent composition and the diluent proximate the dispenser outlet.

According to an aspect of the application, the detergent composition is diluted and added directly to the reservoir tank. The detergent composition may be provided to the reservoir tank from a dispensing system as described previously.

According to another aspect of the application, the detergent composition is added directly to the water stream or pipe coming from the reservoir tank and going to the wash tank.

According to another aspect of the application, the water reuse system of the application is built into and sold with a wash machine. In another aspect, the water reuse system of the application is adapted onto an existing machine, e.g. as a kit for retrofitting an existing machine.

The methods, systems, and/or apparatuses of the application may be conducted at low temperature conditions. For example, the entire wash cycle, using the kit of the application, may occur at a temperature of about 30° C. to about 190° C., preferably between about 30° C. to about 90° C. and more preferably between about 40° C. to about 70° C.

The methods, systems, and/or apparatuses of the application can be used with generally any type of detergent composition in generally any industry. For example, the application may be used with a detergent composition that is tailored to the washing environment, e.g. low temperature wash conditions, low water wash conditions, and/or the presence of high quantities and diversity of soil. Further, the application may be used with a detergent composition that is tailored to the type of soils to be removed, e.g. detergent compositions comprising an enzyme, a bleaching/brightening agent, a chelant, builder, and/or sequestering agent, and/or varying levels of alkalinity. Further, it should be appreciated that the application can be used in generally any type of industry requiring soil removal, for example the restaurant industry, the hotel and service industries, hospitals and other nursing facilities, prisons, universities and any other on premises laundry site.

The present application is not to be limited to or by these objects, features and advantages. No single embodiment need provide each and every object, feature, or advantage.

The embodiments described herein are not limited to particular types of CII laundry cleaning methods, apparatuses or systems, which can vary based on particular uses and applications. It is further to be understood that all terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting in any manner or scope. For example, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” can include plural referents unless the content clearly indicates otherwise. Further, all units, prefixes, and symbols may be denoted in its SI accepted form.

Numeric ranges recited within the specification are inclusive of the numbers defining the range and include each integer within the defined range. Throughout this disclosure, various numeric descriptors are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges, fractions, and individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6, and decimals and fractions, for example, 1.2, 2.75, 3.8, 1½, and 4¾ This applies regardless of the breadth of the range.

So that the disclosure is be more readily understood, certain terms are first defined. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood in the art. Many methods and materials similar, modified, or equivalent to those described herein can be used in the practice of the systems, apparatuses and methods described herein without undue experimentation, the preferred materials and methods are described herein. In describing and claiming the systems, methods, and apparatuses, the following terminology will be used in accordance with the definitions set out below.

The term “about,” as used herein, refers to variation in the numerical quantity that can occur, for example, through typical measuring techniques and equipment, with respect to any quantifiable variable, including, but not limited to, mass, volume, time, distance, pH, and temperature. Further, given solid and liquid handling procedures used in the real world, there is certain inadvertent error and variation that is likely through differences in the manufacture, source, or purity of the ingredients used to make the compositions or carry out the methods and the like. The term “about” also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term “about”, the claims include equivalents to the quantities.

The term “actives” or “percent actives” or “percent by weight actives” or “actives concentration” are used interchangeably herein and refers to the concentration of those ingredients involved in cleaning expressed as a percentage minus inert ingredients such as water or salts.

The term “weight percent,” “wt-%,” “percent by weight,” “% by weight,” and variations thereof, as used herein, refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. It is understood that, as used here, “percent,” “%,” and the like are intended to be synonymous with “weight percent,” “wt-%,” etc.

As used herein, the term “cleaning” refers to a method used to facilitate or aid in soil removal, bleaching, microbial population reduction, and any combination thereof. As used herein, the term “microbial population” refers to any noncellular or unicellular (including colonial) organism, including all prokaryotes, bacteria (including cyanobacteria), spores, lichens, fungi, protozoa, virinos, viroids, viruses, phages, and some algae.

As used herein, the term “detergent composition” includes, unless otherwise indicated, detergent compositions, laundry detergent compositions, and detergent compositions generally. Detergent compositions can include both solid, pellet or tablet, paste, gel, and liquid use formulations. The detergent compositions include laundry detergent cleaning agents, bleaching agents, sanitizing agents, laundry soak or spray treatments, fabric treatment or softening compositions, pH adjusting agents, and other similar detergent compositions.

As used herein, the term “wash water” “wash water source,” “wash liquor,” “wash water solution,” and the like, as used herein, refer to water sources that have been contaminated with soils from a cleaning application and can be used in circulating and/or recirculating water containing detergents or other cleaning agents used in cleaning applications. Alternatively, wash water can be regularly discarded and replaced with clean water for use as wash water in cleaning applications. For example, certain regulations require wash water to be replaced after a set number of hours to maintain sufficiently clean water sources for cleaning applications. Wash water, according to the application, is not limited according to the source of water. Exemplary water sources suitable for use as a wash water source include, but are not limited to, water from a municipal water source, or private water system, e.g., a public water supply or a well, or any water source containing some hardness ions.

As used herein, the terms “recirculated water” or “recirculated wash water” refer to wash water, i.e. water from the wash cycle, which is recaptured and recirculated back into the wash tank, during the same wash phase. Recirculated water may be recirculated one or more times in a single wash cycle; it may be an intermittent or a continuous recirculation, a short or long duration recirculation; preferably, it is the water in a wash cycle containing a detergent composition that is recirculated one or more times in a single wash phase and/or cycle. Recapturing and recirculating water allows for lower water use during a given wash cycle.

The terms “rinse water,” “rinse water source,” “rinse liquor,” “rinse water solution,” and the like, refer to water sources used during the rinse phase of a washing cycle. Each rinse is usually drained from the machine before the next rinse is applied, although alternative processes are known whereby the first rinse can be added to the machine without draining the wash liquor-draining and subsequent rinses can then follow. Further, as used herein, the term “intermediate rinse” means a rinse which is not the final rinse of the laundry process, and the term “final rinse” means the last rinse in a series of rinses. Rinse water, according to the application, is not limited according to the source of water. Exemplary water sources suitable for use as a wash water source include, but are not limited to, water from a municipal water source, or private water system, e.g., a public water supply or a well, or any water source containing some hardness ions.

As used herein, the term “reuse water” refers to water that has been used in a separate process or process step, such as a phase in a wash cycle, which is recaptured, pumped to a reservoir tank for holding/storage, and transferred back into the wash tank. Reuse water can be transferred back into the wash tank during any phase of the wash cycle, although reuse water is preferably used in the wash phase of a subsequent wash cycle. Reuse water can comprise all, or part of the aqueous stream used in the relevant phase, e.g. the reuse water can comprise at least part of the first feed aqueous stream in the wash phase of a wash cycle. The reuse water is typically treated, such as sanitized, before reuse.

The term “dilutable” or any related terms as used herein, refer to a composition that is intended to be used by being diluted with water or a non-aqueous solvent by a ratio of more than 50:1.

The terms “dimensional stability” and “dimensionally stable” as used herein, refer to a solid product having a growth exponent of less than about 3%. Although not intending to be limited according to a particular theory, the polyepoxysuccinic acid or metal salt thereof is believed to control the rate of water migration for the hydration of sodium carbonate. The polyepoxysuccinic acid or metal salts thereof may stabilize the solid composition by acting as a donor and/or acceptor of free water and controlling the rate of solidification.

The term “laundry” refers to items or articles that are cleaned in a laundry washing machine. In general, laundry refers to any item or article made from or including textile materials, woven fabrics, non-woven fabrics, and knitted fabrics. The textile materials can include natural or synthetic fibers such as silk fibers, linen fibers, cotton fibers, polyester fibers, polyamide fibers such as nylon, acrylic fibers, acetate fibers, and blends thereof including cotton and polyester blends. The fibers can be treated or untreated. Exemplary treated fibers include those treated for flame retardancy. It should be understood that the term “linen” is often used to describe certain types of laundry items including bed sheets, pillow cases, towels, table linen, table cloth, bar mops and uniforms.

“Soil” or “stain” refers to a non-polar oily substance which may or may not contain particulate matter such as mineral clays, sand, natural mineral matter, carbon black, graphite, kaolin, environmental dust, etc. “Restaurant soil” refers to soils that are typically found in the food service industry and include soils animal grease, synthetic greases, and proteinaceous soils.

As used herein, a solid detergent composition refers to a detergent composition in the form of a solid such as a powder, a particle, an agglomerate, a flake, a granule, a pellet, a tablet, a lozenge, a puck, a briquette, a brick, a solid block, a unit dose, or another solid form known to those of skill in the art. The term “solid” refers to the state of the detergent composition under the expected conditions of storage and use of the solid detergent composition. In general, it is expected that the detergent composition will remain in solid form when exposed to temperatures of up to about 100° F. and greater than about 120° F. A cast, pressed, or extruded “solid” may take any form including a block. When referring to a cast, pressed, or extruded solid it is meant that the hardened composition will not flow perceptibly and will substantially retain its shape under moderate stress or pressure or mere gravity, as for example, the shape of a mold when removed from the mold, the shape of an article as formed upon extrusion from an extruder, and the like. The degree of hardness of the solid cast composition can range from that of a fused solid block, which is relatively dense and hard, for example, like concrete, to a consistency characterized as being malleable and sponge-like, similar to caulking material. In some embodiments, the solid compositions can be further diluted to prepare a use solution or added directly to a cleaning application, including, for example, a laundry machine.