Abstract:
A laundry filtration system for a washing machine that combines water and one or more chemical agents to form a wash mixture. The washing machine receiving laundry with at least one contaminant. The washing machine washing the laundry during a washing operation and separating the at least one contaminant from the laundry to be in the wash mixture. The system including an extraction system in communication with the washing machine. The extraction system filtering at least part of the wash mixture to remove the at least one contaminant from the wash mixture to form a filtered wash mixture. The filtered wash mixture can be recirculated into the washing machine during the washing operation.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/997,518, filed Jun. 3, 2014. 
       INCORPORATION BY REFERENCE 
       [0002]    The disclosure of U.S. Provisional Patent Application No. 61/997,518, filed Jun. 3, 2014, is hereby incorporated by reference for all purposes as if presented herein it its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present invention generally relates to industrial laundry systems, e.g. systems for cleaning and/or treating various textiles and textile products. 
       BACKGROUND 
       [0004]      FIG. 1  illustrates a “wet cleaning” or laundry processes  10  that utilizes water to clean or launder a wide variety of materials, including specifically textiles, namely commercial textile products, woven and non-woven fabrics, linens and knits, as typically known or practiced in the art of textiles and industrial textile cleaning. By way of example, the various types of laundered textiles can include clothing, gloves, equipment covers, wipers, towels, rags, filters, sleeves, gauntlets, capes, hoods, booties, boots, shoe covers, aprons, frocks, coveralls, suits, shirts, pants, lab coats, bedding or gurney sheets, drapes, mops or mop heads, commercial floor mats or walk-off mats, table cloths, napkins, and the like. In addition, the sources for the textiles that require laundering can include, but are not limited to, the healthcare, industrial, retail and hospitality industries. 
         [0005]    As shown, a laundry process  10  generally utilizes water (e.g., from a municipal water source  20 ) that has been heated  24  (this step is typical, but optional) prior to introduction into a washing machine  30  that contains soiled textiles. The water is generally introduced into the washing machine  30  at pre-determined temperatures during the various stages or segments of a washing cycle, such as during a pre-wash stage, a break stage, a carry-over stage, a rinse stage, and the like. At some point in the washing cycle one or more chemical agents  40  or detergents are combined with the water in the washing machine, especially during the break stage, to form a wash or break bath in the washing machine  30 . The washing machine is then operated to agitate the textiles within the break bath to loosen and remove the foreign material from the textile surfaces. The break stage is often followed by one or more rinse stages in which additional chemistry can be added to the rinse water bath to further clean or treat the washed articles. 
         [0006]    The wash water with suspended contaminants is then disposed (e.g., into a laundry water recovery system or the municipal sewer system  50 ) for laundry water or heat recovery and reuse, and/or eventual processing at a waste water treatment plant. In addition, in some cases a water softening or water purification treatment  22  is applied to the municipal water to prior to heating  24  to reduce the build up of hard water scale within the heater and to improve the effectiveness of the chemical agents or detergents in the cleaning process. 
         [0007]    Despite the broad acceptance of the wet cleaning processes  10  detailed in  FIG. 1 , certain drawbacks and disadvantages remain. For example, textiles that are washed in a typical laundry process often undergo abrasion and degradation that shortens their useful life. In addition, treatments that include the use of strong chemicals, including but not limited to nonylphenol ethoxylates (NPE&#39;s), are often required to clean adequately articles that have been heavily soiled. A need therefore exists for a wet cleaning or laundry process that is more effective in cleaning and less damaging to the textiles that are being washed, and that also allows for the use of chemical treatments that may be more environmentally friendly, or “green”. It is to the provision of such a wet cleaning or laundry process that addresses these and other needs that the present disclosure is primarily directed. 
       SUMMARY 
       [0008]    Briefly described, a recirculation and filtration system receives a stream of contaminated wash water withdrawn from a washing machine during one or more pre-wash, break, or rinse stages in a washing cycle, filters the wash water to remove metallic particle, non-metallic particles such as suspended solids, dissolved solids, and other impurities, and delivers a return stream of cleaned (filtered) wash water to the washing machine. The continuous, closed loop recirculation and filtration of the wash water provides a dynamic water exchange that maintains the wash water in the washing machine, such as in a pre-wash bath, a break bath or a rinse bath, in an improved state of cleanliness that is beneficial for extracting and capturing foreign material and contaminants from the textile surface, for improving the effectiveness of the wash cycle stage, and for reducing abrasive wear on the textiles caused by the agitation of the washing machine. 
         [0009]    Those skilled in the art will appreciate various advantages and benefits of various embodiments of the present invention upon reading the following detailed description of the embodiments with reference to the below-listed drawing figures. 
         [0010]    According to common practice, the various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a block diagram of an industrial washing process as generally known in the prior art. 
           [0012]      FIG. 2  is a block diagram of an industrial washing process in accordance with one representative embodiment of the present disclosure 
           [0013]      FIG. 3  is a block diagram of a soil constituent extraction system, in accordance with another representative embodiment. 
           [0014]      FIG. 4  is a block diagram of a soil constituent extraction system, in accordance with yet another representative embodiment. 
           [0015]      FIG. 5  is an exemplary rendering of an industrial washing machine in combination with the soil constituent extraction system of  FIG. 4 . 
           [0016]      FIG. 6  is a block diagram of an industrial washing process, in accordance with yet another representative embodiment of the present disclosure. 
           [0017]      FIG. 7  shows a soiled glove prior to cleaning. 
           [0018]      FIG. 8  shows the soiled glove of  FIG. 7  after cleaning in an industrial washing process utilizing the soil constituent extraction system of the present disclosure. 
           [0019]      FIG. 9  shows metallic material that has been extracted from soiled textile articles and captured utilizing the soil constituent extraction system of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The present disclosure relates to a recirculation and filtration system that can be combined with the industrial laundry processes described above to better clean textiles and to preserve the textiles from the incidental wear and damage that can often occur during the washing process. In one embodiment of the disclosure shown in  FIG. 2 , the washing machine  130  in the laundry process  100  can include a soil constituent extraction/removal (SCE) system  134  that receives a withdrawn amount or stream  132  of contaminated wash water from the washing machine  130  during one or more stages or segments of a washing cycle, filters the wash water to remove metallic particle, non-metallic particles such as suspended solids, dissolved solids, and other impurities, and then outputs a return stream  136  of cleaned wash water to the washing machine  130 . The continuous closed loop recirculation of the wash water throughout the various segments of the washing cycle can provide for a dynamic water exchange that maintains the wash water in the washing machine, or break bath, in an improved state of cleanliness. 
         [0021]    As understood by one of skill in the art, a washing cycle or washing profile in an industrial laundry process can often include a plurality of wash stages or segments that are sequentially ordered to enhance the cleaning of the articles that are being washed. For example, a washing cycle can often include a pre-wash stage, a break stage, a carry-over stage, and a plurality of rinse stages, with both the temperature of the water and any added chemistry being controlled create a wash water bath that best performs a function at that particular stage in the washing cycle. Furthermore, the sequence, temperature and chemistry of each wash stage in a washing cycle may also be tailored for particular fabrics or soiling conditions to create customized washing profiles that are optimized to clean those particular textile articles or remove a particular type of contaminant. 
         [0022]    Filtering wash water in the washing machine  130  can be advantageous for extracting and capturing foreign material and contaminants from the textiles and for improving the effectiveness of the wash cycle. For instance, immediately removing the contaminants from the wash water with the SCE system  134 , such as during the break stage, can substantially reduce the re-deposition of the contaminant materials, such as suspended solids or dissolved solids, onto the surface of another article. In addition, immediately removing hard particulate contaminants, such as metallic dust, non-metallic dust, industrial shavings, solid particles, and the like, can also substantially reduce any abrasion on the textiles resulting from rubbing contact on the individual strands of yarn, filaments, or other textile constituent fibers during agitation of the washing machine. 
         [0023]    Also shown in  FIG. 2 , one or more chemicals  140  or chemical agents, including but not limited to detergents, solvents, PH boosters, PH reducers, softening agents, anti-microbial agents, and the like, can be combined with the water in the washing machine during the various stages of the washing cycle to create a pre-wash bath, a break bath, or a rinse bath that best performs a function at that particular stage in the washing cycle. In one aspect, the enhanced cleanliness of the wash water provided by the soil constituent extraction system  134  can further allow for the use of “green” chemistry or detergents having a reduced impact on the environment, but which otherwise may be considered less effective for cleaning in traditional industrial washing processes in which the wash water becomes progressively more contaminated such as, or example, during the break stage. 
         [0024]    One exemplary embodiment  160  of the soil constituent extraction system  134  is illustrated in  FIG. 3 , in which a single filter  162  is used to clean the withdrawn stream  132  of contaminated wash water. In one aspect the filter  162  can include any type of filter, e.g., a porous or fibrous filtration media  163 , which removes particles and impurities at or above a predetermined size range, such as those particles that are greater than or about 25 micrometers in diameter or greater than or about 5 micrometers in diameter, for example. In addition to capturing the suspended solid particles, the filtration media  163  can also be absorbent to and capture dissolved solids, oils, and other hydrocarbon-based impurities. 
         [0025]    The filter  162  of the SCE system  160  of  FIG. 3  can also include one or more magnets  164  for attracting and capturing magnetic or ferrous metallic particles from the contaminated wash water. As these metallic particles can be larger than many other types of suspended soil particles in the contaminated wash water, the filter  162  can be configured so that the withdrawn wash water stream  132  encounters the magnet  164  early in the filtration process. This can facilitate the capture and removal of metallic particles prior to encountering the filtration media  163 , thereby preventing premature saturation of the filtration media  163  with contaminates that would require maintenance or replacement. 
         [0026]    Another embodiment  170  of the soil constituent extraction system  134  having a first stage filter  172  and a separate second stage filter  176  is illustrated in  FIG. 4 . In this configuration, the first stage filter  172  can be provided with a coarser filtration media  173  configured to remove substantially all of the larger non-magnetic particles and impurities (e.g. those that are greater than or about 25 micrometers in diameter), and, optionally, one or more magnets  174  for capturing the metallic contaminants. The second stage filter  176  can be provided with fine filtration media  177  configured to remove substantially all of the remaining particles and impurities (e.g. those that are greater than or about 5 micrometers in diameter). As the fine filtration media  177  generally are more expensive than coarser filtration media  173 , staging the filters may provide for a more efficient and economical configuration that reduces the cost of operating, maintenance, and replacement. In one aspect the second stage filter  176  can also be provided with one or more magnets  178  for capturing any magnetic material that was not captured in the first stage. 
         [0027]    In addition, it is to be appreciated that additional stages and types of filtration or treatment of the wash water in the SCE system, including make-up heating and the addition of additives, are also possible and may be considered to fall within the scope of the present disclosure. For example, the SCE system could include three or more filtration vessels or stages, or the filtering could be performed by self cleaning-type filters as well as disposable media-type filters. In addition, two SCE system could also be installed to a single washing machine with a programmable control valve that directs the withdrawn wash water to a selected SCE system depending on, or example, the stage of the washing cycle or the type of textile articles in the washing system. 
         [0028]      FIG. 5  is a picture of an exemplary industrial washing machine  130  that has been combined with the soil constituent extraction system  170  illustrated in  FIG. 4  having a first stage filter  172  and a second stage filter  176 . Although not visible within its casing, the first stage filter  172  can include a magnet described above. Both filters  172 ,  176  can be isolated from the closed loop recirculation of the soil constituent extraction system  170  with valves and drained for individual maintenance or replacement of the filter media, as the rate at which the two filters become saturated with contaminants can vary independently. The soil constituent extraction system  170  can further include a variety of sensors (e.g. temperature, pressure, flow rate, etc.), control valves, actuators, and electronic control devices (e.g. a programmable logic controller (PLC) or similar processor-based controller) that control the operation of the SCE system  170  during the various washing stages (e.g. pre-wash stage, break stage, rinse stage) of the washing machine. The control system can also be configured to optimize the flow rate of the withdrawn stream  132  of contaminated wash water (e.g. pre-wash water, break water, rinse water) to maintain the bath within the washing machine  130  to a preferred degree of cleanliness. 
         [0029]    In another embodiment of the disclosure shown in  FIG. 6 , the industrial laundry process  200  can include a variety of water pre-treatment stages or steps in addition to soil constituent extraction (SCE) system  234 . These pre-treatment stages can further treat and purify the water from the municipal water source  210  before it is directed into the heater  220  and the washing machine  230 , and provide the initial volume of wash water with a “higher” level of cleanliness that, in turn, can improve the capacity of the industrial laundry process  200  for extracting and capturing foreign material and contaminants from the textile surfaces. As stated above, the enhanced cleanliness of the wash water can also reduce the incidental wear and damage on the washed textiles that is caused by the washing process or that is caused by interaction of the textile with impurities in the water, e.g. those removed from the textile or other textiles being laundered. 
         [0030]    One of the pre-treatment steps may comprise reverse osmosis (RO) purification  214  along with a RO hold/feed tank  216 . As known to one of skill in the art, RO purification  214  entails a constant but typically slow diffusion of the water through a semi-permeable membrane that can, in one aspect, purify the water to medical grade or pharmaceutical standards by removing substantially all of the salts, metal ions and other contaminants, etc. that are initially present in the municipal water. As the RO purification rate is generally slow, the hold/feed tank  216  may be required to build up a volume of purified water sufficient to fill the washing machine  230  prior to initiation of the laundry process. 
         [0031]    Another pre-treatment step can comprise subjecting the wash water or purified RO water to ultraviolet (UV) radiation  218  that kills any remaining small and active organic molecules, such as bacteria and viruses, which may still be present in the water. The highly purified water can then be heated in a water heater  220  prior to being directed into the washing machine  230 . 
         [0032]    As may be appreciated by one of skill in the art, starting a pre-wash stage, break stage, or rinse stage in the washing machine  230  with highly purified water can reduce the load of contaminants that must be removed in the SCE system  234 , thereby making it easier to maintain the bath at a high level of cleanliness during the various stages of the washing cycle. As discussed above, elevating the cleanliness of the bath can be advantageous for extracting and capturing contaminant material from the soiled textile surfaces, substantially reducing the re-deposition of the contaminants onto the surfaces of another article, and decreasing abrasion damage cause by contact between hard particulate mater, whether metal or non-metal, and the individual strands of yarn or filaments during agitation of the washing machine. 
         [0033]    Because the water bath in the washing machine  230  is maintained at a higher level of cleanliness than the bath in traditional laundry processes, the wash water may generally be considered in better condition for disposal  250  into a municipal sewer system. Nevertheless, in situations where it may be beneficial to reduce the overall consumption of water, in one aspect the industrial laundry process  200  can further include a recicle line  290  that recycles the used wash water back to the RO purification stage  214 , such as after the completion of the break cycle or any other stage, as appropriate. Additionally, it can be appreciated that the RO purification system and UV system could be moved or duplicated into loops in the laundry process other than where shown in the figures (e.g. adding an RO or UV cleaning system in the loop comprising the soil constituent extraction system, or elsewhere). 
         [0034]      FIGS. 7-9  together illustrate the effectiveness of the recirculation and filtration system, or soil constituent extraction system, of the present disclosure.  FIG. 7  is a photograph of a glove  302  that has been highly-soiled with metallic and non-metallic particles before cleaning. The same glove is shown in  FIG. 8  after washing in an industrial laundry process that includes an SCE system, and illustrates the removal of a substantial amount of particulate matter from the glove.  FIG. 9  is representative photograph showing metallic and non-metallic particles that have been extracted and captured from contaminated wash water using an SCE system with a magnet, such as those depicted in  FIGS. 3 and 4 . 
         [0035]    The foregoing description of the disclosure illustrates and describes various embodiments of the present invention. As various changes could be made in the above-described laundry recirculation and filtration system without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Furthermore, the scope of the present disclosure covers various modifications, combinations, alterations, etc., of the above-described embodiments of the present invention that are within the scope of the claims. 
         [0036]    Additionally, while the disclosure shows and describes only selected embodiments of the laundry recirculation and filtration system, it will be understood that the present invention further is capable of use in various other combinations and environments, and is capable of various changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings, and/or within the skill or knowledge of the relevant art. Furthermore, certain features and characteristics of each embodiment may be selectively interchanged and applied to other illustrated and non-illustrated embodiments of the disclosure.