Patent Grant
7210182
Conventional household clothing washers use anywhere from about 60 liters to about 190 liters of water to wash a typical load of clothing articles. The spent water and cleaning agents are then dumped into sewage. Furthermore, the water is frequently heated to improve wash effectiveness and usually requires a large amount of energy to be put into the articles as heat in order to vaporize the retained water and dry the articles. The combination of high water usage, high-energy usage and disposal of cleaning additives in the detergent can put a large strain on the environment.
Conventional perchloroethylene (PERC) professional dry cleaning solvent has been shown to be hazardous to human health as well as to the environment. Use of a cyclic siloxane composition as a replacement for PERC is described in Kasprzak, U.S. Pat. No. 4,685,930 and Dullien et al., U.S. Pat. No. 6,063,135. The use of a siloxane solvent in laundering has been shown to result in reduced wrinkling, superior article care, and better finish than water washing. Furthermore, the siloxane solvent has a lower heat of vaporization than water. Compared to water, the siloxane solvent can be more easily dried out of the article. If a washing machine contained a solvent based cleaning cycle, the solvent cycle could replace some or all of the washing currently being done in water, which would result in a significant reduction in energy and water use.
There are currently commercial dry cleaning machines, which use a cyclic siloxane dry cleaning process, but these machines present several barriers to in-home use. Known commercial dry cleaning machines are generally much larger than typical home washing machines, and would not fit within typical washrooms. These commercial dry cleaning machines typically require high voltage power (>250V) and often require separate steam systems, compressed air systems, and chilling systems to be attached externally. The solvent amount generally stored in the commercial dry cleaning machines is usually more than about 190 liters, even for the smallest capacity commercial machines. The typical dry cleaning facility has both solvent cleaning and water cleaning machines on the premises and uses each machine for their separate functions. Known commercial dry cleaning machines are typically designed to be operated by a skilled employee and do not contain appropriate safety systems for either in-home locations or for general use. In many states, the use of commercial dry cleaning machines by the general public is forbidden.
U.S. patent application Ser. No. 10/127,001, titled “Apparatus and Method for Article Cleaning”, filed on Apr. 22, 2002, commonly assigned to the same assignee of the present invention, represents one innovative implementation of an appliance that provides solvent, or water-based cleaning (or combination thereof). As set forth in the foregoing patent application, this appliance may be advantageously accommodated either in an in-home or in a coin-operable laundry setting. That is, an appliance that may be used not just for commercial dry cleaning applications, but also having the appropriate small size, cost, and user-interface considerations for a home-based laundry system.
Presently, the standard technique of solvent reclamation in a commercial dry cleaning process is distillation of the PERC solvent. Impurities may be concentrated in the distillate bottoms, and disposed of. Unfortunately, significant exposure to the solvent as well as the impurities is possible.
Another technique of solvent reclamation is through an adsorption system. Although known adsorption systems may provide some cleaning action to the solvent, this technique generally needs to be used in conjunction with a distillation set-up in order to provide long term use of the recycled solvent. In the industrial setting that this technique is used, the adsorption system typically requires use of large canisters that are cumbersome and may lead to user exposure to the solvent and contaminants.
Water removal in industrial dry cleaning equipment is usually minimal, and many dry cleaning machines are equipped with a decanter for this purpose. These known decanters are typically operated in a continuous fashion. It is believed that continuous operation of decanting equipment would not be suitable for home use.
In view of the foregoing considerations, it would be desirable to provide a system and process that is economically affordable for quickly and reliably purifying and reclaiming siloxane cleaning solvent for reuse, as may be utilized in a solvent cleaning appliance, such as described in U.S. patent application Ser. No. 10/127,001. It is further desirable that such a system be configurable to meet the unique considerations of an in-home appliance as well as those of commercial scale units, such as coin-operable laundry machines.
Generally, the present invention fulfills the foregoing needs by providing in one aspect thereof, an article cleaning apparatus comprising an air management mechanism, a cleaning basket assembly, a fluid regeneration device, a working fluid device, a clean fluid device, and a controller. The working fluid device is coupled to the fluid regeneration device, the cleaning basket assembly, and the air management mechanism. The working fluid device comprises a fluid filter/separator assembly for substantially removing an aqueous phase that may be present in a solvent-based cleaning fluid that passes therethrough. The clean fluid device is coupled to the cleaning basket assembly and the fluid regeneration device. The controller is coupled to the air management mechanism, the cleaning basket assembly, the working fluid device, the regeneration device, and the clean fluid device. The controller is configured to control a cleaning process.
The present invention further fulfills the foregoing needs by providing in another aspect thereof, a method for recovering and purifying a solvent used in an article cleaning appliance. The method allows passing solvent-based cleaning fluid from a wash basket through a coarse filter configured to remove relatively large particulates from the cleaning fluid. The method further allows passing cleaning fluid from the coarse filter through a particulate filter configured to remove relatively fine particulates from the cleaning fluid. An aqueous phase that may be present in the cleaning fluid is separated by decanting and coalescing through a separator/filter assembly. The cleaning fluid may then be passed through a regeneration cartridge for removing any water that may remain in the cleaning fluid, and for adsorbing organic contaminants that may be present in the cleaning fluid. Recovered solvent may be stored in a tank for subsequent use in a cleaning process performed by the appliance.
In yet another aspect thereof, the present invention provides apparatus for purifying and recovering a solvent used in an article cleaning appliance. The apparatus comprises a coarse filter coupled to receive solvent-based cleaning fluid from a wash basket, the coarse filter configured to remove relatively large particulates from the cleaning fluid. The apparatus further comprises a particulate filter coupled to receive cleaning fluid from the coarse filter. The particulate filter is configured to remove relatively fine particulates from the cleaning fluid. A fluid filter/separator assembly is coupled to receive cleaning fluid from the particulate filter. The assembly is configured to separate an aqueous phase that may be present in the cleaning fluid. A regeneration cartridge is coupled to receive cleaning fluid from the filter/separator assembly. The regeneration cartridge comprises water adsorption media for removing any water that may remain in the cleaning fluid. The regeneration cartridge further comprises adsorption media configured to adsorb organic contaminants that may be present in the cleaning fluid. A tank is provided for storing recovered solvent for subsequent use in a cleansing process performed by the appliance.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
The present invention includes an apparatus and method for the cleaning of articles,at home or in a coin-op laundry setting. As used herein, the term, “articles” is defined, for illustrative purposes and without limitation, as fabrics, textiles, garments, and linens and any combination thereof. As used herein, the term, “solvent based cleaning fluid” is defined for illustrative purposes and without limitation, as comprising a cyclic siloxane solvent and, optionally, a cleaning agent. If water is present in a solvent based cleaning fluid, the water is present in an amount in a range from about 1 percent to about 8 percent of the total weight of the solvent based cleaning fluid. In another embodiment of the present invention, if water is present in the solvent based cleaning fluid, the water is present in an amount in a range from about 1 percent to about 2 percent of the total weight of the solvent based cleaning fluid. As used herein, the term, “cleaning agent” is defined for illustrative purposes and without limitation, as being selected from the group consisting of sanitizing agents, emulsifiers, surfactants, detergents, bleaches, softeners, and combinations thereof. As used herein, the term, “water based cleaning fluid” is defined for illustrative purposes and without limitation, as comprising water and, optionally, a cleaning agent. In the present invention, the article cleaning apparatus 1000 of
The article cleaning apparatus 1000 comprises the air management mechanism 1, the cleaning basket assembly 2, and a fluid regeneration device 7. The article cleaning apparatus 1000 further comprises a working fluid device 6 that is coupled to the fluid regeneration device 7, the cleaning basket assembly 2, and the air management mechanism 1. The article cleaning apparatus 1000 further comprises a clean fluid device 8 that is coupled to the cleaning basket assembly 2 and the fluid regeneration device 7. The article cleaning apparatus 1000 further comprises a controller 5 which is coupled to the air management mechanism 1, the cleaning basket assembly 2, the working fluid device 6, the regeneration device 7, and the clean fluid device 8. The controller 5 is configured to perform the cleaning process 350.
The cleaning basket assembly 2 of
As shown in
In one embodiment of the present invention, the working fluid device 6 comprises a check valve 40 in a drain conduit line 70 that couples the cleaning basket assembly 2 to a working tank 45. Fluid from the cleaning basket assembly 2 passes through the check valve 40 and is collected in the working tank 45. The fluid in the working tank 45 is defined as a working fluid 165. A drain tray 73 is disposed in the air management mechanism 1 to collect condensate. An additional drain conduit 71 couples the working tank 45 to the drain tray 73. Condensate in the drain tray 73 is typically gravity drained to the working tank 45, where it is collected as part of the working fluid 165. A regeneration pump 115 is coupled to the working tank 45 and to a conductivity sensor 151. A waste water drain valve 155 is disposed between the conductivity sensor 151 and the fluid regeneration device 7. The waste water drain valve 155 is coupled to waste water discharge piping 154.
In one embodiment of the present invention, the controller 5 of
In another embodiment of the present invention, a water separator 152 is disposed in the working tank 45. In another embodiment of the present invention, the water separator 152 is disposed between the waste water drain valve 155 and the fluid regeneration device 7. In another embodiment of the present invention, a bypass line 145 of
In one embodiment of the present invention, the water separator 152 is fabricated from materials selected form the group consisting of calcined clay, water adsorbing polymers, sodium sulfate, paper, cotton fiber, lint, and any combination thereof. In another embodiment of the present invention, the water separator 152 comprises a distillation device that utilizes heat to remove water.
A desirable feature for a washer appliance embodying aspects of the present invention would be to provide at least three different operational (e.g., wash) cycle options, such as: Wash Cycle 1—an option for waterless wash, essentially using just solvent or solvent plus approximately 0.25 to 1.5% water or other polar solvent; Wash Cycle 2—an option for cleansing moderately soiled delicates, e.g., using a suitable spot-remover or pre-spotter and from approximately 1.0 to 6.5% water or other polar solvent; and Wash Cycle 3—a solvent/water/detergent option with approximately 4 to 15% water or other polar solvent and approximately 0.01 to 0.5% detergent by weight of the total fluid charge providing a more aggressive wash for heavy-duty laundry.
Removal of the aqueous phase before the solvent can be recycled is desirable. This is desirable both for carbon adsorption efficiency and to minimize odors and bacterial growth. In one exemplary embodiment, a desirable goal would be to provide approximately 98% water removal efficiency using a fluid filter/separator assembly 2000 (
Water/detergent (bottom or aqueous phase) that may be present in the working fluid (e.g., cleansing fluid) may be separated from the SB32 solvent by filter/separator assembly 2000. Decanter stage 2002 can be comprised of a water drain tube 2010, a water collector bowl 2012 and a turbine centrifuge 2014. In operation, decanter stage 2002 is in fluidic communication with filter stage 2004, as represented by the plurality of arrows indicative of various exemplary fluid flow paths shown in filter/separator assembly 2000. Filter stage 2004, in one exemplary embodiment, may be made of paper. In another exemplary embodiment, filter stage 2004 may comprise hydrophobic material, e.g., a polymer or resin-coated paper, designed to concentrate and contain the aqueous phase within the decanter while allowing passage to the non-polar phase, e.g., solvent. In one exemplary embodiment, the filter stage may comprise a single-ply, axially-pleated filter media 2005. As suggested above, the filter media may be treated to block passage to any fine droplets of water from the solvent passing therethrough. One exemplary type of hydrophobic media believed to be effective for purposes of the present invention, based on preliminary experimental results, is manufactured by Parker-Hannifin Corporation of Cleveland Ohio under the mark/designation Aqua-bloc. It will be understood that the composition, structure and efficiency of the filter media can be configured to match the particular needs of any given application. It will be appreciated that the filter media may be formed from conventional material and may be manufactured using conventional filter media manufacturing techniques. Commercially available filter/separator assemblies that are well suited to perform decanting and coalescing include, for example, the Amsoil/Dahl filter/separator assemblies Model Nos. ADF10, and ADF20, and the Racor filter/separator assembly Model No. 1000FG. Each of such filter/separator assemblies have been designed and used for fuel systems, such as diesel fuel systems, to remove water, the more dense phase, from the diesel fuel, which is slightly less dense, thereby allowing for clean, water-free fuel to pass for optimal engine performance. The inventors of the present invention have innovatively recognized that such fuel filter/separator assemblies may be advantageously used for achieving aspects of the present invention, such as removing the denser water phase from the slightly less dense, but immiscible silicone cleaning fluid (i.e., cyclic siloxane solvent).
For readers desirous of background information in connection with the physical science mechanisms involved in the settling (e.g., decanting), and coalescing stages of such filter/separator assemblies, reference is made to U.S. Pat. Nos. 4,298,465 and 3,931,011, each of which is incorporated herein by reference. The description provided in such patents should be construed as representative of the type of fluid filter/separator assembly contemplated in accordance with aspects of the present invention, and should not be construed as limiting the present invention. As used herein the expression “filter/separator assembly” refers to assemblies or apparatus that through respective mechanisms of fluid settling (e.g., decanting) and coalescing are able to substantially separate water from a fluid that is slightly less dense than water—traditionally fuel has comprised the fluid being separated from water. However, as innovatively recognized by the inventors of the present invention, in a washer appliance, such as described in U.S. patent application Ser. No. 10/127,001, the fluid being separated from water and/or cleaning agents comprises cyclic siloxane solvent.
Tests for determining water separation were conducted as follows: a gallon jug was filled with a gallon of D5 cleaning fluid and 100 ml of water/detergent. The phases were vigorously mixed with a mechanical stirrer (e.g., 500 rpm) to simulate mixing under washing conditions. The mixture was pumped with a peristaltic pump into the filter/separator assembly through an inlet port (e.g., inlet port 2009 (
The experimental results are summarized in Table 1 which is divided into 4 sections, I) Experiments with Dahl filter/separator assembly ADF10; II) Experiments with Dahl filter/separator assembly ADF20; III) Experiments with Racor filter/separator assembly 1000FG without surfactants and amine; and IV) Experiments with Racor filter/separator assembly 1000FG with surfactants and amine. As seen in the first section of Table 1, initial results with the Dahl ADF10 filter/separator assembly showed that at 400 ml/min, in the absence of any detergent, the aqueous phase can readily be removed to approximately 98–99% efficiency. However, at increased flow rates, e.g., 600 ml/min and with ⅛% detergent, the water removal efficiency was reduced to approximately 70%.
To achieve greater flow rates a larger fluid filter/separator assembly, the Dahl filter/separator assembly Model ADF20, was tested. Dahl filter/separator assembly ADF20 comprises an increased volumetric capacity (approximately 2.8 liters as compared to 0.85 liters for Dahl filter/separator assembly ADF10) and a corresponding increased residence time. In addition, the filter stage of filter/separator assembly ADF20 is larger and has a greater surface area than the one for filter/separator assembly ADF10. The second section of Table 1 showed some improved results. Efficient water removal (>99%) was achievable at increased flow rates with ⅛% detergent and with water levels of 2.5 and 5%.
To further enhance cleaning, in addition to the detergent, surfactants and dodecylamine were added to the cleansing fluid. As may be expected, this resulted in an aqueous phase that was relatively more difficult to separate. When surfactants and dodecylamine were added to the cleansing fluid, the performance of the Dahl filter/separator assembly ADF20 in terms of water removal efficiency dropped off to approximately 80%.
The next iteration of tests involved the Racor filter/separator assembly 1000FG. The volume of this filter assembly is slightly larger (approximately 3.2 liters) and has a filter stage, which is believed to be conducive to more efficient water separation. As suggested above, the filter element comprises a filter medium coated with a hydrophobic polymer or resin (traded in commerce under the mark/designation Aqua-bloc) designed to repel the aqueous phase. It should be recognized that any number of polymer compositions with hydrophobic character would be suited for this application. The filter element also has an exposed pleat design, which allows the aqueous phase to run off the filter element and down into the water-collecting bowl. The results were excellent under various testing conditions. Three different flow rates and two different pore size elements were tested. As seen in the third section of Table 1, with detergent only, the aqueous phase removal efficiency was >99% at flow rates as high as 1300 ml/min. The same set of tests was run with surfactants and amine as well as detergent. The results are listed in the fourth section of Table 1. Even under the most stringent conditions, e.g., the combination of detergent, surfactants and dodecylamine, the aqueous phase removal efficiency was excellent, e.g., approximately 99.6–99.7% at an exemplary flow rate of 650 ml/min for both the 10 and 30 micron pore size. At higher flow rates, e.g., 975 and 1300 ml/min, the 30-micron filter element performed slightly better than the 10-micron filter element. In view of the foregoing results, it is felt that aqueous phase removal, with or without surfactants, and dodecylamine has been experimentally demonstrated at flow rates sufficiently high to allow for relatively fast real-time reloading (e.g., recapturing, or recycling) of the solvent as a washing cycle is being performed.
As will be appreciated by those skilled in the art, other types of separators for polar/non-polar phase separations may be considered, such as centrifuge, or electrostatic-based separators, however, it is believed that the present relatively high cost of such separators would not provide an economically competitive solution at this time.
After passing the cleaning fluid through the coarse and particulate filters to capture solids, the cleaning fluid may be optionally stored in a holding tank 3006 for further purification processing. In one exemplary embodiment, the purification process may continue immediately upon receiving fluid into the holding tank, or, in an alternative embodiment, the fluid may be stored for later purification.
As described in detail in the context of
As suggested above, the adsorption media may comprise an array of packed bed columns or cartridges and may be in the form of a single cartridge or groups of cartridges in parallel and/or series. Cartridges coupled in parallel may provide a more convenient size for handling and can increase the L/D ratio of the cartridge bed without changing the total cartridge volume. Cartridges coupled in series can increase adsorption capacity as well as increase processing speed. A design with multiple cartridges may also be placed on a carousel for accessibility and ease of replacement.
As will be now appreciated by those skilled in the art, the size of the cartridge comprising the adsorption media is believed to be an important design parameter. While a large adsorbent bed or cartridge would remain in service for longer periods, a large bed or cartridge may be cumbersome, occupy significant space in the appliance and may be difficult for one individual to replace. In one exemplary embodiment, based on preliminary small-scale lab experiments, the organic adsorption media may be comprised of an 18 liter cartridge and may include a total of 15 lbs of carbon. An exemplary target for the solvent purification time would be approximately eight minutes and the cartridge would be replaced approximately every 3 months or 100 washes (approximately 800 lbs. of clothing). It is contemplated, however, that for some applications a smaller cartridge may be desirable, e.g., it would save space and could be replaced easily by a single individual. It is further contemplated to regenerate the carbon and/or clay portions of the cartridge for reuse. For home use equipment, it is desirable to have a relatively small size for the cartridge, as well as small machine size. It is also desirable to have the capability of cleaning several loads of clothing sequentially, without having a large storage tank of clean solvent, and thus, instant or rapid reload of purified solvent would be desirable. Another exemplary embodiment contemplates a single cartridge with two bed sections. In this embodiment, the cartridge may comprise a carbon bed containing approximately 3.75 lbs. of carbon to remove dissolved impurities in the solvent. A second section of the cartridge may comprise clay for water adsorption. The percent of clay in this cartridge section may vary from about 0% to about 50% of the carbon weight, depending on the separation efficiency of the fluid filter/separator assembly and the quantity of water used in the wash load. For this embodiment, the regeneration cartridge may be replaced approximately every 22 washes. One exemplary temperature range for solvent processing may be approximately 20–40 degrees Calcius.
Exemplary configurations for the components used for solvent purification and recovery may include separate filters for the respective coarse and particulate filters, and the organic adsorption media, or, in an alternative arrangement, each may be combined as an “all-in-one” unitary regeneration cartridge. In the case of separate filters (e.g., separate coarse and particulate filters), it may be desirable to arrange for these filters to be upstream of holding tank 3006 to avoid settling of any contaminants at the bottom of the tank. In the case of a unitary regeneration cartridge, it may be desirable to pass the solvent through the unitary cartridge at least twice. The first pass may be performed at a relatively high flow rate (e.g., first flow rate) to primarily remove, for example, lint and particulates. A subsequent pass may be performed at a lower flow rate (e.g., second flow rate), which may be desirable for facilitating adsorption of soluble organic contaminants. The fluid filter/separator assembly 2000 may be situated anywhere upstream of the regeneration cartridge as either an integral component of the unitary cartridge, or as a separate unit.
In one exemplary embodiment, the first and second flow rates for purifying and recovering the solvent may be configured to reduce cycle time and use a relatively small storage tank (e.g., tank size of approximately 10 gal) for the recovered and purified solvent, see Scenario 1) in Table 2 below. Table 2 further illustrates two additional exemplary scenarios for purifying the solvent. Scenario 2) contemplates one single relatively slower flow rate (e.g., approximately 0.172 gal/min or 1304 mm/min) that would result in a longer overall cycle time. Scenario 3 contemplates a relatively larger tank (e.g., tank size is approximately 15 gal) and the single relatively slower flow rate. Still another scenario that is contemplated (not specifically illustrated in Table 2) would be to provide one relatively faster flow rate that would result in either a smaller tank size and/or a shorter total cycle time. It will be appreciated that the foregoing numerical values are merely illustrative and should not be construed as limiting the present invention since the values of flow rates and tank size may be adjusted to meet the requirements of any given application.
Means for introducing additives, such as detergents, perfumes, disinfectants, etc., may be positioned at or near the exit side of the organic adsorption media for dispensing these additives into the solvent exiting the column for a subsequent wash as the solvent from a present or a previous wash is purified for storage in a tank 3010 for holding the recovered (e.g., purified solvent).
It is contemplated that any spent cartridges may be appropriately disposed of or recycled to conserve adsorbent and SB32 solvent. For example, solvent may be drained prior to removal of the cartridge to minimize solvent replacement. Clean “make-up” solvent for replenishment purposes can be added back to the system by storing it in the replacement cartridge. Each cartridge may be configured with leak proof seals to reduce the possibility of leaks and fluid contact with the user. Each cartridge may be appropriately cleansed for recycling purposes either within the appliance or at a location off-line by backflushing the respective particulate and coarse filters and then passing a de-adsorption solvent over the adsorbent bed, such as clean silicone solvent, steam, or water. Solvent condensed in the drying system may be respectively passed through the water separator and the coarse and particulate filters for washing, rinsing, or backflushing of impurities in the solvent recovery system.
To enable sequential washes with immediate or rapid solvent reload, it would be desirable to, for example, purify the solvent during the drying cycle or store a sufficient amount of clean solvent for reload, or both. One exemplary method for enhancing this solvent reload capability while reducing adsorbent bed volume would be to process the solvent at a sufficiently high flow rate to partially remove contaminants from the solvent. The solvent can then be re-processed when the sequence of washes ends so that any remaining contaminants in the solvent are removed. The re-processing steps may comprise at least a second or third pass through the purification system, reprocessing at a slower rate and continuing until removing the contaminants to a desired level.
Another exemplary technique for enabling rapid reload capability with reduced cartridge size and reduced processing time would be to pass the solvent through each respective filter, e.g., the coarse and particulate filters, and the organic adsorption bed (or the unitary cartridge assembly) at a relatively high flow rate. The partially cleaned solvent can then be diluted or mixed with previously purified solvent to enable immediate reload with the mixed partially purified, or “gray” solvent. It is contemplated to dilute the partially cleaned solvent with at least 50% of purified solvent to avoid any relatively high contamination to the overall mix. The mixed partially purified solvent may then be more highly purified when the sequence of washes ends. It is contemplated that if the cartridge is sized such that the processing time for recovering and purifying the solvent exceeds the processing time for the remainder of the cycle, one may optionally pass the solvent just through the coarse and particulate filters for a desired number of wash cycles. Any organic soluble contaminants in the solvent may then be removed via the organic adsorption media later. Another option would be to continuously process the contaminated solvent by recycling. Although this option may allow for faster processing and smaller adsorption beds, this option may require a tank with larger storage capacity for the purified solvent.
One exemplary flow rate of solvent through the purification column, based on a given volume for the carbon bed, is approximately 6 bed volumes/hr. The system may be run at flow rates ranging from approximately 3–9 bed volumes/hr with diminishing benefit at lower flow rates, or higher ones. After a sequence of approximately 3–6 wash loads, the solvent may be more thoroughly cleaned upon passing a second time through the purification system. A large solvent purification bed can also be utilized to maximum advantage if several machines are connected to a single solvent recovery system, such as may be the case at coin-operated laundry facilities, or in a larger scale device.
In certain instances, where it is desirable to wash with an aqueous phase comprising soluble detergent, it is also desirable to rinse the wash load for removing the detergent from the clothing. In these instances, it may be desirable to rinse the clothing with a mixture of solvent and water, which, as suggested above, would be subsequently processed through the fluid filter/separator assembly 2000 to remove the aqueous phase from the mixture. For example, to enable the rinse immediately following a wash and spin cycle, either clean solvent for the rinse should be retrieved from storage, or the wash fluid should be processed through the fluid filter/separator assembly during such drain and spin cycles, or both. For example, solvent for the rinse may be generated from wash fluid from the holding tank and passed through the fluid filter/separator assembly. The solvent may then be optionally passed through the adsorption bed and returned for the rinse, or the solvent may bypass the adsorption bed, and be returned for rinsing. In one exemplary embodiment, a portion of the clean solvent for rinsing may be extracted from previously purified solvent stored in storage tank 3010, and another portion of the solvent for rinsing may be processed (e.g., recovered) from the wash fluid. This combination is believed to allow both reducing the size of the tank for storing clean solvent and reducing the flow rate of fluid through the fluid filter/separator assembly. In one exemplary embodiment, the wash fluid volume may comprise approximately 60–90% of the volume of the clean solvent storage tank (e.g., 6–10 gallon wash cycle, and a 10–15 gallon clean solvent storage tank). The rinse may utilize a solvent volume which comprises approximately 40%–100% of the volume of the wash solvent volume and a water volume which is approximately 0%–8% of the rinse solvent volume. For this exemplary solvent volume, approximately 45% would be stored in the tank for storing clean solvent, and approximately 55% would be processed from the wash cycle.
The fluid regeneration device 7 comprises a regeneration cartridge 141. The inlet side of the regeneration cartridge 141 is typically coupled to the working fluid device 6. The regeneration cartridge 141 typically comprises at least a water adsorption media 130 coupled to a cleaning fluid regeneration adsorption media 135. In one embodiment of the present invention, the regeneration cartridge 141 further comprises a mechanical filter 120 and a particulate filter 125. In one embodiment of the present invention, the working fluid 165 passes sequentially through the mechanical filter 120, particulate filter 125, water adsorption media 130, and cleaning fluid regeneration adsorption media 135. The cleaning fluid regeneration adsorption media 135 contains a portion of the solvent based cleaning fluid 30 in order to replenish the solvent based cleaning fluid 30 that is consumed during the solvent wash/dry process 500 of
In one embodiment of the present invention, the cleaning fluid regeneration adsorption media 135 is selected from a group consisting of a packed bed column, a flat plate bed, a tortuous path bed, a membrane separator, a column with packed trays, and combinations thereof.
In one embodiment of the present invention, the materials to fabricate the cleaning fluid regeneration adsorption media 135 are selected from the group consisting of activated charcoal, carbon, calcined clay, Kaolinite, adsorption resins, carbonaceous type resins, silica gels, alumina in acid form, alumina in base form, alumina in neutral form, zeolites, molecular sieves, and any combination thereof. Both the amount of solvent based cleaning fluid regeneration and the speed of solvent based cleaning fluid regeneration depend on the volume of the cleaning fluid regeneration adsorption media 135.
In one embodiment of the present invention, the regeneration cartridge 141 containing the cleaning fluid regeneration adsorption media 135 in the packed bed column form is disposed in a single packed bed column cartridge form. In another embodiment of the present invention, the regeneration cartridge 141 comprising the cleaning fluid regeneration adsorption media 135 in the packed bed column form is disposed in a plurality of packed bed column cartridges. In an alternative embodiment of the present invention, the regeneration cartridge 141 comprises the cleaning fluid regeneration adsorption media 135 in a plurality of packed bed column cartridges, which are disposed in series with respect to one another. In yet another embodiment of the present invention, the regeneration cartridge 141 further comprises the cleaning fluid regeneration adsorption media 135 in the plurality of packed bed column cartridges, which are disposed in parallel with respect to one another.
In another embodiment of the present invention, the mechanical filter 120 of
In another embodiment of the present invention, the mechanical filter 120 of
In one embodiment of the present invention, mechanical filter 120 has a mesh size in a range from about 50 microns to about 1000 microns. In one embodiment of the present invention, the particulate filter 125 has a mesh size in a range from about 0.5 microns to about 50 microns.
In one embodiment of the present invention, the particulate filter 125 is a cartridge filter fabricated from materials selected from the group consisting of thermoplastics, polyethylene, polypropylene, polyester, aluminum, stainless steel, metallic mesh, sintered metal, ceramic, membrane diatomaceous earth, and any combination thereof.
After the working fluid 165 passes through the regeneration cartridge 141, it exits the regeneration cartridge 141 as the solvent based cleaning fluid 30. An outlet side of the regeneration cartridge 141 is typically coupled to an optical turbidity sensor 140. The optical turbidity sensor 140 is typically coupled to a storage tank 35 in the clean fluid device 8. The optical turbidity sensor 140 is tuned to a specific adsorbance level that provides information about the cleanliness of the solvent based cleaning fluid 30. When the solvent based cleaning fluid 30 exiting the optical turbidity sensor 140 reaches a preset specific adsorbance level, the controller 5 of
The storage tank 35 of
The air management mechanism 1 of
The cooling coil 65 is configured to have a cooling medium disposed to flow across one side of a heat transfer surface of the cooling coil 65, while the airflow 53 passes across the opposite side of the heat transfer surface of the cooling coil 65. The heat transfer surface of the cooling coil 65 separates the cooling medium and the airflow 53. The inlet temperature of the cooling medium utilized is typically cooler that the temperature of the airflow 53 in order to condense vapors in the airflow 53. As used herein, the term, “cooling medium” is defined, for illustrative purposes and without limitation, as being selected from water, refrigerants, air, other gasses, ethylene glycol/water mixtures, propylene glycol/water mixtures and any combination thereof. The drain tray 73 is disposed under the cooling coil 65 and is coupled to the working tank 45 as described above.
In one embodiment of the present invention, the air management mechanism 1 typically further comprises an air intake 156 and an air exhaust 157. The air intake 156 and air exhaust 157 are disposed to provide air exchange between the airflow 53 and the air that is outside of the air management mechanism 1 to promote the drying of articles that have been subjected to the water cleaning process 600 of
A solvent vapor pressure sensor 59 detects the vapor pressure of the solvent based cleaning fluid 30 in the airflow 53 that circulates between the cleaning basket assembly 2 and the air management mechanism 1. The solvent vapor pressure sensor 59 is used to determine when solvent vapor pressure level reaches a predetermined level that indicates that the airflow 53 is no longer entraining substantial amounts of the solvent based cleaning fluid 30 of
The cooling coil 65 of
As shown in
The vapor compression cycle attains a higher coefficient of performance (COP) for solvent wash/dry process 500 of
In another embodiment of the present invention, the air management mechanism 1 further comprises an auxiliary heater 158 of
The inputs to the controller 5 of
The controller 5 is further configured to perform a solvent based cleaning fluid recirculation process. In the solvent based cleaning fluid recirculation process, the solvent based cleaning fluid 30 passes through the fluid processing mechanism 4 and cleaning basket assembly 4 as discussed above for a predetermined amount of time. The solvent based cleaning fluid recirculation process is performed when the article cleaning apparatus 1000 is not engaged in either the cleaning process 350 of
The cleaning basket assembly 2 of
The air management mechanism 1 of
In one embodiment of the present invention, the enclosure 230 has an overall volumetric shape of about 0.7 meters in width, by about 0.9 meters in depth, by about 1.4 meters in height. This volumetric shape represents the typical space available in an in-home laundry setting.
The regeneration cartridge 141 of
Additionally, in one embodiment of the present invention, the regeneration cartridge 141 of
The controller logic in the controller 5 of
In one embodiment of the present invention, the clean fluid device 8 of
In another embodiment of the present invention the article cleaning apparatus 1000 of
In one embodiment of the present invention, the article cleaning apparatus 1000 of
A plot of retained moisture content as a percentage of an article's weight versus the relative humidity is provided in
In one embodiment of the present invention, a process selection 310 of
The start of the solvent based cleaning cycle 375 of
After completing the humidity sensing process 400, the solvent wash/dry process 500 of
The solvent vapor pressure in the rotating basket 14 of
In one embodiment of the present invention the rotating basket 14 of
In another embodiment, the typical amount of articles in a laundry load range from about 2.7 kg to about 5.4 kg. The corresponding total capacity of the solvent based cleaning fluid 30 per laundry load is generally in a range from about 11.3 liters (4.2 liters/kg times 2.7 kg) to about 67.5 liters (12.5 liters/kg times 5.4 kg). The total amount of solvent based cleaning fluid 30 in the article cleaning apparatus 1000 of
In another embodiment, the ratio of liters of solvent based cleaning fluid 30 of
In order to reduce the total capacity of the solvent based cleaning fluid 30 in the article cleaning apparatus 1000 of
In another embodiment of the present invention, the solvent wash/dry process 500 adds water to the solvent based cleaning fluid 30 of
Steps 560 of
The controller 5 of
The water cleaning process 600 begins with the initial conditions of the cleaning agents loaded into the dispenser 300, and the door lock 19 engaged and the door lock sensor 18 verifying that the basket door 15 in the locked position at the start step 610 of
Rinse water is then added to the rotating basket 14 of
In another embodiment of the present invention, the operator selects an additional rinse process. The additional rinse process reperforms step 670, step 680, and step 690. The additional rinse process occurs after step 690 and before the basket door 15 is unlocked in step 695. The additional rinse process assists in removing the entrained cleaning agents that are not removed during steps 670, 680, and 690. The additional rinse process is especially useful when using soft water. As used herein, the term “soft water” is defined as comprising less than about 10 grains of hardness per about 3.8 liters of water.
In another embodiment of the present invention, the article cleaning apparatus 1000 of
In another embodiment of the present invention, a timed basket drying process 705 of
It is important that a large amount of the water is not inadvertently directed to the working tank 45 of
In one embodiment of the present invention, the cycle interruption recovery process 800 starts by verifying the locked status of door lock 19 of
If the basket conductivity cell 170 of
If the basket conductivity cell 170 of
After generating the warn operator fail-safe message in step 880 of
The cycle interruption recovery process 800 of
The foregoing description of several embodiments of the article cleaning apparatus 1000 and the method of using the article cleaning apparatus 1000 of the present invention has been presented for purposes of illustration. Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is intended by way of illustration and example only and is not to be taken by way of limitation. Obviously many modifications and variations of the present invention are possible in light of the above teaching. Accordingly, the spirit and scope of the present invention are to be limited only by the terms of the appended claims.
This application is a continuation-in-part of co-pending and commonly assigned U.S. patent application Ser. No. 10/127,001 filed Apr. 22, 2002.
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| Number | Date | Country | |
|---|---|---|---|
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| Number | Date | Country | |
|---|---|---|---|
| Parent | 10127001 | Apr 2002 | US |
| Child | 10330734 | US |
