Patent Application
20080092602
The present invention is useful in many different types of appliances having a washing or cleaning cycle, such as clothes washers, dish washers, clothes refreshers, dry cleaning appliances, etc., in which various types of articles are to be treated. For the purposes of disclosing an embodiment of the invention, the environment of a clothes washer is used, although the invention is not limited to such an appliance, or to the particular type of clothes washer illustrated.
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The washer also includes a disinfecting unit 30, which may be connected to an external water supply via a conduit 32 and to the wash tub 14, or elsewhere in the enclosure formed by the outer cabinet 12, via a conduit 34. The location for the disinfecting unit 30 is only schematically illustrated, and it could actually be located in a variety of different locations in the cabinet 12, where space permits, or even remote from the cabinet, such as in an adjacent cabinet or appliance. The invention can also be used with clothes washers that do not include a vertical agitator, such as those that agitate by other mechanisms, such as nutating plates, baffles on the basket, etc., as well as horizontal axis washers which provide agitation via tumbling. Other washing or cleaning appliances do not agitate the materials being washed or cleaned, but rather provide sprays or mists of water or other cleaning, washing, refreshing and rinsing fluids.
In other embodiments, the water container 36 may include an openable cap 50 (
The water container 36 includes a water dispenser 54, which also may be electrically or mechanically controlled, to cause drops of water to be dispensed into the steam chamber 40, preferably located below the water container. The heating element 38 is thermally associated with a portion of the steam chamber 40 to heat the water drops that have entered the steam chamber. Although depicted as being at the bottom of the steam chamber 40, one skilled in the art will recognize that the heating element 38 could be associated with the steam chamber in a number of configurations. For example, the heating element 38 could surround the steam chamber 40, or it could be located in the center of the chamber. When the heating element 38 is located at the bottom of the steam chamber 40, the water drops from the water container 36 will fall on a surface 56 heated by the heating element, and will quickly be converted to steam.
A passageway 58 allows steam to flow along a path from the steam chamber 40 to the mixing chamber 44. The chemical dispenser 48 allows chemical drops from within the chemical container 42 to flow along the wire 46 into the mixing chamber 44. These drops will coat a large surface area of the wire 46, allowing for quick and efficient absorption or adsorption of the chemical by the steam in the mixing chamber 44. One skilled in the art will recognize that other configurations or arrangements to dispense the chemical into the mixing chamber 46 can be used. For example, the chemical could be a solid that dissolves upon contact with the steam, or the chemical could automatically travel down the wire without the dispenser, like a wick.
A wide variety of chemicals may be used with the invention, including various pesticides, for example, common EPA registered antimicrobials, such as the full list of “MICROBAN” products. Also, hydrogen peroxide and its variations, silver, copper or zinc ions, chlorine bleach, and in some instances, simply steam.
The steam chamber 40 may have a collection sump 60 for receiving any condensate from the steam that has not exited the steam chamber. The mixing chamber 44 may have a bottom wall or floor 62 which is sloped downwardly towards the passageway 58, also to allow condensate, or excess chemical liquid, to flow into the collection sump 60 in the steam chamber 40. If the disinfecting unit 30 is permanent or refillable, the sump may have an openable drain to allow removal of collected liquids from time to time. Alternatively, a liquid moving mechanism, such as a pump or piston, could be used to redirect the condensate back to the surface 58 heated by the heating element 38 to assure that all of the chemical and water is dispensed with the steam.
In operation, when a disinfecting cycle is initiated, the water dispenser 54, operated by a control 61, permits drops of water to leave the water container 36 and fall into the steam chamber 40. The heating element 38, also operated by the control 61, heats the water in the steam chamber 40 until steam is formed (step 63,
The heating element 38 continues to heat the water until the temperature in the wash tub 14 reaches a threshold temperature for a given duration (step 66). Temperature sensors 70 provided at appropriate locations within the appliance, which communicate with the control 61, measure the temperature in the region of the wash tub. The threshold temperature may be 65° C., 70° C., 75° C. or higher for durations of 5 minutes, 10 minutes, 15 minutes, or longer to kill the microorganisms. Preferably, the temperature will be elevated to 67-70° C. for 10 minutes, as determined by a clock 74 in the control 61. With increased temperatures, the duration may be shortened and with decreased temperatures, the duration may be increased. After the threshold temperature is reached for the given duration, the control 61 terminates operation of the heating element 38 to stop the heating of the water (step 76) and terminates the dispensing of water and chemical. For some chemicals, such as silver, copper or zinc ions, would allow for ambient temperatures to be used, rather than elevated temperatures for some given period of time.
The steam impregnated with the chemical is used to thermally and/or chemically kill any microorganisms that exist in the appliance, or to provide other chemical treatment in the appliance, such as scale removal. The steam is able to transport the chemical to areas that are not typically reachable by other means, e.g., by rinsing the washer tub or basket with chemically treated water. In a washer environment, the present invention allows for treatment of the inside and outside of the basket, the tub, the sump, and all of the hoses.
The bio prevention (or other chemical treatment) cycle can be performed as an automatic cycle by the control operating the washer 10, such as at the end of each complete wash cycle. Alternatively, or in addition, the bio prevention cycle could be initiated by the user via a manual selection on a control panel of the washer.
The use of the present invention could also provide for reduced water usage in a wash cycle. The water usage savings could come from the utilization of steam as the vehicle to deliver heat to the wash load, rather than a deep water fill. Less energy would be required to heat a smaller volume of water into steam for the heating, in addition to using less water in the wash cycle.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.
