METHOD OF THE INVENTION
The invention relates generally to methods for dry cleaning textiles and clothing. More specifically, the present invention relates to a dry cleaning apparatus and modifications thereto which removes excess dry cleaning solvent from the system and is thereby more environmentally friendly.
BACKGROUND OF THE INVENTION
Dry cleaning of textiles and, in particular, fine clothing is a well known process in which the garment is immersed in a cleaning solvent other than water which loosens any dirt, grease or grime from the fibers of the garment fabric which is then, in one way or another, evaporated off. There are any number of different solvents and methods for doing this.
In conventional dry cleaning systems, the effluent vapors or fumes of the solvent such as perchlorethylene (PERC) emanating from the dry cleaning washing machine and dryers generally are vented directly to the atmosphere and thus pollute the atmosphere. By being so vented, they are also lost for reuse. Thus, the escaping vapors not only produce an environmental hazard, but their loss is extremely costly to the dry cleaning establishment.
Attempts have been made to remove the solvent vapor contained in the air-stream through a bed of activated carbon. The carbon absorbs the solvent vapor or gas held in the air-stream, allowing the thus cleaned air to pass through the carbon bed to atmosphere. See U.S. Pat. Nos. 3,203,110 and 3,538,615 to Fuhring et al. Unfortunately, the carbon bed will only absorb approximately one gallon of solvent per 80 lb. of carbon before becoming saturated with solvent vapor, and must then be de-absorbed by passing a “blanket” of steam through the carbon bed in a reverse direction to that of the absorption flow. The steam and solvent vapors form an azeotrope which must then be condensed, and the resultant water and liquid solvent must be separated according to their specific gravities. Thereafter, the solvent may then be recycled for reuse.
U.S. Pat. No. 4,622,039 to Merenda discloses and claims a method and means to recapture the cleaning solvent and to reuse the same so that as a result thereof, the solvent is not vented to the atmosphere and thus pollution of the atmosphere is avoided. A dry cleaning washer and a dryer are arranged in a closed cycle system so that the effluent solvent vapor from the washer is delivered to an accumulator chamber simultaneously with the delivery from the dryer of effluent hot air. The hot air superheats the solvent vapor thereby increasing its volatility and the heated and highly volatile solvent vapor is then passed to a condenser which contains feed coils for supplying clean air to the dryer. In passing through the condenser, the superheated solvent vapor instantly liquifies giving off its heat to the cool air, thus pre-heating the clean air prior to its entry into the dryer. The liquified solvent is returned to the washer, or to a storage reservoir.
U.S. Pat. No. 3,951,597 to Mooring discloses and claims a method of dry cleaning fabrics, draperies or clothing, in situ, by forcefully infusing the fabric in the open atmosphere with special fast-acting, versatile dry cleaning solvent so as to dissolve and suspend various stains and soils in the fabric, even though firmly set due to age. Ambient air is promptly drawn in and droplets of soil-laden solvent is promptly drawn therethrough by suction into a closed waste and suction chamber where the soil is deposited in the form of a sludge, while the carrier air and solvent is discharged to the atmosphere. A special, highly effective, fast-acting, non-flammable and non-toxic solvent such as methylene chloride, trichloro-ethylene is useful for these purposes.
U.S. Pat. No. 4,086,705 to Wehr discloses a dry cleaning apparatus wherein petroleum solvent vapors which are discharged from a dry cleaning dryer in a heated gaseous mixture of vapors and air are condensed and recovered, and heat energy is recovered for productive use elsewhere. The gaseous mixture of vapors and air is sprayed with relatively cool water to condense the solvent vapors. The resulting liquid mixture of water and solvent is withdrawn from the spray chamber and is subjected to gravitational separation. Water reclaimed in the separation process is reused in the spray chamber. Recovered solvent is reused in a dry cleaning washer. The gravitational separation process is preferably carried out in a series of gravitational separators, and heat is withdrawn from at least one of the separation units for productive use in a heat-consuming device.
U.S. Pat. No. 3,807,948 to Moore teaches a method of dry cleaning of goods in which the majority of the solvent present in the goods at the conclusion of the actual cleaning is recovered by circulating air, by means of a fan, through the goods in a dry cleaning drum and through a water-cooled condenser and a heating element. A small remaining amount of solvent is removed from the goods by a deodorizing operation, in which air is passed in a closed circuit through the goods in the dry cleaning drum and over a refrigerated surface on which the solvent is condensed.
Finally, U.S. Pat. No. 3,928,660 to Alderson et al., discloses a dry cleaning finishing method and apparatus for use in combination with a steam clothes press for mixing and pressurizing a liquid so that it can be easily applied to garments being pressed. The apparatus comprises a supply tank that meters the liquid material into a pressure tank. Steam condensate is mixed with steam from the clothes press and this provides the chemically pure water, heat and pressure to the pressure tank that mixes with the sizing concentrate and forces the water-sizing mixture to a spray gun for use when needed or desired by the pressman.
All of the aforementioned dry cleaning methods either require considerably more steps added to the overall dry cleaning process thereby requiring additional time and expense in carrying out the procedure or additional pieces of dry cleaning machinery which takes up space and also adds to the expense of the operation.
It is an object of the present invention to provide a dry cleaning means and method for its operation for removing excess cleaning solvent from the fabrics cleaned during the dry cleaning process thereby rendering it more environmentally friendly. The removed solvent is recaptured and contained rather than emitted into the atmosphere.
SUMMARY OF THE INVENTION
The dry cleaning method and apparatus of the present invention removes excess perchlorethylene (PERC) and other volatile cleaning solvents from clothing and fabric by injecting a predetermined amount of steam into a dry cleaning unit or vat wherein the solvent saturated clothing and fabric have been treated. The hot steam further volatilizes any additional PERC remaining in or on the fabric and this is removed from the container by vacuum. The PERC/steam mixture is then condensed and the two components separated for re-use.