Dry Cleaning Systems and Methods

Abstract

The present invention provides a method for cleaning fabric articles which comprises the steps of: washing the fabric articles with a cleaning solvent in a rotatable drum; rotating the drum at a high spin speed for a high spin period of time after the performance of said washing step; and heating the fabric articles for at least a period of time during the performance of said rotating step. During the heating step, at least some of the cleaning solvent is removed from the fabric articles in both liquid and vapor phases. Heating the fabric articles decreases attractive forces between the liquid phase cleaning solvent and the fabric articles, facilitating the separation and hence removal of additional quantities of the cleaning solvent from the fabric articles.

I claim: 
     
         1 . A method for cleaning fabric articles, said method comprising the steps of:
 washing the fabric articles with a cleaning solvent in a rotatable drum having opposite axial ends and a wall; and drying the washed fabric articles in the drum, said drying step including the steps of rotating the drum at a spin speed for a spin period of time such that the fabric articles move toward the wall of the drum so as to cause removal from the fabric articles of at least a portion of the cleaning solvent remaining in the fabric articles and so as to form an unobstructed pathway extending between the axial ends of the drum; and providing a heated gas into the drum from an inlet located adjacent one of the axial ends of the drum during the spin period, the heated gas being injected into the drum from the inlet such that the heated gas flows from the one of the axial ends of the drum through the pathway toward the other of the axial ends of the drum, at least some of the heated gas flowing directly to the other of the axial ends through the pathway such that the heated gas is distributed along the entire length of the drum, the heated gas flowing radially outwardly from an interior of the drum to an exterior of the drum through the fabric articles so as to cause at least another portion of the cleaning solvent remaining in the fabric articles to evaporate and be removed therefrom.   
     
     
         2 . The method of  claim 1 , wherein at least some of the cleaning solvent is removed from the fabric articles in both liquid and vapor phases during the performance of said drying step. 
     
     
         3 . The method of  claim 2 , wherein heat in the fabric articles decreases attractive forces between the liquid phase cleaning solvent and the fabric articles, facilitating the separation and hence removal of at least some of the liquid phase cleaning solvent from the fabric articles. 
     
     
         4 . The method of  claim 1 , wherein the rotation of the drum at the spin speed creates centrifugal forces causing the fabric articles to be radially pressed against the wall of the drum during the rotation of the drum, causing at least a first portion of the liquid phase cleaning solvent in the fabric articles to flow in a radially outward direction from the interior of the drum to the exterior of the drum. 
     
     
         5 . The method of  claim 4 , wherein the centrifugal forces cause the heated gas to flow in the radially outward direction through the fabric articles from the interior of the drum to the exterior of the drum, causing at least a second portion of the liquid phase cleaning solvent in the fabric articles to evaporate into vapors, the centrifugal forces causing the vapors to flow in the radially outward direction from the fabric articles to the exterior of the drum together with the at least a first portion of the liquid phase cleaning solvent. 
     
     
         6 . The method of  claim 1 , wherein the heated air has a temperature within a range from about 70 degrees Fahrenheit to about 200 degrees Fahrenheit. 
     
     
         7 . The method of  claim 1 , wherein the spin speed is within a range from about 350 revolutions per minute to about 1200 revolutions per minute. 
     
     
         8 . The method of  claim 7 , wherein the spin period of time is within a range from about 0.5 minute to about 10 minutes. 
     
     
         9 . The method of  claim 1 , wherein said drying step includes the step of performing a tumble spin period by rotating the drum at a tumbling speed for a tumble period of time, either before or after the performance of said rotating step, or both before and after the performance of said rotating step. 
     
     
         10 . The method of  claim 9 , wherein the tumbling speed is within a range from about 10 rotations per minute to about 20 rotations per minute; and the tumble period of time is within a range from about 0.25 minute to about 15 minutes. 
     
     
         11 . The method of  claim 9 , wherein said tumble spin period is performed after the performance of said rotating step, said drying step further comprising the steps of: performing a second rotation period by rotating the drum at a second spin speed for a second spin period of time after the performance of the tumble spin period; and providing a second heated gas into the drum from the inlet during the performance of said second spin period. 
     
     
         12 . The method of  claim 9 , wherein the tumble spin period is performed before and after the performance of said rotating step, said drying step further comprising the steps of performing a second rotation period by rotating the drum at a second spin speed for a second spin period of time after the performance of the tumble spin period; providing a second heated gas into the drum from the inlet during the performance of said second spin period; and performing another tumble spin period after the performance of said second spin period. 
     
     
         13 . The method of  claim 1 , further comprising the step of performing a second spin period by rotating the drum at a second spin speed, which is lower than the spin speed of the spin period, for a second spin period of time, after the performance of said washing step, and before or after the performance of said rotating step, or both before and after the performance of said rotating step. 
     
     
         14 . The method of  claim 1 , wherein the cleaning solvent comprises an aqueous solvent or a non-aqueous dry cleaning solvent. 
     
     
         15 . Apparatus for cleaning fabric articles, said apparatus comprising a rotatable drum having opposite axial ends and a wall, said drum being sized and shaped so as to receive the fabric articles such that the fabric articles can be washed with a dry cleaning solvent in said drum, said drum being rotatable at a spin speed for a spin period of time after the washing of the fabric articles such that the fabric articles move toward said wall of said drum so as to cause removal from the fabric articles of at least a portion of the cleaning solvent remaining in the fabric articles and so as to form an unobstructed pathway extending between said axial ends of said drum; and a supply system for supplying a heated gas into said drum during said spin period, said supply system having an inlet located adjacent one of said axial ends of said drum for injecting the heated gas into said drum during said spin period such that the heated gas flows from said one of said axial ends of said drum through said pathway toward the other of said axial ends of said drum, at least some of the heated gas flowing directly to said other of said axial ends through said pathway such that the heated gas is distributed along the entire length of said drum, the heated gas flowing radially outwardly from an interior of said drum to an exterior of said drum through the fabric articles so as to cause at least another portion of the cleaning solvent remaining in the fabric articles to evaporate and be removed therefrom.