Dishwasher with vacuum drying and method

Abstract

An automatic dishwasher, having a wash cycle and a drying cycle, includes an openable and closeable washing chamber, at least one spray apparatus inside the washing chamber, and a vacuum pump in fluid communication with the washing chamber. The washing chamber has an interior configured to contain articles to be washed, and is configured to withstand vacuum pressure when closed. The at least one spray apparatus is configured to spray a cleaning fluid upon the articles to be washed during the wash cycle. The vacuum pump is configured to evacuate the interior of the washing chamber to a selected vacuum pressure level during at least a portion of the drying cycle.

What is claimed is: 
     
         1 . An automatic dishwasher having a wash cycle and a drying cycle, comprising:
 an openable and closeable washing chamber, configured to withstand vacuum pressure when closed, having an interior configured to contain articles to be washed;   at least one spray apparatus, inside the washing chamber, configured to spray a cleaning fluid upon the articles to be washed during the wash cycle; and   a vacuum pump, in fluid communication with the washing chamber, configured to evacuate the interior of the washing chamber to a selected vacuum pressure level during at least a portion of the drying cycle.   
     
     
         2 . A dishwasher in accordance with  claim 1 , further comprising a heating device, associated with the washing chamber, configured to heat the interior of the washing chamber to a selected heat level during the drying cycle. 
     
     
         3 . A dishwasher in accordance with  claim 2 , wherein the heating device is an electric heating element. 
     
     
         4 . A dishwasher in accordance with  claim 1 , wherein the selected vacuum pressure level is at least 1 psi below atmospheric pressure. 
     
     
         5 . A dishwasher in accordance with  claim 1 , wherein the selected vacuum pressure level is at least 5 psi below atmospheric pressure. 
     
     
         6 . A dishwasher in accordance with  claim 1 , wherein the selected vacuum pressure level is at least 10 psi below atmospheric pressure. 
     
     
         7 . A dishwasher in accordance with  claim 1 , further comprising a blower system, configured to blow air into, and withdraw air from, the washing chamber during a portion of the drying cycle. 
     
     
         8 . A dishwasher in accordance with  claim 1 , further comprising a controller, coupled to the vacuum pump, configured to control a duration and vacuum pressure level of operation of the vacuum pump during the drying cycle. 
     
     
         9 . A dishwasher in accordance with  claim 8 , wherein the controller comprises a microprocessor device having a processor and system memory and provided with programming instructions for controlling the spray apparatus and the vacuum pump and for controlling the wash cycle and the drying cycle. 
     
     
         10 . A dishwasher in accordance with  claim 8 , further comprising a sensor, disposed within the washing chamber and coupled to the controller, configured to sense at least one of pressure, temperature and humidity within the washing chamber, the controller being configured to determine the duration and pressure level for the drying cycle based on a signal from the sensor. 
     
     
         11 . A dishwasher, comprising:
 a washing tub, having a door and walls enclosing an interior configured to contain articles to be washed, the washing tub being configured to withstand vacuum pressure in the interior when the door is closed;   at least one spray apparatus, disposed in the interior of the washing tub, configured to spray a heated cleaning fluid upon the articles to be washed during a wash cycle of the dishwasher;   a vacuum pump, in fluid communication with the interior of the washing tub, configured to evacuate the interior of the washing tub to a selected vacuum pressure level during at least a portion of a drying cycle of the dishwasher; and   a controller, coupled to the spray apparatus and the vacuum pump, configured to control a duration and vacuum pressure level of operation of the vacuum pump during the drying cycle.   
     
     
         12 . A dishwasher in accordance with  claim 11 , wherein the selected vacuum pressure level is at least 1 psi below atmospheric pressure. 
     
     
         13 . A dishwasher in accordance with  claim 11 , wherein the selected vacuum pressure level is at least 5 psi below atmospheric pressure. 
     
     
         14 . A dishwasher in accordance with  claim 11 , further comprising a heating device, disposed within the washing tub, configured to heat the interior of the washing tub to a selected elevated temperature during at least a portion of the drying cycle. 
     
     
         15 . A dishwasher in accordance with  claim 11 , further comprising a sensor, disposed within the washing tub and coupled to the controller, configured to sense at least one of pressure, temperature and humidity within the washing chamber, the controller being configured to determine the duration and pressure level for the drying cycle based on a signal from the sensor. 
     
     
         16 . A method for washing articles in a dishwasher having a washing chamber, comprising:
 spraying a cleaning fluid upon the articles within the washing chamber during a wash cycle of the dishwasher; and   evacuating the washing chamber to a vacuum pressure level during at least a portion of a drying cycle of the dishwasher.   
     
     
         17 . A method in accordance with  claim 16 , wherein evacuating the washing chamber to the vacuum pressure level comprises evacuating the washing chamber to a pressure that is at least 1 psi below atmospheric pressure. 
     
     
         18 . A method in accordance with  claim 16 , wherein evacuating the washing chamber to the vacuum pressure level comprises evacuating the washing chamber to a pressure that is at least 5 psi below atmospheric pressure. 
     
     
         19 . A method in accordance with  claim 16 , further comprising blowing air into and withdrawing air from the washing chamber during a portion of the drying cycle and not while evacuating the washing chamber. 
     
     
         20 . A method in accordance with  claim 16 , further comprising heating an interior of the washing chamber during at least a portion of the drying cycle.