Dishwasher with ozone generator

Abstract

A dishwasher comprises a treating chamber for receiving dishes therein for treatment according to a cycle of operation, at least one sprayer providing a spray of liquid into the treating chamber, and an ozone generator for selectively providing ozone gas to the treating chamber for sanitizing the dishes in the treating chamber during a cycle of operation.

What is claimed is: 
     
         1 . A method of controlling an operation of a dishwasher having a treating chamber with an access opening through which dishes may be received for treatment according to at least one automatic cycle of operation, and a closure operable to selectively open and close the access opening, the method comprising:
 introducing ozone gas into the treating chamber;   maintaining the ozone gas in the treating chamber at a sanitizing concentration of 5 ppm or less by controlling the introduction of ozone gas; and   maintaining the ozone gas at the sanitizing concentration for a sanitizing time sufficient to sanitize the dishes.   
     
     
         2 . The method of  claim 1  wherein sanitizing the dishes comprises at least a 5 log reduction of at least one species of bacteria. 
     
     
         3 . The method of  claim 1  wherein the at least one species of bacteria is  Escherichia coli.    
     
     
         4 . The method of  claim 1  wherein the introducing ozone gas comprises introducing the ozone gas while the closure closes the access opening. 
     
     
         5 . The method of  claim 4  wherein the introducing ozone gas while the closure closes the access opening comprises introducing the ozone gas while the closure remains fully operable. 
     
     
         6 . The method of  claim 5  wherein fully operable comprises the closure being in an unlocked state. 
     
     
         7 . A method of controlling an operation of a dishwasher having a treating chamber with an access opening through which dishes may be received for treatment according to at least one automatic cycle of operation, and a closure for selectively closing the access opening, the method comprising:
 introducing ozone gas into the treating chamber while the closure closes the access opening;   maintaining the ozone gas in the treating chamber at a sanitizing concentration where opening of the closure would result in a 5 ppm or less concentration of ozone exterior of the dishwasher upon an opening of the closure; and   maintaining the ozone gas at the sanitizing concentration until the dishes are sanitized.   
     
     
         8 . The method of  claim 7  wherein sanitized comprises at least a 5 log reduction of at least one species of bacteria. 
     
     
         9 . The method of  claim 8  wherein the at least one species of bacteria is  Escherichia coli.    
     
     
         10 . The method of  claim 7  wherein the ozone gas is maintained at the sanitizing concentration for 30 minutes. 
     
     
         11 . The method of  claim 7  wherein the treating chamber has a volume of 0.12 cubic meters. 
     
     
         12 . The method of  claim 7  wherein the introducing ozone gas while the closure closes the access opening comprises introducing the ozone gas while the closure remains fully operable. 
     
     
         13 . The method of  claim 12  wherein fully operable comprises the closure being in an unlocked state. 
     
     
         14 . A method for sanitizing dishes in a dishwasher having a treating chamber with an access opening through which dishes may be received for treatment according to at least one automatic cycle of operation, and a closure operable to selectively open and close the access opening, the method comprising sanitizing any dishes within the treating chamber by introducing ozone gas into the treating chamber to maintain a 5 ppm or less sanitizing concentration of ozone gas within the treating chamber for a time sufficient to obtain a 5 log reduction in at least one species of bacteria, while the closure remains fully operable. 
     
     
         15 . The method of  claim 14  wherein the at least one species of bacteria is  Escherichia coli.    
     
     
         16 . The method of  claim 14  wherein the ozone gas is maintained at the sanitizing concentration for 30 minutes. 
     
     
         17 . The method of  claim 14  wherein fully operable comprises the closure being in an unlocked state. 
     
     
         18 . A dishwasher for treating dishes according to a cycle of operation, comprising:
 a tub at least partially defining a treating chamber;   a sprayer providing a spray of liquid into the treating chamber;   a recirculation circuit recirculating the sprayed liquid from the treating chamber to the sprayer at a first pressure;   an ozone circuit fluidly coupling the recirculation circuit to the sprayer;   an ozone generator outputting ozone gas;   a venturi in fluid communication with the ozone circuit and the ozone generator such that when liquid passes through the venturi from the ozone circuit, the ozone gas is drawn into the liquid passing through the venturi to form an ozone gas-liquid mixture and the ozone gas-liquid mixture is emitted from the venturi to the sprayer, with the ozone gas-liquid mixture being at a second pressure, which is less than the first pressure;   a valve selectively coupling the ozone circuit to the recirculation circuit; and   a controller operably coupled to the valve to control an introduction of the ozone gas-liquid mixture to the sprayer according to the cycle of operation.   
     
     
         19 . The dishwasher of  claim 18  further comprising a filter in fluid communication with the recirculation circuit, and the ozone circuit fluidly couples to the recirculation circuit downstream of the filter. 
     
     
         20 . The dishwasher of  claim 18  wherein the sprayer comprises at least one rotating spray arm. 
     
     
         21 . The dishwasher of  claim 18  wherein the controller is configured to introduce the ozone gas-liquid mixture into the treating chamber to maintain the ozone gas in the treating chamber at a sanitizing concentration of 5 ppm or less to sanitize the dishes. 
     
     
         22 . The dishwasher of  claim 21  wherein sanitizing the dishes comprises at least a 5 log reduction of at least one species of bacteria. 
     
     
         23 . The dishwasher of  claim 18  further comprising a closure operable to selectively open and close an access opening to the treating chamber, and wherein the closure remains fully operable during the introduction of the ozone gas-liquid mixture. 
     
     
         24 . A method of operating a dishwasher having a treating chamber in which dishes are received for treatment according to a cycle of operation, the method comprising:
 recirculating liquid within the treating chamber to treat the dishes;   providing ozone gas to a low pressure input of a venturi;   generating an ozone gas-liquid mixture by diverting the recirculating liquid through the venturi to draw the ozone gas into the liquid passing through the venturi; and   supplying the ozone gas-liquid mixture to the treating chamber.   
     
     
         25 . The method of  claim 24  wherein the supplying of the ozone gas-liquid mixture occurs during a rinse phase of the cycle of operation. 
     
     
         26 . The method of  claim 24  further comprising filtering the liquid prior to generating the ozone gas-liquid mixture. 
     
     
         27 . The method of  claim 24  further comprising spraying the recirculating liquid in the treating chamber. 
     
     
         28 . The method of  claim 24  further comprising draining liquid from the treating chamber prior to diverting the recirculating liquid through the venturi. 
     
     
         29 . The method of  claim 24  wherein the diverting the recirculating liquid through the venturi occurs for a predetermined period of time. 
     
     
         30 . The method of  claim 29  further comprising actuating a heater upon expiration of the predetermined period of time. 
     
     
         31 . The method of  claim 24  wherein the recirculating the liquid within the treating chamber occurs at a first pressure. 
     
     
         32 . The method of  claim 31  wherein the supplying the ozone gas-liquid mixture to the treating chamber occurs at a second pressure, lower than the first pressure. 
     
     
         33 . The method of  claim 24  wherein the supplying the ozone gas-liquid mixture to the treating chamber comprises spraying the ozone gas-liquid mixture through at least one sprayer. 
     
     
         34 . The method of  claim 24  further comprising supplying the ozone gas-liquid mixture to maintain the ozone gas at a sanitizing concentration of 5 ppm or less to sanitize the dishes. 
     
     
         35 . The method of  claim 34  wherein sanitizing the dishes comprises at least a 5 log reduction of at least one species of bacteria.