Removal of heat and water vapor from commercial dishwashing machines

Abstract

A water-driven jet or venturi extraction means is used to remove, capture and cool the hot, highly humid air created within commercial dishwashers during a wash rinse or sanitization cycle. A cold water spray is used to create a pressure reduction zone which serves to draw in hot, highly humid air from the dishwasher. Water vapor cools and condenses on contact with the cold water spray within the venturi. The invention also serves to help vent the dishwasher. Cool, fresh air is drawn into the dishwasher while the hot air is drawn into the venturi.

1. A dishwashing machine that can be cooled after completing one or more cycles, said machine using water of elevated temperature, said machine producing a hot humid atmosphere, the machine comprising:
 (i) a machine enclosure comprising at least one inlet in fluid communication between the machine interior and the machine exterior, and  
 (ii) extraction means comprising a housing comprising a water jet with a spray nozzle, and at least one conduit in fluid communication between the machine enclosure interior and the housing, the spray nozzle providing a water spray effective to create a zone of reduced pressure within the housing for removing the hot humid atmosphere from within the machine enclosure through the conduit, while causing entry of fresh air into the machine through the inlet.  
 
     
     
       2. The dishwasher of  claim 1  wherein the water jet comprises a source of water between about 35° F. and 100° F. and between about 10 and 60 psi. 
     
     
       3. The dishwasher of  claim 2  wherein the water jet comprises a source of water between about 35° F. and 70° F. and between about 30 and 60 psi. 
     
     
       4. The dishwasher of claim  3    1  wherein the water jet comprises a spray nozzle with a spray angle of about 30° and a flow rate of about 3 gallons per minute at a supply pressure of about  40 psi  p.s.i . 
     
     
       5. The dishwasher of  claim 1  wherein the housing comprises a 1 to 3 inch ID pipe, the conduit comprises a 1 to 3 inch ID pipe, the housing ending in a discharge section comprising a 1 to 4 inch ID pipe. 
     
     
       6. The method  dishwasher of  claim 1  wherein the extraction means operates  is configured to operate for a duration of 10 to 30 seconds at the end of a final rinse period. 
     
     
       7. The method  dishwasher of  claim 1  wherein the extraction means operates  is configured to operate intermittently. 
     
     
       8. The method  dishwasher of  claim 1  wherein the water jet has a spray angle of at least 15° F. 
     
     
       9. The method  dishwasher of  claim 8  wherein the water jet contacts the side walls of the discharge pipe. 
     
     
       10. The method  dishwasher of  claim 8  wherein the water jet has a spray angle of between about 15° and 50° F. 
     
     
       11. The method  dishwasher of  claim 8  wherein the water jet has a flow rate of between about 0.5 and 10 gallons per minute and a supply pressure of between about 10 and 60 p.s.i. 
     
     
       12. A dishwashing machine, comprising:
  an air inlet defined in the dishwashing machine providing fluid communication between a dishwashing machine interior and a dishwashing machine exterior; and    a vent in fluid communication with the dishwashing machine interior, the vent comprising a conduit and a spray nozzle constructed and arranged to direct a spray of fluid through the conduit section and create a zone of reduced pressure within the vent so that air and moisture within the dishwashing machine interior is drawn into the vent and ambient air from the dishwashing machine exterior is drawn through the air inlet.   
     
     
       13. The dishwashing machine of  claim 12  wherein the conduit is a vertical conduit. 
     
     
       14. The dishwashing machine of  claim 13  wherein spray nozzle is located in a top portion of the vertical conduit. 
     
     
       15. The dishwashing machine of  claim 12  wherein the air inlet is a gap adjacent to a door of the dishwashing machine. 
     
     
       16. The dishwashing machine of  claim 12  wherein the vent is configured to operate the spray nozzle intermittently. 
     
     
       17. The dishwashing machine of  claim 12  wherein the spray nozzle is configured so that the spray of fluid contacts a wall of the conduit. 
     
     
       18. The dishwashing machine of  claim 12  wherein the spray nozzle is configured to direct the spray of fluid to have a spray angle of at least  15  degrees. 
     
     
       19. The dishwashing machine of  claim 18  wherein the spray angle is between about  15  degrees and  50  degrees. 
     
     
       20. The dishwashing machine of  claim 12  wherein the conduit directs fluid from the spray nozzle to a drain outside of the dishwashing machine interior. 
     
     
       21. The dishwashing machine of  claim 12  wherein the vent is configured to remove gas or vapor from the dishwashing machine interior at a rate of at least about  20  cubic feet per minute. 
     
     
       22. The dishwashing machine of  claim 12  wherein the vent is configured to reduce the temperature within the dishwashing machine interior by at least about  20  degree F. within about two minutes of operation. 
     
     
       23. The dishwashing machine of  claim 12  wherein the vent is configured to reduce the humidity within the dishwashing machine interior from substantially saturated to a humidity approximating the humidity in the dishwashing machine exterior within about a half minute of operation. 
     
     
       24. The dishwashing machine of  claim 12  wherein the zone of reduced pressure comprises a pressure difference from an ambient pressure at the dishwashing machine exterior of at least about  2  inches of water. 
     
     
       25. The dishwashing machine of  claim 12  wherein the spray nozzle is in fluid communication with a source of fluid at a temperature of between about  35  degree F. and  100  degree F. 
     
     
       26. The dishwashing machine of  claim 12  wherein the spray nozzle is in fluid communication with a source of fluid at a temperature of between about  35  degree F. and  70  degree F. 
     
     
       27. The dishwashing machine of  claim 12  wherein the spray nozzle is in fluid communication with a source of fluid with a pressure of about  10  to  60  p.s.i. 
     
     
       28. The dishwashing machine of  claim 27  wherein the spray nozzle is configured to discharge fluid at a flow rate between about  0 . 5  and  10  gallons per minute. 
     
     
       29. The dishwashing machine of  claim 12  wherein the spray nozzle is in fluid communication with a source of fluid with a pressure of about  30  to  60  p.s.i. 
     
     
       30. The dishwashing machine of  claim 12  wherein the conduit comprises a first pipe section having an inner diameter of about  1  to  3  inches and a second pipe section having an inner diameter of about  1  to  4  inches. 
     
     
       31. The dishwashing machine of  claim 12  wherein the vent is confirmed to operate the spray nozzle for a duration of about  10  to  30  seconds at the end of a final rinse period. 
     
     
       32. A dishwashing machine, comprising:
 an air inlet defined in the dishwashing machine providing fluid communication between a dishwashing machine interior and a dishwashing machine exterior; and    a vent in fluid communication with the dishwashing machine interior, the vent comprising a conduit and a spray nozzle constructed and arranged to direct a spray of fluid to create a zone of reduced pressure within the vent so that air and moisture within the dishwashing machine interior is drawn into the vent and ambient air from the dishwashing machine exterior is drawn through the air inlet.   
     
     
       33. The dishwashing machine of  claim 32  wherein the spray nozzle is positioned within the conduit and directs a spray of fluid through the conduit. 
     
     
       34. A dishwashing machine, comprising:
 an air inlet defined in the dishwashing machine providing fluid communication between a dishwashing machine interior and a dishwashing machine exterior; and    a vent in fluid communication with an interior of the dishwashing machine, the vent comprising a conduit and a spray nozzle constructed and arranged to direct a spray of fluid through the conduit section and create a zone of reduced pressure within the vent so that air and moisture within the dishwashing machine interior is drawn into the vent and ambient air from the dishwashing machine exterior is drawn through the air inlet, wherein the conduit directs fluid from the spray nozzle to a drain outside of the dishwashing machine interior.