Steam system for continuous cleaning of hood fans

Abstract

A device and method for cleaning fans in range or stove hoods by spraying steam onto the fan impeller area on which soot and cooking fumes condense to clean the impeller and wash the accumulated condensates down a drain. By using steam above atmospheric pressure as the cleaning fluid, the device uses significantly less water that other devices that spray water or an aqueous solution to clean the fan blades.

1 . A hood for ventilating a home cooking area, comprising: 
 a hood enclosure;    a fan disposed in the enclosure for exhausting cooking fumes, the fan having an impeller and a fan housing; and    a steam generator within the hood enclosure for generating pressurized steam from a water supply, the steam generator having an outlet, and the outlet being fluidly connected to the fan housing effective to direct pressurized steam onto the impeller, the pressure of the steam generated being above atmospheric pressure.    
   
   
       2 . The hood of  claim 1 , further comprising 
 a steam generator housing having a mating base and cover enclosing the steam generator, and    a pump mounted on the steam generator housing and fluidly connected between the water supply and the steam generator.    
   
   
       3 . The hood of  claim 1 , wherein the steam generator further comprises a heating coil, at least one temperature regulator controlling the temperature at which the heating coil shuts off, and at least one second temperature regulator controlling the temperature at which the heating coil is turned on.  
   
   
       4 . The hood of  claim 1 , wherein the steam generator has a low profile.  
   
   
       5 . The hood of  claim 3 , further comprising a temperature-sensitive fuse controlling power to the induction heating coil by sensing the temperature of the steam generator.  
   
   
       6 . The hood of  claim 3 , wherein the steam generator comprises a base and a cover, said heating coil is disposed in the base, and a plate having a plurality of small holes and disposed immovably between the base and the cover.  
   
   
       7 . The hood of  claim 1 , further comprising a user-accessible controller for initiating a cleaning cycle, the controller including a timer, and the controller energizing the pump and the heating coil during the cleaning cycle.  
   
   
       8 . The hood of  claim 7 , further comprising a water reservoir attached to the hood and fluidly connected to the steam generator, and a low level sensor connected to the controller, the controller adapted to de-energize the heating coil on a low level sensed.  
   
   
       9 . A method for degreasing the impeller of a fan mounted in a cooking exhaust hood installation in a home, comprising: 
 A. providing a hood installation including said fan;    B. providing water and heating the water to steam in a low profile vessel wholly within the hood installation to generate steam above atmospheric pressure; and    C. directing said steam from said vessel against the impeller of said fan in an amount effective to degrease the impeller.    
   
   
       10 . The method of  claim 9 , wherein the pressurized steam is generated at a temperature of at least about 140° C.  
   
   
       11 . The method of  claim 10 , wherein the pressurized steam is generated at a temperature of at least about 175° C.  
   
   
       12 . The method of  claim 11 , wherein the pressurized steam is generated up to a temperature of about 200° C.  
   
   
       13 . The method of  claim 9 , further comprising the step of stopping the heating when the temperature of the steam generated exceeds about 215° C.  
   
   
       14 . The method of  claim 9 , further comprising pumping water to said vessel.  
   
   
       15 . The method of  claim 9 , further comprising restricting the flow of steam from said vessel onto said impeller with a nozzle.  
   
   
       16 . The method of  claim 9 , further comprising providing a refillable reservoir of water, and providing the water by pumping the water from the reservoir, and further comprising automatically shutting off the steam generator if water in the reservoir falls below a predetermined level.  
   
   
       17 . The method of  claim 9 , further comprising cycling the heating between two predetermined temperatures for a predetermined period of time.  
   
   
       18 . The method of  claim 17 , further comprising a user-accessible control for starting the cycling.  
   
   
       19 . The hood of  claim 1 , wherein the steam generator has a low profile.