Gas pilot system and method having improved oxygen level detection capability and gas fueled device including the same

Abstract

A pilot system including a pilot including a nozzle and a light sensor adjacent to the nozzle. The light sensor determines whether or not the pilot flame is in a predetermined position relative to the nozzle.

I claim:  
     
         1 . A pilot system for generating a pilot flame, comprising: 
 a pilot including a nozzle; and    a light sensor adjacent to the nozzle.    
     
     
         2 . A pilot system as claimed in  claim 1 , wherein the light sensor comprises an infrared light sensor.  
     
     
         3 . A pilot system as claimed in  claim 1 , further comprising: 
 a ignitor positioned adjacent to the nozzle;    wherein the light sensor faces a region located between the nozzle and the ignitor.    
     
     
         4 . A pilot system as claimed in  claim 1 , further comprising: 
 a light shield substantially surrounding the nozzle and defining an open region that faces the light sensor.    
     
     
         5 . A pilot system as claimed in  claim 1 , further comprising: 
 a mixing chamber located upstream of the nozzle including a gas inlet, an air inlet and a gas/air mixture outlet in communication with the nozzle.    
     
     
         6 . A pilot system as claimed in  claim 1 , wherein the pilot is constructed such that the pilot flame will be located in a first position in response to a first oxygen level and a second position in response to a second oxygen level, the second oxygen level being less than the first oxygen level, and the light sensor will receive a level of light indicative of an allowable oxygen level when the pilot flame is in the first position and will not receive a level of light indicative of an allowable oxygen level when the pilot flame is in the second position.  
     
     
         7 . A gas fueled device, comprising: 
 a burner;    a pilot including a nozzle associated with the burner; and    a light sensor adjacent to the nozzle.    
     
     
         8 . A gas fueled device as claimed in  claim 7 , wherein the burner comprises a ceramic plaque.  
     
     
         9 . A gas fueled device as claimed in  claim 7 , wherein the light sensor comprises an infrared light sensor.  
     
     
         10 . A gas fueled device as claimed in  claim 7 , further comprising: 
 a ignitor positioned adjacent to the nozzle;    wherein the light sensor faces a region located between the nozzle and the ignitor.    
     
     
         11 . A gas fueled device as claimed in  claim 7 , further comprising: 
 a light shield substantially surrounding the nozzle and defining an open region that faces the light sensor.    
     
     
         12 . A gas fueled device as claimed in  claim 7 , further comprising: 
 a mixing chamber located upstream of the nozzle including a gas inlet, an air inlet and a gas/air mixture outlet in communication with the nozzle.    
     
     
         13 . A gas fueled device as claimed in  claim 7 , wherein the pilot is constructed such that the pilot flame will be located in a first position in response to a first oxygen level and a second position in response to a second oxygen level, the second oxygen level being less than the first oxygen level, and the light sensor will receive a level of light indicative of an allowable oxygen level when the pilot flame is in the first position and will not receive a level of light indicative of an allowable oxygen level when the pilot flame is in the second position.  
     
     
         14 . A gas fueled device as claimed in  claim 13 , further comprising: 
 a gas inlet operably connected to the pilot; and    a control device operably connected to the light sensor that prevents gas flow from the gas inlet to the pilot when the light sensor does not receive a level of light indicative of an allowable oxygen level.    
     
     
         15 . A gas fueled device as claimed in  claim 13 , further comprising: 
 a gas inlet operably connected to the burner; and    a control device operably connected to the light sensor that prevents gas flow from the gas inlet to the burner when the light sensor does not receive a level of light indicative of an allowable oxygen level.    
     
     
         16 . A method of monitoring a pilot flame produced by a gas pilot, comprising the steps of: 
 determining whether light is being emitted from a predetermined region associated with the pilot; and    preventing gas flow from flowing to the pilot in response to a determination that light is not being emitted from the predetermined region.    
     
     
         17 . A method as claimed in  claim 16 , wherein the step of determining whether light is being emitted comprises determining whether infrared light is being emitted from a predetermined region associated with the pilot.  
     
     
         18 . A method as claimed in  claim 16 , wherein the gas pilot includes a nozzle and an igitor defining a region therebetween and the step of determining whether light is being emitted from a predetermined region comprises determining whether light is being emitted from the region between the nozzle and the ignitor.  
     
     
         19 . A method as claimed in  claim 16 , wherein the step of preventing gas flow from flowing to the pilot comprises closing a valve.  
     
     
         20 . A method as claimed in  claim 16 , wherein the gas pilot includes a nozzle, the method further comprising the step of: 
 mixing gas with ambient air to form an air/gas mixture; and    providing the air/gas to the nozzle.