Water Heater Burner Clogging Detection and Shutdown System with Associated Burner Apparatus

Abstract

A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. All of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner. The pilot burner may be mounted on the main burner in a variety of locations thereon.

1 . Fuel-fired heating apparatus comprising: 
 a combustion chamber;    a main fuel burner disposed in said combustion chamber and having: 
 a hollow body with a perforate section cloggable by particulate matter entrained in combustion air being delivered to the interior of said hollow body during firing of said main fuel burner, and  
 an air-receiving structure coupled to said hollow body and having an interior communicating with the interior of said hollow body, and defining a passage for flowing primary combustion air into the interior of said hollow body from outside of said combustion chamber;  
   a pilot fuel burner disposed in said combustion chamber and being mounted on one of said hollow body and said air receiving structure, said pilot fuel burner being operative to generate a pilot flame useable to ignite said main fuel burner and having: 
 an air inlet portion extending into the interior of said main fuel burner and having an air inlet opening operative to receive combustion air from within said interior of said main fuel burner, and  
 a cloggable perforate structure interposed in the path of combustion air being received by said air inlet opening; and  
   a shutdown system for terminating combustion in said combustion chamber prior to said perforate section of said hollow body becoming clogged to a predetermined degree, said shutdown system being operative to monitor the condition of said pilot fuel burner flame and terminate combustion within said combustion chamber when said condition becomes indicative of a predetermined degree of clogging of said cloggable perforate structure of said pilot fuel burner.    
   
   
       2 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said fuel-fired heating apparatus further comprises a fuel supply system for delivering fuel, from a source thereof, to said main and pilot fuel burners, said fuel supply system including a fuel valve, and    said shutdown system is operative to close said fuel valve in response to detecting said condition of said pilot burner flame.    
   
   
       3 . The fuel-fired heating apparatus of  claim 2  wherein: 
 said shutdown system includes a thermocouple positioned to be impinged upon by said pilot burner flame and operatively coupled to said fuel valve.    
   
   
       4 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said fuel-fired heating apparatus is a fuel-fired water heater.    
   
   
       5 . The fuel-fired heating apparatus of  claim 4  wherein: 
 said fuel-fired water heater is a gas fired water heater.    
   
   
       6 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said main fuel burner is a radiant burner.    
   
   
       7 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said pilot fuel burner is mounted on said hollow body of said main fuel burner, and    said air inlet portion of said pilot fuel burner extends into the interior of said hollow body portion of said main fuel burner.    
   
   
       8 . The fuel-fired heating apparatus of  claim 7  wherein: 
 said hollow body of said main fuel burner has a side wall extending downwardly from said perforate section, and an end wall extending downwardly from said perforate section and disposed opposite said air-receiving structure.    
   
   
       9 . The fuel-fired heating apparatus of  claim 8  wherein: 
 said pilot fuel burner is mounted on said side wall of said hollow body with said air inlet portion of said pilot fuel burner extending into the interior of said hollow body of said main fuel burner.    
   
   
       10 . The fuel-fired heating apparatus of  claim 8  wherein: 
 said pilot fuel burner is mounted on said end wall of said hollow body with said air inlet portion of said pilot fuel burner extending into the interior of said hollow body of said main fuel burner.    
   
   
       11 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said pilot fuel burner is mounted on said air receiving structure of said main fuel burner, and    said air inlet portion of said pilot fuel burner extends into the interior of said air receiving portion of said main fuel burner.    
   
   
       12 . The fuel-fired heating apparatus of  claim 11  wherein: 
 said air receiving structure has a top wall and a side wall extending downwardly from said top wall.    
   
   
       13 . The fuel-fired heating apparatus of  claim 12  wherein: 
 said pilot fuel burner is mounted on said top wall of said air receiving structure.    
   
   
       14 . The fuel-fired heating apparatus of  claim 12  wherein: 
 said pilot fuel burner is mounted on said side wall of said air receiving structure.    
   
   
       15 . The fuel-fired heating apparatus of  claim 1  wherein: 
 said cloggable perforate section of said hollow body of said main fuel burner is of a metal mesh material, and    said cloggable perforate structure of said pilot fuel burner is of a metal mesh material having a finer mesh size than the mesh size of said cloggable perforate section of said hollow body of said main fuel burner.    
   
   
       16 . Fuel burner apparatus operatively positionable in the combustion chamber of a fuel-fired heating appliance, comprising: 
 a radiant main fuel burner having a hollow body with a perforate top wall section cloggable by particulate matter entrained in combustion air being delivered to the interior of said hollow body during firing of said radiant main fuel burner, said hollow body having a side wall and an end wall extending downwardly from said top wall section, and an air-receiving structure coupled to said hollow body opposite said end thereof and having an interior communicating with the interior of said body for flowing primary combustion air into the interior of said hollow body directly from outside the combustion chamber;    a pilot fuel burner mounted externally on one of said hollow body and said air receiving structure and being operative to generate a pilot flame useable to ignite said radiant fuel burner; and an air inlet portion extending from said pilot fuel burner into the interior of said radiant main fuel burner and having an air inlet opening operative to receive combustion air from within the interior of said main radiant fuel burner, and a cloggable perforate structure interposed within the path of combustion air being received by said air inlet opening, said cloggable perforate structure, relative to said perforate cloggable top wall section of said hollow body, being more readily cloggable by particulate matter in combustion air within the interior of said main radiant fuel burner.    
   
   
       17 . The fuel burner apparatus of  claim 16  wherein: 
 said perforate top wall section of said hollow body and said cloggable perforate structure are each of a metal mesh construction, with the metal mesh of said cloggable perforate structure being of a finer mesh size than the mesh size of said perforate top wall section of said hollow body.    
   
   
       18 . The fuel burner apparatus of  claim 16  wherein: 
 said pilot fuel burner is externally mounted on a top side portion of said air-receiving structure, and said air inlet portion of said pilot fuel burner extends into the interior of said air-receiving structure.    
   
   
       19 . The fuel burner apparatus of  claim 16  wherein: 
 said pilot fuel burner is externally mounted on a side portion of said air-receiving structure, and said air inlet portion of said pilot fuel burner extends into the interior of said air-receiving structure.    
   
   
       20 . The fuel burner apparatus of  claim 16  wherein: 
 said pilot fuel burner is externally mounted on said side wall of said hollow body, and said air inlet portion of said pilot fuel burner extends into the interior of said hollow body.    
   
   
       21 . The fuel burner apparatus of  claim 16  wherein: 
 said pilot fuel burner is externally mounted on said end wall of said hollow body, and said air inlet portion of said pilot fuel burner extends into the interior of said hollow body.