Hot Surface Igniter With Fuel Assist

Abstract

A large-scale combustion system has a fuel line having a burner end, a burner at the burner end of the fuel line, a source of fuel flowing through the fuel line to the burner, a hot surface igniter adjacent to the fuel line, a flame holder disposed adjacent to the hot surface igniter, and a source of igniter combustion air. The hot surface igniter is activated to ignite the source of fuel, the ignited fuel leaving the burner, and the hot surface igniter is protected from a heat caused by the ignited fuel. A flame detector detects ignition of the source of fuel and in response to detection of ignition the hot surface igniter is deactivated.

What is claimed is: 
     
         1 . A large-scale combustion system, comprising:
 a fuel line having a burner end;   a burner at the burner end of the fuel line;   a source of fuel flowing through the fuel line to the burner;   a hot surface igniter adjacent to the fuel line;   a flame holder disposed adjacent to the hot surface igniter; and   a source of igniter combustion air;   wherein the hot surface igniter is activated to ignite the source of fuel, the ignited fuel leaving the burner; and   wherein the hot surface igniter is protected from a heat caused by the ignited fuel.   
     
     
         2 . The system of  claim 1  wherein the hot surface igniter is protected from the heat by a side stream in the fuel line, the hot surface igniter disposed in the side stream, some of the source of fuel flowing through the side stream and cooling the hot surface igniter when deactivated. 
     
     
         3 . The system of  claim 1  wherein the hot surface igniter is protected from the heat by a retractor retracting the hot surface igniter away from the heat when deactivated. 
     
     
         4 . The system of  claim 1  further comprising a flame detector detecting ignition of the source of fuel at the burner, the hot surface igniter deactivated in response to detection of ignition. 
     
     
         5 . The system of  claim 1  wherein the hot surface igniter is deactivated after a predetermined amount of time. 
     
     
         6 . The system of  claim 1  further comprising a controller controlling the amount of fuel or air to the burner. 
     
     
         7 . The system of  claim 1  wherein the source of fuel comprises natural gas. 
     
     
         8 . The system of  claim 1  wherein the source of fuel comprises a liquid fuel. 
     
     
         9 . The system of  claim 1  wherein the hot surface igniter is activated when no flame is detected at the burner. 
     
     
         10 . The system of  claim 1  wherein the large-scale combustion system comprises an industrial boiler. 
     
     
         11 . The system of  claim 1  wherein the large-scale combustion system comprises a power generator. 
     
     
         12 . A large-scale combustion system, comprising:
 a fuel line having a burner end;   a burner at the burner end of the fuel line;   a source of fuel flowing through the fuel line to the burner;   an ignition device adjacent to the fuel line, the an ignition device activated to ignite the source of fuel, the ignited fuel leaving the burner;   a side stream in the fuel line, the ignition device disposed in the side stream, some of the source of fuel flowing through the side stream and cooling the ignition device when deactivated; and   a flame detector detecting ignition of the source of fuel at the burner, the ignition device deactivated in response to detection of ignition.   
     
     
         13 . The system of  claim 12  wherein the ignition device comprises a hot surface igniter. 
     
     
         14 . The system of  claim 12  wherein the ignition device comprises a direct spark type ignition device.