Spark Ignition Pilot Assembly

Abstract

An apparatus for lighting a burner of a heat exchanger includes a mounting plate configured to be mounted to the heat exchanger, the mounting plate including a first and second opening, a pilot ignition rod assembly installed in the first opening, the pilot ignition rod assembly including a flame ionization rod and a terminal, and a sleeve coupled to and aligned with the second opening and configured to extend substantially through a refractory material lining a combustion chamber of the heat exchanger, the sleeve being joined to a ground rod on a distal end and a gas orifice mount on a proximal end, the gas orifice mount including a gas venturi surrounded by the sleeve, wherein the sleeve is sized to extend from the mounting plate through an opening in the refractory material lining the combustion chamber, wherein the sleeve includes a sleeve opening adjacent to the gas venturi, the sleeve opening configured to allow air from the combustion chamber to the gas venturi.

What is claimed is: 
     
         1 . A heat exchanger including an apparatus for lighting a burner, comprising:
 a combustion chamber having a wall lined with a refractory material; and   an ignition rod assembly having a sleeve fixed to a ground rod and having a flame ionization rod insulator surrounding a flame ionization rod,   wherein the sleeve and the flame ionization rod insulator extend into the combustion chamber through an opening formed in the wall of the heat exchanger and the refractory material.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the ignition assembly further comprises a mounting plate designed to seal the opening formed in the wall of the heat exchanger. 
     
     
         3 . The heat exchanger of  claim 2 , wherein the mounting plate is mounted outside of the combustion chamber of the heat exchanger. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the flame ionization rod is electrically connected to a terminal located outside of the combustion chamber of the heat exchanger. 
     
     
         5 . The heat exchanger of  claim 4 , wherein the terminal further includes a terminal insulator provided in the form of a material that is heat resistant and electrically insulating. 
     
     
         6 . The heat exchanger of  claim 1 , wherein the sleeve is further fixed to a gas venturi. 
     
     
         7 . The heat exchanger of  claim 6 , wherein the gas venturi creates a venturi effect designed to draw air from the combustion chamber into the sleeve through a sleeve opening. 
     
     
         8 . The heat exchanger of  claim 1 , wherein the sleeve is connected to a gas orifice mount located outside of the combustion chamber of the heat exchanger. 
     
     
         9 . The heat exchanger of  claim 1 , wherein the flame ionization rod is configured to monitor current flow in the ignition rod assembly. 
     
     
         10 . An apparatus for lighting a burner, comprising:
 an ignition rod assembly comprising a flame ionization rod and a terminal; and   a ground rod joined to a sleeve at a first end of the sleeve,   wherein a spark is generated in a gap between the flame ionization rod and the ground rod when a high voltage is applied to the terminal, and wherein a current is generated that can be monitored to detect a presence of a flame when a low voltage is applied to the terminal.   
     
     
         11 . The apparatus of  claim 10 , wherein the sleeve is joined to a gas orifice mount and the spark generates a flame when the spark interacts with a gas supplied through the gas orifice mount. 
     
     
         12 . The apparatus of  claim 11 , wherein the gas orifice mount is configured to be press-fit or threaded into the sleeve. 
     
     
         13 . The apparatus of  claim 10 , wherein the sleeve comprises a slot designed to retain the ground rod via a press fit connection or via welding. 
     
     
         14 . The apparatus of  claim 10 , wherein the flame ionization rod is provided in a hook shape. 
     
     
         15 . An apparatus for lighting a burner, comprising:
 a mounting plate comprising a first opening and a second opening;   an ignition rod assembly installed in the first opening, the ignition rod assembly provided in the form of a flame ionization rod and a terminal; and   a sleeve coupled to and aligned with the second opening, the sleeve in communication with a ground rod on a distal end and a gas orifice mount on a proximal end,   wherein the sleeve includes a sleeve opening configured to allow air to flow from a combustion chamber of a heat exchanger to the gas orifice mount.   
     
     
         16 . The apparatus according to  claim 15 , wherein the ground rod is grooved or coated with other alloy materials. 
     
     
         17 . The apparatus of  claim 15 , wherein the flame ionization rod has a tip that is sharpened. 
     
     
         18 . The apparatus of  claim 15 , wherein the flame ionization rod is coated with an alloy material suitable for heat resistance, oxidation resistance, or low electric resistance. 
     
     
         19 . The apparatus of  claim 15 , wherein the flame ionization rod is made from alumina, Kanthal™, or Nichrome. 
     
     
         20 . The apparatus of  claim 15 , further comprising a terminal insulator made from alumina, ceramic, or another material that is heat resistant and electrical insulating.