Inward fired low nox premix burner

Abstract

A burner assembly ( 40 ) for providing a flame and combustion gas to a plurality of inlets includes a support member ( 70 ) having a back surface and an inner surface. An elongated opening ( 72 ) is formed in the support member. A burner ( 74 ) is connected to the support member adjacent the opening and extending upstream from the back surface. The burner is arranged in fluid communication with the plurality of inlets. An interior surface of the burner is contoured to direct flames generally inwardly.

What is claimed is: 
     
         1 . A burner assembly for providing a flame and combustion gas to a plurality of inlets, comprising
 a support member having a back surface and an inner surface, an elongated opening being formed in the support member; and   a burner connected to the support member adjacent the opening and extending upstream from the back surface, the burner being arranged in fluid communication with the plurality of inlets, wherein an interior surface of the burner is contoured to direct flames generally inwardly.   
     
     
         2 . The burner assembly of  claim 1 , wherein the interior surface of the burner is concave. 
     
     
         3 . The burner assembly of  claim 1 , wherein the interior surface of the burner is contoured to direct flames from the interior surface to a focus. 
     
     
         4 . The burner assembly of  claim 3 , wherein an outlet of the burner is arranged within a plane, and the focus is arranged opposite the burner relative to the plane. 
     
     
         5 . The burner assembly of  claim 4 , wherein the interior surface of the burner is elliptical in shape. 
     
     
         6 . The burner assembly of  claim 3 , wherein the interior surface of the burner is circular in shape. 
     
     
         7 . The burner assembly of  claim 1 , wherein the burner is formed from a porous material. 
     
     
         8 . The burner assembly of  claim 1 , wherein an outlet end of the burner comprises a flange, the flange being mounted to the inner surface of the support member such that the burner extends through the opening. 
     
     
         9 . The burner assembly of  claim 1 , further comprising:
 an igniter arranged adjacent a first end of the opening; and   a flame sensor positioned adjacent a second, opposite end of the opening.   
     
     
         10 . The burner assembly of  claim 9 , w herein the igniter is offset from the inner surface of the support member such that the igniter is positioned downstream from the burner relative to a direction of flow through the burner. 
     
     
         11 . A furnace comprising:
 a heat exchanger including a plurality of coils; and   a burner unit including:
 a burner box defining a mixing chamber for receiving a mixture of fuel and air; and 
 a burner assembly including a burner arranged within the mixing chamber and being substantially aligned with the plurality of coils, wherein an interior surface of the burner is contoured to direct flames generally inwardly. 
   
     
     
         12 . The furnace of  claim 11 , wherein the burner unit further comprises a support member having an opening, the burner being positioned generally adjacent the opening. 
     
     
         13 . The furnace of  claim 11 , wherein the interior surface of the burner is contoured to direct flames from the interior surface to a focus. 
     
     
         14 . The furnace of  claim 13 , wherein an outlet of the burner is arranged within a plane, the focus and the burner being disposed on opposing sides of the plane. 
     
     
         15 . The furnace of  claim 14 , wherein the interior surface of the burner is elliptical in shape. 
     
     
         16 . The furnace of  claim 13 , wherein the interior surface of the burner is circular in shape. 
     
     
         17 . A method of operating a furnace, comprising:
 providing a mixture of fuel and air to a mixing chamber;   igniting the mixture of fuel and air as it flows from the mixing chamber through a burner assembly including a burner; and   supplying flames and combustion from the burner to a plurality of coils of a heat exchanger.   
     
     
         18 . The method of  claim 17 , further comprising directing flames from an interior surface of the burner generally inwardly. 
     
     
         19 . The method of  claim 18 , wherein directing flames from an interior surface of the burner generally inwardly comprises directing the flames to a focus. 
     
     
         20 . The method of  claim 19 , wherein an outlet of the burner is arranged within a plane and the focus and the burner are disposed on opposing sides of the plane.