Patent ID: 6869277

Claim:
A burner for the combustion of fuel in a furnace, said burner comprising: (a) a burner tube having a downstream end, and having an upstream end for receiving fuel and air, flue gas and mixtures thereof, a burner tip being mounted on the downstream end of said burner tube adjacent to a first opening in the furnace, so that combustion of the fuel takes place downstream of said burner tip; (b) at least one passageway having a first end at a second opening in the furnace and a second end adjacent to the upstream end of said burner tube; (c) means for drawing flue gas from said furnace through said passageway in response to an inspirating effect created by uncombusted fuel flowing through said burner tube from its upstream end towards its downstream end; and (d) at least one tube disposed in said passageway wherein air which is cooler than the flue gas flows through said at least one tube into a secondary air chamber permitting heat to be transferred from the flue gas to the air to create preheated air.