BRENNER

摘要

An internally recirculating burner designed to operate at a low level of excess air without producing intolerable levels of particulate (smoke) and oxides of nitrogen using ambient or highly preheated atmospheric air as an oxidant. The burner operates with a flame front outside of the burner in the combustion chamber with recirculation of furnace gas being provided by the geometric configuration of the burner and the energy provided by the incoming combustion air. A nozzle means for controlling the combustion air flow is disclosed concentric with the burner center body. The nozzle is comprised of a fixed ceramic nozzle plate having annularly arranged distribution holes and a nozzle plus also preferably of ceramic supported to open and close the annular flow passage between the nozzle and the burner center body as well as the annular flow distribution holes. The air discharged through the nozzle flows along the surface of the center body creating a pressure depression at the point of discharge causing the furnace gas to flow from the furnace chamber to the passage formed by the burner barrel and the outside diameter of the recirculating sleeve. The recirculated gas joins the incoming combustion air and flows parallel to the combustion air through the annular passage formed by the inside diameter of the recirculating sleeve and the outside diameter of the center body. Some mixing of the combustion air and the recirculating gas occurs within the recirculating sleeve. A flame holder forming a portion of the center body central tube at the discharge end of the burner creates eddies and provides for a flame holding zone in which the fuel can be injected and the flame sustained. The flame thus formed extends into the combustion zone to the point at which the combustion reaction is completed.