Abstract: This disclosure pertains to wall burners which are used to raise the temperature of a gas stream flowing through a duct. Wall burners are mounted outside the duct and fire into the duct through a porthole formed in the duct wall. The present invention is uniquely characterized by a pre-main combustion chamber wherein a combusting fuel-air mixture is generated using only a small amount of the total fuel expended by the burner. The combusting mixture travels downstream through an accelerator ring and into the duct at high velocity and momentum. On the downstream side of the accelerator ring, main fuel ports inject the major portion of the fuel expended into the combusting fuel-air mixture whereupon a transfer of heat and momentum takes place which carries the unburned main fuel into the duct where the main combustion process takes place.

Abstract: A wall burner is described for firing a flame laterally into a duct of the type generally known as a waste heat recovery duct wherein hot exhaust gases are passed in a heat exchange relationship with a second fluid downstream from the wall burner. The wall burner may be used as an igniter for a grid burner system disposed within the duct or the wall burner may itself be used to reheat the hot exhaust gases. The wall burner includes a combustion chamber pipe and ignition means located outside the duct so that ignition occurs outside the duct thereby obviating instabilities inherent in trying to ignite a combustible mixture within the hot exhaust gas path.

Abstract: In a combined cycle power plant, gas turbine exhaust gas is passed through a heat recovery steam generator (HRSG) wherein it may be reheated upstream from a boiler tube section prior to passing through the boiler tube section in a non-contact heat exchange relation with a feedwater supply to produce steam for driving a steam turbine. A plurality of air-atomized, liquid fuel wall burners are utilized, each in combination with a "vee"-shaped flameholder to heat the gas turbine exhaust gas. Each wall burner may be disposed in a recessed opening in the HRSG duct wall and each wall burner has a nozzle portion which may be directed upstream relative to the exhaust gas flow. Each flameholder is approximately parallel to its respective wall burner nozzle axis having one end fixed to the duct wall, upstream from the nozzle axis, and a free end disposed within the HRSG duct.