Hot gas recycle for starved-air combustor

摘要

A hot combustion gas recycle apparatus for a starved-air combustor for mixing hot combustion gas with significant amounts of air to heat the air. The heated air is injected as underfire air into the first combustion zone of the combustion chamber to heat and to dry the fuel in the fuel bed as an aid to combustion efficiency. The recycle device includes a temperature control system for controlling the ratio of gas to air and a control valve to completely shut off the flow of combustion gas to the recycle device if the gas and air mixture exceeds a preset maximum.