Two-Stage Combustion

a method of burning fuels that have a low combustion reaction, such as anthracite. Some of the air required for combustion is introduced into the furnace not through the primary burners but through supplementary nozzles located 1.5–2 m above the burners. With this method the stream of coal dust and air is reduced; consequently, the heating of the stream by the flue gases is accelerated, and the conditions of ignition are improved. The supplementary air is carried to the torch in a zone where burning has already developed.