COAL HEATING PLANT OPERATION

摘要

Coal is passed in a two-stage process through a drying and heating zone. The coal coming from the drying zone is separated from the heat carrier gas which is then passed into the atmosphere after going through an electrodust separator. The dried coal is delivered into the heating zone. The hot gas for the heating zone is furnished by a combustion device. The exhaust gas from the heating zone is separated from the heated coal which is recovered while the exhaust gas is passed back into the drying zone. Part of the hot combustion gas coming from the combustion chamber is branched off and passed into the exhaust gas coming out of the drying zone either directly behind the drying zone or behind the separator for separating the dried coal from the exhaust gas. The temperature of the exhaust gas from the drying zone is thus prevented from sinking below the sulfuric acid dewpoint or water vapor dewpoint which might result in corrosive damage to the apparatus, particularly to the electrodust separator.