Ash Removal

removal from the boiler area of ash and slag accumulated in ash and slag bunkers of steam boilers when solid fuel (coal, peat, shales) is burned. At electric power stations, removal of ash with water is most often used; less frequent is pneumatic removal. Mechanical ash removal using scraper equipment, skip hoists, and scraper and apron conveyors is employed extensively in industrial boilers burning fuel in grate-fired furnaces. These devices carry ash and slag away from the boiler room to a collecting bunker, from which they are removed by railroad cars or dump trucks. With small boilers giving under 200 kg per hr of ash and slag, use is made of small narrow-gauge cars with dumping bodies, monorail suspension transport, and gravity-discharge containers. To avoid dust, the slag and ash are wetted with water before removal from the bunkers. Up to 80 tons per hour of ash and slag are removed from modern boiler plants.