Steam boiler need to manage not only about coal handling but also about ash handling. Ash is a remaining product of combustion. Ash will be many found in steam boiler which uses coal as its fuel. Steam boiler needs some places to collect ash and then remove and dispose it together in a system which is used to take care about ash.
From the place collection, ash can be classified into two types; bottom ash and fly ash. Ash which be collected in the furnace or under stoker is called bottom ash, while the ash which be collected in the other areas such as boiler bank, air heater, economizer, and multi cyclone is called fly ash. Bottom ash tends to agglomerated clinkers and hard. Fly ash is often not heavy, soft and easy flow.
Handling management for bottom ash and fly ash are to be better if performed separately. Therefore steam boiler must be equipped for bottom ash handling equipments and fly ash handling equipments respectively. Bottom ash can be re-used for treatment in winter road, etc and fly ash can be re-used to be sold again to concrete manufacturer. This condition will be great advantage on economic side for the owner.
Large scale boiler usually applies more complete ash handling equipments than small scale boiler. Ash handling equipments are generally classified into three types as the following below: