Method of treating sewage sludge

摘要

A method of treating sewage sludge is disclosed. The method makes use of an unitary multi-hearth furnace and the sewage sludge is dried in an upper part of the furnace and subjected to pyrolyzation in a lower part thereof to cause the sewage sludge to be reduced to ashes whereby a relatively small amount of exhaust gas is produced. The exhaust gas is also utilized as a heat supply source.