摘要 |
Continuously flowing solid material, such as municipal waste, is pretreated in an air-starved hot moving grate carbonizer furnace to drive off low temperature volatiles, and then further devolatized in a shaft furnace wherein limited amounts of air are let into a downwardly moving stack of the precarbonized material at a plurality of locations spaced sufficiently apart as to preclude formation of hot spots, i.e., localized regions of intense reaction, such as would cause clinkers to be formed. Low Btu gas is exhausted from the pretreatment carbonizer and shaft furnace and sterile ash residue is discharged from the bottom of the shaft furnace. |