The invention discloses a double-
cyclone coal pyrolysis gasification step converting device and a double-
cyclone coal pyrolysis gasification step converting method, and relates to a combusting device and a combusting method. The device is characterized in that a
cyclone pyrolyzing furnace is communicated with a cyclone gasifying furnace by a material backing device and a pyrolyzing semi-
coke channel; the cyclone gasifying furnace is communicated with the cyclone pyrolyzing furnace by a high-temperature raw
coal gas channel; the cyclone pyrolyzing furnace is communicated with a cooling device by a pyrolyzing gas-mixing channel; an oxidant
spray nozzle and a vapor
spray nozzle are arranged on the outer wall of the cyclone gasifying furnace. The method is as follows: firstly, feeding
coal dust into the cyclone pyrolyzing furnace under blocking and feeding of the high-temperature raw
coal gas; secondly, pyrolyzing the
coal dust in the cyclone pyrolyzing furnace, exhausting the pyrolyzed gas mixture into the cooling device, cooling, and conveying back the pyrolyzed semi-
coke to the cyclone gasifying furnace; thirdly, spraying the oxidant and the vapor into the cyclone pyrolyzing furnace by the oxidant
spray nozzle and the vapor spray
nozzle at the same time, wherein the produced high-temperature raw
coal gas is re-fed into the cyclone pyrolyzing furnace as a coal pyrolyzing
gas heater carrier; coal residue in the cyclone gasifying furnace is exhausted through an ash residue
discharge hole in the form of
solid or liquid. The double-cyclone
coal pyrolysis gasification step converting device and the double-cyclone
coal pyrolysis gasification step converting method are used for gasifying
clean coal gas.