Heat treatment of solids in rotary hearth furnace - used esp. for the redn. of iron ore via brown coal, or the conversion of brown coal to coke

摘要

A layer(26) of solid fuel is fed onto the hearth, and is covered by a layer(28) of solids contg. carbon. The burning and/or reactions in the layers produce gases which heat layer(28), and also solid materials which travel towards an exit together with ash and any unburnt fuel. A gas, esp. a gas contg. oxygen, may be fed into layers (26,28). The process is pref. used to convert coal, esp. brown coal, into coke, or to mfr. iron from a mixt. of ore and brown coal. The pref. furnace has an inlet for fuel(26) near its periphery, and a second inlet for solids(28), plus an igniter for fuel(26), and baffles driving the solids towards an axial exit in the hearth.