Abstract: A pyroscrubber for combustion of large carbon particles in a stream of waste gas, particularly the waste gas from a coke calcination furnace comprises a generally U-shaped combustion chamber having a first passage arranged parallel with (preferably above) a second passage, so that there is a reversal in gas flow direction between the two passages. The combustion chamber has an exhaust gas inlet and an array of air inlets at the inlet end of the first passage. A gas outlet preferably leads laterally out of the side of the structure at the outlet end of the second passage to secure an abrupt change in the direction of gas flow.

Abstract: In the calcination of petroleum coke in a rotary kiln, procedure wherein air is controllably supplied internally of the kiln to burn the removed volatiles, as by selection or adjustment of the amount of such air and of the speed of coke travel down the kiln, so that all or nearly all of the heat for calcining the coke is provided by such combustion, and so that a suitably high temperature is reached for effective calcination at an efficiently large feed rate of coke, a special feature being to maintain a significantly long travel time of the coke from a region of intense calcining activity to the product discharge end of the kiln. High production rates, of coke calcined well and uniformly, are economically attained, with ease of control and with unusual stability of kiln operation.