Abstract: Combustion gases containing free oxygen and a carbonaceous feed are introduced into a carbon black reactor, with the combustion gases being at a temperature sufficient to pyrolyze the feed hydrocarbon to produce combustion products containing particulate carbon black. The combustion products are cooled by quenching to form a gaseous effluent containing particulate carbon black. The effluent is discharged from the reactor to an indirect heat exchange means for further cooling the effluent. Carbon black is introduced into the effluent inlet of the indirect heat exchange means for removing carbon black which has become deposited on surfaces defining the flow path or flow paths for the effluent flowing through the heat exchange means. The effluent after cooling in the indirect heat exchange means is passed to separating means for separating the effluent into a gaseous portion and a particulate carbon black portion. Thereafter, the particulate carbon black portion can be pelleted.