Abstract: In the baking of carbon anodes (for aluminum reduction cells) or the like, in so-called ring-type furnaces where green carbon bodies are deposited in pits, each of which is circumstanced successively for preheating stages, one or more baking stages, and cooling stages, while air travels in heat exchange relation through flues past a series of pits respectively undergoing such cooling, baking and preheating operations, improvement is effected by introducing water spray into the air as it flows past the pits at a cooling region. Such water, first as spray and then as vapor, increases the quantity of heat that can be absorbed by the air flow and also increases the heat transfer coefficients of the flue walls in the cooling regions, so as to provide recovery or removal of heat in greater amount or more rapidly.