Apparatus for heat exchange between fine material and gas

Counterflow heat exchanger apparatus for heat exchange between fine material and gas, comprising a generally vertical reaction vessel which is divided by funnel-like constrictions into a number of individual chambers, and which has at least one inlet for introducing fine material into the top of the uppermost of such chambers and an opening at the bottom of the lowermost of such chambers for withdrawing heated fine material and for introducing hot gas to be exhausted from said uppermost chamber, each individual chamber being defined by a substantially cylindrical vertical wall of the reaction vessel surrounding the major portion of the chamber, an upwardly frusto-conical tapering cover at the top of the chamber and a funnel-shaped wall of the reaction vessel adjoining the lower edge of the cylindrical vertical wall of the reaction vessel, said funnel-like constrictions between two coaxially superimposed chambers being defined on the one hand by a lower funnel-shaped wall of an upper chamber and on the other hand by a cover of a lower chamber, a central scattering cone at the upper end of each of said funnel-shaped walls, and guide elements for the fine material extending downwardly along the inner surface of at least one funnel-shaped wall, the guide elements being distributed around said inner surface of said at least one funnel-shaped wall.