Abstract: A cyclone heat exchanger particularly adapted for direct heat exchange between a granular product and hot exhaust gases from a kiln used in the production of cement, the heat exchanger comprising a housing, a gas feed pipe introducing hot gases tangentially of the housing, a cover extending across the top of the housing, a discharge at the base of the housing for discharging product therefrom. The improvement consists of an immersion pipe extending through the cover and into the housing, the immersion pipe consisting of a plurality of segments extending in the longitudinal direction of the immersion pipe. Holding devices are provided for releasably holding segments in the cover.