Description
Class F28C : HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION
Subclass 3/18: Other direct-contact heat-exchange apparatus one heat-exchange medium at least being a fluent solid, e.g. a particulate material the heat-exchange medium being a particulate material and a gas, vapour, or liquid the particulate material being contained in rotating drums