F28CHEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION safety devices in general F16P; fluid heaters having heat generating means F24H; with an intermediate heat-transfer medium coming into direct contact with heat-exchange media F28D15/00 - F28D19/00; details of heat-exchange apparatus of general application F28FIn this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme. F28C1/00 F28C1/00Direct-contact trickle coolers, e.g. cooling towers building construction E04H5/12; enclosed spaces cooled by trickle F25; components parts of trickle coolers F28F25/00; indirect-contact cooling towers F28B1/06 F28C1/003comprising outlet ducts for exhaust gases F28C2001/006Systems comprising cooling towers, e.g. for recooling a cooling medium for condensers F28B9/06 F28C1/02with counter-current only F28C1/04with cross-current only F28C1/06with both counter-current and cross-current F28C1/08Arrangements for recovering heat from exhaust steam F28C1/10Arrangements for suppressing noise F28C1/12Arrangements for preventing clogging by frost F28C1/14comprising also a non-direct contact heat exchange F28C2001/145with arrangements of adjacent wet and dry passages F28C1/16Arrangements for preventing condensation, precipitation or mist formation, outside the cooler F28C1/14 takes precedence F28C3/00Other direct-contact heat-exchange apparatus F28C3/005one heat-exchange medium being a solid F28C3/10 takes precedence F28C3/02the heat-exchange media both being gases or vapours F28C3/04the heat-exchange media both being liquids F28C3/06the heat-exchange media being a liquid and a gas or vapour temperators for cooling steam F22 F28C3/08with change of state, e.g. absorption, evaporation, condensation generating steam under pressure F22 F28C3/10one heat-exchange medium at least being a fluent solid, e.g. a particulate material F28C3/12the heat-exchange medium being a particulate material and a gas, vapour, or liquid F28C3/14the particulate material moving by gravity, e.g. down a tube F28C3/16the particulate material forming a bed, e.g. fluidised, on vibratory sieves F28C3/18the particulate material being contained in rotating drums