HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION

Description

F28C covers heat exchangers where thermal energy transfers directly between two fluids or media in contact without intermediate barriers or chemical reactions occurring. This subclass includes contact condensers, cooling towers, spray-type exchangers, and direct-contact gas-liquid or liquid-liquid systems where mixing or intimate contact facilitates heat transfer. Devices classified here typically rely on physical heat exchange mechanisms such as evaporative cooling, direct immersion, or fluid spraying rather than separated surface heat transfer covered by other F28 subclasses.