AIR HEATER Russian patent published in 1999 - IPC

FIELD: preheating air delivered for combustion, as well as for drying and aeration of fuel. SUBSTANCE: air heater has heat exchanger mounted in supply air line for preheating of air. Each section of this heat exchanger is brought in communication with respective section of air heater forming passage for flow of preheated air from previous section of air heater to subsequent intermediate section of air heater through section of heat exchanger in turn. Supply and discharge sections of passage for flow of warm air through heat exchanger are communicated through bypass branch pipe fitted with flow regulator. This bypass branch pipe is also used for communicating the supply and discharge air ducts. Air supply duct may be provided with branch pipe for reception of hot air from an outside source. heat exchanger for preheating air is so located in supply air duct that its sections are opposite respective intermediate sections of air heater, thus increasing thermal head even in one intermediate section of air heater for compensation for losses of heat for preheating air at simultaneous reduction of air resistance. EFFECT: enhanced efficiency. 5 cl, 1 dwg