AIR HEATER Russian patent published in 2009 - IPC F24H3/00 

FIELD: heating systems.

SUBSTANCE: invention refers to heat-process engineering, and can be used for air heating, in drying processes, and in hot-air heating systems. Air heater consists of an air duct which has inlet and outlet air chambers and wherein there arranged are gas ducts which include a furnace made in the form of a fire tube, at least two turning gas ducts, and at least two convection banks in the form of bank of smoke tubes; at that, fire tube and the first turning gas duct are enveloped with air ducts with intermediate heat-absorbing water walls; additionally, the inlet of the first convection bank consists of a separate bank of short smoke tubes and a separate air supply duct to that bank; at that in air duct there installed is a flue gas duct and a transverse tube sheet, in relation to longitudinal axis of air heater, on which rests the fire tube, the turning chamber and the first bank of smoke tubes; at that, lower edge of transverse tube sheet is installed on the support, and intermediate heat-absorbing water walls are installed at fixed distances without contacting them; besides, the aforesaid water walls are also connected by means of installed retaining clamps to the air duct walls of fire tube and turning chamber. Between the burner tube and fire tube there installed is a flexible membrane, and transverse tube sheet is provided with a thermal expansion compensator wherein installed is an internal rib, an outer division wall and sealing strips. Internal rib is welded to heating surfaces, and outer division wall is installed with a gap relative to internal rib; air ducts between heating surfaces of fire tube and turning chamber from fire tube to convection bank, and intermediate heat-absorbing water walls are extended at least 1.5 times in comparison to air ducts between intermediate heat-absorbing water walls and air duct walls.

EFFECT: improving air heater efficiency.

3 cl, 3 dwg