Gas fired hot water boiler - has four vertical and finned water coils with water entering central space through lower header

摘要

The boiler has a rectangular casing with insulating lining (5). A gas burner (2) fires into a combustion chamber (3) in the lower part of the casing. Four helical water tube coils (12) are arranged symmetrically in the upper part of the casing. Each coil is made from a finned tube wound so that the outside edges of consecutive fins touch each other. Water enters the coils through a bottom header (17) which also closes the cylindrical space within each coil. Water leaves the coils through an upper header (20) which has flue gas openings above the cylindrical spaces within the coils and blanks off the whole of the top of the boiler outside the coils.