Forced draught burner with automatic air-fuel ratio control - has air throttle held in bimetallic disc to keep mass flow constant

摘要

The forced-draught burner for gaseous or liq. fuel is of the constant fuel rate, variable air rate type with an adjustable throttling device coaxial with the conically-divergent mixture outlet. This device is mounted at one end of an axial spindle whose other end is held, flange-fashion, in a bimetallic disc forming the inlet-end closure of the burner air duct. The disc characteristics are chosen so that its deflection, due to variation of the temp. difference between ambient and combustion air, moves the throttle axially to keep the air mass flow constant.