Ansaugstutzen für die Verbrennungsluft eines Heizgerätes

摘要

A suction pipe (2) for the combustion air of a heater, in particular a motor vehicle heater, has a variable cross-section of flow. The object of the invention is to improve the operation of the device that modifies the cross-section of flow and to allow it to be more rationally produced. In addition, it should allow the suction air to be filtered in association with said means without extending the axial length of the heater. For that purpose, the suction pipe (2) is designed as an axially closed tube with radial openings whose cross-sections may be changed by a coaxial, rotary ring (4) set on the outside of the pipe and provided with radial openings. A hood (15) may be axially drawn over the ring (4) on the housing (1) of the heater. Suction air may be filtered in said hood (15), either by centrifugation in spiral channels (18 or 19) arranged in the hood (15) or by using a ring-shaped filter through which the suction air flows in the radial direction.