Process and apparatus to modify the volume flow of a fan

摘要

Volumetric flow rate of a suction blower (23) is controlled independently of the feed rate of the tubular preform and is effected by a control member (28) which varies the free cross-section available for air flow in the suction channel (25). An Independent claim is made for a mechanism for varying the flow rate of a suction blower in a suction blowing machine fed with tubular thermoplastic preforms. The mechanism comprises a controlled throttle system with throttle flap (27) and an associated control member in the suction channel of the suction blower.