Auxiliary power take off valve for turbo jet engine - has an under cut throttle valve to allow an air flow in the closed position

摘要

The variable power take off valve is an independent unit fitted by a flange to the compressor and contains a throttle flap turned by a shaft. The throttle flap is undercut so that a gap is formed in the completely closed position. A venturi is provided above the throttle plate and forms the large opening area by completely open throttle valve position. The throttle valve actuator works with a combination of air propulsion pressure and atmospheric pressure. Compressor air enters the chamber via the aperture below the throttle valve and the calibrated jet to press against a plate which is subjected to atmospheric pressure. Air for the auxiliaries can only be tapped off according to its availability.