Accession Number : ADD007853

Title :   Flow-Closing Bleed Valve Assembly.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Springman,G F

Report Date : 23 Jul 1980

Pagination or Media Count : 15

Abstract : This application discloses an adjustable, spring-loaded poppet valve assembly for use in combination with a turbofan engine having deteriorated clearances in the compressor section which result in difficulty in starting the engine. The assembly initially is biased in the open position; and, it permits starting of the engine by bleeding overboard (through an engine duct outlet) some of the fore-to-aft compressor airlfow, until the engine starts. The assembly remains in the open position until the pressure of the air that it is bleeding is sufficient to overcome the force of the biasing spring; and, then the assembly is forced to the closed position by the pressure of that air. The assembly stays in the closed position, until the engine is shut-down (i.e. turned off). The pressure of the compressor air then falls, the compressor air flow eventually ends, and the compressed spring expands, with the assembly thereby returning to the open position.

Descriptors :   *Patent applications, *Engine valves, *Turbofan engines, Inventions, Engine starters, Air flow, Bleed systems, Compressors

Subject Categories : Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE