Gas turbine engine with booster stage

Claim 1

In a gas turbine engine having a compressor, combustor and compressor driving turbine operatively connected in a gas generator, together with a power turbine in downstream serial flow arrangement, there is also provided means for reducing the amount of extraneous matter which might otherwise enter the engine and improving the performance of the compressor, said means comprising: a compressor booster stage drivably connected to the power turbine; a particle separator having an inlet in downstream flow communication with the booster, said inlet having stationary turning vane means disposed therein for centrifuging the air exhausted from the booster, whereby a particle entrained in the airstream centrifuged by the turning vane means will have both tangential and axial velocity components; collection chamber means for receiving the particles centrifuged by the turning vane means; a row of variable angle inlet guide vanes in upstream serial flow relation to the booster stage; a scavenge duct communicating with the collection chamber and terminating in a modulating flow control valve wherein the airflow exits from the particle collection chamber through the duct and modulating flow control valve; wherein the inlet to the gas generator compressor is disposed downstream of the turning vane means so as to receive the centrifuged air flowing therefrom, and includes deswirl vane means for removing the circumferential velocity component of the airstream entering the gas generator compressor whereby the pressure rise imparted to the airflow through the booster stage increases the centrifuging effect of the separator as well as the power and performance of the engine, and wherein the compressor booster stage is driven at a substantially uniform speed.

Claim 12

A method of separating the particles entrained in the air ingested by, while simultaneously improving the performance of, a gas turbine engine of the type which includes an inlet supplying air through variable guide vanes to a booster, particle separator and gas generator in downstream serial flow relation comprising the steps of: rotating the booster at a substantially uniform speed, centrifuging any particles entrained in the booster airflow by directing the booster airflow through a plurality of turning vanes, collecting centrifuged particles in a collection chamber disposed downstream of the turning vanes, deswirling the centrifuged air exiting from the booster by directing the booster air through a plurality of deswirl vanes to the gas generator, varying the inlet guide vane angle as a function of gas generator speed to match the characteristics of the booster airflow with that of the gas generator in a range within which the pressure rise in the airflow through the booster remains sufficiently high to impart a minimum temperature increase thereto, to thereby inhibit ice formation downstream of the booster, bleeding a portion of the booster airflow through a scavenge duct in flow communication with the collection chamber and terminating in a flow control valve, varying the position of the flow control valve as a function of gas generator speed so as to match the characteristics of the airflow from the booster with that of the gas generator in a range within which further matching of the characteristics of the airflow from the compressor with that of the gas generator by controlling the inlet guide vane angle would cause the temperature rise in the airflow through the booster to fall below the minimum temperature.

Claim 13

A method of separating the particles entrained in the air ingested by, while simultaneously improving the performance of, a gas turbine engine of the type which includes an inlet supplying air through variable guide vanes to a booster, particle separator and gas generator in downstream serial flow relation comprising the steps of: rotating the booster at a substantially uniform speed, centrifuging any particles entrained in the booster airflow by directing the booster airflow through a plurality of turning vanes, collecting centrifuged particles in a collection chamber disposed downstream of the turning vanes, deswirling the centrifuged air exiting from the booster by directing the booster air through a plurality of deswirl vanes to the gas generator, varying the inlet guide vane angle as a function of gas generator speed to match the characteristics of the booster airflow with that of the gas generator in a range within which the pressure rise in the airflow through the booster remains sufficiently high to impart a minimum temperature increase thereto, to thereby inhibit ice formation downstream of the booster, bleeding a portion of the booster airflow through a scavenge duct in flow communication with the collection chamber and terminating in a flow control valve, varying the position of the flow control valve as a function of gas generator speed so as to match the characteristics of the airflow from the booster with that of the gas generator in a range within which further matching of the characteristics of the airflow from the compressor with that of the gas generator by controlling the inlet guide vane angle would cause the temperature rise in the airflow through the booster to fall below the minimum temperature.