Anti-icing system for a gas turbine engine

Claim 2

In a gas turbine engine having a bullet nose, a compressor, a combustor, and at least one turbine arranged in serial flow relation together with at least one seal continuously pressurized by compressed airflow bled from the compressor and a hollow shaft driven by a turbine, there is also included an anti-icing system comprising: a plenum contiguous with the inside surface of the bullet nose for receipt of a portion of the compressed airflow bled from the compressor after the compressor bleed airflow has been utilized for seal pressurization, first conduit means for ducting the compressed bleed airflow from the pressurized seal to the plenum, and second conduit means for ducting the compressed bleed airflow away from the plenum through the bore of the shaft and out the downstream end thereof into the ambient airstream.

Claim 3

The anti-icing system of claim 1 wherein the first conduit means a central conduit extending along the center axis of the engine, the downstream end of which is disposed to receive the compressed bleed airflow from a pressurized seal through a plurality of circumferentially spaced apart radially extending ducts and the upstream end of which communicates with the plenum for the discharge of the compressed bleed airflow therein.

Claim 4

The anti-icing system of claim 2 wherein the second conduit means includes an outer cylindrical wall member spaced radially apart from the central conduit defining an annular conduit therebetween for the receipt of compressed bleed airflow from the plenum for discharge into the ambient airstream.

Claim 5

The anti-icing system of claim 2 wherein the plenum communicates with only the upstream tip portion of the inside surface of the bullet nose and includes an annular wall member spaced downstream of the inside surface of the bullet nose to define the downstream limit of the plenum together with a plurality of circumferentially spaced apart outlet ports provided about the outer edge of the annular wall member establishing flow communication with tHe annular conduit.

Claim 6

In a turbofan gas turbine engine having a bullet nose, a fan, a compressor, a combustor, a high pressure turbine and a low pressure turbine connected in serial flow relation together with an annular compressor shaft interconnecting the compressor for rotation with the high pressure turbine and a hollow fan shaft interconnecting the fan for rotation with the low pressure turbine, there are also included bearings for journalling the shafts, and seals continuously pressurized by compressed airflow bled from the compressor together with an anti-icing system comprising: a plenum contiguous with the inside surface of the bullet nose for receipt of a portion of the compressed airflow bled from the compressor after the compressor bleed airflow has been utilized for seal pressurization, and first conduit means for ducting the compressed bleed airflow from the pressurized seal to the plenum, and second conduit means for ducting the compressed bleed airflow away from the plenum through the bore of the hollow fan shaft and out the downstream end thereof into the ambient airstream.

Claim 7

In a turbofan gas turbine engine having a bullet nose, a fan, a compressor, a combustor, a high pressure turbine and a low pressure turbine connected in serial flow relation together with an annular compressor shaft interconnecting the compressor for rotation with the high pressure turbine and a hollow fan shaft interconnecting the fan for rotation with the low pressure turbine, there are also included bearings for journalling the shafts, and seals continuously pressurized by compressed airflow bled from the compressor together with an anti-icing system comprising: a plenum contiguous with the inside surface of the bullet nose for receipt of a portion of the compressed airflow bled from the compressor after the compressor bleed airflow has been utilized for seal pressurization, and first conduit means for ducting the compressed bleed airflow from the pressurized seal to the plenum, and second conduit means for ducting the compressed bleed airflow away from the plenum through the bore of the hollow fan shaft and out the downstream end thereof into the ambient airstream.

Claim 8

The anti-icing system of claim 5 wherein compressed bleed airflow, after pressurizing a forward seal around the annular compressor shaft, is ducted upstream between an outside compressor disc and the hollow fan shaft and then ducted through the fan shaft by a plurality of circumferentially spaced apart inlet ports communicating with the downstream end of the first conduit means; said first conduit means including a central conduit spaced inwardly of the fan shaft defining an annular space therebetween and extending along the center axis of the engine such that the downstream end thereof receives the compressed bleed airflow from the fan shaft inlet ports through a plurality of circumferentially spaced apart ducts extending radially through the annular space and the upstream end thereof communicates with the plenum for the discharge of compressed bleed airflow therein.

Claim 9

The anti-icing system of claim 6 wherein the second conduit means includes an outer cylindrical wall member spaced radially apart from the central conduit defining an annular conduit therebetween for the receipt of compressed bleed airflow from the plenum whereupon the compressed bleed airflow is then directed to the annular space between the central conduit and fan shaft for discharge into the ambient airstream through the downstream end of the hollow fan shaft.

Claim 10

The anti-icing system of claim 6 wherein the plenum communicates with only the upstream tip portion of the inside surface of the bullet nose and includes an annular wall member spaced downstream of the inside surface of the bullet nose to define the downstream limit of the plenum together with a plurality of circumferentially spaced apart outlet ports about the outer edge of the annular wall member establishing flow communication with the annular conduit.