Patent ID: 8276388

Claim:
An injection system comprising: a fuel injector of main axis; an annular expansion ring coaxial about said injector, said ring presenting holes distributed around the main axis and opening out into an upstream face of said ring, the holes allowing air to pass towards a zone downstream from said ring; a primary swirler coaxial about the same axis as said ring and placed downstream from said injector; and a venturi placed downstream from said primary swirler, wherein said ring includes a conical annular groove that converges downstream, that is open downstream, and that has said holes opening out into an upstream portion of said annular groove, an axis of each of the holes making an angle relative to the main axis that is strictly greater than an angle made by a generator line of a cone defining said annular groove relative to said main axis, such that the air exiting said holes impacts against an inner wall of the annular groove, the inner wall of said annular groove being closer to the main axis, wherein the air leaves said annular groove in a direction that is substantially parallel to a flow direction of air leaving said primary swirler, such that these two air flows do not mix, and wherein said expansion ring comprises an axial cylindrical portion with a radially inner surface in contact or nearly in contact with an outer surface of said injector.