Relief device for a turbojet and a turbojet comprising same

A relief device designed to divert a portion of a main flow toward a by-pass flow in a turbojet, comprising:

• a main flow stream, a by-pass flow stream and an interstream compartment provided between the main flow stream and the by-pass flow stream, said interstream compartment including an inner shroud separating said interstream compartment from said main flow stream and an outer shroud separating said interstream compartment from said by-pass flow stream;
• an intermediate casing furnished with an upstream wall and a downstream wall;
• inner openings of the inner shroud, positioned upstream of the intermediate casing;
• outer openings of the outer shroud, positioned downstream of the intermediate casing;
• a relief circuit connecting said inner openings to said outer openings through the interstream compartment, said relief circuit including, arranged upstream to downstream, a manifold, upstream holes provided in said upstream wall of said intermediate casing, downstream holes provided in said downstream wall of said intermediate casing, and an annular channel defined between said downstream wall of said intermediate casing, said outer shroud and a connecting partition which rests on said intermediate casing so as to encompass said downstream holes provided in said downstream wall and which rests on said outer shroud so as to encompass said outer openings provided in said outer shroud;
• and
• a relief ring disposed upstream of said intermediate casing and provided with relief apertures,
• wherein said manifold is an annular part with relief passageways extending from inner orifices provided on an inner face of said manifold to outlet orifices provided on a downstream face of said manifold in fluid communication with said upstream holes provided in said upstream wall of said intermediate casing, said inner orifices are in fluid communication with said inner openings, and
• wherein said relief ring moves in axial rotation between an open position of said relief circuit in which said relief apertures coincide at least partially with said inner orifices of said manifold, and a closed position of said relief circuit in which said relief apertures do not at all coincide with said inner orifices of said manifold.