US 5,491,974 A · Removable afterburner flameholder

Abstract

A flameholder is disclosed for use in an afterburner of an aircraft gas turbine engine. The flameholder comprises at least one annular ring and a plurality of open ended slots around the forward end of the ring with the open end of each slot open through the forward edge of the ring for accepting a plurality of fuel spraybars. One particular embodiment provides two or more sub-pluralities of slots having two or more differing axial lengths to accommodate different axially spaced sub-pluralities of spraybars such as primary and pilot spraybars. A fastening means is provided for attaching the annular ring to the outer engine casing and is accessible through the exhaust nozzle of the engine. One embodiment provides a fastening means with an anti-rotation means on a connecting link into which a bolt head may be slipped and held from rotating during torquing of a nut. Another feature of the present invention is the use of a bolt having a thread diameter smaller than the bolt shank diameter which is particularly useful when the threads are seized due to high temperature exposure. Overtorqing the nut will fail the bolt at the threads facilitating removal of the flameholder.

Claims12

Dependent claims

A flameholder for use in an aircraft gas turbine engine afterburner having spraybars for introducing fuel into the afterburner, said flameholder comprising:

an annular flameholder circumscribed about an axis and having a forward end upstream of an aft end with respect to a downstream airflow direction of the afterburner,
a plurality of open ended slots circumferentially disposed around said forward end, and
a plurality of corresponding open ends of said slots that are open through a forward edge of said forward end.

A flameholder assembly for use in a afterburner having spraybars for introducing fuel into the afterburner of an aircraft gas turbine engine having an exhaust nozzle aft of the afterburner, said flameholder assembly comprising:

an annular flameholder having a forward end,
a plurality of open ended slots circumferentially disposed around said forward end,
a plurality of corresponding open ends of said slots that are open through a forward edge of said forward end,
mounting means including fastening means that is accessible through the exhaust nozzle of the engine, and
said mounting means comprises a plurality of rotatable retaining links connected to said flameholder by said fastening means and said each of said fastening means comprises;
a bolt having a bolt head and said bolt being disposed through a first aperture in a member of said link,
an anti-rotation means disposed about said first aperture,
said bolt being secured to said flame holder by a nut,
one of said bolt head and said nut being anti-rotationally engaged by said anti-rotation means, and
the other of said bolt head and said nut being accessible from interior of said flameholder.

7 more elements

An afterburner for use in an aircraft gas turbine engine having an exhaust nozzle aft of the afterburner, said afterburner comprising:

an annular casing,
a plurality of spraybars disposed circumferentially about and projecting radially through said casing for introducing fuel into the afterburner,
a flameholder assembly comprising;
an annular flameholder having a forward end,
a plurality of open ended slots circumferentially disposed around said forward end wherein each plurality of spraybars is radially disposed through one of said plurality of open ended slots,
a plurality of corresponding open ends of said slots that are open through a forward edge of said forward end,
a mounting means disposed between said flameholder and said casing, and
said mounting means including a fastening means that is accessible through the exhaust nozzle of the engine.

5 more elements

Dependencies are inferred from the claim text.

Removable afterburner flameholder

Life of this patent

Removable afterburner flameholder

Life of this patent

Abstract

Claims12