Abstract The invention relates to combustion devices wherein a flame stabilisation zone is formed in the wake of a body disposed in a swiftly moving gas stream. The invention provides a combustion device comprising a bluffbody disposed in a gas stream, the body having an aerodynamically smooth upstream-facing portion terminating downstream through a step change of section in a substantially flat downstream-facing surface extending transversely to the direction of flow of the stream, and means for influencing flow over the body to induce stable vortex formation adjacent said downstream facing surface. Preferably such means comprise suction means, suction being applied from the interior of the body in each region of the step change of section. Combustion devices according to the invention may include a flow divider extending downstream of the downstream facing surface to separate vortices originating at the step change of section.
A combustion device for installation in a gas flow duct to form therein a flame stabilisation zone, said combustion device comprising a member having a bluff-body configuration including an aerodynamically smooth upstream-facing portion, said portion terminating downstrEam through a step change of section of the member in a substantially flat downstream facing surface extending transversely relative to the direction of said flow, and suction means establishing low pressure in the interior of the member to influence said gas flow over said member, a stable vortex formation adjacent said downstream-facing surface being induced thereby, said member having at least one opening in each region of step change at opposite edge portions of said downstream-facing surface wherethrough suction is applied.
Claim 2
Dependent Claim
118 words
A combustion device for installation in a gas flow duct to form therein a flame stabilisation zone, said combustion device comprising a member having a bluff-body configuration including an aerodynamically smooth upstream-facing portion, said portion terminating downstrEam through a step change of section of the member in a substantially flat downstream facing surface extending transversely relative to the direction of said flow, and suction means establishing low pressure in the interior of the member to influence said gas flow over said member, a stable vortex formation adjacent said downstream-facing surface being induced thereby, said member having at least one opening in each region of step change at opposite edge portions of said downstream-facing surface wherethrough suction is applied.
Claim 3
Dependent Claim
37 words
A combustion device as claimed in claim 1 including a flow divider extending downstream of said downstream-facing surface whereby vortices originating at said step change of section at opposite edge portions of said downstream-facing surface are separated.
Claim 4
Dependent Claim
34 words
A combustion device as claimed in claim 1, said member having two openings therein, each said opening comprising a slot, said slots extending along opposite edges of said downstream-facing surface wherethrough suction is applied.
Claim 5
Dependent Claim
27 words
A combustion device as claimed in claim 1 wherein said member is of annular form, said member occupying a plane normal to the direction of gas flow.