Patent ID: 6832482
Filing Date: 2004-12-21
Classification: F23R

Abstract:
An improved low emission (NOx) combustor for use with gas turbine engine comprising:a liner having a first generally annular wall with an outer surface and including a premix chamber for mixing fuel and air and a combustion chamber for combusting said fuel and air, said premix chamber in communication with said combustion chamber, said first generally annular wall having at least one first aperture and at least one second aperture, said second aperture being radially outward of said premix chamber, and a deflector fixed to said outer surface of said first generally annular wall proximate said at least one first aperture, said deflector comprising: a generally annular ring having a forward end, an aft end in spaced relation to said forward end thereby defining a first length therebetween, an inner ring surface, an outer ring surface radially outward from said inner ring surface thereby defining a first height, a forward face, an aft face, each of said faces extending from said inner ring surface to said outer ring surface, said forward face in spaced relation to said aft face, said aft face having a first region of curvature with a first radius R1; a venturi having a second generally annular wall that includes a first converging wall and a first diverging wall, said first converging wall abutting said first diverging wall at a first plane, said first plane generally perpendicular to said first generally annular wall, said venturi further containing a throat portion at said first plane, said throat portion being positioned between said premix chamber and said combustion chamber, said second generally annular wall being radially inward from said first generally annular wall and having an aft end adjacent said at least one first aperture, said venturi having a third generally annular wall being radially outward of said second generally annular wall and radially inward of said first generally annular wall, said third generally annular wall including a second converging wall and a second diverging wall, said second converging wall connected to said second diverging wall at a second region of curvature proximate said first plane and having a second radius R2; a passageway for flowing cooling air through said venturi, said passageway extending from said at least one first aperture to said at least one second aperture, said passageway including a first portion radially inward from said third generally annular wall and radially outward from said second generally annular wall, and said passageway including a second portion radially outward from said first portion of said passageway, said second portion extending from said passageway first portion to said at least one second aperture, and said first aperture being radially outward from said first portion, and said first portion of said passageway having a third region of curvature with radius R3 proximate said throat; and, a blocking ring extending from said aft end of said second generally annular wall to said first generally annular wall in sealing contact therewith, said blocking ring preventing cooling air that is in said first portion of said passageway from flowing directly into said combustion chamber without flowing through said second portion of said passageway; wherein said aft face of said deflector directs cooling air into said passageway through said at least one first aperture and said passageway communicates with said premix chamber through said at least one second aperture, such that cooling air, after being heated by cooling said venturi, exits from said passageway into the premix chamber thereby increasing the efficiency of the combustion process and reducing NOx emissions.