Patent ID: 6446438
Filing Date: 2002-09-10
Classification: F23R

Abstract:
An improved low emission (NOx) combustor for use with gas turbine engine comprising:a liner having a first generally annular wall 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; a venturi having a second generally annular wall that includes a converging wall and a diverging wall, said converging wall connected to said diverging wall thereby defining a throat portion of the venturi, 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; 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 first 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, a blocking ring extending from said aft end of said second generally annular wall to said first generally annular wall and sealingly connected thereto, 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 passageway is in fluid communication with said at least one first aperture and said at least one second aperture, said passageway communicates with said premix chamber through said at least one second aperture, and 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.