Smoke reduction combustion chamber

Abstract

A combustion chamber either an annular or can-annular type, which substantially eliminates the production of smoke while maintaining all other performance parameters of the combustion chamber. The combustion chamber is provided with a front end configuration which substantially eliminates local fuel rich regions and which provides a means for mixing the incoming fuel and air.

We claim: 
     
       1. A combustion chamber comprising a housing, a liner supported by the housing and spaced radially therefrom, the liner having a substantially closed end and an open end spaced axially therefrom with a first wall means therebetween, the first wall means having a plurality of openings along its axial length, the liner providing a zone for combustion of a fuel-air mixture, the combustion products being discharged through the open end, and fuel nozzle means positioned at the closed end of the liner for supplying fuel to the combustion zone wherein the improvement comprises: said fuel nozzle means including a plurality of fuel nozzles,   swirl vanes surrounding each fuel nozzle,   the closed end of the liner having a central opening therein,   inner wall means extending from the edge of said opening into said liner,   said fuel nozzles being located in said closed end spaced around said inner wall means,   air tube means positioned in said inner wall means and said first wall means downstream of each fuel nozzle and being substantially in axial alignment with the cooperating swirl vanes of the nozzle to direct air into the swirling air from the swirl vanes and the fuel from the fuel nozzle, and   said air tube means and said swirl vanes forming a recirculation zone therebetween.   
     
     
       2. A combustion chamber as set forth in claim 1 wherein: said air tube means including first air tubes and second air tubes,   said first air tubes being positioned in the inner wall means to direct air from the central opening towards said first wall means,   said second air tubes being positioned in said first wall means for directing air from around the liner towards inner wall means, and   said flow of air from said first and second air tubes being directed into swirling airflow from the swirl vanes surrounding each fuel nozzle.   
     
     
       3. A combustion chamber as set forth in claim 2 wherein: there are at least three but not more than four air tubes in said first wall means downstream of each fuel nozzle.   
     
     
       4. A combustion chamber as set forth in claim 2 wherein: there is one air tube in the inner wall means downstream of each fuel nozzle.   
     
     
       5. A combustion chamber as set forth in claim 2 wherein: there are at least three but not more than four air tubes in said first wall means downstream of each fuel nozzle, and   there is one air tube in the inner wall means downstream of each fuel nozzle.   
     
     
       6. A combustion chamber as set forth in claim 2 wherein: the openings of the air tubes downstream of each fuel nozzle are radially opposed and axially offset with respect to the combustion zone, the openings of the second air tubes on the first wall means being further downstream than the opening of the first air tube on the inner wall means.