Burner with progressive fuel injection

Abstract

The present invention relates to a burner with staged fuel injection, in which at least two separate stages ( 4 a , 4 b ) for fuel injection are arranged along the swirl body ( 1 ). The burner is distinguished in that, between the first and the second stage ( 4 a , 4 b ), a separating element ( 8 ) is provided, which extends in the direction of the combustion chamber ( 3 ) and separates the combustion air flow which enters in the region of the first stage ( 4 a ) from the combustion air flow which enters in the region of the second stage ( 4 b ). The proposed burner can be operated with low combustion pulsations even in the case of low burner powers.

1 . A burner with staged fuel injection, essentially consisting of a swirl generator ( 1 ) for a combustion air stream and means for the introduction of fuel into the combustion air stream, the means for the introduction of fuel into the combustion air stream comprising at least one first fuel supply ( 4   a ) with a first group of fuel outlet orifices ( 2   a ) and a second fuel supply ( 4   b ) with a second group of fuel outlet orifices ( 2   b ) downstream of the first group of fuel outlet orifices ( 2   a ), and the first and second group of fuel outlet orifices ( 2   a ,  2   b ) and also inlet orifices for the combustion air stream being arranged along a swirl space ( 1   a ) formed by the swirl generator ( 1 ), and, in the transitional region between the first and the second group of fuel outlet orifices ( 2   a ,  2   b ), a separating element ( 8 ) being arranged in the swirl space ( 1   a ), said separating element separating, at least over a portion of a longitudinal axis ( 7 ) of the burner, a first combustion air stream, which enters the swirl space ( 1   a ) in the region of the first group of fuel outlet orifices ( 2   a ), from a second combustion air stream which flows into the swirl space ( 1   a ) in the region of the second group of fuel outlet orifices ( 2   b ).  
     
     
         2 . The burner as claimed in  claim 1 , characterized in that the separating element ( 8 ) is formed by one or more partitions which surround the longitudinal axis ( 7 ) of the burner.  
     
     
         3 . The burner as claimed in  claim 1  or  2 , characterized in that the separating element ( 8 ) is of essentially tubular or bowl-shaped design.  
     
     
         4 . The burner system as claimed in one of  claims 1  to  3 , characterized in that the separating element ( 8 ) has cooling ducts ( 11 ) passing through it.  
     
     
         5 . The burner system as claimed in  claim 4 , characterized in that the cooling ducts ( 11 ) have outlet orifices toward the combustion chamber ( 3 ).  
     
     
         6 . The burner system as claimed in one of  claims 1  to  5 , characterized in that the burner has a central fuel lance ( 5 ) which extends into the volume formed by the separating element ( 8 ).