Latest rotary kiln burner technology: possibilities and experiences

The author describes the development of a rotary kiln burner for pulverized coal. A distinction is made between three generations of burners, with their typical design and process philosophies. Since environmental concerns led to considerable research on the mechanisms of the formation and behavior of nitrogen oxides in rotary kilns, the possibilities burners give for less NO_x formation are given special attention. Experience with the latest developments in burners is described, and recommendations are given for further improvements. The author concludes that the latest flame philosophy, producing a slim, slightly longer but concentrated flame without divergence, is the right way to reduce NO_x formation and gives the best process results