Burning alternative fuels in rotary cement kilns

Various types of alternative fuels can be used in rotary kilns depending on the local supply availability, and each one has a specific influence on the flame pattern. Low calorific value waste fuels must be limited to a small portion of the total heat release as they tend to lower flame temperature, but a compromise can be reached when firing high and low calorific value alternative fuels simultaneously, which enables control of both the calcining process and the NOx emissions. Therefore, a flexible burner is required to allow firing any kind of residue combination depending on the supply available, while maintaining kiln production levels, clinker quality and environmental standards. Basic burner design for alternative fuels and experience from several plants firing solid and liquid wastes was detailed in this paper