Reinforced Suspension Preheater (RSP) Process of Cement Manufacture--Suspension Preheater with Special Furnace for Boosting Calcination of Raw Meal

The reinforced suspension preheater (RSP) process for the production of portland cement comprises a suspension preheater equipped with precalcining vessels designated as swirl burner and swirl calciner. The process has been demonstrated through the operation of a 235 metric ton per day plant. The swirl burner and swirl calciner provide effective heat transfer and permit control of temperature to obtain raw meal decarbonation of 85-90 percent. Data are presented describing sulfur absorption at various stages of the process. Nitrogen oxide emissions are limited due to the low temperature maintained in the swirl calciner. Excellent cement quality has been obtained.