Roasting wet crude cement etc. - using spray dryer connected to precalcining chamber and rotary drum furnace, from which exhaust gas flows in countercurrent fashion

摘要

The wet material or slurry is fed into a dryer which is also used for preheating. The dry and preheated material is then suspended in the exhaust gases leaving a rotary drum furnace and carrying the material into a precalcining chamber. The exhaust gases leaving this chamber are fed into the dryer after being sepd. from the precalcined material, the temp. of the gases being adequate for drying the initial wet material or slurry; and the precalcined material leaving the above chamber is collected in a cyclone and fed into the drum furnace. The pref. plant includes a spray dryer in which the exhaust gases from the chamber carry the dry and preheated material into a cyclone separator delivering the solids to the inlet of the drum furnace, which has a gas duct leading to the precalcining chamber.