Efficient high temperature calcining for plaster production

Rotary Drum Coolers can process up to 100 tonnes per hour of calcined gypsum products. The hot material is cooled via the counter-current indirect principal in whom cooling air is moved along through a bundle of tubes in the direction opposite the material flow. As material moves through rotating drum its heat energy is indirectly transferred to the air through the tube walls and exhausted from the system. This exhaust airflow can readily be captured and use as pre-heated combustion air for other plant processes greatly increasing efficiency. The rotating action of the drum also serves to mix and further homogenize the output product. Retention time of the material in the cooling unit is carefully controlled to avoid the formation of unwanted by-products like soluble anhydrite and dihydrite.