Early systems used rotary coolers, which were rotating cylinders similar to the kiln, into which the hot clinker dropped. The combustion air was drawn up through the cooler as the clinker moved down, cascading through the air stream. In the 1920s, satellite coolers became common and remained in use until recently.
Prior systems utilized rotary coolers, cylindrical structures similar to kilns, where hot clinker dropped in. Combustion air was drawn up through the cooler as the clinker moved downward, cascading through the airflow. In the 1920s, satellite coolers became standard and remained in use until recently.