A rotary cooler is designed using a rotating cylinder. The material to be cooled is fed into one end of the cylinder and cooled either directly, by showering the material through a cool air stream utilizing lifting flights, or indirectly, by spraying water onto the external surface of the cylinder, it is then discharged at the other end.
Direct Air-swept Rotary Cooler
The direct air-swept cooler design consists of a rotating cylinder with internal flighting. This cooler design brings hot product into direct contact with the cooling medium, in a counter current flow configuration. The cooling medium may be ambient air, cooled air or special gases.
Indirect Water Cooled Rotary Cooler
The indirect water spray cooler design consists of a rotating cylinder housed along its active length in a water jacket. Arranged within the water jacket are series of water spray nozzles that direct cooling water over the exterior of the cylinder. Evaporation of the water cools the wall of the cylinder which cools the material inside. Clean water is the recommended cooling media; however, special nozzles and water distribution systems are available for operations that require use of waste water or recirculated water that may have suspended particulate matter.