Rotary coolers are designed to cool down products coming from dryers or calciners up to an acceptable temperature for successive handling.
Idreco can propose two different kinds of rotary coolers in function of inlet temperature of product, desired outlet temperature and of type of product as well as:
- Air Rotary Coolers
- Water Rotary Coolers
Air Rotary Coolers
Construction of Air Rotary Coolers is similar to Direct Rotary Dryers.
The product is fed inside a cylinder internally provided with spiral and lifting flights in order to achieve the contact between fresh air and the hot product to be cooled.
The heat of product is dissipated by convection by a stream of fresh air which flows in counter current configuration.
Air Rotary Coolers are mostly applied to cool down product at exit of Direct Rotary Dryers (temperature approx 100 °C).
Water Rotary Coolers
In Water Rotary Coolers heat transfer occurs by radiation since water is sprayed against the wall of a rotating cylinder.
Sprayed water that did not evaporate is collected in the bottom of a hood and then recycled to the spraying device.
Cylinder can also consist of a various number of tubes connected each other in order to increase the cooling efficiency.
Water Rotary Coolers find application to cool down products at higher temperatures than the ones operated with Air Rotary Coolers (up to 900 °C and more) and for dusty products and products that cannot go in contact with air.