Rotary Coolers and Driers – Some Related Aspects of Design

This paper gives an account of performance tests carried out on rotary coolers in fertiliser plants, and of small scale experiments on the behaviour of granular solid materials falling from lifting flights.

The equation of Saeman and Mitchell, giving the hold-up in such a cooler as a function of the solid feed rate, the cooler dimensions, speed and slope, and the gas velocity, has been tested experimentally and found to be the best guide so far available.

In so far as the behaviour of granular solids in a rotary drum equipped with lifting flights is common to rotary coolers and driers, the conclusions of this paper can be applied to machines for either operation.

Suggestions are made for an approach to the design of equipment of this type.