Applications

The applications of air classification are many and varied. Some of the more important uses are:

1. Scalping off of the coarse end from a pulverized product, usually for further milling. This prevents overgrinding and saves power.

2. The "tailoring" of several size fractions from a heterogeneous mixture of particulate matter. In this application, each fraction has a different particle size distribution meeting commercial specifications or requirements of a dry beneficiation process.

3. The scalping off of the fine end of the product for "de-dusting," "de-fuming" or changing the flow, apparent density or other physical characteristics of the coarse fraction.

4. Beneficiation of a mixture by the removal of impurities contained in a narrow particle size range of the mixture or the separation of mixed products having substantial difference in settling velocities in an air stream.

Reference:

Harmond, J.E., Brandenburg , N.R., and Klein, L.M. (1968) Mechanical seed cleaning and handling. Agricultural Handbook 354. USDA-ARS , Washington , DC.

Winnowing

Winnowing is defined as the process separating grains from chaff by tossing them in the air.

Applications:

Offset-cam vibration system used in the blueberry industry.

Reference:

Donahue, D.W., Bushway, A.A., Moore , K.E., and LaGasse, B.J. (1999) Evaluation of current winnowing systems for Maine wild blueberries. Applied Engineering in Agriculture . 15(5):434-427.