A qualitative fluidisation segregation test for pneumatic transport

Segregation is a constant problem in industrial processes concerning bulk solids. It is generally either of a mechanical nature or a product of fluidization or pneumatic transport.

The mechanical effect is called granular convection in which mechanical agitation of a granular medium segregates the particles, such that the largest particles end up on top.

The opposite effect is observed in fluidized systems such as pneumatic conveyance systems, where the larger particles are unable to be carried into the airstream, so that segregation leaves them on the bottom of the system.

In this work we will exemplify uses of these opposing effects to quickly evaluate the propensity of a fluidized system to segregate.

Segregation is a known issue in the pneumatic transport of milk permeate. Since the subsequent processing step—dissolving the permeate—is highly sensitive to particle size, it would be helpful to have a method for determining the propensity of the granular medium to segregate under airflow.

In an experiment run by Anton Paar GmbH, a short screening test for fluidization segregation is demonstrated.

Click on the link above to download the Application Report and to learn about the results of their experiment.