All that you require for compressability measurements is a shallow ring (4" dia, 0.5" depth), a close fitting lid with a central spigot and a hanger to locate onto the spigot from which you can hang weights.

Fill the ring with material, place the lid and hanger arrangement on top. Place a dial gauge onto the uppermost point of the lid. For each placement of weight on the hanger, measure the reduction in volume of the cylinder (i.e. the distance that the lid depresses).

Knowing the weight of the material sample, change in cylinder volume and calculating applied stress, you can now plot a compressability curve for the powder (bulk density versus normal stress).

It is important to ensure that the cylinder is filled homogenously (i.e. no abnormal voids).

Hope this helps!

Regards

Richard Farnish

e-mail: r.j.farnish@gre.ac.uk

The Wolfson Centre for Bulk Solids Handling Technology, Univ.Greenwich, London

www.bulksolids.com ■