Powder flow problems? I should cocoa

Cocoa powder storage in silos, hoppers and bins can be fraught with blockage problems such as bridging and 'ratholing' because of its cohesive nature.

A big producer of cocoa powder in the north east of England was experiencing just such problems, even though some of its silos had been designed with fluidising cones in their lower section to overcome them. While the cones did help to some extent, material was still bridging in the upper section of the silo cone and thereby interrupting flow.

To resolve the problem, the company equipped seven 14t silos each with two Mucon Promoflow discharge aids mounted diametrically opposite each other above the fluidising cones. These controlled the amount of vibration into the material and ensured consistent flow of product.

And when two additional 2.5t capacity storage hoppers were installed, they were also equipped with these discharge aids.

The discharge aids comprise internally mounted screens or grids actuated by externally mounted pneumatic vibrators. They transmit vibration directly into the material and not into the bin.