Varying degrees of difficulty are experienced in transporting granular items and bulk materials. The containers or silos used cannot always provide a sufficient outlet diameter within the process, so a range of different discharge aids are used, some of which require a supply of energy.
A distinction is made between three different kinds of discharge aids, each of which requires a supply of energy:
Pneumatic discharge aids: function using fluidisation, gasification, air blasts, air cushions
Mechanical discharge aids: function using vibration, discharge agitation, sliding frame
Manual discharge aids: tapping, poking etc.
Discharge aids without a supply of energy are fitted e.g. in gravity bunkers.
A typical discharge aid is a vibrating discharge feeder, used in vibration technology for example to remove granular items and bulk material from the pre-bin.