Some of the most common powder handling problems arise when conveying from storage silos or bins into production.
Often the powder or grain will have been motionless for hours, days, or even weeks before flow is required. Over this time, most powders or granules will compact with the result that far more energy is needed to cause flow than in aerated samples. On the other hand, powders used immediately after transport, which may have involved agitation or more pronounced vibration, will have been aerated and flow more easily than others that have been stored.
