Abstract
The influence of the geometry of a cylindrical flat-bottomed hopper orifice on the mass discharge rate of six free-flowable powder excipients with the size fraction 0.050-0.063 cm was investigated. Sixteen combinations of the orifice diameter and the height were used.
The influence of the orifice geometry on the powder discharge rate was indirectly studied by the parameters of the Beverloo equation. The mean relative differences between the actual discharge rate at the combination of the orifice diameter and its height and the average discharge rate allowed a direct study of the effect of the orifice geometry.
The complex nature of the orifice height impact on the powder discharge rate through the hopper opening has been determined. Based on the results, the orifice diameter of 0.8 cm with the height less than 0.8 cm is recommended.