Čes. slov. farm. 2002, 51(5):236-239
Influence of Fractal Dimension on the Flow Rate of Powdered Auxiliary Substances
- Katedra farmaceutické technologie Farmaceutické fakulty Univerzity Karlovy, Hradec Králové
Fractal dimension of the particles of powdered auxiliary substances expresses the raggedness oftheir surface, which can influence both the bulk density and their flow rate through the opening ofthe powder funnel. In the size fractions of 0.20-0.25 mmof six powdered auxiliary substances, theirlinear fractal dimensions within a range of 1.031 to 1.109 and the corresponding flow rates throughthe circular openings of the powder funnel of diameters of 6; 8; 10, and 12 mm were found.A significant correlation has been demonstrated between the flow rate expressed in volume (cm3/s)and the fractal dimension, which after an increase by one unit characterizes the surface of theparticles.With increasing fractal dimension, the porosity of freely poured layer of powdered auxiliarysubstances is increased and simultaneously also their flow rate expressed in volume.For the usuallyreported flow rate expressed in weight (g/s), such influence is not significant.
Keywords: flow rate; bulk density; fractal dimension; auxiliary substances
Published: May 1, 2002 Show citation