Related Experiment Video
Updated: May 25, 2026

Frugal Imaging Technique of Capillary Flow Through Three-Dimensional Polymeric Printing Powders
Published on: October 4, 2022
The influence of orifice height on flow rate of powder excipients
1Department of Pharmaceutical Technology, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Czech Republic.
Abstract:
The influence of the orifice height of a cylindrical, flat-bottomed hopper on the mass flow rate of the free-flowable size fractions of sodium chloride and boric acid was investigated. It was observed that a zone of sudden acceleration of the mass flow under gravity occurred when a critical orifice height had been achieved. Based on the results, an orifice diameter equal to 12 mm with a height of between 8-16 mm is recommended for the faster flow of sodium chloride while an orifice diameter equal to 8 mm with a height of less than 8mm is appropriate for the slower flow of boric acid. In summary, the orifice height should be taken into consideration as an important parameter of a cylindrical test hopper in order to obtain a reproducible and comparable mass flow as the single-point characteristic of powder flowability.
Related Concept Videos
Pipe Flowrate Measurement
The orifice meter is a simple,...
Factors Affecting Dissolution: Particle Size and Effective Surface Area
Factors Influencing Drug Absorption: Pharmaceutical Parameters
Pipe Flowrate Measurement: Problem Solving
Dose Size and Dosing Frequency: Determination Methods
Formulation and Manufacturing Process: Physical Attributes of Generic Tablets and Capsules

