Optimization of Operating Conditions in a High-Shear Mixer Using DEM Model: Determination of Optimal Fill Level

• Published in: Chemical & pharmaceutical bulletin Vol. 50; no. 12; pp. 1550 - 1557
• Main Authors: Terashita, Keijiro, Nishimura, Takehiko, Natsuyama, Susumu
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 01.12.2002; Maruzen
• Subjects: Biological and medical sciences; discrete element method; Drug Compounding - instrumentation; Drug Compounding - methods; Drug Industry - instrumentation; Drug Industry - methods; fill level; General pharmacology; granulation; high-shear mixer; kinetic energy; Kinetics; Medical sciences; Models, Theoretical; optimization; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Powders; Rotation; Tablets; Pharmaceutical technology; Granulation; fill level; Mixer; high-shear mixer; Filling; Velocity distribution; Discrete element method; Kinetic energy; Velocity; Optimization; Operating conditions
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.50.1550

For the purpose of evaluating optimal fill level of starting materials in a high-shear mixer, discrete element method (DEM) simulation was conducted to visualize kinetic status between particles. The simulation results obtained by changing fill levels were used to determine solid fraction of particles, particle velocity, particle velocity vector, and kinetic energy and discuss the flow pattern. Optimal fill level was obtained from the information on these matters. It was pointed out that understanding the kinetic energy between particles in an agitating vessel was effective in determining the optimal fill level. Granulation experiment was conducted to validate the optimal fill level obtained by the simulation, confirming the good agreement between these two results. It was pointed out that determination of kinetic energy between particles through the simulation was effective in obtaining an index of the kinetic status of particles. Further, it was confirmed that the simulation could provide more information than conventional granulation experiments could provide and also helpful in optimizing the operating conditions.