Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM

Area of Science:

• Pharmaceutical Engineering
• Particle Technology
• Computational Science

Background:

• Spiral jet mills are crucial in pharmaceutical manufacturing for particle size reduction and classification.
• Understanding fluid-solid interactions is key to optimizing jet mill performance.
• Coupled computational fluid dynamics (CFD) and discrete element models (DEM) are essential for studying these complex phenomena.

Purpose of the Study:

• To investigate particle dynamics and collision statistics in a 50-mm spiral jet mill using CFD-DEM simulations.
• To analyze the influence of operating conditions and particle loading on particle behavior.
• To quantify the impact of particles on fluid dynamics within the milling chamber.

Main Methods:

• Coupled CFD-DEM simulations were performed on a 50-mm spiral jet mill model.
• Particle dynamics, velocity, and collision statistics were analyzed.
• Simulations were conducted under varying operating pressures and three distinct particle loading conditions.

Main Results:

• Particle presence significantly decelerated the fluid flow within the milling chamber.
• Particle velocity was found to be dependent on both particle loading and operating pressure.
• Lower operating pressures and higher particle loadings resulted in reduced particle velocities.
• Particle-particle collisions were observed more frequently than particle-wall collisions.

Conclusions:

• CFD-DEM simulations provide valuable insights into particle dynamics within spiral jet mills.
• Operating parameters like pressure and loading critically affect mill efficiency and particle behavior.
• The findings highlight the dominance of inter-particle interactions in the milling process, informing optimization strategies.