Reactive mixing performance for a nanoparticle precipitation in a swirling vortex flow reactor

Area of Science:

• Chemical Engineering
• Fluid Dynamics
• Reaction Engineering

Background:

• Investigating mixing performance in consecutive competing reaction systems is crucial for optimizing chemical processes.
• Swirling vortex flow reactors (SVFR) offer unique flow characteristics beneficial for reactions.
• Understanding macro- and micro-mixing scales is essential for predicting reaction outcomes.

Purpose of the Study:

• To evaluate the mixing performance of a swirling vortex flow reactor (SVFR) for competing reactions.
• To assess the impact of ultrasound irradiation on mixing uniformity and reaction efficiency.
• To determine the suitability of SVFR for fine-particle synthesis.

Main Methods:

• Computational fluid dynamics (CFD) modeling using the direct quadrature method of moments with interaction by exchange with the mean (DQMOM-IEM).
• Analysis of macroscale mixing via mean mixture fraction and microscale mixing via variance and Bachelor length scale.
• Evaluation of reaction progress variable and reactant conversion to indicate side reactions.

Main Results:

• SVFR achieves rapid macroscale mixing due to swirling flow; microscale mixing is turbulence-dependent.
• Ultrasound irradiation significantly enhances mixing uniformity, eliminating stagnant zones and reducing microscale variance.
• Strong turbulence and fast micromixing in SVFR minimize by-product formation, favoring homogenous particle precipitation.
• Ultrasound further intensifies turbulence via cavitation, creating an even reaction environment with low conversion rates and minimal by-products.

Conclusions:

• SVFR demonstrates efficient mixing for competing reactions.
• Ultrasound intensification of SVFR leads to superior mixing uniformity and reduced side reactions.
• SVFR, particularly with ultrasound, is highly suitable for fine-particle synthesis processes.