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Mixing in process vessels used in biopharmaceutical manufacturing
1Biopharmaceutical Operations, WSO, SmithKline Beecham Pharmaceuticals, 709 Swedeland Road, King of Prussia, Pennsylvania 19406, USA. kripa_ram@biogen.com
Biotechnology Progress
|April 8, 2000
Summary
Nonbaffled mixing vessels, common in biopharma, require off-center impellers for effective mixing. This study successfully correlated mixing performance to vessel geometry in scaled-up systems.
Area of Science:
- Chemical Engineering
- Biopharmaceutical Manufacturing
- Fluid Dynamics
Background:
- Nonbaffled vessels are increasingly used in the biopharmaceutical industry for mixing.
- Their mixing performance is not yet fully understood, necessitating further research.
- Standard tanks without baffles can lead to swirling, reducing mixing efficiency.
Purpose of the Study:
- To characterize mixing performance in nonbaffled vessels.
- To investigate the effect of off-center impeller orientation on mixing.
- To establish correlations between mixing performance and vessel geometric factors.
Main Methods:
- Utilized geometrically similar vessels ranging from 100 to 5000 L working volume.
- Employed hydrofoil axial flow impellers mounted off-center at a 10-degree angle to the vertical.
- Focused on characterizing mixing dynamics and identifying key geometric influences.
Main Results:
- Demonstrated that off-center impeller orientation is crucial for enhancing mixing and preventing swirling in nonbaffled tanks.
- Successfully developed correlations linking mixing performance to specific vessel geometric factors.
- Validated the scalability of mixing performance across different vessel volumes.
Conclusions:
- Off-center impeller placement is an effective strategy for optimizing mixing in nonbaffled biopharmaceutical vessels.
- Vessel geometry significantly influences mixing efficiency, allowing for predictable performance.
- The findings provide a basis for the design and scale-up of nonbaffled mixing systems.
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