Scale vessel volume using tip speed or power. Review oxygen transfer, mixing time, and airflow. Support faster, safer process development across production scales today.
| Case | Source Volume (L) | Target Volume (L) | Criterion | Source RPM | Estimated Target RPM | Gas Mode |
|---|---|---|---|---|---|---|
| Bench to pilot | 5 | 50 | Constant tip speed | 350 | 162.5 | Constant vvm |
| Bench to production | 5 | 500 | Constant power per volume | 350 | 125.7 | Constant vvm |
| Pilot to demo | 50 | 1000 | Match target kLa | 180 | 136.9 | Constant superficial gas velocity |
| Shear sensitive scale-up | 10 | 200 | Constant Reynolds number | 220 | 60.7 | Constant vvm |
Geometric similarity: Linear scale factor = (Vt / Vs)1/3
Target tank diameter: Dt,target = Dt,source × (Vt / Vs)1/3
Target impeller diameter: Di,target = Di,source × (Vt / Vs)1/3
Tip speed: Utip = π × N × Di
Power: P = Po × ρ × N3 × Di5 × n
Power per volume: P/V = P ÷ V
Reynolds number: Re = ρ × N × Di2 ÷ μ
Superficial gas velocity: ug = Qg ÷ Atank
Estimated kLa relation: kLa,target = kLa,source × [(P/V)target ÷ (P/V)source]α × [ug,target ÷ ug,source]β
Mixing time heuristic: tmix,target = tmix,source × (Vt ÷ Vs) × [(Nsource × Disource3) ÷ (Ntarget × Ditarget3)]
These equations are useful for early process design. Final operating limits still need experimental confirmation, motor review, gas dispersion checks, and biological performance testing.
Enter source vessel data from the process you already trust. Add working volume, tank diameter, impeller diameter, rpm, airflow, kLa, and mixing time.
Choose the target working volume you want to reach. Then select the scale-up rule that best matches your process objective.
Use constant tip speed when shear is a major concern. Use constant power per volume when bulk mixing or energy density matters more.
Use constant Reynolds number for hydrodynamic similarity checks. Use target kLa matching when oxygen transfer is the controlling requirement.
Pick a gas scaling method. Constant vvm keeps volumetric aeration the same. Constant superficial velocity keeps gas face velocity comparable.
Review the target rpm, power, airflow, and estimated kLa. Compare them with equipment limits, oxygen demand, and cell sensitivity.
Download the summary as CSV or PDF for design reviews, batch records, tech transfer notes, or scale-up meeting documentation.
Bioreactor scale-up is never a simple volume multiplication. Fluid motion changes with diameter. Gas dispersion changes with vessel area. Power demand changes with impeller size and rotational speed. A small mismatch can alter oxygen transfer, nutrient gradients, foaming, and cell stress.
This calculator helps process teams compare a trusted source vessel with a larger target vessel. It estimates target tank diameter, impeller diameter, agitation speed, power, power density, airflow, superficial gas velocity, Reynolds number, and expected kLa. These outputs support fermentation planning before running expensive trials.
No single criterion works for every organism or process. Constant tip speed can reduce shear risk. Constant power per volume can keep mixing intensity closer to the source system. Constant Reynolds number is useful for flow similarity checks. Matching kLa helps when oxygen transfer limits productivity.
Scale-up decisions affect sparger design, motor sizing, heat removal, and gas supply. They also affect product quality. A structured comparison lets scientists and engineers discuss tradeoffs using the same numbers. That reduces guesswork and shortens review cycles.
This tool is best for preliminary design and scenario testing. It does not replace characterization data, oxygen uptake studies, foam analysis, or biological validation. Use it to screen options quickly, document assumptions clearly, and move into pilot work with a stronger engineering starting point.
The best criterion depends on the process bottleneck. Shear-sensitive cultures often use tip speed. Oxygen-limited systems may use kLa. Bulk mixing studies often start with power per volume.
Under geometric similarity, impeller diameter becomes larger as volume increases. To keep tip speed, power density, or Reynolds behavior comparable, the larger vessel often needs lower rotational speed.
No. Constant vvm keeps the gas rate proportional to liquid volume, but it does not preserve superficial gas velocity. Large vessels can show different gas hold-up and transfer behavior.
Yes. It estimates target kLa using a common engineering relation based on power density and superficial gas velocity. The result is directional and should be verified experimentally.
Power number links impeller design to agitation power. Different impellers have different values. Use a value that matches your impeller type and flow regime.
Real mixing depends on vessel internals, baffles, rheology, gas loading, and impeller placement. The calculator uses a practical scaling estimate, not a full computational fluid dynamics model.
Yes, but with care. Microbial systems often tolerate stronger mixing. Mammalian systems may be limited by shear, bubbles, and foam. Select the criterion that matches the biology.
Use the output as a planning baseline. Final settings should come from pilot runs, process characterization, equipment capability checks, and product quality data.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.