Estimate blend time from speed and geometry. Review circulation, Reynolds number, turnover, and power draw. Plan efficient tank mixing with practical engineering decision support.
| Volume | Tank Diameter | Liquid Height | Impeller | Impeller Diameter | Speed | Density | Viscosity | Uniformity | Estimated Mixing Time |
|---|---|---|---|---|---|---|---|---|---|
| 5.0 m³ | 1.8 m | 1.9 m | Pitched Blade | 0.60 m | 180 rpm | 998 kg/m³ | 0.0012 Pa·s | 95% | 38.46 s |
This calculator uses an engineering estimate based on circulation time and correction factors.
The constant K changes with impeller type and flow regime. Transitional and laminar estimates apply extra penalties because viscous systems circulate more slowly.
Mixing time is a core process design value. It shows how long a tank needs to reach a chosen level of uniformity. Engineers use it in chemical blending, wastewater treatment, food production, and pilot plant work. A shorter time can improve throughput. A longer time can increase energy cost. The right estimate helps size motors, compare impellers, and plan batch cycles. It also supports better quality control when solids, liquids, or additives must disperse evenly through the vessel.
Several inputs change the final answer. Impeller speed raises circulation and usually lowers blending time. Impeller diameter affects flow and power strongly. Tank diameter and liquid height shape the flow path inside the vessel. Density and viscosity influence Reynolds number, which identifies laminar, transitional, or turbulent behavior. Impeller style also matters. A hydrofoil moves liquid efficiently. A Rushton turbine creates stronger shear. Baffles limit swirling and improve top-to-bottom turnover. Target uniformity adds another layer because higher blending quality needs more circulation passes.
This calculator combines geometry, fluid properties, and impeller data into a practical estimate. It calculates Reynolds number, circulation rate, turnover time, power draw, tip speed, and specific power. Those outputs help during process review and scale-up. You can compare operating points before running plant trials. You can also test how speed changes energy demand. When the Reynolds number is high, turbulent mixing is dominant and the estimate becomes more circulation driven. At lower Reynolds values, viscosity slows flow and the time rises.
Use the result as an engineering estimate, not an absolute guarantee. Real tanks may include coils, off-center probes, gas injection, or multiple phases. Those details can change blending behavior. Even so, a structured calculation is better than guessing. It gives a repeatable basis for equipment checks, process optimization, and operator planning. For best results, verify the estimate with plant data, tracer testing, or a pilot trial. That step strengthens scale-up decisions and supports safer, more efficient tank mixing. Document assumptions for later audits and troubleshooting. Clear records support future optimization. They also help compare formulas, test conditions, and operator settings.
Mixing time is the estimated period required for a vessel to reach a selected degree of uniformity after agitation begins or conditions change.
Higher viscosity resists circulation and slows bulk motion. That lowers Reynolds number, weakens turbulence, and usually increases the time needed to achieve uniform blending.
Yes. Baffles reduce vortex formation and convert swirl into vertical and radial circulation. That usually improves turnover and shortens blending time in standard stirred tanks.
There is no universal winner. Hydrofoil and pitched blade designs often give fast circulation at lower power, while Rushton turbines provide stronger shear for gas or dispersion duties.
It can still provide an estimate, but laminar systems are more sensitive to geometry, viscosity, and nonideal flow zones. Validation with test data is strongly recommended.
Many engineering checks use 90% to 95% uniformity. Tight product specifications may need higher values, but higher targets usually increase the estimated blending time.
Yes. Custom coefficients help when you have vendor data, pilot results, or internal correlations for a specific impeller and vessel configuration.
Yes. Tracer studies, conductivity tests, and sampled concentration checks can confirm the estimate and show whether internals or process conditions change real performance.
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.