Automated CFD Simulation for mixing Tank

MixIT is the next generation collaborative mixing analysis and scale-up tool designed to facilitate comprehensive stirred tank analysis using lab and plant data, empirical correlations and advanced 3D CFD models. It combines knowledge management tools and mixing science in a unified environment deployable enterprise-wide.
Solution to your Mixing Challenges:

  • Analysis of mixing performance at lab, pilot and plant scales
  • Accelerating process scale ups and technology transfers
  • Optimization of process conditions and critical process parameters
  • Controlling loss of yield due to poor mixing
  • Achieving consistent batch to batch product quality
  • Dealing with non-standard equipment geometries
  • Reducing number of batch trials and batch cycle times
  • Full capacity utilization

Why use MixIT?

  • Connect the dots between recipe, process and product attributes
  • Archive and Share Organizational Knowledge
  • Accelerate process scale up
  • Reduce uncertainties during tech transfer
  • Resolve quality issues
  • Reduce Energy
  • Improve asset utilization

Who should use MixIT?

  • R&D Chemists
  • Process Development Engineers
  • Manufacturing Support Engineers
  • Stirred tank designers
  • Scale up and Tech Transfer Engineers
  • Supply Chain Engineers
  • Quality Control Chemists

Where is MixIT used?

  • Chemicals
  • Paints
  • Petrochemicals
  • Dyes & Pigments
  • Industrial Resins
  • Pharmaceuticals
  • Water Treatment
  • Biotechnology
  • Oil & Gas
  • Agitator OEM

Hexon Engineering would like to know the effect of impeller speed on solid suspension process.
The process consists of solid-liquid mixing simulation with constant impeller speed 95 RPM .
The parameters considered for this simulation is only about impeller speed along with a fully loaded vessel with constant fluid properties. CAD file considered for simulation as shared by the Hexon standard as below in Figures:

The geometry considered for this mixing simulation based on the Hexon standard with tank height 1700mm, width 1400mm. The stirrer & blade nomenclature is needed to be considered based on the mixing phenomenon and as per mixing blade profile there are three consecutive blades kept along the height of the vessel with regular intervals of 300mm from the bottom of the vessel.

  1. Mixing is an important unit operation:
  2. Enhance the reduction of inhomogeneity to achieve desired process results.
    • Inhomogeneity: Concentration, Phase & Temperature
    • Process Results: Efficient mass/heat transfer, reaction rate, product properties
      • Impact of poor mixing
  3. Low yield/poor selectivity in chemical reactors
  4. Wide particle size distribution in crystallization/polymerization
  5. Non-uniform gas distribution & nutrient transport in bioreactors.

Results & Discussion :

Velocity contours show the distribution of velocity magnitude in the vessel. The color gradient shows the velocity impact with respect to impeller speed from low velocity region (blue) to high velocity region (red). The scale range is in logarithmic. Typically, regions with velocity less than 10% of the tip speed are considered as ‘dead zones’.

Strain rate contour gives an idea about shear rate distribution which induces the thermal & chemical effect in the vessel. The high shear rate (red color zone) indicates immediate contact region of impeller & the fluid/solid present in the vessel. The scale range is in logarithmic. The uniform shear rate distribution is important for bioreactors, crystallizers and processes optimization where particle size takes place into consideration.

The Stirred Tank Reactor Mixing Analysis Tool, provides deep insights and prudent solutions to solve scale up and troubleshooting problems. You can instantly get performance parameters, such as mixing intensity, power per unit volume, blend time, critical suspension speed, gas hold-up and mass transfer coefficients using industry accepted correlations. The automated CFD analysis modules help you visualize the process and mix with confidence. With this final outcome of the mixing profile shows the mixing time with more than 95% uniformity within stipulated time of 8 seconds.

MixIT predicts vortex shape and vortex depth for top-mounted, centrally located impellers under fully un-baffled conditions. The predicted vortex shape can then be used (instead of flat top surface) while performing CFD analysis.

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