Bladeless Mixer: A system to stir liquids without the use of any stirring tool.


September 13, 2021

Background / Context / Abstract:

By the laboratory experiments and numerical simulations on supercomputers, the inventors have revealed that a constant spin about a single axis of a smooth container drives non-trivial container-size flow (namely, “twisted flow”) of a liquid partially filled in the container. The twisted flow is spontaneously produced due to the existence of an interface between the liquid and air and it sustains small-scale turbulence in the container.

Technology Overview:

A system and a method to stir liquids by complex motion with “twisted flow” of liquids which are partially filled in a container spinning under appropriate conditions.
✓ The inventors have conducted laboratory experiments to visualize the flow of water in a spinning sphere. When the volume fraction of the water is not too large, turbulence with the twisted flow is sustained. They have also verified this phenomenon by numerical simulations (figure 1).
✓ Their numerical simulations show that only ten spins are sufficient for the almost perfect mixing of the fluid when the volume fraction of the fluid is about 50% (figure 2).
✓ Details of the dependence on the container shape and parameters are under investigation.
✓ This phenomenon occurs only in liquids (granular materials show a different behavior).


■ No blades or baffle plates in the container.
■ Complex flow driven by a simple motion (i.e. constant spin) of the container.
■ Low construction and running (e.g. washing) costs.
■ Contamination free.
■ Easy control of shear rates.

Potential Applications / Potential Markets:

Liquid stirring system.

State of Development / Opportunity / Seeking:

・Available for exclusive and non-exclusive licensing
・Exclusive/non-exclusive evaluation for defined period (set up for options)
・Collaborative/supportive research

1. Development partner
2. Licensing 

IP Status:

Applied in Japan (JPO), not yet published.



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