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Blending

Fluid Blending covers a wide range of application areas, from gas mixing and turbulent liquid blending to laminar blending operations.

Laminar Fluid Blending relies on the build up of layers or striations of fluid, by a combination of a splitting, and rotating action of the mixing elements.

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The thickness of the striations, d, can be defined as shown following: -

9

where D is the inside diameter of the pipe, and N is the number of elements.

Turbulent flow conditions increase the intensity of radial mixing in a static mixer, allowing much shorter mixing lengths. Turbulent flow in an empty pipe occurs at a Reynolds number of approximately 2000, however in a static mixer, turbulence will develop at a much lower Reynolds number due to the increased velocities caused by the elements. Turbulence will develop at a Reynolds number of 1000.

Radial mixing ....

  • Creates both Macro-scale and Micro-scale turbulence with total stream inversion.Eliminates radial gradients of fluid properties such as concentration, temperature, density and velocity.
  • Creates a residence time distribution which more closely approaches true plug flow when compared with empty pipes or agitated tanks.