Investigation of Horizontal Velocity Fields in Stirred Vessels with Helical Coils by PIV

Abstract EN

Horizontal velocity flow fields were measured by particle image velocimetry for a stirred vessel with baffles and two helical coils for enlargement of heat transfer area.

The investigation was carried out in a cylindrical vessel with flat base and two different stirrers (radial-flow Rushton turbine and axial-flow propeller stirrer).

Combined velocity plots for flow fields at different locations are presented.

It was found that helical coils change the flow pattern significantly.

Measurements for the axial-flow Rushton turbine showed a strong deflection by the coils, leading to a mainly tangential flow pattern.

Behind baffles large areas of unused heat transfer area were found.

First results for the axial-flow propeller reveal an extensive absence of fluid movement in the horizontal plane.

Improved design considerations for enhanced heat transfer by more compatible equipment compilation are proposed.