(546b) Challenges In Gas Dispersion Impeller Design

Gas dispersion impellers have been long used in the industry, such as Rushton, Smith, ICI Gas Foil (Middleton), PMSL GDX, and others  with sharp concave blades. Often it is necessary to retrofit existing impellers with new impellers to accommodate process changes and/or energy savings. 

The ability of adjusting impeller characteristics is very important while retrofitting the existing equipment.  Often the rotational speed of mixer and its diameter cannot be changed therefore the only way to retrofit is to adjust impeller geometry and specifically Power Number. Geometry change also affects the gas/ungassed characteristics which can be determined by experiment only.  The paper presents experimental data and analysis of family of gas dispersion impellers that is based on the original GDX Gasfoil (PMSL’s GDX gas dispersion impeller) design. In addition, the structural strength and the cost also were considered.

Test impellers were made by the stereo lithography process that allows for precise production from 3D CAD models.