Rotating Filtration

Laboratory for Applied Fluid Dynamics
Northwestern University, Evanston, Illinois


 
 
Because of the unique weight and durability demands of long term space missions, the efficient recycling of wastewater is necessary.  To this end, rotating filters are being studied as devices that resist the fouling that plaques conventional filtration  systems.  These rotating systems consist of a porous cylindrical filter that rotates concentrically within another cylinder.  We are working to experimentally determine whether the shear force, the centrifugal force, or the Taylor vortices is the dominant anti-fouling mechaism.

The rotating filter apparatus. 
The white inner cylinder is porous and rotates

 
This graph shows concentration of the suspension in the space between the filter and outer housing as a function of speed.  At higher speeds, the higher concentration means fewer particles are fouling the filter surface.
Funded by NASA