Controlled Diffusion Separator

Application ID: 12641

This model simulates an H-shaped micro-cell designed for diffusion-controlled separation. The cell puts two different laminar streams in contact for a controlled period of time. The contact surface is well-defined and, by controlling the flow rate, it is possible to control the amount of species that are transported from one stream to the other through diffusion. By this procedure, it is possible to separate species with high diffusivity from species with low diffusivity.

For example, if a species with high diffusivity enters through the lower inlet, it will diffuse across the thickness of the horizontal channel and exit through both outlets. A species with low diffusivity that enters the lower inlet will stay in its stream and also exit through the lower outlet.

This example was originally formulated by Albert Witarsa under Professor Bruce Finlayson's supervision at the University of Washington in Seattle. The work was done as part of a graduate course assignment to evaluate the potential of patents in microfluidics through mathematical modeling.

This model example illustrates applications of this type that would nominally be built using the following products: