Resolution deterioration and optimal operating conditions in centrifugal SPLITT fractionation. Part II: Unstable density gradients

✍ Scribed by Supriya Gupta; Phillip M. Ligrani; Marcus N. Myers; J. Calvin Giddings

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 193 KB
• Volume: 9
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/(sici)1520-667x(1997)9:4<307::aid-mcs9>3.0.co;2-5

✦ Synopsis

Resolution deterioration and optimal operating conditions are investigated in a thin, rotating centrifugal SPLITT channel with unstable density gradients. Flow mixing is believed to result from secondary flows which are induced by these unstable density gradients as they interact with inertial, viscous, and Coriolis forces in the channel. When present, this mixing occurs between the feed and carrier substreams and significantly disrupts nominal separation. The mixing onset boundary, where separation resolution begins to degrade, is quantified where the fractional loss in resolution is 10% of the resolution measured with stable density gradients in the channel. This boundary is compared to mixing onset boundaries, based on similar criteria, for centrifugal SPLITT channels with stable density gradients, and for gravitational SPLITT channels with unstable density gradients. The onset of mixing in centrifugal SPLITT channels with unstable density gradients shows complex dependence on the Reynolds number, Richardson number, Ekman number, Rossby number, and other flow parameters.