Pervaporation mass transfer with liquid flow in the transition regime

In this work, the mass transfer of a model volatile organic compound throug h silicone rubber membrane tubes has been investigated for the transition b etween laminar and turbulent flow regimes. Results showed that a flow trans ition region occurred over the expected Reynolds number range, from 2300 to 5500. Two correlations have been established for flow during transition an d early turbulence: Sh = 1.1 Re-0.35 Sc-0.33, for 2800 < Re <less than or e qual to> 5500, and Sh = 0.010 Re-0.93 Sc-0.33, for 5500 < Re < 10,000. A co st analysis showed that significant reductions in total costs are obtained for operating conditions in the nonlaminar regime, although membrane burst pressure may prevent working at cost optimal Reynolds numbers. (C) 2001 Els evier Science B.V. All rights reserved.