O'Reilly logo

Separation Process Engineering: Includes Mass Transfer Analysis, Third Edition by Phillip C. Wankat

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

7.2 Minimum Reflux: Underwood Equations

For binary systems, the pinch point usually occurs at the feed plate. When this occurs, an analytical solution for the limiting flows can be derived (King, 1980) that is also valid for multicomponent systems as long as the pinch point occurs at the feed stage. Unfortunately, for multicomponent systems there will be separate pinch points in both the stripping and enriching sections if there are nondistributing components. In this case an alternative analysis procedure developed by Underwood (1948) is used to find the minimum reflux ratio.

The development of the Underwood equations is quite complex and is presented in detail by Underwood (1948), Smith (1963), and King (1980). Since for most practicing engineers ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required