This preview shows page 1. Sign up to view the full content.
Unformatted text preview: te the leak. Exercise 7.19 (continued) Exercise 7.20
Effect on reflux and boilup compositions of reducing the feed rate to a distillation Subject: column when the reflux and boilup rate are held constant Given: Column with 3 theoretical plates, a total condenser, and a partial reboiler. Feed is a saturated liquid of 50 mol% A and 50 mol% B, fed to the bottom tray. At a feed rate of 100 kmol/h, desired products of distillate with 90 mol% A and bottoms of 20 mol% A can be achieved, when a reflux corresponding to L/V = 0.75 is used. Relative volatility of A to B is constant at 3.0. Assumptions: Constant molar overflow. Saturated liquid reflux. Find: Compositions of reflux and boilup when feed rate is inadvertently reduced to 25 kmol/h, while keeping the reflux and boilup flow rates constant. Analysis: First, verify the separation for a feed rate of 100 kmol/h. This is shown in the McCabe-Thiele plot below in terms of mole fractions of A, the more volatile component. The equilibrium curve is computed from Eq. (7-3),...
View Full Document