# 7 46 h 4dt 4405 162 ft exercise 746 subject sizing

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: s: Liquid rate leaving drum = (3 + 1)120 = 480 lbmol/h Assume properties of pure n-hexane. From Fig. 2.4, boiling point of nC6 at 1 atm = 150oF. From Fig. 2.3, L = 0.63 g/cm3 = 39 lb/ft3 Assume a liquid residence time in the reflux drum of 5 minutes (0.0833 h), half full. From Eq. (7-44), 2 LM L t 2(480)(86.2)(0.0833) VV = = = 177 ft3 L 39 From Eq. (7-46), V DT = V 1/ 3 177 = 3.14 1/ 3 = 3.83 ft From Eq. (7-46), H = 4DT = 4(3.83) = 15.3 ft Might use a drum of 4 ft diameter and 16 ft long. Exercise 7.47 Subject: Sizing of a sieve-tray distillation column separating methanol and water. Given: Column top and bottom conditions in Fig. 7.50. Assumptions: Column feed is a bubble-point liquid. Constant molar overflow. Find: (a) Column diameters at top and bottom. Should column be swaged? (b) Length and diameter of horizontal reflux drum. Analysis: First, compute the liquid and vapor flow rates at the top and bottom of the column. Molecular weight of distillate = 0.9905(32.04) + 0.0095(18.02) = 31.91 Distillate flow rate = D = 462,385/...
View Full Document

## This note was uploaded on 09/08/2008 for the course CHE 244 taught by Professor Selebi during the Spring '06 term at Lehigh University .

Ask a homework question - tutors are online