7 17 r ld lvmin1 lvmin 03771 0377

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

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: iddle section to see if the operating line there is below the equilibrium curve. The liquid rate in the middle section = L' = L + F2 = 60.5 + 83.3 = 143.8 kmol/h. The vapor rate in the middle section = V' = V = L + D = 60.5 + 100 = 160.5 kmol/h. Therefore the slope of the operating line in the middle section = L'/V' = 143.8/160.5 = 0.896. As seen in the McCabe-Thiele diagram on the next page, this operating line does not cross over the equilibrium curve. Therefore, the pinch does occur at Feed 2 (the upper feed). For an operating reflux ratio of 1.33 times minimum, L = 1.33(60.5) = 80.5 kmol/h. The vapor rate in the upper section = L + D = 80.5 + 100 = 180.5 kmol/h. Analysis: (continued) Exercise 7.30 (continued) Therefore the upper section operating line has a slope, L/V = 80.5/180.5 = 0.446 and passes through the point y = x = 0.95. It intersects the vertical q-line at x = 0.6 and for the slope of 0.446 = (0.95 - y)/(0.95 - 0.6), y = 0.794. For the middle section, L' = L + F2 = 80.5 + 83.3 = 163.8 k...
View Full Document

Ask a homework question - tutors are online