申論題

Problem 11 Fill-in-the-Blank (10 points)
A continuous rectifying column handles a mixture consisting of 40 per cent of benzene by mass and 60 per cent of toluene at the rate of 4 kg/s, and separates it into a product containing 97 per cent of benzene and a liquid containing 98 percent toluene. The feed is liquid at its boiling-point. In such an operation the mass flow of distillate is (a) 2ptand the mass flow of waste liquor is(b) 2pt . If a reflux ratio of 3.5 is employed, (c) 3pt plates are required in the rectifying part of the column. Ifthe plate-efficiency is now requires 60 percent, then (d) 3pt actual number of plates are needed.