A sieve-tray tower is to be designed for stripping an aniline $left(mathrm{C}_{6} mathrm{H}_{7} mathrm{~N} ight)$-water solution with

A sieve-tray tower is to be designed for stripping an aniline $\left(\mathrm{C}_{6} \mathrm{H}_{7} \mathrm{~N}\right)$-water solution with steam. The circumstances at the top of the tower, which are to be used to establish the design, are

The equilibrium data at this concentration indicate that $m=0.0636$ (Treybal, 1980).

(a) Design a suitable cross-flow sieve tray for such a tower. Take $d_{0}=5.5 \mathrm{~mm}$ on an equilateral-triangular pitch $12 \mathrm{~mm}$ between hole centers, punched in stainless steel sheet metal $2 \mathrm{~mm}$ thick. Use a weir height of $40 \mathrm{~mm}$. Design for a $75 \%$ approach to the flood velocity. Report details respecting tower diameter, tray spacing, weir length, gas-pressure drop, and entrainment in the gas. Check for excessive weeping.

(b) Estimate the tray efficiency corrected for entrainment for the design reported in part (a).

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Temperature = 371.5 K Liquid: Pressure 100 kPa Rate 10.0 kg/s Composition = 7.00 wt% aniline Density=961 kg/mViscosity = 0.3 cP Surface tension = 58 dyn/cm Diffusivity 4.27 x 10-5 cm2/s (est.) Vapor: Rate 5.0 kg/s = Density = 0.670 kg/m Diffusivity 0.116 cm/s (est.) Foaming factor = 0.90 Composition = 3.6 mol% aniline Viscosity = 118 P (est.)