# 7 carry out the calculations at the bottom tray based

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Unformatted text preview: rate, kmol/h Molecular weight Density, kg/m3 Gas 630 18.5 0.657 Liquid 1,192 18.0 940 Estimate liquid diffusivity of methanol in water at 212oF = 373 K. From Perry's Handbook, DL = 1.6 x 10-5 cm2/s at 25oC. The viscosity of water at 212oF = 0.25 cP. Using Eq. (3-39) to correct for temperature and viscosity, DL = 1.6 x 10-5 (373/298)(1/0.25) = 8 x 10-5 cm2/s Estimate gas diffusivity of methanol in water vapor from Eq. (3-36). T = 373 K MAB = 2/[(1/32) + (1/18)] = 23. Using Table 3.1, = 15.9 + 2.31(4) + 611 = 31.3, . = 131 . V V methanol water 0.00143(373)1.75 DV = = 0.30 cm2/s 1/ 2 1/ 3 1/ 3 2 (151 / 14.7)23 [31.3 + 131 ] . . Required tray dimensions: DT = 6 ft, A = 3.14(6)2/4 = 28.3 ft2 = 2.63 m2 Aa = 0.91 A = 0.91(2.63) = 2.39 m2 = 23,900 cm2, Lw = 42.5 in. = 1.08 m Tray conditions: = 1 - 0.617 = 0.383, qL = 47,300/(60)(8.33) = 94.6 gpm = 5,970 cm3/s From Eq. (6-54), Cl = 0.362 + 0.317 exp[-3.5(2)] = 0.362 From Eq. (6-51), f = 0.40, 94.6 hl = 0.383 2.0 + 0.362 (42.5)(0.383) 2/3 = 1.21 in. =...
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## 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 .

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