8- 308.54 (cont’d) d. TTfa2345061=°⇒= °C CT&E, 2136552CT&Ee. In an adiabatic system, when a liquid evaporates, the temperature of the remaining condensed phase drops. In this problem, the heat transferred from the air goes to (1) vaporize 90% of the acetone in the feed; (2) raise the temperature of the remaining wet film above what it would be if the process were adiabatic. If the feed air temperature is above about 530 °C, enough heat is transferred to keep the film above its inlet temperature of 35 °C; otherwise, the film temperature drops. 8.55TpsetpsiaF=≈°200100bg(Cox chart – Fig. 6.1-4) a.Basis:3.00 10 SCF 1 lb - moleh359 SCFlb mole h C H338×=⋅8357.8.357 lb-mole C3H8(v)/h 8.357 lb-mole C3H8(l)/h 200 psia, 100oF 200 psia, 100oF ±m(lb - mole H O(l) / h2±m(lb - mole H O(l) / h270oF85oF The outlet water temperature is 85oF. It must be lessthan the outlet propane temperature; otherwise, heat would be transferred from the water to the propane near the outlet, causing
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This note was uploaded on 01/07/2012 for the course CH E 210 at Pennsylvania State University, University Park.