7.5. It is necessary on a new installation to preheat 149,000 lb/hr of 34°API crude oil from 170°F to a temperature of 285°F, corresponding to that of thefeed plateof a fractionating tower. There is a utility 33°API gas oil line running near the tower at
530°F of relatively unlimited quantity. Because the pumping cost for cold gas oil is prohibitive, the temperature of the gas oil from the heat exchanger, returning to the line, should not be less than 300°F.
Available on the site is a 25 in. ID 1-2 exchanger containing 252 tubes 1 in. OD. 13 BWG, 16'0" long arranged on a six-pass 11⁄4-in. triangular pitch layout. The shell
baffles are spaced at 5-in. centers.
oil line and 15 psi on the feed line.
if so, what will the fouling factor be?
at 530°F and 0.7 centipoise at 300°F.
poise at 285°F and 2.1 centipoise at170°F. (Interpolate by plotting °F vs. centipoise on logarithmic paper.)
between 390 and 200°F is used to heat 143,000 l b/ h r of 34°API Mid-continent crude from 100 to 170°F in a 662-ft° exchanger (Example 7.3). The clean co- efficient is 69.3 Btu/(br)(ft?)(°F). When the 1-2 exchanger is clean, what outlet
A pumping head of1 0 psi is allowable on the gas Will the exchanger be acceptable fi cleaned, and For the soil the viscosities are 0.4 centipoise
For crude oil the viscosities are 0.9 cents-