Calculate the pressure exerted on the bottom of a 69 foot distillation column by a ten foot hydrocarbon level. Specific gravity is .67. Vapor pressure at 240 F is 236. 100 psi is added to the column giving a top gauge reading of ___ psi and a bottom gauge reading of ___ psi?
A) top 236 psi, bottom 238.9 psi
B) top 336 psi, bottom 338.9 psi
C) top 136 psi, bottom 138.9 psi
D) top 36 psi, bottom 38.9 psi

Question

Quizplus · Accepted Answer

The pressure at the bottom of the column is calculated by adding the hydrostatic pressure due to the hydrocarbon level to the vapor pressure and the additional 100 psi. The hydrostatic pressure (P) is given by P = hρg, where h is the height of the liquid column (10 feet), ρ is the density of the liquid (specific gravity of 0.67 times the density of water, which is approximately 62.4 lb/ft³ for water), and g is the acceleration due to gravity (approximately 32.2 ft/s²). This gives a hydrostatic pressure of about 2.9 psi. Adding this to the vapor pressure of 236 psi and the additional 100 psi gives a total bottom gauge reading of 338.9 psi. The top gauge reads the vapor pressure plus the additional 100 psi, totaling 336 psi.

Calculate the Pressure Exerted on the Bottom of a 69