Page 322 - Introduction to Petroleum Engineering

ACTIVITIES 311
15.9 The lightest product from the distillation tower is Vacuum Tower Bottoms
(VTB), or “resid.”
15.10 Refrigeration and cryogenics are liquefaction processes.

15.5.3 Exercises
3
15.1 The density of oil is 900 kg/m . What is the pressure (in Pa) at the bottom of a
cylindrical storage tank containing a column of oil that is 10 m high? Assume
the pressure of air at the top of the oil is 1 atm and the acceleration of gravity
is 9.8 m/s . Recall that 1 atm = 1.01 × 10 Pa.
2
5
15.2 A. The height h of the liquid level in a cylindrical tank with a 50 ft radius
above the midpoint of a circular valve with radius 0.25 ft is 50 ft. What is
the speed of the liquid flowing from the tank (in ft/s)? Assume the
2
acceleration of gravity is 32 ft/s and that the potential energy at an eleva-
tion of 50 ft equals the kinetic energy of liquid flowing from the tank.
b. How fast does the liquid level change in the tank compared to flow from
the tank?
15.3 A. A cylindrical steel pipe with 24‐in. inner diameter is 0.10 in. thick. The
pipe carries oil under an internal pressure p 60 psi. The circumferential
(hoop) stress in the steel is S pdt, where p is the internal pressure, d
/2
is the inner diameter of pipe, and t is the pipe thickness. Calculate cir-
cumferential stress S in the steel.
b. If the pressure is raised to 100 psi in the 24‐in. inner diameter steel pipe,
what thickness of steel would be required for an allowable circumferen-
tial stress S 10000 psi?
/2
Hint: solve S pdt for t.
C. Do you need to replace the steel pipe?
15.4 Verify the k‐value calculation in Example 15.1.

15.5 Verify the two‐phase check in Example 15.2.
15.6 Verify the flash calculation in Example 15.3.
15.7 Verify the flash calculation in Example 15.4.