Ethylene gas is to be pumped along a 6 in. I.D. pipe for a distance of 8 km at a

Question

Ethylene gas is to be pumped along a 6 in. I.D. pipe for a distance of 8 km at a steady mass flow rate of 1 kg/s. The delivery pressure at the end of the pipe is to be 2 atm absolute, and the flow may be considered isothermal, at 15C.

4. Ethylene gas is to be pumped along a 6 in. ID. pipe for a distance of 8 km at a steady mass flow rate of 1 kg/s. The delivery pressure at the end of the pipe is to be 2 atm absolute, and the flow may be considered isothermal, at 15°C. If the friction factor f is given as 0.003, calculate the required inlet pressure. Assume ideal gas behavior, and justify any further assumptions. (See page 150 of your textbook.)

Explanation / Answer

Given data

Dia of pipe D = 6 in x 1m/39.37in = 0.1524 m

Area A = (3.14/4) x 0.1524 m x 0.1524 m = 0.01823 m2

Distance L = 8 km x 1000m/km = 8000 m

Mass flow rate m = 1 kg/s

Density x area x velocity = 1 kg/s

0.9740 kg/m3 x 0.01823 m2 x V = 1 kg/s

V = 56.32 m/s

Delivery pressure P2 = 2 atm x 101325 Pa /atm = 202650 Pa

Inlet pressure P1 =?

Friction factor f = 0.003

From the Darcy Weisbach equation

Head loss hf = (4 x f x L x V2) / (D x 2g)

= (4 x 0.003 x 8000 x 56.322) / (0.1524 x 2 x 9.81)

= 101838.63 m

P1 - P2 = density x g x hf

P1 - 202650 = 0.9740 x 9.81 x 101838.63

P1 = 1175711.99 Pa x 1atm/101325Pa

P1 = 11.6 atm

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.