Gasoline Pipeline with pump We wish to pump gasoline from ta

Gasoline Pipeline (with pump): We wish to pump gasoline from tank B to tank A as shown in the figure. We will use the 6 in diameter pipe and install a centrifugal pump (pump chart given below). Using this pump, what would be the gasoline flow rate, operating head, efficiency, and brake horsepower? Assume highly turbulent flow. Gasoline has a vapor pressure of vapor pressure of 4.0 psia. For the conditions in part (a), will the pump cavitate? .

Solution

Pa= 10 Psig= 0.687 bar= 6.87 m

Pb = 40 Psig = 2.76 bar = 27.6

Suction head= 27.6 + 10

D = 6 x 2.54/100= 0.1524m

2. As tank have 40 psig on liquid against the 4 psia, so cavitation will not happen.

1. Turbulent flow so Re > 4000, Take 4100 Re

Re = Denisty of gasolene x velocity of fluid x Dia of pipe/ dynamic viscosity

4100 = 720 x v x ( 6* 2.54/100)/ 0.0006 v= 0.022 m/s

Flow Q = A x V= 1.44 cmh

Hf suction = 4 f l v^2/ 2gd, where f = 0.002 derive from 0.005 ft, Hf disch= 0.0017m

= 0.0003 m

Operating head = (27.6+3.1-0.00003)-(12.3+6.8-0.0016)= 11.60 m

h = flow x density x g x h / 1000 = 0.032kW

Efficiency low power pumping & high efficiency.