Learning task No. 4 Incompressible Flow

1. An oil having a density of 833 kg/m3 and a viscosity of 3.3 x 10-3 Pa-s is pumped from an open tank to a pressurized tank held at 345 kPa. The oil is pumped from an inlet at the side of the open tank through a line of commercial steel pipe having an inside diameter of 0.07792 m at a rate of 3.494 x 10 -3 m3/s. The length of straight pipe is 122 m, and the pipe contains two 90o elbows and a globe valve half open. The level of the liquid in the open tank is 20 m above the liquid level in the pressurized tank. The pump efficiency is 65%. Calculate the kW power of the pump.

2. Crude oil flows through a level section of a pipeline at a rate of 250,000 m3/day. The pipe inside diameter is 1.2 m; its roughness is equivalent to that of galvanized iron. The maximum allowable pressure in the pipe is 8.3 MPa while the minimum pressure required keeping dissolved gases in solution in the crude oil is 340 KPa. The crude oil has an S.G. of 0.93 and a viscosity of 0.017 kg/m-s. For these conditions, determine the possible spacing between pumping stations.

3. Gasoline (specific gravity 0.76 and viscosity 0.65 cP) flows in a long, underground pipeline at a constant temperature of 15oC. Two pumping stations at the same elevation are located 13 km apart (equivalent length). The pressure drop between the two stations is 1.4 MPa. The pipeline is made from 0.6 m diameter pipe. Although the pipe is made from commercial steel, age and corrosion have raised the pipe roughness to approximately that for galvanized iron. Compute the volume flow rate.