Q In the equipment shown in the figure a pump draws a soluti

Q. In the equipment shown in the figure, a pump draws a solution (specific gravity 1.85) from a storage tank through a 7.5cm (Diameter) steel pipe in which the flow velocity is 1.0 m/s. The pump discharges through a 5cm (Diameter) steel pipe to an overhead tank, the end of the discharge pipe is 15 m above the level of the solution in the feed tank, and the friction losses in the entire piping system are 5 m.

a. Find the power delivered by the pump. Take pump efficiency as 60%.

Solution

a) Q   = pi * 0.075^2 * 1 / 4   = 0.0044718 m^3/s

    Pump head   = 15 + 5   = 20 m

    Pump Power = rho * Q * g * h

                        = 1.85 * 1000 * 0.0044718 * 9.8 * 20    = 1.602 kW

    Power required by pump   = 1.602 / efficiency   = 1.602 / 0.6   = 2.67 kW

b)   Pump power   = (P2 - P1) * Q

      P2 - P1   = 1.602 * 10^3 / 0.0044718    = 358.245 kPa