The 11.25-in impeller option of the Taco Model 4013 FI Series centrifugal pump is used to pump water at 400 gpm at 25°C from a reservoir whose surface is 4.0 ft above the centerline of the pump inlet. The piping system from the reservoir to the pump consists of 10.5 ft of cast iron pipe with an ID of 4.0 in and an average inner roughness height of 0.02 in. There are several minor losses: a sharp-edged inlet (K, 0.5), three flanged smooth 90° regular elbows (K,= 0.3 each), and a fully open flanged globe valve (K, = 6.0). Determine whether there is a danger of cavitation at this flow rate or not. Discuss how you might increase the maximum flow rate while still avoiding cavitation. For water at 25°C, r=997kg/m’, m=8.91 x10* Pa.s and P=3.169 kPa. %3D

4.21.* A steady-flow 100% efficient water power plant has the following inlet and outlet conditions: Pressure, P, psig Elevation, z, ft Velocity, V, ft/s Temperature, T, °F Inlet 0 75 400 70.0 Outlet 0 0 50 70.1 The plant is adiabatic. How much work does it deliver per lbm of fluid flowing through?

3. 14-35E A water pump is used to pump water from one large reservoir to another large reservoir that is at a higher elevation. The free surfaces of both reservoirs are exposed to atmospheric pressure. The dimensions and minor loss coefficients are provided in the figure. The pump's performance is approximated by the expression Havailable = Ho - a V², where the shutoff head, Ho = 125 ft of water column, coefficient a = 2.50 ft/(gpm)², available pump head Havailable is in units of feet of water column, and the capacity V is in units of gallons per minute (gpm). Estimate the capacity delivered by the pump. Answer: 6.34 gpm 22-2₁ = 22.0 ft (elevation difference) D 1.20 in (pipe diameter) KL. entrance KL, valve 1 KL, valve 2 = 6.8 (valve 2) KL. elbow = 0.34 (each elbow-there are 3) = 0.50 (pipe entrance) 2.0 (valve 1) KL, exit = = 1.05 (pipe exit) L = 124 ft (total pipe length) e = 0.0011 in (pipe roughness) P v₁ Reservoir V₁0 22-71 55 Valve 1 Pump V/₂20 Reservoir Valve 2

3. What factors should we take into account for the selection of the pipe size and design of the piping system to conduct compressed air in industrial plants?4. What is a fluidized bed?