Question

Please show work, i will rate. Thank you!

2. At the power plant, the water for cooling must be removed at a minimum rate of 65 gal/min. A pump is found in storage that has a displacement of 4.8 ins/rev. A motor is also found; it operates at 960 rpm, 230 VAC, and 22.5 A. The power factor on the motor has an overall n=89%. If a 4" pulley is attached to the motor, what size pulley should be attached to the pump to meet this minimum flow rate (pulleys only come in 74" increments)? (8 points) Then what is the torque on the pump with this pulley installed on it, in ft-lbs? (8 points)

Answer 1

First calculate the rotational speed of thepump required and then calculate the diameter of the pump pulley from rotational speed ratio of the pulley and the motor.

Power input to the motor, Pi = VI (PF) P; = (230V) (22.5)(089) P; = 5175W Rotational speed of motor, Num= 9605 km Rotatioad speed of pump; Np- ? Q = 63x23ling 123lin3 1933 min De 14553 in3 min Pump displacement, 2 = 48 in /her N = Qor N = 14 553 in 3 win 4.8 in /rev N = 3031.8750pm.

Do I 6 G 4-Dm orfen Np= 3031.8750pm wing. De 4 • (3031-875) Dm Np Dp=1260). - D = 1-266" so, itak Yy" round-off Pp = 1.25"] wp=? Np=30720pm/ Diameter of the pump pulley is 1.25" Power transfered to Pump: P = 5175W P = Tpump w the pump

Bump=5175W pay 25-43 Trump = 16.09Nm or T bumb= 16.09 40.7375 Trump = 11.866 lb-ft Tosque on the pump is 11.866 Uft.