Question

2. The characteristics of a 0.7 m diameter centrifugal pump impeller running at 750 rpm are as follows: 2 (m*/min) H (m) 4(%) 0 7 4 2 28 354 49 56 40 40.6 40.4 39.3 38.0 33.6 25.6 145 0 0 460 74 83 83 51 0 (a) f the pump is initially used to transfer water from one reservoir to another at the same level, determine the pump operating point if the head lost to frictional and other resistances is 35m at 25 m/min. (b) The pump is then used to transfer water between two reservoirs having difTerence in levels of 15m through a pipe of 045m diameter. If the pipeline is 93m long with a frietion factor of 0.004 and pipe entry and exit loss coefficients of 0.5 and 1.0 respectively, find the volume flow rate and power absorbed. (c) If the pump is now changed to one of 0.51 m diameter and the motor is changed to one running at 975 rpm, what is the new volume fnow rate and power absorbed?

Answer 1

0 oase Gifven thot othev total 33.6 35

150 60 26 (181 x686 /4 2.5x5 62.5 139 121 2 92 2Xg.

凸 2 x98 1.62 2_ hend se 35 4ue 775 8.829 2 ess due to eatvy aod exft 27

entr 고- 2x9.8) 62 2x1XY 19.62. b) ou de ne to leve ea d o35es in prpc 2 15-0· 9.124V

2- 5 0. 2124 10.621-v 2 -→ volume- Li ox) absov hed fr f0aht 1000רא.glx,-33x,5 pouves →

2_ 150 X6-45 - 33 TI5 x 0.3265 750x 0.091125 1. 33 68.34 129. 33 2 29.334 (0Y eauatnq. - hec Cne

15 150大6-115 (115x0 51) 337.5 17.15) 3 15 37 u43359.375 122948822 5 3.1018 122T4822.95 12.27488 22.15 x3.9018 c.442 2. 1000 X 2.517 X 9.81 УЧ8 (toutia.tobd -ne5. 2.tu))