Question

Final Sem2 20182019 03 04.pdt - Adobe Acrobat Reader DC File Edit View Window Help Home Tools ilovepdf merged (4). Final Sem 2018201... X Sign In C @ (1 of 2) 100% Jo Share Question 3 a) By the aid of an idealized radial-flow impeller velocity diagram, determine the best pump design constanta, and a from the theoretical head curve equation of Egn. Q3 H = Ro - 9,0 Egn. 03 where, H, is the theoretical head in m Q is the discharge in mº's (4 marks) b) A centrifugal pump is designed to pump a liquid refrigerant of density, p = 1226 kg/m3. The dimensions of the impeller are given in Table 03. The pump is to deliver 0.25 m/s of the liquid refrigerant at a net head of 14.5 m when the impeller rotates at 1700 rpm. Assuming ideal conditions operation and no pre-rotation, determine (inlet and outlet blade angles (ii) brake power, if the pump overall efficiency is 80 percent Radius Width 1100 mm b, = 50 mm - 180 mm b- 30 mm Table Q3 (5 marks) 9 DENG 2:32 PM 1/7/2020

Answer 1

© Given: ④ By diagram the aid of an idealized radial flow impeller velocity determine the best pump design Constanta, and a from the theoreehical head curve equation H = 90-9, V3 for the given yelocity diagram of the centrifugel pump best theoretical efficiency, n = 1 n = ght VWzU2 Hy = VW242 g hv=v6 Mt = (42- Visa COFR2) 42 už - al content C = лов, V, TTD B 2 Compare ega and ① Castent, 9,5 Cotku2 KZ B2 Iw = 1226 kglm, volume flow rate, p= 0.25 m3/s het head, Honer = 14.5m rotutimal speed, N= 1700rpm rja 100mm, by = Somm, 82= 180 mm bz= 30mm CÔ inler and outlet blade angle (P. & P) - un inler velocity fruingle 4,5 211VN, 211x.1x1700 v=vh 60 60 U = 17.8 m/s CS Scanned with CamScanner and a = ITO, BI VA 0.25 ete = 11 X 2 * 05 X VG

If = 7.95 m/s tanß = Vh Ba fanya maar ! 17.8 inler Blode angle, (P = 24° outlet velocity triangle 42 Per U₂ = TOON TV 60 U2 = 1+ 2x. 18 + 1700 60 U2 = 32mis Q = TQB 2 Vf 0.25 = TX 24. 1840.03 x Vf2 = Uf = 7.36 m/s and Vo = Vr (nowhirl Jugetup Vr2 = 19.5 ms sain 82' VE Vr₂ f2 = sin | 7.3.16 outlet Blade angle, B2 = 20.7 11 Brake power When ap= 804 Brake power, Pa sagther mp pa 1226x0.25x921414:57 8 P = 50.5kw CS Scanned with CamScanner