what is the motor horsepower?

Question

a pump is pumping 1.6 MGD from a clearwell 12ft below the pump to a storage tank 60 ft above the pump. The pump efficiency is 68% and the motor is 89% efficient. What is the motor horsepower? 20.2mhp, 29.7mhp. 33.4mhp or none of the above?

Answer 1

I will take a wack at it.

pPump = rWater*pWater/(Kp*Ke)

where rWater = 1.6 Mgal/day
pWater = 72 ft *0.433 psi/ft
Kp = 68%
Ke = 89%

Plug in the numbers and you get 24.9 kW.

So I guess the anser is none of the above.

Answer 2

Brake horsepower = gpm x psi/1714 x eff.

= ((1,600,000/(24 x 60)) x (60 + 12)/(2.31))/1714 x 0.68

= 29.71 BHP