Question

A large pump operates with a flow of 1000 KL/hr and develops

a pressure of 20 kg/cm2

. What is the power in HP that is delivered by the pump

Answer 1

Given :

Flow of pump : 1000 KL per hour.

Pressure : 20kg per square centimetres.

To find :

Power in horse power.

Solution :

Work done by pump :

$= volume \times pressure$

Power delivered by pump : Work done per unit time.

$= \frac{volume \times pressure \: }{time} \: \\ = flow \times pressure$

(equation 1)

We know that Flow through the pipe : 1000 kL per hour.

changing kL

unit into meter cube and 1 hour in terms of seconds,

we get,

Flow :

$= \frac{1000}{1} \frac{kL}{hour} = \frac{1000}{3600} \frac{ {m}^{3} }{s} = \frac{5}{18} \frac{ {m}^{3} }{s} \: \:$

(equation 2)

We know that Pressure through the pipe : 20 kg per cm²

changing kg per cm² in terms of pascal, we get,

unit into meter cube and 1 hour in terms of seconds,

we get,

Pressure :

$= 20\frac{kg}{ {cm}^{2} } = 2000000 \: pascal \: = 2 \times {10}^{6} pascal$

= 2 MPa

(equation 3)

Putting values of equation 2 and 3 in equation 1,

we get

Power delivered by pump :

$\bf \: = \frac{5}{18} \frac{ {m}^{3} }{s} \times 2 \times {10}^{6} MPa \: \\ \\ \bf= 555555 \: watt$

As we got the power delivered by pump, but we need to know the power in terms of horse power.

Horsepower :

It is a unit to measure power, or the rate at which work is done, usually in reference to the output of engines or motors. One mechanical horsepower

(or imperial horsepower), is about 745.7 watts.

Converting power from watts to horse power (hp)

Power delivered by pump :

$\bf = \frac{5555555 }{745.7} = 745.01 \: hp$

So,

Power delivered = 745.01 hp