The motor of a pump consumes 1.05 hp of electricity. The pump increases the pressure of water from 120 KPa to 1100 KPa at a rate of 35 Umin. If the motor efficiency is 94 percent determine the pump?

To determine the pump efficiency, we first need to calculate the power output of the pump.

Power output of the pump can be calculated using the formula:

Power output = (Pressure increase * Flow rate) / 600

Where:
Pressure increase = 1100 KPa - 120 KPa = 980 KPa
Flow rate = 35 U/min

Power output = (980 * 35) / 600
Power output = 57.17 hp

Next, we need to calculate the actual power input to the pump, taking into account the motor efficiency.

Power input = Power output / Motor efficiency
Power input = 57.17 / 0.94
Power input = 60.85 hp

Therefore, the pump consumes 60.85 hp of electricity.

Given:

- Motor power: 1.05 hp
- Pressure increase: 1100 KPa - 120 KPa = 980 KPa
- Water flow rate: 35 L/min
- Motor efficiency: 94%

Solution:

1. Convert Motor Power to Watts:

1.05 hp - 746 W/hp = 786.3 W

2. Calculate Water Power (Pump Power):

Water power = (Pressure increase) - (Flow rate) / (1000 kg/m³)

Using the density of water as 1000 kg/m³:

Water power = (980 kPa) - (35 L/min - (1 min / 60 s)) / 1000 kg/m³
= 588 W

3. Calculate Input Power (Electricity Power):

Input power = Water power / Motor efficiency

Input power = 588 W / 0.94
= 625.53 W

Therefore, the pump efficiency is:

Pump efficiency = Water power / Input power
= 588 W / 625.53 W
= 0.94 or 94%