Question

A double acting reciprocating pump having piston area 0.1 m² has a stroke length 0.30 m. The pump is discharging 2.4 m³ of water per minute at 45 r.p.m. through a height of 10 m. What is the slip of the pump ?
1. 0.005 m³/s
2. 0.015 m3/s
3. 0.025 m3/s
4. 0.035 m3/s

Answer 1

Correct Answer - Option 1 : 0.005 m³/s

Concept:

The theoretical discharge through pump is given by:

\({Q_{th}} = \frac{2{ALN}}{{60}}\)

Where,

A = Cross – Sectional area, L = Stroke length

N = Speed, D = Dia. of Piston

Calculation:

Given,

L = 30 cm, N = 45 rpm, Piston area = 0.1 m²

\({Q_{th}} = \frac{{{ }{} \left( 2\times {{{0.1}^2}} \right) \times 0.3 \times 45}}{{60}}\)

Q_th = 0.0450 m³/s

Qactual = 2.4 m3/min = 0.04 m³/sec

We know that

Slip = Q _the - Q _act = 0.045 - 0.04 = 0.005 m³/sec

∴ Slip = 0.005 m3/sec