Question

It is proposed to pump 1500 m3 of a liquid (density 1100 kg m-3) each day through a total head of 10 m (including all losses) by using either a centrifugal pump or a reciprocating pump. The centrifugal pump discharges 2.0 m3 min-1 when driven by an electric motor supplying a power of 5 kW. The reciprocating pump has a discharge rate of 1.75 m3 min-1 when driven by an electric motor supplying 3.5 kw. (a) Calculate the efficiency of each pump (b) If electricity costs 8p per kWh, select the most economical pump and determine the cost saving over 300 days of operation. (c) State two other factors which should be considered before a final choice of pump is made.

Answer 1