When Pump Inefficiency Won't Wash

The customer contacted ERIKS over an issue with their operators’ misuse of washdown lances. Because the volume and pressure of water being supplied to the lances weren’t considered high enough for the job, operators were unscrewing the lance nozzles so they could deluge the washdown areas.

The simple solution was to specify lances with nozzles which couldn’t be unscrewed. But ERIKS’ engineers wanted to get to the root of the problem.

A survey of the customer’s existing pump set revealed that it was unsuited to the demands made of it, as well as being inefficient in its energy and water use. So ERIKS proposed a highly cost-effective solution.

Pumping to order

The existing pump set wasn’t fit for purpose for a number of reasons:

1. It operated to a fixed speed. Designed to pump sufficient water for 15 lances, that’s what it did – even when only one lance was in use.
2. Despite its specification, when all the lances were in operation water flow and pressure at the nozzles were still too low.
3. It ran 24 hours a day, regardless of whether or not it was needed.

ERIKS’ solution was to specify a Grundfos Hydro MPC-E pump set with Variable Speed Technology and a CU 352 Controller.

The controller is able to measure the water pressure entering the pump set, as well as the water being consumed, then to calculate the differential and instruct inverters to vary the pumping speed up or down, according to pressure and demand.

The pump set was also specified to accommodate the worst case load profile of all lances operating simultaneously (which was sometimes the case during a weekend washdown), but to pump at a slower speed – therefore saving energy – when only one or two lances are in use. When no lances are in use, the pump switches off completely.

Monitoring and maintenance

The controller is integrated into the customer’s SCADA system, allowing remote monitoring from the plant’s control room. Information provided includes amps, pressures and running hours. This not only enables more efficient management of the water supply, but also more effectively planned maintenance.

Because of the reduced hours of pump operation, reduced loading, and reduced wear, maintenance has been reduced and the working life of the pump set increased.

Before the installation of the new system, electrical running costs alone were £5,256 per annum. After installation, these are estimated at just £1,673 per annum. Add in reduced maintenance costs and a longer service life, and the savings are even more impressive.

Meanwhile the operators are getting the pressure and flow they need at the hose end, water consumption is reduced – helping to achieve one of the customer’s KPIs – and the process equipment is sparkling.  

For more details on how to shrink your energy bills in the wash – or anywhere else you use a pump – contact your usual ERIKS Service Centre on 0121 508 6000.