Economise on power consumption at Unilever

Bookmark and Share

logoUnilever Ice Cream UK produces a wide variety of ice cream worldwide. Since the factory opened 25 years ago, the product range and internal manufacturing processes have undergone considerable modification to keep pace with hygiene guidelines and an ever-evolving product range.

With a Grundfos Pump Audit, Unilever saw an opportunity to economise on power consumption, to reduce their carbon footprint and to save operational costs. Unilever Ice Cream UK produces a wide variety of ice cream worldwide. Since the factory opened 25 years ago, the product range and internal manufacturing processes have undergone considerable modification to keep pace with hygiene guidelines and an ever-evolving product range. With a Grundfos Pump Audit, Unilever saw an opportunity to economise on power consumption, to reduce their carbon footprint and to save operational costs.

Task

Despite the many changes to the processes on Unilever Ice Cream UK's product lines, the process water supply remains the same as it was on day one 25 years ago. After an initial survey of some 60 pumps on the site, a more detailed evaluation was performed on ten supply systems. The evaluation highlighted numerous sources to energy wastage, such as over-pumping, valving back, oversized pumps and inefficient motors. "Our process has seen many changes over the years so we needed an accurate study of the current duty requirements", explains Grant Burgess, engineering technician at Unilever. The 37 kW single-speed pumps supplying the process water were getting on in years. They were running constantly, and the flow was controlled by valving back the water.

Solution

pumpOn the 37 kW pumps the Pump Audit tested a duty point that was specific to the site's requirements. The audit concluded that they were costing more than €20,000 per annum to operate. Once the correct duty point had been calculated, it was agreed that replacement pumps could be rated at 15 kW.

Result

Reducing motor size from 37 kW to 15 kW meant that even a fixed-speed pump could be operated at less than half the cost.

To further increase savings by 20%, Unilever opted to install Grundfos variable-speed pumps. The variable-speed solution has given Unilever greater control over the process, and the new pumps need only operate at a running speed of 45 Hz to supply the process. The payback period for the new pumps was a mere 12 months. The new pumps installed at Unilever Ice Cream UK are: Grundfos NBE end-suction E-pumps, CRNE multistage centrifugal E-pumps, F&B-HYGIA single-stage end-suction sanitary pumps, multi booster sets and NOVAlobe rotary lobe pump with positive displacement.

"The use of variable-speed pumps will give even more savings and leave us with the flexibility to speed up the pump to accommodate any future additions to the process load".

Grant Burgess, Engineering Technician at Unilever