Unilever

Client

With a turnover of around £27 billion, 179,000 employees in approximately 100 countries and over 400 different brands ranging from soups to soaps, mayo to moisturiser, Unilever is one of the world's leading suppliers of fast-moving consumer goods.

Unilever's global food brands include Pro-Active, Flora, Hellmann's, Lipton, Brooke Bond, Bertolli, Knorr, Slim-Fast and Wall's and Ben & Jerry's ice-cream.

Their global home care brands include Cif, Domestos, Radiant, Persil, Comfort and Surf and personal care products include Dove, Lux, Pond's, Vaseline, Signal and Sunsilk.

objective

To cool a ZR315 and a ZE4VSD Air Compressor with drier, requiring a flow rate of 20.5m³/hr.

Solution

To provide cooling water/glycol at 30°C, at a flow rate of 35.4 m³/hr, Stadco Cooling recommended the use of the existing Pump Module and Air Blast Radiator which was rated to dissipate a heat load of 565kW, which actually dissipated 576kW when cooling water/glycol from 45°C to 30°C, in ambient temperatures up to 26°C.

Also it was recommended that the existing Air Blast Radiator that provided cooling water/glycol at 30°C, for the flow rate of 20.5m³/hr was suitable for their requirements. This unit was rated to dissipate a heat load of 315kW, which actually dissipated 333kW when cooling water/glycol from 45°C to 30°C, in ambient temperatures up to 26°C. A new Pump Module was needed to deliver the necessary flow of water/glycol for the flow rate of 20.5m³/hr.

Stadco recommended a Pressurisation Set for initial fill/make up, which also eliminated the necessity for a high level mains break tank. This was supplied as a skid mounted pre-piped unit.

An electrical control cabinet was also supplied to accommodate basic manual switching control at the lower end of the range up to fully automatic control systems at the other.

The system comprised:

• Sealed Dual Pump Module, fitted with two 4.0 kW pumps (1 duty, 1 standby).
• Each pump rated to deliver the required system flow rate at a pressure differential of 3.5 bar measured at the pump.
• Fitted to the pump module was a Pressurisation Set for initial fill/makeup, comprising a mains break tank with type A air gap, complying with bylaw 30, pump, expansion tank, pressure switch, pressure reducing valve and safety valve. This was mounted on a common skid base frame with all mechanical and electrical connections fully assembled.
• Electrical control cabinet

Result

• Reduction in operating costs
• Improved performance
• Significant reduction of downtime for servicing and/or maintenance purposes
• Improved reliability – sediment free water
• Water conservation as evaporation of water does not occur
• Reduction in corrosion - free air is physically extracted from the air blast radiator and this dramatically reduces internal corrosion of process plant and cooling equipment
• Elimination of limescale - fully sealed systems are not subject to the continual ingress of solids-laden make-up water, which would create a heat insulation barrier between coolant and process
• Reduction in maintenance costs
• Elimination of chemical treatment – as the coolant is not subjected to varying solids and atmospheric conditions, on-going chemical treatment is not required
• Health risk reduction – the coolant is totally sealed within the system and does not depend on vaporisation to effect heat transfer

Endorsement

Tim Bullock, Project Engineer, Unilever says: "Stadco Cooling were really flexible and their support was fantastic. The system they provided has achieved enormous benefits for Unilever. We needed a solution up and running very quickly and implementation had to be quick and simple and easy to use, Stadco Cooling provided this and from my experience I can whole-heartedly recommend them."