Ian Elliott reveals how electric process control valves contribute to Coca-Cola Enterprises’ environmental improvements.
Electric control valve technology is helping Coca-Cola Enterprises (CCE) to increase efficiency and reduce energy costs at its Wakefield production plant. CCE has invested over £100 million over the past five years at the Wakefield site, which is the largest soft drinks production plant in Europe, as part of a long-term programme that highlights its commitment to local manufacturing and the development of new technologies. Since installing and acting on the information produced by an energy monitoring system, the company has so far reduced electricity consumption at the plant by 13% since 2009.
An important part of the plan involves saving the on-going cost of providing and maintaining an instrument air supply for traditional pneumatic control valve actuation. This is being implemented at Wakefield by the introduction of the Rotork control valve actuator (CVA) to perform modulating and failsafe valve duties. A recent example is on the production line, where the adoption of Rotork CVA technology for a demanding valve duty has considerably reduced the cost of energy consumption with no loss of performance. Previously, electrically actuated valves could not respond quickly enough to maintain good pressure control in the bottle filling machine. Rotork was confident that the CVA actuator would not only give a similar performance to the existing valve, but would also be cheaper to run.
Proving the theory
Andy Reynolds, automation engineer at the Wakefield plant, takes up the story: “To prove this, the performance of the existing pneumatic control valve on the main product feed into the filling machine was first monitored and recorded. Using an adaptor made at Rotork’s facility in Leeds, the CVA actuator was then fitted to the same valve and connected to the existing 4-20mA control signal from the PLC.
“After running and monitoring the CVA actuator in a 24-7 operation for on month, the results from the two actuators were compared. The results clearly show that in production mode the CVA performs equally well, if not better than the pneumatic actuator. However, when in CIP (Clean in Place) cleaning mode, the performance of the CVA is much better than the pneumatic. This is because the CVA actuator does not overshoot the set point like the pneumatic actuator does when the set point is lower and back pressure in the circuit is higher when in CIP mode. As an alternative to pneumatic control valves the use of the CVA actuator also represented a minimum saving of £857 per annum per valve.
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Ian Elliott is sales manager for Rotork Site Services, based at Rotork UK’s head office in Leeds.