Rotork and the Chocolate factory

Rotork IQ intelligent electric valve actuator installed in a key area of a chocolate moulding plant.

"People cannot believe how complicated chocolate bar production is" says Mark Smith, Process Engineer at Cadbury's Bournville factory, who has just completed a project to install a Rotork IQ intelligent electric valve actuator in a key area of a moulding plant.

The Rotork actuator has replaced a hydraulic cylinder to regulate the flow of re-melted chocolate back into the production stream - an apparently simple duty which in fact demands a very accurate level of modulating valve control.

Mark explains: "This highly automated Moulded plant operates 24 hours a day and makes more than sixty different chocolate bar variants. Precise modulating control of the re-melt valve is essential for the maintenance of product consistency and weight variation performance".

The IQ actuator was introduced to provide a more reliable and accurate valve control performance than the hydraulic cylinder, whilst also reducing maintenance requirements and removing the risk of hydraulic fluid leakage. In addition to providing cleaner electrical operation the IQ also provides simplified connectivity with the Allen Bradley PLC that supervises the operation of the plant - in this instance the device is hard wired to the output card. Even so, the complicated nature of chocolate handling is illustrated by the PLC software used to control the operation of the actuator. Specially developed for the application by Mark, the logic is based on intricate equations involving vessel weight, viscosity, flow rates, temperature and time.

Rotork's specialist Site Services Department was responsible for the sizing and mechanical installation of the IQ actuator, including the design and fabrication of the valve adaptation. Chocolate production at Bournville originally started in 1879 and the site remains Cadbury's single largest production facility. The site is equally famous for the adjacent Bournville Village, created by Richard and George Cadbury to provide a pleasant 'green' environment for their employees, in stark contrast to the oppressive conditions of the Victorian industrial scene