Plantwide control of fruit concentrate production

Fruit concentrates are key ingredients in many fruit based Unilever products. We have designed a novel continuous fruit concentration process involving a decanter, an evaporator and a recombination process. In order to ensure best product quality and highest capacity a methodology for control structure design for complete processing plants (plantwide control) was applied. This included defining the control objectives, degrees of freedom analysis, definition of inventory and production rate control and the development of a non-linear dynamic model. Using the methodology, control alternatives were systematically analyzed and eliminated. The chosen control structure was successfully applied and implemented in a Unilever factory.