Groningen sugar factory: Practical experiences with a falling film plate evaporator having a heating surface of 6000 m2

For the 1995 campaign a falling film plate evaporator, built by Messrs. Balcke-Dürr AG, having a heating surface of 6000 m2, was commissioned at the Groningen sugar factory of the Coöperatie Suiker Unie U.A., The Netherlands. The equipment in question, which is applied as a pre-evaporator, is the largest existing plate evaporator in the sugar industry at present. The compact construction of this particular evaporator type and the high heat transfer coefficients (k-values) made it possible to reach the required water evaporation of approximately 115 t/h at the given pressure drop with this single apparatus. Heat transfer and color formation were compared with the other evaporators in the evaporator station and a thermal balance was carried out. The mean k-value of the evaporator was determined as 3152 W/(m2 · K). This corresponds to a kvalue which is approximately 30% higher when compared with a tube-bundle falling film evaporator.