OPERATING EXPERIENCE WITH A FALLING-FILM PLATE EVAPORATOR

Since the 1992 campaign, the evaporator station of the Waghausel sugar factory (Sudzucker AG Mannheim/Ochsenfurt) has been equipped with a falling-film plate evaporator in the thick juice stage. This evaporator which has a heating surface of 1500 m2, was supplied by Balcke-Durr AG. In order to install it, the steam chamber of a natural recirculating (Robert evaporator) was removed and a plate evaporator module integrated in the pressure tank, it being possible to retain the peripheral piping to a large extent. In 1993 the significantly improved juice distribution in comparison with the campaign of 1992, permitted steady operation with the heating surface being uniformly wetted with juice. The heat transfer behaviour and the colour formation were studied and compared with the evaporators connected in series. The effects of the new evaporator on the overall pressure difference in the evaporator station were also observed.