MSE membrane filter presses for the filtration of phosphate sludge in the automotive manufacturing industry
Since 2015, two automated MSE membrane filter presses have been successfully in operation at the Swedish automobile manufacturer Volvo in Gothenburg. These are used in a pre-treatment plant (VBH) for the untreated bodies. The medium to be filtered is phosphate sludge with kryalite components, which can be relatively difficult to dewater. The conveying of the medium into the filter press is done by means of a volume and pressure-controlled free-flow pump.
The filter press plant used is distinguished by its high availability and operational safety. To meet the requirements of the Swedish car maker, the filter presses were designed with an automatic plate shifting device and an automated filter cloth washing system. Furthermore, the filter presses have an extensive splash guard to minimise the possible pollution of the surroundings and, above all, to ensure the highest possible protection of the personnel. Sliding doors at this point allow access for maintenance work as well as for emptying the filter press after filtration has been completed. As an option, the core blower unit was additionally selected. This blows compressed air in front of the opening to the filter chambers via a valve in the turbidity channel and thus frees the core bore of the suspension.
Optimisation of the filtration process
The resulting, acidic starting medium was a phosphate sludge, which had a pH of 3-4. Because of this, it was necessary to convert this acidic filter cake into an alkaline solid filter cake and to optimise the filtration to this effect. This was done using caustic soda, which neutralises the built-up filter cake throughout the special membrane filter plates prior to the opening the filter press. This type of filter cake optimisation has been unique in the automotive industry to date. After neutralisation, the treated filter cake had a pH of 11 and a consistent filter cake thickness of 20 mm after filtration.
Also, the filter cake was dewatered after neutralisation with a consistently high dry matter content, thus ensuring trouble-free disposal. With this, MSE Filterpressen® with its tailor-made filtration solutions proves its world-wide, market-dominant position in the automotive sector. Find out more about our range of filter presses.