Using mechatronics for the interpretation and modelling of the pressure filter cycle

An experimental apparatus combining the principles of mechatronics with a dead-end pressure leaf filter is described. The computer controlled and sequenced apparatus was used to monitor performance during the cake formation, gas dewatering and displacement washing phases of filter cycles. Data relating to cake properties and liquor transport rates were acquired through electrical resistance measurements and suitable transducers. The data illustrate the versatility and accuracy of the apparatus and they are used to compare with predictions given by existing theories, particularly for cake formation. Batch experimental results obtained with aqueous suspensions of calcite are shown to compare favourably with theoretical predictions for important design parameters such as cake height and cumulative volume of filtrate whereas data for more compressible talc systems tended to show more deviation. The work presented highlights the benefit of a mechatronics approach to experimentation and emphasizes the importance of data acquisition and system control to future developments in filter design.