Semi-empirical full cycle optimisation of fill, squeeze and blow plate and frame pressure filters

Investigation of the response of plate and frame filter performance to changes in design and operating variables is complicated by the large matrix of potential variables and the inter-dependent kinetics of the fill, press and air blow stages. However, through some key simplifying constraints an integrated optimisation framework has been developed. An example application is presented for an iron ore fines material from the North West of Australia, which indicates an optimum filling duration exists for all conditions investigated and illustrates the throughput benefits of higher feed solids and pressing pressures and larger cavity thicknesses. Significantly, the optimum filling duration is not constant and depends on the ratio of pressing to filling pressure and cavity thickness employed, largely due to the important role of the pressing stage not from the perspective of compression, but rather from that of an increased rate of secondary filtration of unfiltered suspension remaining at the end of the filling stage. Although simplistic in the form presented and limited to incompressible systems, with the integration of more rigorous theoretical treatments of the individual filter stages, the applicability of the approach could be broadened to all types of substrates.