A new approach to variable pressure filtration

The widespread reliance on heuristics for the design and specification of particle/fluid separation devices has prompted a new, mechatronic based approach to dead-end pressure filtration. A computer driven experimental apparatus was used to facilitate proportionally controlled filtrations over a range of pressure/flow regimes whilst maintaining inherent suspension properties. Preliminary results from constant flow experiments using distilled water and aqueous suspensions of calcite are presented where the air pressure within the filter is controlled through a combination of flow & pressure transducers and an electronically adjusted pressure regulator. The effects of controller type, controller gain, sampling time and set point flow on system response are shown to illustrate what can be achieved using mechatronics. Predictions of constant flow filtration experiments are made using data from constant pressure tests and reasonably good agreement is achieved. A simulation, based on classical filtration and control theories, is also presented and shown to compare well with the filtrate flow responses observed from the filtration apparatus.