PROJECT IS TO INCREASING THE FLOW CAPACITY OF PREGNANT LIQUOR PURIFICATION FILTERS BY INSTALLING A NEW DESIGN OF FILTER BAG FRAME

Objective

To increase the flow by >20% through a conventional horizontal or vertical pressure filter by the installation of a new design of filter cloth frame. Previous trials of frames with increased filter surface area had produced encouraging flows but had all failed due to cloth damage after a few days on line. The failures where caused by the extra material in the filter bag not evenly conforming to the undulating surface of the frame. For this reason particular attention was paid to the method of attaching the filter cloth to the frame so that it conformed to the new frame shape and retained its position throughout the filter bag life.

Key conclusions

A small size frame was manufactured in the new design and all trials where conducted in a vertical filter that had flow valves fitted to 2 of its small frame filtrate outlets, this allowed the flow from the new frame and a standard flat filter frame to be continuously monitored. The first trial produced increased flows though the new design of between 30-15%, with most cycles averaging 26 – 20%. Trials are ongoing to confirm these flow performance figures and also to provide online cloth hours comparable to conventional flat filter frames.