In biological processes, the main concern is to maximise the surface area of the packing on which the bacteria inhabit, whilst maintaining open access for two-phase contact.Much of the random media currently in use is based on the original Raschig Ring. Even though this packing is cost-effective to produce, the internal surface contact is poor and it is susceptible to blockages, thereby reducing the flow through the bed. Other more open media have been developed with internal webs and ribs to provide additional surface area but these produce notches and crevices where dead bacteria and debris can form.
In contrast, The Pall Ring Company’s random media for biological processes mirrors the original Raschig Ring, in that it is a smoothly shaped ring but with a corrugated surface, free from internal protrusions, thereby giving good access to its open, inner surfaces and excellent flow through characteristics. This media is manufactured from polypropylene and will float in a flooded filter, clear of bottom inlet and outlet ports, and, it requires only minimal upward retention. Also, since it floats, the movement caused by liquid flowing over the media, will deter solids built-up.
The Pall Ring Company’s BIOLOGICAL FILTRATION MEDIA is available sized 300, 200, 150 and 100 m2/m3.