The Filtration ‘Top Ten’: What Would You Pick?

As part of our 50th Anniversary series of articles, I recently commissioned our longest serving contributor and filtration industry stalwart, Ken Sutherland, to select a ‘Top Ten’ of developments, events, people or indeed anything that he believed had shaped the industry over the past half-century. I did this in the full knowledge that after publication I would undoubtedly be receiving correspondence as to all the others that should never have been left out. However, the debate should fuel some interesting articles in the future. So in this column I thought I would summarize Ken’s suggestions for you and maybe provoke some additional suggestions – particularly as none are directly adhesive-related!

1) Multi-media packed beds – the multi-media idea has extended the life of the sand bed by a considerable amount, which is good because it is a very simple filter.
2) Moving bed filters – a considerable aid in the need for finer particle sized products, and the need to be able to cope with hotter systems.
3) Cross-flow filtration – widespread use in membrane processing, but applications for them as concentrators are increasingly being developed.
4) Polyelectrolyte flocculants – have allowed major improvements in the clarification processes, but have also created process opportunities for several types of separation equipment, no more so than with the decanter centrifuge.
5) Spunmelt nonwovens – these materials can be co-extruded to give composite fibres, and treated in other ways, to give a tremendous variety of finished media, and correspondingly useful range of filtration applications.
6) Membranes as media – starting with the development of reverse osmosis 50 years ago, this technology has developed progressively ‘looser’ membranes that are able to separate at higher molecular and then actual particle sizes, from nanofiltration through ultrafiltration and then microfiltration.
7) Ceramic media – can resist corrosive fluids and the problem of brittleness has now been solved either by the use of a coarsely porous block of ceramic material with a fine layer of filter medium sintered onto one face, or by making the substrate out of a thick layer of ceramic fibres.
8) Mini-pleats – an acceptable air filter must allow for the use of the most up-to-date filter media material, which in turn must be packed as economically as possible into the available filter housing volume.
9) The consultant – the role of the consultant has grown significantly in the filtration business over the past 50 years as it has grown in complexity and the need for advanced technical and process knowledge has expanded.
10) Society foundation – the Filtration Society in the UK closely followed the founding of Filtration+Separation. However, the Society’s creation triggered the formation of others around the world, including the AFS, and gave rise to great many filtration events that have pushed the industry forward.