WET News

NOVEMbEr 2015 WET NEWS 23 W hen facilities manage- ment and water treat- ment company MSS Group was called in to clean up the process water in a globally renowned manufacturer of semi conductor wafers, the company was presented with an untreat- ed water system suffering from significant corrosion. The ongoing performance of the plant was suffering heavily due mainly to the fact that the murky brown process water had been accepted as being the norm. Water quality tests and particulate analysis had never been carried out and part of the plant's processing facility had deteriorated to such an extent that some of it had worn away. The resulting debris was repeatedly blocking the flow of water so the process was continually overheating and tripping out. The amount of scrap was considerable and costs were escalating to tens of thousands of pounds over a 12-month period. With MSS' core business being the treatment of water using chemicals, in this particular instance the company had to find a process that would co-exist with its chemical treatment and filter out the high particulate content. Having known Industrial Purification Systems (IPS) for some time, Dave Robertson, director of MSS, called the company in to provide a solution. Robertson says: "It so happened that IPS had just completed a similar project where the process was almost identical. Over a six-month period, water filtration technology that had been installed by IPS had proven to be highly effective." An untreated water system that had significant corrosion was incurring repeated blockages. The challenge: Filtering out blockages The CrossFlow filtrer uses a vortex bed stabiliser INSIGHT FilTrATiON & sCrEENiNg After analysis was carried out, iPs's CrossFlow 300 was selected as the filter of choice. A solution: CrossFlow 300 does the job H aving been called in by MSS, IPS carried out a particulate spread anal- ysis. It was determined that IPS's CrossFlow 300 high quality water filter would be installed because it incorporat- ed a new controller with an electrically operated valve, ensuring that smooth transition between online operation and offline cleaning could be instigated. Operationally, the high quality water filter system utilises a patented vortex bed stabiliser that maintains flat bed filtration with high surface turbulence. This ensures that no bio-fouling can be seeded whilst holding filtered contamination in suspension above the media bed. This gives lower pressure drops, longer filtration and shorter backwash cycles making direct savings on operational costs. The high interstitial void volume of the media allows for greater dirt holding capacity and contamination interaction for the Zeta potential of the media to remove the finer particulates down to 0.45 micron Backwash times Compared with conventional media filtration, the inlet configuration allows for high flow rates, these being five times higher than the normal accepted flux rates of conven- tional filters. Backwash volume used is also significantly lower, especially when the longer operational period is taken into consideration. It is also more effective with backwash times per unit being as low as two minutes. This technology has been shown to provide a high efficiency removal rate of more than 86% at 1.0 micron in one single pass, whereas conventional filters have to undertake multiple passes to get anywhere such efficiency. Robertson continues: "There was an improvement in the water quality within a fortnight. AŸer six to eight weeks we saw a remarkable improvement. The water filtration technology is now running concurrently with a chemical package to eradicate future corrosion. "My relationship with IPS goes back a number of years and I have always been satisfied that its technology would do what I hoped it would. "The end user has been so pleased with the results that it has bought another filtration unit for another system." NEED TO KNOW 1 Debris was repeatedly blocking the flow of water 2 some of the processing facility had deteriorated worn away 3 Murky brown water had been accepted as the norm 4 The process was continually overheating and tripping out ThE CONCEpT • The filter system utilises a vortex bed stabiliser that maintains flat bed filtration with high surface turbulence • Finer particulates down to 0.45 micron can be removed • The technology provides a high efficiency removal rate of more than 86% at 1.0 micron in one single pass • The backwash volume used is significantly lower ThE VERDICT • There was an improvement in the water quality within a fortnight. After six to eight weeks there was "a remarkable improvement" • The technology provides a high efficiency removal rate of more than 86% at 1.0 micron in one single pass

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