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Technology news 12 Filtration+Separation July/August 2013 Upgraded microscreen offers improved performance and durability Hydro International has upgraded its DynaDisc ® microscreen filtration unit. The company says that the upgrade promises higher reliability and plant availability, leading to reduced downtime and lower operating costs. Relaunched to build on more than eight years of successful operation for final effluent polishing in the UK, Hydro adds that the compact Dynadisc ® unit also provides high-grade treatment for recycled or discharged process and cooling waters used by the paper and pulp, metal processing, power generation and chemical industries. “The DynaDisc ® is already recognised as a highly-effective solution for the removal of suspended organic particles from treated water,” says Chris Day, Operations Director of Hydro Wastewater. “The new design uses the same proven microscreening technology, but with many improvements which further enhance its long operating life, and make it easier and cheaper to maintain and service.” The new DynaDisc ® includes patented new microfiltration cassette designs, with GRP frames and high durability filter fabric. The result is a long design life and high- strength integrated seals to prevent cross contamination between raw and filtered water. The filtration cassettes are even quicker to install and replace than previously, reducing maintenance costs. The new DynaDisc ® drive design replaces the previous chain drive to the central drum shaft with a non-corroding carbon- reinforced polyester belt system to the outside of the drum. As well as offering low torque drive for energy efficiency, the non- corroding belt drive features a 10-12 year design life for lower operating costs and less downtime. The integrated level tank of the Dynadisc ® is designed with a long filtrate level weir for simplifying controls and ensuring cleaner backwash water for higher consistency and better quality results. By using newly filtered water for backwash, possible biological contamination is avoided, unlike other systems where backwash water is circulated from outside storage tanks. Cleaning and maintenance of the DynaDisc ® is achieved using Hydro’s automated acid spray system which, uniquely, uses the filtrate level tank to bathe the cassettes for contaminant removal. The integrated design enables the cleaning process to be self-contained and prevents possible acid leakage into other parts of the treatment works. Other elements of the DynaDisc ® design, such as rotating and sliding bearings and ceramic backwash nozzles, have also been uprated for a longer working life in a difficult environment. [email protected] The upgraded DynaDisc from Hydro International Dynaflow Inc. has developed a microbubble generator based on its Stratojet ® technology. The company adds that the Straojet ® bubble generator utilises a passive acoustic resonance created by flow interaction with the nozzle and upstream chambers to induce the formation of large vortical structure which break up cavities to generate very fine bubbles. A special design allows the user to introduce air or other gases to enhance gas transfer. The Straojet ® bubble generators can generate high void fraction Microbubble generator enhances separation techniques bubbly flows dominated by very small micro sized bubbles. The Straojet ® bubble generators are scalable and versatile, and can be made to different scales and flow rates and can be custom designed and fabricated to meet specific application requirements of customers. The Dynaflow bubble generators have applications in areas such as wastewater treatment for enhanced aerobic reaction, and fractionation and separation. www.dynaflow-inc.com
