Continuous Gravity Fed Sand Filters Expand Product Portfolio

Aquarion Group (Aquarion AG) (Switzerland), a global water treatment solutions provider, has added the Toveko Continuous Gravity Fed Sand Filter to the portfolio of technologies offered by its group companies to customers around the world.

“As a major company in the global water treatment industry, Aquarion Group is committed to providing leading-edge water and wastewater treatment technologies. Toveko Sand Filters, which were initially provided only through Hager + Elsaesser, now increase the range of options available through all our group companies,” said Karl Michael Millauer, CEO of Aquarion Group.

Toveko filters are highly efficient for treating wastewater from industrial and small municipal sources. Typical applications include tertiary filtration of wastewater (industrial and municipal), filtration of river water, removal of suspended solids in cooling tower recycling loops, and removal of residual oil prior to wastewater discharge.

With their unique design, the filters offer an array of advantages over conventional sand filters. Toveko filters do not require the large backwash water tanks associated with conventional sand filters. This feature along with the unit’s rectangular construction and low unit height of only 2.3 metres means that the space requirement is less than other options, and they can fit inside standard height buildings when required.

The Toveko filter’s unique design also results in a lower wash water requirement – typically only 3-5% of feed flow going into the filter.

During operation of the Toveko Filters, the dirty water enters the inlet launder that runs along the entire length of the filter and is then directed into the bottom of the filter bed. As the water rises to the surface, the suspended solids are left behind, so the water gets gradually cleaner as it rises up through the filter sand. Once the water is above the sand bed, it overflows along the length of the filter.

The configuration of the inlet launder enables the filter to cope with large fluctuations in feed flow and pressure drop across the sand bed. In addition, there are no dead zones because the entire sand bed is part of the cleaning process with the Toveko Filter.

Importantly, unlike other filter types, each Toveko filter features an automatic head loss detection system that starts, adjusts and stops the sand lifting and washing process and, most importantly the amount of water used for washing it. This makes Toveko filters especially suitable for un-manned sites or those where the quality of the feed water varies regularly.

Toveko filters are manufactured in various grades of stainless and duplex steels in a range of sizes from 0.75 – 12 square metres of filter area. Each filter is fully pre-assembled and tested prior to delivery and comes to the site complete with its own control system. The unit requires only a flat concrete slab on which it sits, power and compressed air supplies and pipework connections to be completed before it can be filled and commissioned. This means that the filter can be operational in only one or two days after arrival at site.