Sand Aquaculture filter DynaSand

DynaSand is widely used worldwide to clean and produce water for drinking, wastewater treatment and industrial processes. DynaSand by Nordic Water is a sand filter with an integrated washing process that cleans the sand continuously, or if desired intermittently. DynaSand has been in the market for more than 30 years. An up-flow, moving bed filter suitable for various media Raw water enters near the top (Feed) and is led to the bottom of the tank by means of a water distributor. Suspended solids are filtered out as the raw water flows up through the media bed. As the water reaches the top of the filter, it passes over the effluent weir as filtrate and is discharged. A small portion of the filtrate is diverted through the sand washer and used for cleaning and transferring the waste solids. The filter employs a backwash rinse that is performed continually while the tank is processing water. An air lift pump, located at the centre of the media, pumps sand from the bottom of the filter up into the wash box. As the media is released into the wash box, it falls into the sand washer where the filtered solids are separated from the sand. From there, the filtrate carries the solids out as waste (Backwash). The washed sand falls onto the media bed for continued use. In most applications the filter media is natural, graded quartz sand. Normally the sand in the filter does not need replacing, but a small amount of refill may be needed on a yearly basis (abt. 0.3% of the volume).