Continuous Deep Bed Filtration

In a continuous sand filter the water passes the filter bed in upward direction. The flow of water through a porous medium results in a hydraulic pressure drop. We call this pressure drop the filter bed resistance.

In a continuous sand filter the water passes the filter bed in upward direction. The flow of water through a porous medium results in a hydraulic pressure drop. We call this pressure drop the filter bed resistance.

In a continuous sand filter the water passes the filter bed in upward direction. The flow of water through a porous medium results in a hydraulic pressure drop. We call this pressure drop the filter bed resistance.

Filter sand is the most common filter media used in deep bed filtration systems. The reason is that it is the perfect filter media: inert, resistant to abrasion, free of impurities, available in a uniform grain-size distribution and relatively cheap.

In a continuous filter, the filtration process takes place simultaneously with the washing of the filter media. The washing process consists of two principles: the highly turbulent airlift transport of dirty sand from the bottom of the filter to the top of the filter and the final separation of sand grains and solids.