Dual media filters contain two layers of media. Each layer is progressively sized in coarseness and layer depth.The media layers are stacked progressively with the coarsest and densest media, typically gravel , at the bottom and the lighter ,finer media ,at the top. A DMF is use to reduce the level of SDI (silt density index), TSS (Total suspended solids) in the incoming feed water.Suspended solids consists of small particles such as silt,clay,grit, organic matter, algae and other microorganisms, Incoming feed water that is high in suspended solids can cause a high pressure drop and reduce the effectiveness of downstream filtration equipment such as membranes, RO membranes etc.DMF is not only used as pretreatment or sometimes used for removal of turbidity coming from wastewater treatment systems.
DMF comprises of vessels available in MS, SS and FRP containing the media,provided externally with a valve and piping to direct and control flow of water during treatment and for cleaning.
The vessel is provided with inlet and outlet header lateral arrangement/bell mouth/strainer box for distribution/ uniform collection.
DMF is provided along with all piping,valves,filter media,instruments and accessories.