Multi Grade Sand Filters

Multi grade sand filters refer to the filter wherein the bed is loaded with different type of sand. Coarse particles are at the top and fine denser particles are at the bottom. As the waste water runs from top to bottom allowing deep and uniform penetration of matter and permit high filtration rate. Even after high-rate backwashing, the layers remain in their proper location in the mixed media filter bed.

Multi Grade sand filter ensures the maximum utilization of the surface area, lesser pressure drop across the filter bed and effective removal of the imopurities even under the conditions of high filtration rate compared to pressure sand filter dual media filter.