Selected Products for Underdrains

Nozzle Underdrains

Underdrain is amonolithic, cast-in-place, open plenumsystem used in concrete gravity filters. The design allows water, air followed by water, or simultaneous air and water to be used as a backwash process. The filter nozzles are designed for either direct media retaining or gravel support bed systems. The concrete for the filter floor and support piers is poured at one time to provide strength and installation cost savings

High Solids

High solids Commonly used as a drinking water plant, this packaged filtration system also works well as a Title 22 Wastewater Reclamation Filter. It consists of an Adsorption clarifier followed by a multi-media sand filter. It is available in sizes ranging from 50-gpm to 1400-gpm, or multiplies thereof. In the first stage, chemically dosed secondary effluent enters the Adsorption Clarifier, where an up-flow treatment process using a buoyant plastic media combines flocculation and clarification in a single step. The clarified water overflows into a trough and finally into the multi-media sand filter. The key behind this system is the Adsorption clarifier, which removes in excess of 75% of the incoming turbidity. The remaining conditioned solids are then easily captured in the multimedia sand filter. This kind of filtration system consistently produces a high quality effluent, and is particularly forgiving against upset conditions in the upstream biological process.

Gravity Filters

Each Filter has four granular media filter cells positioned around a central distributor column. Circular weirs evenly divide the water to each operating cell for filtration. The water then flows down through the filter media and through the underdrain and out into an effluent chamber and over the effluent weirs. During backwash, the effluent weirs provide backwash head to clean the filters with water from in-service cells. Backwash waste is discharged from the bottom of the distribution column.