US Water backwashing filters are water filters that clean themselves by periodically rinsing away impurities they have filtered from the water.
A backwashing water filter may look like a water softener but it is entirely different. Softeners work on the principle of ion exchange and backwashing filters rely greatly upon simple mechanical filtration.
A backwashing filter is a simple device that consists of a large tank called a media tank that is filled with a filtering medium such as the following:
Granular Activated Carbon
Catalytic Absorbative Carbon
Zeo-Right Sediment Media
Calcite or Manganese Oxide
Backwashing Filter Operation
Water enters the top of the tank through a control valve and passes downward through the media, which removes impurities and holds them. Some media, such as Greensand Plus and Catalytic Carbon simply facilitate oxidation, while filtering precipitate in the process. Calcite, dissolves and in the process increases the pH of acidic water. The treated water then enters a distributor at the bottom of the media tank, passes upward through the tube and exits the filter through the control valve.
When the filter media is saturated with contaminants, the control valve initiates a backwash. The backwash is an operation in which water passes backward through the filter at a rapid rate. It enters the tank at the bottom distributor assembly, then passes upward through the filter media to the drain - all of this operation is controlled by the control valve. The rapid backwash in an upward flow, washes away impurities, fluffs, re-classifies and resettles the media bed, preparing it for another filtering cycle.