| 摘要 |
In a filtering system (10) a liquid containing suspended pollutants is pumped into a top inlet (14) of a filter vessel (20) containing a granular filter media (22) formed in a bed (24). As the liquid flows through the bed (24), the pollutants are entrapped by the media allowing the liquid to be discharged through a bottom outlet (30) in a purified condition. Upon the filter media (22) becoming saturated with the pollutants, the media is rejuvenated in a two stage procedure. During the first stage, the media (22), entrapped polutants and liquid are formed into slurry by pumping such at a higher rate in a closed loop path so that the pollutants and filter media are separated. In the second stage, the pumping rate is reduced allowing the filter media (22) to reaccumulate in the vessel (20) while the entrapped pollutants and liquid continue to circulate and be selectively drawn off through a top outlet (46) in the vessel. |
