초록 ▼

A water filtration system is provided by an upflow filter vessel containing a buoyant filter media in series with a downstream downflow filter vessel containing a nonbuoyant filter media. The buoyant media filter vessel and nonbuoyant media filter vessel comprise two compartments of a common tank, s

A water filtration system is provided by an upflow filter vessel containing a buoyant filter media in series with a downstream downflow filter vessel containing a nonbuoyant filter media. The buoyant media filter vessel and nonbuoyant media filter vessel comprise two compartments of a common tank, separated by a central wall. Water from the upflow filter vessel passes over the top of this wall, or through one or more openings in this wall, to the downflow filter vessel. A common waste trough extends from one end of the tank to the other. Weir plates are fastened to the upper edges of this trough such that the trough steps upwardly in elevation at the central wall. Waste materials from the upflow filter vessel pass over the lower of these weir plates and into the waste trough during cleaning of the buoyant media filter. In contrast, waste materials from the nonbuoyant media filter flow over the upper weir plates and into the trough during cleaning of this latter filter. An adjustment mechanism, such as adjustable weir plates, are provided for adjusting the size of the openings through the central wall to minimize the passage of waste materials from the upflow filter vessel through the opening to the downflow filter vessel during cleaning of the buoyant media filter bed. In addition, a gate may be provided for selectively closing the openings during cleaning of the buoyant media filter to further minimize the pass through of waste material during cleaning of the buoyant media filter.

대표청구항 ▼

A filter apparatus comprising: a hollow elongated upright tank; an internal upright wall separating the interior of the tank into an upflow filter vessel and a downflow filter vessel, said upflow filter vessel having an upflow filter inlet, an upflow filter outlet located above the upflow filter inl

A filter apparatus comprising: a hollow elongated upright tank; an internal upright wall separating the interior of the tank into an upflow filter vessel and a downflow filter vessel, said upflow filter vessel having an upflow filter inlet, an upflow filter outlet located above the upflow filter inlet, and defining an upflow passageway for liquid from the upflow inlet to the upflow outlet; an amount of buoyant particulate filter media in the upflow filter vessel sufficient to form a buoyant filtration bed in the upflow passageway between the upflow inlet and upflow outlet, said downflow filter vessel having a downflow filter inlet coupled to said upflow filter outlet, a downflow filter outlet located below the downflow filter inlet, and defining a downflow passageway for liquid from the downflow inlet to the downflow outlet; an amount of nonbuoyant particulate filter media in the downflow filter vessel sufficient to form a nonbuoyant filtration bed in the downflow passageway between the downflow inlet and outlet, said upflow filter vessel having an upflow filter vessel waste outlet at a first elevation which is above the elevation of the upflow filter outlet, said downflow filter vessel having a downflow filter vessel waste outlet at a second elevation which is above the elevation of the upflow filter vessel waste outlet; and drain means coupled to said upflow and downflow filter vessel waste outlets, said drain means comprising a waste trough having upright first and second side walls and a base, said waste trough extending lengthwise within an upper region of said tank so as to position at least a portion of said trough within the upflow filter vessel and at least a portion of said trough within the downflow filter vessel, at least a portion of one of said side walls comprising a first spill over wall and being positioned within the upflow filter vessel at the first elevation so as to comprise the upflow filter vessel waste outlet, at least a portion of one of said side walls comprising a second spill over wall and being positioned within the downflow filter vessel at the second elevation so as to comprise the downflow filter vessel waste outlet. A method of filtration of water comprising: providing an upflow filter vessel that has a. an upflow filter outlet, and b. an upflow filter vessel distribution outlet at an elevation which is above the elevation of the upflow filter outlet; forming a buoyant filtration bed by positioning an amount of buoyant particulate filter media in the upflow filter vessel; providing a downflow filter vessel that has a. a downflow filter inlet coupled to the upflow filter outlet, b. a downflow filter outlet, and c. a downflow vessel distribution outlet; forming a nonbuoyant filtration bed by positioning an amount of nonbuoyant particulate filter media in the downflow filter vessel; providing a distribution vessel which communicates with the distribution outlets; cleaning an influent stream of water by flowing the water upwardly through the buoyant filtration bed and then flowing the water downwardly through the nonbuoyant filtration bed; cleaning the upflow filter vessel by selectively closing the downflow filter outlet to maintain the level of liquid in the downflow filter vessel, expanding the buoyant filtration bed to release solids trapped in the buoyant filtration bed during filtration, and flowing buoyant filtration bed cleaning water upwardly through the buoyant filtration bed to carry the released solids away from the upflow filter vessel via the upflow filter vessel distribution outlet, and the distribution vessel; cleaning the downflow filter vessel by selectively expanding the nonbuoyant filtration bed to release solids trapped in the nonbuoyant filtration bed during filtration, and flowing nonbuoyant filtration bed cleaning water upwardly through the nonbuoyant filtration bed to carry the released solids away from the downflow filter vessel via the downflow filter vessel distribution outlet, and the distribution vessel.