Water filtration apparatus having upflow buoyant media filter and downflow nonbuoyant media filter

A filter apparatus comprising:

• an elongated hollow tank means;
• internal wall means separating the interior of said tank means into a first upflow filter compartment and a second downflow filter compartment,
• said first compartment having an upflow filter inlet for receiving raw water to be filtered, an upflow filter outlet located above the upflow filter inlet, and defining an upflow passageway for water 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 second compartment having a downflow filter inlet, a downflow filter outlet for delivery of treated water from the filter apparatus, said downflow filter outlet being located below the downflow filter inlet, said second compartment also defining a downflow passageway for water 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 downflow outlet;
• water flow pathway means providing a water pathway from the upflow filter outlet to the downflow filter inlet,
• said first compartment having an upflow filter waste outlet at a first elevation which is above the elevation of the upflow filter outlet and said second compartment having a downflow filter waste outlet at a second elevation above the first elevation;
• and
• drain means coupled to said upflow and downflow waste outlets, said drain means including waste trough means having a first spill over wall portion positioned within said upflow filter compartment at the first elevation, said waste trough means also including a second spill over wall portion positioned within said downflow filter compartment at the second elevation, said upflow filter waste outlet comprising said first spill over wall portion and said downflow filter waste outlet comprising said second spill over wall portion, said waste trough means extending from end to end of said tank, said waste trough means comprising a channel having first and second spaced apart upright side walls and a base, the side walls of said channel stepping up where the channel crosses the internal wall means such that the portions of the first and second side walls of the channel at the downflow filter vessel side of the internal wall are at the second elevation and the portions of the first and second side walls of the trough at the upflow filter vessel side of the internal wall are at the first elevation;
• means for cleaning said buoyant filtration bed comprising means for selectively interrupting the flow of treated water from the downflow filter outlet while permitting the flow of influent water to the upflow filter inlet, means for injecting air into the first compartment to expand and scour the buoyant filtration bed, such that water within the first compartment rises and flows through said upflow filter waste outlet to flush deposited waste materials from said buoyant filtration bed to said drain means, partially treated water within the second compartment being conserved due to the positioning of the downflow filter outlet at the second elevation above the elevation of the upflow filter waste outlet;
• and
• means for cleaning said nonbuoyant filtration bed comprising means for selectively delivering backflush water upwardly through the nonbuoyant media filtration bed, such that water within the second compartment rises and flows through said downflow filter waste outlet to flush deposited waste materials from said nonbuoyant filtration bed to said drain means.

A filter apparatus comprising:

• an elongated hollow tank means;
• internal wall means separating the interior of said tank means into a first upflow filter compartment and a second downflow filter compartment,
• said first compartment having an upflow filter inlet for receiving raw water to be filtered, an upflow filter outlet located above the upflow filter inlet, and defining an upflow passageway for water 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 second compartment having a downflow filter inlet, a downflow filter outlet for delivery of treated water from the filter apparatus, said downflow filter outlet being located below the downflow filter inlet, said second compartment also defining a downflow passageway for water 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 downflow outlet;
• water flow pathway means providing a water pathway from the upflow filter outlet to the downflow filter inlet,
• said first compartment having an upflow filter waste outlet at a first elevation which is above the elevation of the upflow filter outlet and said second compartment having a downflow filter waste outlet at a second elevation above the first elevation,
• the upper edge of the internal wall means being at an elevation above the second elevation and at least one wall opening being defined through an upper region of the internal wall means at an elevation below the first elevation such that the water flow pathway means passes through the wall opening of the internal wall means;
• a first weir plate means positioned to cover a lower portion of the wall opening and a second weir plate means positioned to cover an upper portion of the wall opening;
• means for adjustably mounting said first and second weir plate means to said internal wall such that said first and second weir plate means are movable to adjust the size of the wall opening;
• drain means coupled to said upflow and downflow waste outlets, said drain means including waste trough means having a first spill over wall portion positioned within said upflow filter compartment at the first elevation, said waste trough means also including a second spill over wall portion positioned within said downflow filter compartment at the second elevation, said upflow filter waste outlet comprising said first spill over wall portion and said downflow filter waste outlet comprising said second spill over wall portion;
• means for cleaning said buoyant filtration bed comprising means for selectively interrupting the flow of treated water from the downflow filter outlet while permitting the flow of influent water to the upflow filter inlet, means for injecting air into the first compartment to expand and scour the buoyant filtration bed, such that water within the first compartment rises and flows through said upflow filter waste outlet to flush deposited waste materials from said buoyant filtration bed to said drain means, partially treated water within the second compartment being conserved due to the positioning of the downflow filter outlet at the second elevation above the elevation of the upflow filter waste outlet;
• and
• means for cleaning said nonbuoyant filtration bed comprising means for selectively delivering backflush water upwardly through the nonbuoyant media filtration bed, such that water within the second compartment rises and flows through said downflow filter waste outlet to flush deposited waste materials from said nonbuoyant filtration bed to said drain means.

A filter apparatus comprising:

• an elongated hollow tank means;
• internal wall means separating the interior of said tank means into a first upflow filter compartment and a second downflow filter compartment, said internal wall means defining at least two spaced apart water flow openings through an upper region thereof;
• said first compartment having an upflow filter inlet located below the water flow openings for receiving raw water to be filtered, and defining an upflow passageway for water from the upflow inlet to the water flow openings;
• 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 water flow openings;
• said second compartment having a downflow filter outlet for delivery of treated water from the filter apparatus, said downflow filter outlet being located below the water flow openings, said second compartment also defining a downflow passageway for water from the water flow openings 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 water flow openings and downflow outlet;
• drain trough means centrally positioned within an upper region of said tank and extending lengthwise across the internal wall means and from end to end of said tank, said drain trough means having a waste water outlet, first and second spaced apart upright side walls, and a base, the upper edges of the side walls at the upflow compartment side of the internal wall means being at a first elevation which is above the elevation of the water flow openings, the upper edges of the side walls located at the downflow compartment side of the internal wall means being at a second elevation which is above the first elevation, the upper edge of the internal wall means being above the second elevation;
• means for cleaning said buoyant filtration bed comprising means for selectively interrupting the flow of treated water from the downflow filter outlet while permitting the flow of influent water to the upflow filter inlet, means for injecting air into the first compartment to expand and scour the buoyant filtration bed, such that water within the first compartment rises to the first elevation and flows over the trough side walls to the trough means to flush deposited waste materials from said buoyant filtration bed to said drain means, partially treated water within the second compartment being conserved because the water level within the second compartment is at an elevation below the second elevation;
• and
• means for cleaning said nonbuoyant filtration bed comprising means for selectively delivering backflush water upwardly through the nonbuoyant media filtration bed, such that water within the second compartment rises to the second elevation and flows over the trough side walls to the trough means to flush deposited waste materials from said nonbuoyant filtration bed to said drain means.

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.