Abstract: A filter system having a filter bed for filtering water or wastewater, where the filter bed is periodically washed between service runs by directing washing liquid and washing gas upwardly through the filter bed. The filter system includes a filter bed and at least one flume. The flume is in fluid communication with the filter bed. Preferably, the flume is configured such that no washing liquid and washing gas interface is present in the flume. The flume may be configured such that during washing of the filter bed between service runs the flume receives a washing gas and directs the washing gas upwardly through the filter bed to assist in cleaning the filter bed between service runs. The flume may further be configured such that during washing the only liquid directed from the flume to the filter bed is residual liquid that may be present in the flume from a prior service run.

Abstract: A dissolved air flotation clarifier for removing impurities from a liquid to be clarified. The dissolved air flotation clarifier includes a housing having an inlet for receiving a liquid to be clarified. The housing further includes a reaction zone, a clarification zone and an effluent channel. The reaction zone has at least one saturated water distributor and at least one dissolved air flotation nozzle operably connected to the at least one saturated water distributor to receive saturated water from the at least one saturated water distributor. The dissolved air flotation nozzle is configured to release micro-bubbles from a saturated water so that the micro-bubbles can mix with the liquid to be clarified to remove impurities from the liquid to be clarified.

Abstract: A filter system having a filter bed for filtering water or wastewater, where the filter bed is periodically washed between service runs by directing washing liquid and washing gas upwardly through the filter bed. The filter system includes a filter bed and at least one flume. The flume is in fluid communication with the filter bed. Preferably, the flume is configured such that no washing liquid and washing gas interface is present in the flume. The flume may be configured such that during washing of the filter bed between service runs the flume receives a washing gas and directs the washing gas upwardly through the filter bed to assist in cleaning the filter bed between service runs. The flume may further be configured such that during washing the only liquid directed from the flume to the filter bed is residual liquid that may be present in the flume from a prior service run.

Abstract: A filter system for filtering water and/or wastewater which includes an underdrain system having a plurality of laterals that are anchored to the floor of a filter by a hold-down assembly. Preferably, the hold-down assembly does not rely on grout or other substance that is applied in a viscous or semi-viscous state and subsequently hardened as the primary means for connecting the underdrain laterals to the floor of the filter. Preferably, the hold-down assembly includes hold-down clips that can move relative to an anchor assembly and corresponding underdrain blocks so that the hold-down clips can cooperate with any desired portion of the corresponding underdrain blocks.

Abstract: A filter system having a filter bed for filtering water or wastewater, where the filter bed is periodically washed between service runs by directing washing liquid and washing gas upwardly through the filter bed. The filter system includes a filter bed and at least one flume. The flume is in fluid communication with the filter bed. Preferably, the flume is configured such that no washing liquid and washing gas interface is present in the flume. The flume may be configured such that during washing of the filter bed between service runs the flume receives a washing gas and directs the washing gas upwardly through the filter bed to assist in cleaning the filter bed between service runs. The flume may further be configured such that during washing the only liquid directed from the flume to the filter bed is residual liquid that may be present in the flume from a prior service run.

Abstract: An apparatus for filtering water and/or wastewater including at least one underdrain lateral having a primary gas chamber and a secondary gas chamber where the secondary gas chamber serves to equalize pressure differences that may occur during the initial distribution due to velocity head changes and friction effects. Preferably, the underdrain lateral includes a plurality of chambers directing a washing fluid into the filter bed where at least one of the plurality of chambers directs a liquid and a gas simultaneously into the filter bed and at least one other chamber of the plurality of chamber directs only one of a liquid and a gas into the filter bed at the same time as that the combination of liquid and gas is directed into the filter bed.

Abstract: An apparatus for filtering water and/or wastewater including at least one underdrain lateral. The underdrain lateral is configured to receive a liquid during a filtration cycle and directs a washing fluid through a filter bed of one or more layers of filter media during a washing cycle. The filter can take any form including but not limited to an upflow clarifier, an upflow filter, a downflow clarifier, a downflow filter and a bi-flow filter. The filter media may be supported by one or more layers of gravel. Alternatively, a porous plate can be attached to the underdrain lateral in place of the gravel layers. The washing cycle can be a liquid only wash, a gas only wash, a combined liquid and gas wash or a combination of any of the aforementioned wash cycles.

Abstract: A filter system for filtering water and/or wastewater which includes an underdrain system having a plurality of laterals that are anchored to the floor of a filter by a hold-down assembly. Preferably, the hold-down assembly does not rely on grout or other substance that is applied in a viscous or semi-viscous state and subsequently hardened as the primary means for connecting the underdrain laterals to the floor of the filter. Preferably, the hold-down assembly includes hold-down clips that can move relative to an anchor assembly and corresponding underdrain blocks so that the hold-down clips can cooperate with any desired portion of the corresponding underdrain blocks.

Abstract: An underdrain system for a filter having filter media. The underdrain system preferably includes a bottom formed of concrete having a plurality of generally cone-shaped depressions formed therein. Fluid flows through the plurality of generally cone-shaped depressions during filtration and washing. The underdrain system further includes a fluid distributor operably associated with at least one of the generally cone-shaped depressions. The fluid distributor preferably has a plurality of elongated slots for distributing the flow of fluid passing into and out of the generally cone-shaped depressions. The slots are sized to prevent filter media supported by the fluid distributor from passing therethrough. An optional insert may be provided to ensure even distribution of fluid through the fluid distributor.

Abstract: A filter system for filtering water and/or wastewater including a sludge blanket clarifier for removing at least some impurities from influent. The sludge blanket clarifier includes a clarifier compartment in which a sludge blanket is to be formed to remove at least some impurities from influent directed into the clarifier compartment and through the sludge blanket. The clarifier compartment has at least one vertical sidewall extending from a bottom of the clarifier compartment to a top of the clarifier compartment. The clarifier compartment has a cross-sectional area that varies over at least a portion of a height of the clarifier compartment such that the velocity of influent just prior to entry into the sludge blanket is less than the velocity of influent just after entering the clarifier compartment.

Abstract: A system and method for uniformly distributing fluids (e.g., washing and in-service) through a filter bed of a filter. The system and method of the present invention can be used with any type of filter that uses media to remove impurities from a fluid. The filter bed can include one or more layers of media. The media can be natural (e.g., sand, gravel, anthracite, etc.) or can be fabricated (e.g., plastic). The filter media can be supported by one or more layers of gravel. Alternatively, the filter media can be supported by a porous plate or other support designed to replace the gravel layers. The present invention includes a system having a distribution member configured to uniformly distribute a fluid through a filter bed of a filter. Preferably, the distribution member can be readily installed by relatively unskilled labor in both existing filters and new filters.

Abstract: A method and apparatus for monitoring an underdrain in a filter system for filtering water or wastewater. At least one diagnostic condition relating to the performance of the underdrain is monitored to determine if the underdrain is operating in an acceptable manner.

Abstract: A filter system for filtering water and/or wastewater which includes an underdrain system having a plurality of laterals that are anchored to the floor of a filter by a hold-down assembly. Preferably, the hold-down assembly does not rely on grout or other substance that is applied in a viscous or semi-viscous state and subsequently hardened as the primary means for connecting the underdrain laterals to the floor of the filter. Preferably, the hold-down assembly includes hold-down clips that can move relative to an anchor assembly and corresponding underdrain blocks so that the hold-down clips can cooperate with any desired portion of the corresponding underdrain blocks.

Abstract: A filter system for clarifying water or wastewater. The filter system includes at least one filter compartment having at least one layer of filter media and an underdrain. The at least one layer of filter media removes impurities from the influent passing therethrough. An influent feed trough is operably associated with the filter compartment for directing influent to the filter compartment for subsequent filtration. Preferably, the influent feed trough is disposed outside of the filter compartment. Further, the influent feed trough preferably includes a bottom that is disposed above the at least one layer of filter media. A control member is provided to control the flow of liquid between the influent feed trough and the at least one filter compartment. The control member can be a weir plate or one of more chamfered surfaces. Alternatively, the control member could include both a weir plate and one or more chamfered surfaces operably associated with the weir plate.

Abstract: A flume for a filter system including at least one filter having a filter bed that is periodically washed with liquid, gas and/or a combination of liquid and gas. The flume includes a chamber having a top wall, a bottom wall, a left sidewall and a right sidewall. The chamber is adapted to receive a liquid, a gas and/or a combination of liquid and gas. Preferably, the flumes includes at least a first inner wall and a second inner wall. Each of the first inner wall and the second inner wall are preferably free of any orifices. The first inner wall is positioned relative to the second inner wall such that an open space is formed between the first inner wall and the second inner wall. The open space creates a first liquid/gas interface upstream of the first inner wall and the second inner wall and a second gas/liquid interface downstream of the first inner wall and the second inner wall when gas and liquid are present in the chamber.

Abstract: A method and apparatus for monitoring an underdrain in a filter system for filtering water or wastewater. At least one diagnostic condition relating to the performance of the underdrain is monitored to determine if the underdrain is operating in an acceptable manner.

Abstract: A system and method for uniformly distributing fluids (e.g., washing and in-service) through a filter bed of a filter. The system and method of the present invention can be used with any type of filter that uses media to remove impurities from a fluid. The filter bed can include one or more layers of media. The media can be natural (e.g., sand, gravel, anthracite, etc.) or can be fabricated (e.g., plastic). The filter media can be supported by one or more layers of gravel. Alternatively, the filter media can be supported by a porous plate or other support designed to replace the gravel layers. The present invention includes a system having a distribution member configured to uniformly distribute a fluid through a filter bed of a filter. Preferably, the distribution member can be readily installed by relatively unskilled labor in both existing filters and new filters. The distribution member is preferably configured to occupy only a small percentage of space in a distribution chamber (e.g., a flume).

Abstract: A filter having a gravel-less underdrain and a filter layer installed directly on top of the gravel-less underdrain. The filter layer is designed such that when fluid is directed through the filter layer at controlled rates a protective barrier is formed by the larger particles of the filter layer directly above the gravel-less underdrain to prevent clogging and/or structural failure of the gravel-less underdrain thereby obviating the need for one or more layers of gravel or torpedo sand.

Abstract: A fluid distribution system for directing fluids through a filter system. The fluid distribution system ensures proper distribution of fluids during the process of filtering as well as the process of washing a filter bed. The fluid distribution system may be used with numerous filter systems including but not limited to an upflow filter, a downflow filter, a combined upflow/downflow filter and/or multiple downflow filters connected in series.