Abstract: An underdrain system having a bottom formed of concrete. The concrete bottom includes a plurality of generally cone shaped depressions formed therein. A porous plate is operably associated with at least one of the generally cone shaped depressions. The underdrain system further includes an insert having at least one distribution orifice for distributing the flow. The insert is positioned beneath the porous plate and at least partially within the at least one generally cone shaped depression. The insert insures thorough distribution of any fluid passing through the porous plate, i.e., the fluid is evenly distributed over the entire surface area of the porous plate. In an alternative embodiment, an underdrain system is provided including a bottom formed of concrete. The bottom has a plurality of generally cone shaped depressions formed therein. A porous plate is operably associated with at least one of the generally cone shaped depressions.

Abstract: A modular filter system and a method of repairing and/or replacing one or more components thereof. The modular filter system includes a traveling backwash hood assembly and a plurality of filter cells having media contained therein. The traveling backwash hood assembly includes a hood and a baffle assembly. Preferably, the hood has at least one opening formed therein and a cover plate operably associated with the at least one opening. The baffle assembly includes a plurality of baffles for directing the flow of fluid. The baffle assembly is detachably connected to the hood to permit the baffle assembly to be moved relative to the hood to permit an individual to readily gain access to the baffle assembly to repair or replace one or more components thereof.

Abstract: A fluid grid system for use with filter systems and other fluid handling devices. Preferably, the fluid grid system is designed such that components thereof may be readily connected to each other without the use of clips or other fasteners. Further, the fluid grid system preferably allows components to be installed and held in place or removed merely by applying a sufficient force to a portion of the component.

Abstract: A modular filter system and a method of repairing and/or replacing one or more components thereof. The modular filter system includes a traveling backwash hood assembly and a plurality of filter cells having media contained therein. The traveling backwash hood assembly includes a hood and a baffle assembly. Preferably, the hood has at least one opening formed therein and a cover plate operably associated with the at least one opening. The baffle assembly includes a plurality of baffles for directing the flow of fluid. The baffle assembly is detachably connected to the hood to permit the baffle assembly to be moved relative to the hood to permit an individual to readily gain access to the baffle assembly to repair or replace one or more components thereof.

Abstract: An improved underdrain block for an underdrain system supporting a filter media bed in a liquid filtration system is provided. The underdrain blocks are preferably made of an extrudable polymeric material that is extruded in relatively long sections to provide light weight, strong, easily manufactured underdrain systems having a lower profile than prior art underdrain blocks. The underdrain block comprises an upper wall, side walls, a lower wall, at least one lateral member between the upper wall and the lower wall, at least two chambers within the underdrain block, each chamber being defined by the lateral member, a plurality of upper orifices in the upper wall of the underdrain block, and a plurality of internal orifices in the lateral member. The underdrain block is substantially greater in longitudinal length than a longitudinal distance between the upper orifices.

Abstract: An underdrain system having a bottom formed of concrete. The concrete bottom includes a plurality of depressions formed therein. A porous plate is operably associated with at least one of the depressions. An anchor assembly is provided for anchoring the porous plate to the concrete bottom in an efficient and cost effective manner. Preferably, the anchor assembly permits the porous plate to be readily replaced. An optional insert may be used to enhance the distribution of the flow of fluid through the porous plate.

Abstract: A filter system employing a modular filter and at least one high rate pre-treatment system for expeditiously and effectively filtering water. The modular filter includes a reservoir housing for containing fluid. A plurality of filter cells are disposed in the reservoir housing for filtering influent passed through the reservoir housing. Each of the plurality of filter cells has at least one layer of media. A moveable backwash assembly is provided for sequentially backwashing the plurality of filter cells. The backwashing procedure is performed on the modular filter system such that while one of the plurality of cells is being backwashed the remaining cells are filtering pre-treated influent processed by the pre-treatment system. The pre-treatment system preferably has a footprint considerably smaller than the footprint of the modular filter.

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.

Abstract: A modular filter system having a mechanism for performing a filter to waste step on the last cell of a multi-cell system following backwashing. A method of operating a modular filter system in which a filter to waste step is performed on the last cell of a multi-cell system after backwashing.

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.

Abstract: An underdrain system having a bottom formed of concrete. The concrete bottom includes a plurality of generally cone shaped depressions formed therein. A porous plate is operably associated with at least one of the generally cone shaped depressions. The underdrain system further includes an insert having at least one distribution orifice for distributing the flow. The insert is positioned beneath the porous plate and at least partially within the at least one generally cone shaped depression. The insert insures thorough distribution of any fluid passing through the porous plate, i.e., the fluid is evenly distributed over the entire surface area of the porous plate. In an alternative embodiment, an underdrain system is provided including a bottom formed of concrete. The bottom has a plurality of generally cone shaped depressions formed therein. A porous plate is operably associated with at least one of the generally cone shaped depressions.

Abstract: A modular filter system having a mechanism for performing a filter to waste step on the last cell of a multi-cell system following backwashing. A method of operating a modular filter system in which a filter to waste step is performed on the last cell of a multi-cell system after backwashing.

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.

Abstract: Sludge collection and removal systems are disclosed. The present invention provides methods and apparatus that include piping system of headers and laterals selectively provided with flow from a central point so that sludge can be removed from areas where it accumulates most rapidly. The adaptable nature of the piping system additionally permits the number of collection laterals and orifices to be varied to suit the sludge accumulation characteristics of the sludge basin. Additionally, improved multiple port valves are disclosed that permit the selective connection of the flow among sections in preferred embodiments of the sludge collection systems.

Abstract: An improved underdrain block for an underdrain system supporting a filter media bed in a liquid filtration system is provided. The underdrain blocks are preferably made of an extrudable polymeric material that is extruded in relatively long sections to provide light weight, strong, easily manufactured underdrain systems having a lower profile than prior art underdrain blocks. The underdrain block comprises an upper wall, side walls, a lower wall, at least one lateral member between the upper wall and the lower wall, at least two chambers within the underdrain block, each chamber being defined by the lateral member, a plurality of upper orifices in the upper wall of the underdrain block, and a plurality of internal orifices in the lateral member. The underdrain block is substantially greater in longitudinal length than a longitudinal distance between the upper orifices.

Abstract: A differential pressure monitor measures the pressure at a plurality of heights in a filter bed. A preferred embodiment of the monitor comprises an elongated body, a plurality of pressure sensors located on the elongated body for obtaining the pressure readings, a control apparatus for determining differential pressures from the pressure readings, each differential pressure being the difference in pressure between pressures measured at two different heights in the filter bed, and transmission apparatus to transmit the pressure readings from the pressure sensors to the control apparatus. Methods of monitoring and controlling the performance of a filter bed during filtration and during backwashing also are provided. Two such methods include measuring turbidity levels in a filter bed and obtaining water samples from a filter bed.

Abstract: Sludge collection and removal systems are disclosed. The present invention provides methods and apparatus that include piping system of headers and laterals selectively provided with flow from a central point so that sludge can be removed from areas where it accumulates most rapidly. The adaptable nature of the piping system additionally permits the number of collection laterals and orifices to be varied to suit the sludge accumulation characteristics of the sludge basin. Additionally, improved multiple port valves are disclosed that permit the selective connection of the flow among sections in preferred embodiments of the sludge collection systems.

Abstract: A differential pressure monitor measures the pressure at a plurality of heights in a filter bed. A preferred embodiment of the monitor comprises an elongated body, a plurality of pressure sensors located on the elongated body for obtaining the pressure readings, a control means for determining differential pressures from the pressure readings, each differential pressure being the difference in pressure between pressures measured at two different heights in the filter bed, and transmission means to transmit the pressure readings from the pressure sensors to the control means. Methods of monitoring and controlling the performance of a filter bed during filtration and during backwashing also are provided. Two such methods include measuring turbidity levels in a filter bed and obtaining water samples from a filter bed.

Abstract: Sludge collection and removal systems are disclosed. The present invention provides methods and apparatus that include piping system of headers and laterals selectively provided with flow from a central point so that sludge can be removed from areas where it accumulates most rapidly. The adaptable nature of the piping system additionally permits the number of collection laterals and orifices to be varied to suit the sludge accumulation characteristics of the sludge basin. Additionally, improved multiple port valves are disclosed that permit the selective connection of the flow among sections in preferred embodiments of the sludge collection systems.

Abstract: Air grid systems for distributing a gas within treatment systems such as underdrain filters and contact clarifiers is disclosed. The air grid is supported from above so that it can be lowered into position and thus modified or repaired. Additionally, this feature permits retrofitting an air grid into an existing system, such as an underdrain filter, in which the bed of media overlies the underdrain is not upset by the installation. Thus, methods of installing or retrofitting air grid systems are also disclosed. In another aspect of the present invention, the air grid is comprised of an air manifold connected to air laterals by a spreader conduit that is inserted through a smooth bore in the walls of the manifold, thereby providing a simple and easy to manufacture structure that avoids problems found in prior art components.