Abstract: A backwash distribution apparatus for a filter having a filter tank and a plurality of underdrain laterals includes a first and second separator device positioned in a common main conduit to define first and second auxiliary flumes. The first and second auxiliary flumes are in fluid communication with the common main conduit and the underdrain laterals. The first separator device has at least one flume liquid metering orifice preferably located near the bottom of the first separator device so that it may be below a gas liquid interface in the first auxiliary flume. The second separator device has either a weir edge or a plurality of metering orifices (or both) for passing backwash liquid from the common main conduit into the second auxiliary flume.

Abstract: An underdrain flume plate for use in a filter including at least one central opening having an upstanding flange to interface with a cut-out in an underdrain lateral to form a passageway for connecting the lateral to the flume. The flume plate may also include at least one raised channel at each end of the plate with a solid or cut-away top surface, and/or holes and/or slots for connection of the flume plate to anchor rods and may be configured to overlap one another when placed side by side. The present invention also includes a method of installing underdrain laterals in a filter, including arranging a grid of anchor rods on a filter floor such that anchor rods are provided on both sides of the flume, and providing at least one underdrain flume plate adapted for attachment to the anchor rods such that the flume plate covers the flume.

Abstract: A media retainer assembly for retaining filter media in a filter assembly includes a top plate for supporting the filter media, the top plate having a top surface, a bottom surface and a plurality of openings extending therethrough; a bottom plate having a top surface and a plurality of openings extending therethrough; and scouring media, the scouring media being adapted to abrade the surfaces of the top and bottom plates. The top plate is connected to the bottom plate such that the top surface of the bottom plate is spaced from the bottom surface of the top plate to define at least one chamber between the top plate and the bottom plate. The top surface of the top plate is in fluid communication with the chamber via the openings in the top plate. The scouring media is supported by the bottom plate within the at least one chamber.

Abstract: The present invention is related to a method and system for cleaning a media support structure in a filter cell in a liquid filter system, wherein a cleaning solution does not significantly enter a filter media zone. The method comprises supplying a cleaning solution to a filter cell to a level sufficient to submerge the media support structure, but not to significantly enter the filter media zone. Additionally, the cleaning solution level is monitored to ensure the cleaning solution does not significantly enter the filter media zone. Alternatively, the cleaning solution may be continuously recirculated and reintroduced to the filter cell during the cleaning operation.

Abstract: An adjustable anchor rod arrangement for use with an underdrain system that includes the a pair of spaced apart legs and an elongated member adjustably attached to the legs, wherein the legs are adjustable along a longitudinal axis of the elongated member and the elongated member is adjustable along a longitudinal axis of the legs.

Abstract: A backwash distribution apparatus for a filter having a filter tank and a plurality of underdrain laterals includes a first and second separator device positioned in a common main conduit to define first and second auxiliary flumes. The first and second auxiliary flumes are in fluid communication with the common main conduit and the underdrain laterals. The first separator device has at least one flume liquid metering orifice preferably located near the bottom of the first separator device so that it may be below a gas liquid interface in the first auxiliary flume. The second separator device has either a weir edge or a plurality of metering orifices (or both) for passing backwash liquid from the common main conduit into the second auxiliary flume.