A filter device having a filter housing (1) for a filter medium formed from fibrous material (2), wherein the filter housing (1) has an inlet for liquid to be filtered and a suction opening (8) for the filtered liquid, in which it is proposed that the filter housing (1) is divided by means of an internal partition plate (4), which is provided with passage openings (11) for the liquid, into a suction-side prechamber (5) and an inlet-side filter chamber (6), wherein the prechamber (5) has a cross section which is widened in comparison to the suction opening (8) or widens from the suction opening (8) to the partition plate (4), and the filter chamber (6) is filled using the filter medium formed from fibrous material (2) and has the inlet. The filter chamber (6) enables a reliable and dimensionally stable receptacle for the fibrous material (2), wherein the risk of compression and compaction of the filter medium is reduced with the aid of the embodiment according to the invention.

A filtration system includes a plurality of underdrain blocks arranged in a side-by-side configuration so as to define a gap therebetween, the gap configured to receive grout. Each underdrain block includes a top wall, a bottom wall, and a plurality of side walls connecting the top wall and the bottom wall. A grout bridge is arranged in the gap between adjacent underdrain blocks so as to form a grout seal between the grout bridge and adjacent side walls of the adjacent underdrain blocks. The adjacent sidewalls each include a rib, each rib defining a slot. The grout bridge is arranged in adjacent slots of the adjacent sidewalls of the adjacent underdrain blocks. A method of arranging a filtration system and a grout bridge are also disclosed.

A filtration system includes a plurality of underdrain blocks arranged in a side-by-side configuration so as to define a gap therebetween, the gap configured to receive grout. Each underdrain block includes a top wall, a bottom wall, and a plurality of side walls connecting the top wall and the bottom wall. A grout bridge is arranged in the gap between adjacent underdrain blocks so as to form a grout seal between the grout bridge and adjacent side walls of the adjacent underdrain blocks. The adjacent sidewalls each include a rib, each rib defining a slot. The grout bridge is arranged in adjacent slots of the adjacent sidewalls of the adjacent underdrain blocks. A method of arranging a filtration system and a grout bridge are also disclosed.

An underdrain assembly in a wastewater filtration unit for providing even distribution of liquid and gas during filter backwashing operations and the uniform collection of filtered water during the normal operation of the filtration unit is provided. The underdrain assembly is provided with a flat, concrete plate with a perimeter matching the shape of the filtration unit. The concrete plate has a plurality of holes with individual PEX tubes in each hole extending from the concrete plate top surface through and protruding below the plate.

An underdrain assembly in a wastewater filtration unit for providing even distribution of liquid and gas during filter backwashing operations and the uniform collection of filtered water during the normal operation of the filtration unit is provided. The underdrain assembly is provided with a flat, concrete plate with a perimeter matching the shape of the filtration unit. The concrete plate has a plurality of holes with individual PEX tubes in each hole extending from the concrete plate top surface through and protruding below the plate.

A sorter for sorting a mixture having at least a first material with a first density from a second material with a second density different than the first density, comprising a container adapted to receive the mixture, a bed forming a base of the container provided with a series of openings extending from a bottom of the base to a top of the base, a granular layer positioned on the bed, and an air supply line providing air to the openings. In operation, the mixture is positioned above the granular layer, and the air supply supplies air to the granular layer at a rate sufficient to allow the sorting of the first material into a separate portion of the container from the second material.

A sorter for sorting a mixture having at least a first material with a first density from a second material with a second density different than the first density, comprising a container adapted to receive the mixture, a bed forming a base of the container provided with a series of openings extending from a bottom of the base to a top of the base, a granular layer positioned on the bed, and an air supply line providing air to the openings. In operation, the mixture is positioned above the granular layer, and the air supply supplies air to the granular layer at a rate sufficient to allow the sorting of the first material into a separate portion of the container from the second material.

An apparatus for removing impurities from water and/or wastewater and a method of installing a fluid distribution system in the apparatus. In the most preferred form of the invention, the fluid distribution system is an air scour system for directing air through the filter bed to assist in cleaning of the filter bed to remove impurities trapped in the filter bed during a service run. In the most preferred form, the method of installing the fluid distribution system in the filter bed is performed by imparting a force to the filter bed to permit the fluid distribution system to be installed in the filter bed without removing media. The fluid distribution system is preferably configured to permit the fluid distribution system to be readily installed in the filter bed and at an optimum orientation.

An apparatus for removing impurities from water and/or wastewater and a method of installing a fluid distribution system in the apparatus. In the most preferred form of the invention, the fluid distribution system is an air scour system for directing air through the filter bed to assist in cleaning of the filter bed to remove impurities trapped in the filter bed during a service run. In the most preferred form, the method of installing the fluid distribution system in the filter bed is performed by imparting a force to the filter bed to permit the fluid distribution system to be installed in the filter bed without removing media. The fluid distribution system is preferably configured to permit the fluid distribution system to be readily installed in the filter bed and at an optimum orientation.

An underdrain apparatus and a method for manufacturing such apparatus are provided. The underdrain apparatus can be extruded in long sections as a unitary part. The underdrain apparatus may be extruded in various sizes, shapes, and materials. Further, the underdrain apparatus may include a passageway for transporting water to and from the filter media and/or air to the filter media. In some embodiments, apertures are formed in the underdrain apparatus during an extrusion process to provide a path between the passageway and the filter media.