초록 ▼

A filter underdrain apparatus comprises plate means forming a plurality of horizontal distributor conduits, the conduits being in juxtaposed, laterally-spaced relationship and constructed and arranged to defined alternating conduits and troughs of a filter underdrain. At least some of the horizontal

A filter underdrain apparatus comprises plate means forming a plurality of horizontal distributor conduits, the conduits being in juxtaposed, laterally-spaced relationship and constructed and arranged to defined alternating conduits and troughs of a filter underdrain. At least some of the horizontal distributor conduits include interior partitions extending along such conduits and dividing the interior of each such conduit into a liquid passage and a gas passage. Liquid metering orifices communicate the interior of the liquid passage with the exterior of the distributor conduit for substantially evenly distributing backwash liquid flows from the liquid passage and for passing filtered liquid flows into the liquid passage. Gas metering orifices communicate the interior of the gas passage with the exterior of the distributor conduit for substantially evenly distributing gas from the gas passage when connected with a pressurized gas source. A screen arrangement may be included to screen the liquid and gas orifices from filter media exterior of the distributor conduits, and the screen may comprise perforate grids. The perforate grids may extend across the troughs between adjacent distributor conduits.

대표청구항 ▼

A filter underdrain apparatus comprising plate means of generally V-shaped cross sections, a plurality of said plate means being assembled in juxtaposed relationship to define alternating V-shaped troughs and inverted V-shaped arches, perforate grid means for extending across each trough proximate t

A filter underdrain apparatus comprising plate means of generally V-shaped cross sections, a plurality of said plate means being assembled in juxtaposed relationship to define alternating V-shaped troughs and inverted V-shaped arches, perforate grid means for extending across each trough proximate the top thereof between adjacent arches for supporting filter media; a first row of air vent holes extending longitudinally of said plate means proximate the top of said arches, a row of water inlet/outlet means extending longitudinally of said plate means beneath said grid means proximate the bottom of each side of each said arch, and partition means in each said arch between said air vent holes and said water inlet/outlet, said partition means dividing the interior of the arch into a lower water passage and an upper air passage.