A nozzle is disclosed for use within a filter for inputting a jetting stream into the filter media to clean the filter media. The nozzle comprises an inlet for communication with a jetting stream source, and a plurality of plates stacked parallel and abutting one another. The plurality of plates comprises at least a top plate and a bottom plate, one of the plates having an aperture through the center thereof for receiving the jetting stream, wherein between adjacent plates at least one space is provided extending from the outside edge of the plates to the interior of plates and in fluid communication with the aperture for channelling the jetting stream radially outward from and substantially parallel with the longitudinal plane of the plate.

A multi-layer media bed filter with an increasing density of media from the finest media on the top to the coarsest media on the bottom is backwashed using air without significantly disrupting stratification of the media layers. When the air is stopped, the contaminants in the liquid above the finest media that were removed by the airflow are flushed away either with liquid injected above the media or by a liquid flow through the media that does not remove the finest media. The amount of contaminants that remain in the finest media with the stratification-maintaining air backwash is significantly less than when using liquid backwash alone, whether the liquid backwash uses a flow rate sufficient to suspend the micromedia or below a suspending flow rate.

A multi-layer media bed filter with an increasing density of media from the finest media on the top to the coarsest media on the bottom is backwashed using air without significantly disrupting stratification of the media layers. When the air is stopped, the contaminants in the liquid above the finest media that were removed by the airflow are flushed away either with liquid injected above the media or by a liquid flow through the media that does not remove the finest media. The amount of contaminants that remain in the finest media with the stratification-maintaining air backwash is significantly less than when using liquid backwash alone, whether the liquid backwash uses a flow rate sufficient to suspend the micromedia or below a suspending flow rate.

In this infiltration intake system, a structural body integrally includes a waster discharge direction control portion controlling a discharge direction for wastewater discharged from a filter toward a raw water side at a backwash time with a backwash mechanism portion in a prescribed wastewater discharge direction.

The invention relates to a fluid distributor (9,10)for a column (1)comprising at least one cell (2) containing a bed of particles (3), the fluid distributor (9, 10) comprising: - a floor (11, 21) comprising at least one injection point (15, 25) providing a fluidic connection on either side thereof; - a layer of resistive medium (12, 22) fixed on one face of the floor(11, 21), the resistive medium being permeable to the fluid; - a spacing device (13, 23) inserted between the floor (11, 21) and the layer of reistive medium (12, 22) and maintaining a space for the circulation of the fluid between the floor (11, 21) and the layer of resistive medium (12, 22). The invention also relates to a column, in particular a chromatography column, provided with this fluid distributor.

A device and method for increasing the area available for passing contaminated stormwater through a granular media. The device comprises of one or more hollow elements that are made of degradable material and are of predetermined size and shape. The increased area available for flow is obtained by introducing a first media into predetermined areas of the device, introducing a second media into predetermined areas that are adjacent to areas containing the first media, and allowing the elements to degrade to bring about contact between the first and second media.

An underdrain system for a media pressure vessel has a set of removable pipe sections located between an external header and the bottom of a vessel. Septa extend upwards from the removable pipe sections into the vessel. The header is attached to the bottoms of the removable pipe sections. Each pipe section, and its associated septum, may be removed individually. To clean the vessel, after media is removed from the vessel the pipe sections are removed sequentially while the header remains otherwise attached to the vessel. While a pipe section is removed, its associated septum is removed so that solids can be removed from the annulus between the septum and the vessel. In this way, media can be cleaned from the annuli without moving the external header or entering the vessel.

A media tank includes a housing having a first housing portion coupled to a second housing portion at an interface between the first and second housing portions, the first and second housing portions collectively defining an interior volume of the housing, and a divider positioned within the interior volume of the housing at the interface between the first and second housing portions to separate the interior volume into a first chamber at least partially defined by the first housing portion and the divider and a second chamber at least partially defined by the second housing portion and the divider. The first housing portion is coupled to the second housing portion via a friction weld at the interface. An annular gap is provided between the divider and the first housing portion. Flash from the friction weld is received within the annular gap.

A media tank includes a housing having a first housing portion coupled to a second housing portion at an interface between the first and second housing portions, the first and second housing portions collectively defining an interior volume of the housing, and a divider positioned within the interior volume of the housing at the interface between the first and second housing portions to separate the interior volume into a first chamber at least partially defined by the first housing portion and the divider and a second chamber at least partially defined by the second housing portion and the divider. The first housing portion is coupled to the second housing portion via a friction weld at the interface. An annular gap is provided between the divider and the first housing portion. Flash from the friction weld is received within the annular gap.

An underdrain system for a media pressure vessel has a set of removable pipe sections located between an external header and the bottom of a vessel. Septa extend upwards from the removable pipe sections into the vessel by up to 16 inches. The septa may have diameters of 6 inches or more. The header is attached to the bottoms of the removable pipe sections. Each pipe section, and its associated septum, may be removed individually. To clean the vessel. after media is removed from the vessel the pipe sections are removed sequentially while the header remains otherwise attached to the vessel. While a pipe section is removed. its associated septum is removed so that solids can be removed from the annulus between the septum and the vessel. In this way. media can be cleaned from the annuli without moving the external header or entering the vessel.