Abstract: The present invention relates to a filtering apparatus (1) for the filtration of liquids, in particular water. It comprises, inside a container (11), a first chamber (50) intended to receive liquid to be filtered, a second chamber (54) intended to receive filtered liquid, a first porous wall (51) and a second porous wall (53) which delimit a filtration chamber (40) between them. The first porous wall (51) divides the first chamber (50) from the filtration chamber (40) and the second porous wall (53) divides the second chamber (54) from the filtration chamber (40), so that the filtration chamber (40) is interposed between the first chamber (50) and the second chamber (54). A granular filter material (4) is housed in the filtration chamber (40) and is enclosed between the first porous wall (51) and the second porous wall (53).

Abstract: Treatment equipment for production water for a polymer-assisted oil recovery operation comprising at least two nutshell filters in series, where the first filter recovers the majority the oil and the second serves as a finisher.

Abstract: In general, the present invention is directed to systems for treating water or wastewater. In accordance with some embodiments of the present invention, the system may utilize a vessel with a plurality of filter beds, at least one inlet, and at least one outlet, and the system may include: a first filtration bed comprising a first granular and/or angular media, the first media having a high surface area and configured for biological and physical treatment of the water or wastewater; a second filtration bed including a second granular and/or angular media, the second media having a lower surface area than the first media; wherein the water or wastewater enters the vessel via the at least one inlet, flows through the first filtration bed and the second filtration bed, and exits the vessel through the at least one outlet.

Abstract: 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.

Abstract: 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.

Abstract: A filter for removing at least some impurities (e.g. foreign matter of any nature including a solid, a liquid or a gas) from water or wastewater. A vibrator operably associated with at least a portion of the filter for imparting a vibrational force to enhance any one or more of numerous aspects of the filtration process including: (i) installation of the filter and/or various components thereof; (ii) servicing of the filter and/or components thereof; and, (iii) operation of the filter during a filtration cycle and a cleaning cycle.

Abstract: An apparatus for filtering water and/or wastewater including at least one underdrain lateral having a primary gas chamber and a secondary gas chamber where the secondary gas chamber serves to equalize pressure differences that may occur during the initial distribution due to velocity head changes and friction effects. Preferably, the underdrain lateral includes a plurality of chambers directing a washing fluid into the filter bed where at least one of the plurality of chambers directs a liquid and a gas simultaneously into the filter bed and at least one other chamber of the plurality of chamber directs only one of a liquid and a gas into the filter bed at the same time as that the combination of liquid and gas is directed into the filter bed.

Abstract: A radial or crossflow media filter comprising a housing such as a vessel or tank (1), the housing containing filter media (9), a contaminated flow inlet (2) and a discharge outlet (8), the inlet comprising a manifold (5) situated within the housing, the manifold (5) having flow outlets (6) which are directed laterally, away from the discharge outlet (8). The flow inlet may comprise a substantially vertically aligned elongate tubular manifold (5) with a plurality of flow distribution holes or slots disposed along its length. Furthermore, the discharge outlet (8) may be accessed through a chamber within the housing which contains a second filter media (11) which is of larger average particle size than the first filter media (9).

Abstract: The present invention relates generally to a system and method for treating wastewater in a filter media apparatus having a draft tube system. The filter media may be walnut shell media.

Abstract: A device for the treatment of an influent with a porous media. The influent passes radially through the porous media and into an internal volume of the device. The treated influent then passes through an open check valve in the internal volume, and then to downstream equipment. During a backwash operation, a backwash fluid is passed into the internal volume of the device in a direction to close the check valve. The blocked path in the internal volume of the device causes the backwash fluid to pass radially outwardly into the porous media and fluidize the same.

Abstract: A filter media backwash removal method and device for transporting backwash fluid and solids away from re-entering a housing containing circulating filter media.

Abstract: A system for filtering organic molecules from an electrolyte solution, including a feed inlet line adapted to carry a solution with organic molecules, a filter vessel secured to the inlet line, and a pump adapted to introduce dissolved air into the solution in the feed inlet line. The filter vessel is a solvent extraction filter having coalescing media above a solution outlet at the bottom of the vessel and an organic vent outlet at the top of the vessel. The system operates by (a) dissolving air into the solution, (b) inputting the solution with dissolved air into the filter vessel, (c) outletting solution from the bottom vessel outlet to flow solution down through coalescing media, and (d) periodically venting floating organic molecules from the top of the vessel.

Abstract: A package plant for treating raw water to yield potable water. The package plant includes an inlet for raw water, followed by an ozonator for disinfecting the water. Next is provided an up flow roughing filter including a chemically active layer, on top. A slow sand filter follows, which is sized and shaped to promote growth of a biomass for water purification. The up flow roughing filter removes particulates, contributes to the removal of dissolved organics, and protects the slow sand biomass by removing disinfection residuals. In another aspect a method of maintaining the plant is provided, including washing the up flow roughing filter by draining water down through it, providing a vigorous up flow to agitate the top layer, and then washing the slow sand filter.

Abstract: The present invention provides an apparatus and method for filtering fluids with a compressible filter media within at least a portion of a housing inwardly compressible.

Abstract: The invention is directed to a filter underdrain for supporting a filter media between at least two dividers forming at least one cell, which includes at least one porous plate for supporting the filter media for filtering a fluid, the porous plate spanning across at least one of the dividers; and a plurality of support members beneath the porous plate, the support members containing at least one port for draining the fluid after the fluid passes through the porous plate. The porous plates may be bound together by a lap joint and an end section may be included between at least two of the support members, the end section containing at least one pocket for holding the porous plate.

Abstract: The filter contaminant loading capacity of a depth granular media filter is increased by imposing a so-called “back-slip” on the filter bed. At intervals between normal backwashing, a volume of liquid is passed upwardly through the media bed under flow conditions selected to displace at least some of the contaminants upwardly in the bed while essentially removing none of the contaminants from the filter vessel. Preferably, the filter bed comprises at least two media types of different but uniform particle sizes and densities, the media types each forming a distinct layer in which the effective particle size of the media in each successive layer decreases in a downward direction in the vessel.

Abstract: The invention is directed to an automatic backwash filter system that includes at least one influent port for introducing a fluid to the filter; a plurality of partitions forming a plurality of compartments for holding a filtering media for filtering the fluid; at least one porous plate for supporting the plurality of partitions; wherein each of the partitions is mounted atop a continuous portion of the porous plate; and at least one effluent port for draining the fluid away from the compartments. The filter may also include a filter media comprising one or more selected from the group consisting of sand, anthracite coal, and activated carbon.

Abstract: A method of coacting a fluid with a media, such as granular particles. The media is moved to an upper portion in an upright media container, and held there during a treatment cycle in which the fluid is coacted with the media. When the media requires regeneration, the media is allowed to fall to a lower portion of the media container where a regeneration fluid is passed through the media.

Abstract: A radial flow fluidized unit (RFFU) (250) employing non-bonded media particles (56) for removing impurities from an influent, that can be backwashed and/or regenerated by fluidizing the media particles (56) to free the impurities therefrom. During a fluidization operation a fluid applies a drag force on a section of the media particles (56) within a volume of the unit where the media co-acts with the influent: (Volume 1). The drag force transports the media particles (56) into a second volume (Volume 2) for fluidization. Under normal conditions the top portion of the unit contains the packed media (56) where the influent co-acts with the media (56) (Volume 1). The RFFU (250) can also operate in the reverse where the bottom or opposite end contains the packed media (56) for co-acting with the influent.

Abstract: A concurrent backwash distribution apparatus for a filter having a filter tank and a plurality of underdrain laterals includes a baffle positioned in a common main conduit to define an auxiliary flume between the baffle and the underdrain laterals. The auxiliary flume is in fluid communication with the common main conduit and the underdrain laterals. The baffle has at least one flume liquid metering orifice preferably located near the bottom of the baffle so that it may be below a gas/liquid interface in the auxiliary flume during concurrent gas/liquid backwash operations. A flow distribution plate may be positioned between the auxiliary flume and the underdrain laterals, the flow distribution plate having at least one liquid metering orifice and at least one gas metering orifice. The baffle may take one of many forms. The baffle creates an adequate liquid pool in the common main conduit for low velocity flow of backwash liquid while at the same time providing uninhibited flow of backwash gas.

Abstract: Regeneration of water treatment media is disclosed which includes a water treatment unit having one or more media therein, and which upon initiation of flow of the water, imparts turbulence and abrasion to the treatment medium to automatically cleanse the medium of light solid contaminants as well as contaminant coatings on the media. This greatly improves the operation of the media and extends its life. In addition, the water treatment unit disclosed may simply be rotated through any one of a number of positions between service, backwash, flush, off, and/or bypass operational modes for further regeneration of the treatment media.

Abstract: A continuous filter device for liquids has a filter chamber that receives a granular bulk material forming a filter bed. The filter chamber has rectangular inner-walls with a liquid-permeable inlet side and a liquid-permeable outlet side positioned opposite the inlet side. A liquid-impermeable outer wall is positioned at the inlet side and forms together with the inlet side an inlet chamber. The inlet side has openings allowing flow of a liquid to be filtered from the inlet chamber into the filter chamber. A liquid-impermeable outer mantle is positioned at the outlet side and forms together with the outlet side a filtrate collection chamber. The outlet side has openings allowing filtrate flow from the filter chamber into the filtrate collection chamber. A cone-shaped removal chamber is connected to a lower end of the filter chamber. A flow discharge chamber is connected to an upper end of the filter chamber.

Abstract: Regeneration of water treatment media is disclosed which includes a water treatment unit having one or more media therein, and which upon initiation of flow of the water, imparts turbulence and abrasion to the treatment medium to automatically cleanse the medium of light solid contaminants, as well as contaminant coatings on the media. This greatly improves the operation of the media and extends its life. In addition, the water treatment unit disclosed may simply be rotated through any one of a number of positions between service, backwash, flush, off, and/or bypass operational modes for further regeneration of the treatment media.

Abstract: A bio-treatment system for removing biological wastes from man-made tanks used to commercially cultivate aquatic animals. The system includes an aqua-culture tank in combination with a filtration tank wherein a screen is attached internally across the cross-section of the filtration tank above a buoyant filter media contained inside the filtration tank, the screen located at a higher level than a water level in the aqua-culture tank. Filtering of the water is accomplished by pumping water from the aqua-culture tank upwardly through the filtration tank and the buoyant filter media in the filtration tank. The filtered water flows out the top of the filtration tank and flows by gravity back to the aqua-culture tank.

Abstract: Electro-magnetic filter apparatus and method of operating to separate and remove oily magnetic solids from wastewaters. The filter apparatus includes a filter assembly having an electro-magnetic coil that encircles a canister. The canister has an interior space defined by a wall surface and a first perforated baffle spaced apart from a second perforated baffle. The interior space contains a ferromagnetic matrix comprising split ring lock washers. The feed side end portion of the canister communicates with the wastewater source that contains the oily magnetic solids, a wash-water supply, a pressurized air supply and a disposal stream. The discharge side end portion of the canister communicates with a recycling stream, the disposal stream and the wash-water supply.

Abstract: In a method for backwashing a water processing system using a buoyant filter layer constrained under wire mesh screen extending across a processing vessel, a water surface level in the processing vessel is lowered below the wire mesh screen. Air is subsequently released from under the buoyant filter layer to separate substances clogging the filter layer, while allowing the release of air out of said vessel from an upper part thereof. By lowering the water surface level below the upper wire mesh screen, the filter material is allowed to move more freely because the filter material is not restricted by the wire mesh screen from making upward movement. Hence, when air is released from under the filter layer, the filter material can move uniformly over the entire filter layer, and the clogging substances such as SS captured by the filter material and the biological film formed on the surface of the filter material can be favorably removed without damaging the filter material.

Abstract: A filtering process for and apparatus separating air bubbles and granular filter medium from a filtrate contaminated by the filter medium and bubbles when passing through a filter bed formed by the filter medium for treatment of a suspension or liquid solution, a gas being passed through the filter medium in contact therewith, includes providing a treated filtrate zone (3) above the filter bed (2), collecting the treated filtrate in the filtrate zone, conducting granular filter medium from the filter bed (2) upwardly through a conveying pipe (4) to a position above the filter bed and thereafter downwardly through a washing apparatus (5) from which the filter medium is precipitated onto a plate (11) above the filter bed.

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.

Abstract: A novel process for treating a fluid is disclosed. Generally, the process utilizes a novel fluidized bed reactor and down flow filter. The process includes filling the reactor, and thereafter fluidizing the media bed contained therein. A catalyst is added, and the entire batch fluid is allowed to react with the catalyst. After appropriate settling of the media bed, the batch fluid is recycled. A filtration step is then included and appropriate disposition of the collected filtrate may be effected.

Abstract: A packed mass transfer tower for establishing intimate gas-liquid contact and efficient mass transfer that is less susceptible to gas or liquid channeling, gas surging and uneven distribution of gas or liquid across the cross-sectional area of the tower. In one embodiment, the packed tower includes a packing arrangement including a loosely packed bed of mobile packing material, and an adjacent, tightly packed bed of mobile packing material. The relatively tightly packed bed of mobile packing material acts as a gas distributor, as well as being a material that causes good gas-liquid contact, to provide an even flow of gas across essentially the entire cross-sectional area of the loosely packed bed of mobile packing material. In another embodiment, mobile packing elements and fixed packing elements are intermixed between the same spaced fluid-pervious grids.

Abstract: There is disclosed a granular filtration system having a separator trough with an air deflection baffle of improved shape and operation, preferably combined with an airlift mechanism for cleaning or removing settled granular media particles from the upper surface of the air deflection baffle. The air deflection baffle is used in a regeneration method for the granular media filtration system in which the granular media is purged of filtered solids by backflushing with air and water. In this application, the air-deflection baffle is installed beneath and adjacent to the open throat of a solids separation vessel, typically which is in the form of a trough spanning the width of the filtration vessel and having an inclined bottom wall with an open throat. The improved configuration of the air deflection baffle is generally an inverted W-shape. A plurality of open-ended tubes are secured on the air deflection baffle, transversely to the longitudinal axis thereof.

Abstract: A solid-liquid separator and a process for washing the same wherein SS (sended solids) caught in space portions of a filter medium in a tank are caused to flow out from the space portions and be suspended while at least part of the filter medium is maintained in a fluidized state by air washing, and rapid drainage through a lower portion of the tank causes the SS in the suspended state to be rapidly removed without being again caught into the space portions of the filter medium.

Abstract: A method and apparatus for filtering a fluid through a particulate filter medium and for periodically scrubbing the particulate filter medium of accumulated contaminating material. During the filtration cycle, the particulate filter medium is retained with a filtration vessel by a bottom screen. During the scrubbing cycle, the particulate filter medium is retained within the filtration vessel by the bottom screen and a top screen. The combined surface area of the bottom screen and the top screen is substantially greater than the surface area of the bottom screen alone. During the scrubbing cycle, the particulate filter medium is fluidized with a scrubbing fluid and violently circulated to remove accumulated contaminating material from the filter medium, thereby suspending the contaminating material in the fluidized mixture.

Abstract: A multiple filter, gravity flow, liquid filtering apparatus includes a plurality of adjacent independent filter chambers with common influent and effluent passages surrounding a centrally located effluent control chamber and having provisions for backwashing at least one filter chamber with the effluent from companion filter chambers. The effluent control chamber preferably has two sections, a lower section which serves to collect filtrate from each of the surrounding filter chambers through a plurality of flow transfer ports which communicate with each filter chamber, and an upper section which houses equipment and controls for filtering and backwash operations. In one embodiment, the lower section includes a vertically disposed outlet conduit with an adjustable weir located at the open end of the conduit. The weir is used to adjust the liquid level in the lower section of the control chamber to control filtering and backwash operations.

Abstract: An improved method for operating a down-flow granular medium filter is disclosed which increases the effective filtration time between backwashes. The filter tank cell is divided into a plurality of subcells, each individually adapted and controlled for periodic intermittent upwardly-directed pulses of fluid passed through the filter bed within each subcell from an array of orifices beneath or in the bed. During the filtration run, one subcell is pulsed to improve the porosity of that portion of the filter bed while the remainder of the subcells continue to filter wastewater. After initiation of the first pulsing cycle for a subcell, additional subcell pulsing cycles are initiated sequentially. At the end of the filtration run the whole filter cell is backwashed to remove particulate matter from the bed and prepare the bed for the next filtration run.

Abstract: A filtration system and method for the removal of suspended solids from a contaminated liquid in which the contaminated liquid is pumped into the top of a vessel and allowed to flow through a bed of polyethylene particles which acts as a filtering medium. Periodically the flow of liquid through the polyethylene filter bed is stopped and a backwash cycle in which the contaminated liquid is pumped in a reverse flow direction through the filter bed is initiated. By thoroughly agitating the filter bed and polyethylene particles, contaminants are loosened and removed from the polyethylene particles and placed back into the liquid. The highly concentrated contaminated liquid is removed from the vessel for further processing. The filter bed is reset and the filtering cycle is again initiated.

Abstract: A suspension is filtered by a granular filtrating layer while flowing through the granular filtrating mass as a vertical ascending current. The granular mass is, for the purpose of being washed with air, driven continuously by a compressed air ejector into a tube where it follows an ascending motion and at the outlet of which it is washed with water above the layer where the filtration is carried out. Thereafter, the washed mass is recycled by gravity onto the upper portion of the filtration layer. The charged granular mass which has been subjected to the first or air washing operation is fluidized above the filtration layer and subjected to an extra washing operation with water and pressurized air.

Abstract: According to the invention, the enclosure (1) contains a granular material (4) having a specific mass less, or respectively greater than that of the liquid to be treated. When the liquid is admitted through an upper inlet line (2), a granular bed is formed at the bottom of the enclosure (1) or at the upper part thereof and the colloidal particles form aggregates there. When the supply of liquid to be treated is interrupted, the granular material rises to the upper, respectively lower, part of the enclosure (1) and releases the aggregates formed, which can be recovered.

Abstract: A method for controlling the pulsing of a granular medium filter, based on determination of the rise rate of liquid level above the filtration medium. A pulse system is activated whereby sub-fluidizing pulses of a fluid are directed upwardly through the filter medium from an array of orifices, and each pulse is initiated whenever the determined rise rate attains a predetermined value. The pulses dislodge solids from the upper surface of the bed and store a portion of the solids within the bed itself at particular loci, for decreasing the resistance of the bed and reducing the rise rate. The frequency of backwash is optimized over a wider range of solids load, liquid load and other factors affecting the filtration.

Abstract: A method and apparatus for backflushing downflow filters is disclosed which comprises providing a closed container having contiguous, vertically adjacent filter layers. A layer of gravel is provided below the filter layers and is separated from the bottom filter layer by a foraminous gravel retention member. Fluid under pressure is introduced through a plurality of fluid nozzles into the gravel layer to backflush the filter layers. Backflush fluid in introduced at a sufficient flow rate to fluidize all of the filter layers to segregate them in accordance with their specific densities and particle size. Introducing the backflush fluid into a gravel layer through a plurality of nozzles helps prevent development of localized areas of high fluid velocity that can cause intermingling of the filter layers during backflush.

Abstract: A filter for removal of suspended solids from fluids utilizes pressurized air for fluidizing filter media as the latter is exposed to backwashing water. The filter includes a casing having upright walls defining an annular chamber in horizontal cross-section, and a portion of the walls have openings that are pervious to liquid and substantially impermeable to the media particles. The flow of the backwash water is directed toward the upright, outer casing wall such that the backwash water flows at a direction at an angle relative to the upward flow of the pressurized air in the bed as the particles are fluidized, to facilitate removal of the accumulated solids without enabling escape of the media particles. Desirably, pressurized air is introduced into the chamber at vertically spaced locations to insure complete fluidization.

Abstract: There is provided an improvement in a waste effluent filter of the type including a tank, a generally flat fine mesh screen over the lower portion of the tank to define an underdrain cavity below the screen and a filter bed of particulate material having an upper surface and a lower general surface adjacent the underdrain cavity. The particle size of the particulate material being greater than the size of the apertures in the fine mesh screen. The filter improvement includes a jet creating grid for creating a plurality of upwardly directed hydraulic jets evenly distributed throughout the filter bed during the filtering of the effluent through the bed wherein the jet creating grid includes a plurality of nozzles in the bed itself substantially below the upper surface of the bed and above the fine mesh screen a selected distance to retain the lower layer of the bed undisturbed.

Abstract: A water filtration system is provided by an upflow filter vessel containing a buoyant filter media in series with a downstream downflow filter vessel containing a nonbuoyant filter media. The buoyant media filter vessel and nonbuoyant media filter vessel comprise two compartments of a common tank, separated by a central wall. Water from the upflow filter vessel passes over the top of this wall, or through one or more openings in this wall, to the downflow filter vessel. A common waste trough extends from one end of the tank to the other. Weir plates are fastened to the upper edges of this trough such that the trough steps upwardly in elevation at the central wall. Waste materials from the upflow filter vessel pass over the lower of these weir plates and into the waste trough during cleaning of the buoyant media filter. In contrast, waste materials from the nonbuoyant media filter flow over the upper weir plates and into the trough during cleaning of this latter filter.

Abstract: A filtrating method for removing suspended solids from a liquid by passing the liquid through a layer of filter medium in a magnetic field, the filter medium layer comprising a collection of organic fibers and ferromagnetic metal fibers. Usual suspended solids and relatively large magnetic suspended solids are arrested by the organic fibers, while fine magnetic suspended solids are arrested by the ferromagnetic metal fibers subjected to the action of the magnetic field. The collection of fibers achieves a high filtration efficiency, has outstanding regeneration characteristics, withstands continued use and is therefore very useful as a filter medium.

Abstract: A liquid is filtered through a bed 7 of granular material and cleaning of the bed is conducted, when necessary, by upflow of wash water through orifices 9 and air through orifices 12 positioned mid-way between the orifices 9. An overflow 13 defines a free water space 15 above the bed and a baffle formed of elements 18, 19 and 20 surrounds the overflow outlet. During cleaning the wash water and air flow upwardly at rates such that some granular material is entrained by upflowing air bubbles and could be carried to the overflow 13 but substantially all the entrained granular material is separated from the entraining air bubbles at or near the top of the free space 15.

Abstract: This invention relates to a backwash outlet assembly for a liquid particulate filter. The outlet is adapted to retain particles which comprise the filter medium while allowing backwash liquid together with impurities to discharge to waste. The outlet comprises an outlet weir, and a substantially non-turbulent flow zone located upstream of the weir. A particle return passage extends from the floor of the zone to the filter bed and means are included to at least restrict back flow in the passage. Filter media particles carried in suspension in the backwash liquid fall under the action of gravity to the floor of the zone and by the velocity of the backwash liquid into the entrance to the return passage. Preferably the particle return passage extends from the zone adjacent the weir and filter media particles trapped in the return passage are automatically conveyed back to the filter.

Abstract: An upflow, buoyant media filter for industrial and municipal water and wastewater treatment is disclosed. The filter bed is supported in a tank such that there is defined an influent reservoir below the filter bed and an effluent reservoir above the filter bed. By inducing a continuous circulating flow of influent within the influent reservoir, the waste is slowly agitated allowing it to coagulate. As the waste particles are carried to the relatively quiescent areas near the perimeter of the tank, those that are heavy enough settle to the bottom of the tank. The lighter particles are carried along in the circulating flow to continue the coagulation process. Waste particles which do not settle out are ultimately removed by the filter media. As the waste particles build up on the surface of the filter media, they agglomerate. As their density increases, these particles tend to drop off of their own weight or may be scoured off by the circulating flow of influent.

Abstract: A device for the distribution of water to be treated into and for the recovery of washing liquid from a water treatment filter apparatus of the type including a tank containing therein a filter material includes a channel coupled to and extending along the length of the tank, the channel receiving therein water to be treated. The channel has an opening into the interior of the tank at a level above the filter material. The opening is defined at the lower portion thereof by an overflow over which the water to be treated flows from the channel to the tank. The overflow includes a first inclined plane inclined downwardly and away from the channel in a direction toward the tank and a second inclined plane inclined downwardly and toward the channel from the first inclined plane. The inclined planes extend into the tank and form a deflector structure to prevent any filter material from passing through the opening during backwashing of the filter material.

Abstract: A process and apparatus for cleaning contaminated raw water, in which raw water and a flocculator are introduced into the reaction space of a pressure vessel, which vessel has such reaction space at the bottom thereof, a filter space above the reaction space and containing a filter made of particles of elastic, granular material, and a clean water space above the filter space so that the raw water passes through the three spaces, whereby the pollution material contained in the raw water becomes enclosed by the cells of the floccules of the flocculator and the floccules become absorbed by the filter particles. Accumulated pollution material is removed from the filter particles by regenerating the filter with a fluid flowing from the clean water space through the filter space into the reaction space. The required extent of purity is achieved by varying the velocity of the raw water introduced into the reaction space, to thereby adjust the percentage of the voids in the filter.