Abstract: A biological filtration apparatus comprises: a raw water introducing section for introducing raw water as water to be processed; a biological filtration section, disposed on the lower side of the raw water introducing section, for biologically purifying/refining/filtrating the raw water so as to yield processed water; a support section, disposed on the lower side of the biological filtration section, for supporting the biological filtration section, the support section having a liquid and gas permeability; and a water collecting section, disposed on the lower side of the support section, for collecting the processed water; the biological filtration section including a packed bed comprising a hollow carrier particle, made of a resin, having a true specific gravity of at least 1.01 g/ml but less than 1.2 g/ml.

Abstract: A water filtration system has a tank partially filled with a floating bead filtration media. A cylindrical diffuser is disposed in the tank and extends from the upper portion to the lower portion thereof. The diffuser in internally partitioned into a lower chamber and an upper chamber and each chamber has slots that communicate with the tank. An supply conduit delivers soiled water from a pond to the lower chamber of the diffuser. The soiled water flows through the openings in the lower chamber and into the tank, upwardly through the filtration media where it is filtered, and into the upper chamber through the openings formed therein. An return conduit delivers filtered water from the upper chamber of the diffuser back to the pond.

Abstract: The invention relates to a method and device for the continuous filtration of liquids containing solid matter, in particular for cleaning wastewater, by means of a filter bed consisting of a particulate filtering medium, which is continuously moved through a vertically positioned cylindrical annular space (2) through which the liquid to be filtered continuously flows radially from the interior to the exterior. The particulate filtering medium containing the separated solid matter is continuously tapped from the lower end of the annular space (2), transported to the top, freed of the filtered solid matter and fed back into the annular space (2) at its upper end. With this kind of method and device, to be able to prevent in a better and more simple manner blockages caused by the separated floc of solid matter, the invention provides that as particulate filtering medium a particle mixture is used with a particle-size range comprising two or more particle sizes, ranging from coarse (2.5 mm) to fine (0.

Abstract: An improved underdrain block for an underdrain system supporting a filter media bed in a liquid filtration system is provided. The underdrain blocks are preferably made of an extrudable polymeric material that is extruded in relatively long sections to provide light weight, strong, easily manufactured underdrain systems having a lower profile than prior art underdrain blocks. The underdrain block comprises an upper wall, side walls, a lower wall, at least one lateral member between the upper wall and the lower wall, at least two chambers within the underdrain block, each chamber being defined by the lateral member, a plurality of upper orifices in the upper wall of the underdrain block, and a plurality of internal orifices in the lateral member. The underdrain block is substantially greater in longitudinal length than a longitudinal distance between the upper orifices.

Abstract: A fluid sanitizer includes a substantially cylindrical cartridge for containing sanitizing media such as a silver bactericide. The sanitizer inserts into an existing filter in the normal filter flow path and permits filtering and backwashing. The cartridge is a full flow design and may either be packed bed or loosely packed to become fluidized under filtering conditions. Sand filters with either top-mounted or side-mounted valves may be retrofitted with the sanitizer with no or minimal modifications.

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: A tank top pretreatment unit and assembly comprises a treatment unit installed inside a water treatment tank, such as a water softener tank, and in the top of the tank for treating the water either prior to its treatment with the primary treating medium in the tank or following such treatment. The treatment unit includes a plurality of chambers which are configured to contain a finely divided water treatment medium of a different kind than the primary treatment medium. Some of the elements may be arranged in series, but many or all are arranged in parallel flow which reduces the pressure drop of the water across the treatment unit, and the inlet openings to the chambers and outlet openings from the chambers are elevationally spaced from each other and the area of the outlet openings is less than the area of the inlet openings to maximize contact and dwell time in the chambers.

Abstract: A water conditioner includes a tank, and an apparatus for backflushing a bed of particulate material in the tank, which includes a tubular casing, a vertical tube in the casing, a cap on the top end of the casing, suitable valves for causing the flow of particulate material upwardly between the casing and tube, and then through a gap between the casing and cap during a backflush operation, and distributor device including a flexible, collapsible, umbrella-shaped body which is mounted on the casing immediately below the cap, and springs for biasing the body to the open position. Inlet tubes extend outwardly from the bottom of the casing approximately the same distance as the distributor for ensuring even distribution of liquid at the bottom of the bed.

Abstract: A filter and hydraulic mixing assembly for a water treatment system. The assembly includes two circulation tubes disposed alongside a center tube. During a backwash cycle fluid is conveyed through the center tube to a housing member where it is discharged immediately below the open bottom ends of the two circulation tubes thereby conveying media from the surrounding tank upwards through the circulation tubes. A cap member is fitted over the upper ends of the circulation tubes within the tank and direct the media being discharged from the circulation tubes into a downward spiraling helical flow pattern which provides enhanced agitation and lifting of the media bed. Discrete filter segments are selectively attachable to the housing member and interchanging the discrete filter segments permits the total filter slot area of the assembly to be adjusted and also permits the filter slot size to be altered. The filter segments are color coded, with each separate filter size having a different corresponding color.

Abstract: A filtering device provided a horizontal drum in which a filter layer made of granular filter material and a space portion are formed in a vertical direction within its interior; a crude water introducing/dirty water discharging first water flow pipe which passes through an axial portion of the horizontal drum from the outside of the horizontal drum and whose a crude water introducing/dirty water discharging first water flow portion is located in the space portion; and a filtered water introducing/washing water discharging second water flow pipe which passes through an axial portion of the horizontal drum from the outside of the horizontal drum and whose a filtered water introducing/washing water discharging second water flow portion is located in an interior of the filter layer.

Abstract: A water filtration technique is designed to maximize the efficient performance of a variety of granular filtration media. The technique maintains the granular filtration media in a compacted state between a perforated outer media container and a perforated inner media container, where the perforated inner media container is a smaller similitude of the perforated outer media container. In the preferred embodiment of the filtration device of the present invention, the perforated outer and inner media containers are substantially spherical. By maintaining the granular filtration media in a static-state throughout filtration, highly efficient filtration is achieved. In contrast, during the backwash function, the normal inward flow is reversed to outward radial flow and granular filtration media is agitated, fluidized and quickly and vigorously cleaned. A plurality of high-velocity centrally-located water jets create the outward radial flow during backwashing.

Abstract: A cooling tower water treatment system removes contaminants include chlorine, calcium carbonate as calcite, and microorganisms from water in the system with redox media in a fluidized bed. The treatment system includes a treatment bed, in the form of a column, having a reaction chamber of a first diameter and a retention chamber of a second diameter, the second diameter being greater than the first diameter. Redox media, in the reaction chamber, is fluidized by water flowing in a direction countercurrent to gravity and is held in place, without the use of screens or filters, by a reduction in flow rate of the fluidizing media resulting from the larger diameter of the retention chamber. Preferably, the treatment system includes a physical filtration unit, such as an automatic backwashing sand filter, to prevent entry of particulates and scale into the reaction chamber.

Abstract: The present invention provides a floating media bioclarifier having an economical structure which allows energy efficient and water conserving backwashing of the floating media. The bioclarifier includes a filter chamber fluidly connected to a charge chamber which is adapted for accumulating air. A trigger device positioned between the charge chamber and filter chamber selectively allows the flow of air from said charge chamber to said filter chamber. An air source is connected to the charge chamber and slowly supplies air thereto. The backwash cycle is initiated by the trigger device allowing air to escape from the charge chamber into the filter chamber and adgitate the floating media. Simaltaneously, water from the filter chamber flows into the charge chamber. After the trigger device closes, air agains accumulate in charge chamber in preparation for another backwash cycle.

Abstract: A filter assembly for use in an air remediation system is provided. The filter assembly includes a first and second filter member, each of which has a plurality of openings to define a plurality of separate flow passages. A granular filter material layer is disposed between the first and second filter members. A frame structure containing each of the first and second filter members as well as the granular filter material forms the self contained filter assembly.

Abstract: A pipe-mounted dual velocity strainer is disclosed including a bottom strainer portion to provide a first velocity flow path in one direction and a top strainer portion to provide a second velocity flow path in the opposite direction. A check valve and coaxial conduit between the two strainer portions provide means for obtaining different velocities dependent upon the direction of flow. The invention is utilized in fluid distribution and collection for ion exchange and filtration systems.

Abstract: A method and apparatus for regenerating an ion exchange resin utilizing recycled solution or reused regeneration solution. At least one tank containing an ion exchange material is provided having a spaced first and second ports which define a fluid flow path through the ion exchange media. Water to be treated is introduced at an inlet and flows through the resin bed ultimately being discharged at the outlet. A polishing zone is located at the outlet which includes highly regenerated, uncontaminated resin. The media is regenerated in a multi-step process in which regeneration solution is introduced into the resin bed in two separate steps. In the first step, a first regeneration solution is introduced into the resin bed upstream from the polishing zone, flows in a countercurrent direction and is discharged through the inlet of the tank. A second regeneration fluid is introduced at the outlet of the tank and flows in a countercurrent direction through the entire resin bed.

Abstract: An improved electro-coalescent/magnetic separation (ECMS) system for removing contaminants from water, including desalinization, comprises a device for exposing a stream of water to be treated to an electric field, followed by introduction of ionized coagulating substances, including ionized gases and/or metal ions, followed by plural filter stages. The first filter stage may comprise a polarizable glass, alumina, or ceramic media provided as a bed in a tank with an underdrain, so as to provide substantial residence time. A polishing filter may comprise a very fine fiber or organic gel filter element confined between relatively flexible electrically-conductive screen members and provided with a DC power supply to polarize the filter. This assembly is confined between relatively rigid, perforated members such that the filter assembly can move slightly upon backwash to dislodge caked-on contaminants or the like, while preserving the structural integrity of the filter assembly.

Abstract: A reactor for treating a liquid containing evolvable and entrained gas has a vessel for containing a bed of particulate media, and a liquid flow distributor mounted in the vessel that includes a manifold connected to receive liquid and introduce it into the bed. The manifold includes a liquid conveying passage having an upper region where any gas that evolves from the liquid can collect and at least one discharging nozzle having an inlet in open communication with the upper region for receiving the liquid, evolved gas or a mixture thereof, and an outlet for uniformly discharging the liquid, gas or mixture thereof into the bed.

Abstract: A travelling bridge filtration unit includes a tank having a bottom wall, a pair of side walls and a pair of end walls arranged to provide a rectangular tank with an open top. An interior partition in the tank extends lengthwise between the pair of end walls forms a filtrate channel between the interior partition and one of the side walls, and a filter basin between the interior partition and the other of the pair of side walls, with a bed of filter media located in the filter basin. A travelling bridge is mounted on the tank for movement therealong in a lengthwise direction, the travelling bridge supporting a backwash pump and a backwash hood for movement across the filter basin in close proximity to the filter bed. A plurality of structural underdrain headers extend between the interior partition and the other of the pair of side walls, the headers having closed ends adjacent one of the side walls, and open ends extending through the interior partition in communication with the filtrate channel.

Abstract: Apparatus for use in an ion exchange unit or column comprising a riser pipe, a port coupled to one end of said pipe, a first rigid cylinder having apertures therein mounted concentrically on the pipe, a port coupled to the space between the pipe and said cylinder, a mesh sleeve concentrically mounted about the cylinder, a sieve mounted about the mesh sleeve, a second rigid cylinder concentric with the pipe and near its outer end, a second mesh sleeve mounted about said second rigid cylinder and a sieve bag containing the second mesh sleeve. The aperture size in said sieve material is only sufficiently fine to prevent the passage of ion exchange resin beads.

Abstract: A filtering device for the clarification of liquids, such as industrial or waste waters, comprising an open tank provided with a floor possessing nozzles and supporting the filtering bed, side channels for arrival of the untreated water, a removal conduit for the filtered water, means for washing the material of the filter and an axial channel for removal of the washing waters, wherein the bottom of the filter, below the floor, is separated along its longitudinal axis by a watertight partition defining two independent cells in the filter.

Abstract: A permeable ditch underwater water purification apparatus purifies source water using the principle of self-purification of water. This apparatus includes impermeable ditch walls on a tapered bottom. The apparatus also has an open top side. A granular filter layer is filled in the ditch body. Collector (counter-rinsing) pipes are provided at the bottom of the granular filter layer, and a filter protecting layer is provided on the surface of the granular filter layer. This apparatus can maintain the thickness of the granular filter layer all the year round. When blockage of the filter layer occurs, water from another ditch is pumped, and the remaining impurities in the granular filter layer can be forced away by water pumped into the collector (counter-rinsing) pipe. After sterilization by adding an appropriate amount of chlorine into the purified water, the quality of water will meet the standards for drinking water in effect in China, and the purified water may be supplied directly for use by the users.

Abstract: A device for backwashing a particulate mineral bed in a water conditioner includes a tubular casing; a tube co-axial with and extending through the casing beyond the ends thereof; a cap slidable on the tube for movement between a closed position on the open top end of the casing and an open position spaced apart from the top end of the casing; a spring biasing the cap to the closed position; an opening in the tube for discharging water into the cap to cause the latter to move away from the casing to the open position; a first valve including a valve body closing the bottom end of the casing; a first passage in the valve body in fluid communication with the bottom end of the tube, the first passage being normally open to the flow of water upwardly from the bed of particulate material into the tube; a ball in the body for closing the first passage when the flow of water is reversed in the tube; a second passage in the top of the body communicating with the first passage; a second valve normally closing the seco

Abstract: An ion exchanger of the countercurrent type includes a pressure vessel for supporting a resin bed. The vessel includes a first port through which water to be treated is supplied to the vessel during a production cycle, a second port through which regenerant is supplied to the vessel during a regenerant cycle, and a third port located intermediate of the first and second ports and connected to a lower in-bed distributor located within the vessel. A recycling loop is provided between the third port and the first port for recycling regenerant during at least a portion of the regeneration cycle. An upper in-bed distributor is located within the vessel slightly above the lower in-bed distributor and has an associated fourth port through which waste regenerant is removed from the vessel during the regeneration cycle.

Abstract: A method and apparatus for regenerating an ion exchange resin utilizing recycled solution or reused regeneration solution. At least one tank containing an ion exchange material is provided having a spaced first and second ports which define a fluid flow path through the ion exchange media. Water to be treated is introduced at an inlet and flows through the resin bed ultimately being discharged at the outlet. A polishing zone is located at the outlet which includes highly regenerated, uncontaminated resin. The media is regenerated in a multi-step process in which regeneration solution is introduced into the resin bed in two separate steps. In the first step, a first regeneration solution is introduced into the resin bed upstream from the polishing zone, flows in a countercurrent direction and is discharged through the inlet of the tank. A second regeneration fluid is introduced at the outlet of the tank and flows in a countercurrent direction through the entire resin bed.

Abstract: A system for distributing both gas and liquid in separate conduits within an underdrain filtration system is disclosed. A tubular liquid conducting conduit also contains a separate air conduit. Extending from each conduit are, respectively, liquid conducting laterals and air laterals. The system is placed within a bed of gravel at the bottom of a filter bed and acts as conventional underdrain blocks and air grids. In a downflow mode, effluent is filtered as it passes through the filter media and filtered water is collected through orifices in the liquid conducting laterals, which in turn feed into the liquid conducting conduit to form a filtrate stream. In a backwash mode, backwash liquid flows through the liquid conducting conduit, out the laterals and up through the filter bed. During backwash, air may be introduced through the air conduit and laterals and rise through the filter media to enhance the effectiveness of the backwash operation.

Abstract: A water treatment tank for use in a water treatment or softening system is disclosed which is operative in a treatment mode to receive untreated water through an inlet port and to pass treated water through an outlet port, and which is operative in a backwash mode to receive wash water through the outlet port and to pass waste water through the inlet port. Treatment tank has a vessel having an interior cavity which is partitioned into a top headspace portion, and a middle treatment bed space portion, and a bottom headspace portion via the placement of a pair of distributor filters mounted within the interior cavity to extend between the side walls thereof. The filters are spaced-apart, respectively, from the top end wall to define therewith the top headspace portion and the bottom headspace portion.

Abstract: A self-supporting modular underdrain member for use in a liquid filtration system comprises a main body or housing including a pair of longitudinally extending inclined walls which may have a pair of generally triangular transverse walls connecting the inclined walls to one another, the inclined walls each being provided with a pair of longitudinally extending recesses and a plurality of orifices communicating with each of the recesses. A pair of flanges are connected to the inclined walls for attaching the underdrain body to a floor surface so that the inclined walls, any transverse walls and the floor surface define a cross-sectionally triangular underdrain chamber. Two pairs of elongate cover plates are attached to the inclined walls over the recesses to form in each of the inclined walls a pair of longitudinally extending plenums for the equalization of backwash air and water flow. Each of the cover plates being provided with a plurality of spaced slots.

Abstract: A two stage raw water clarifier with first stage flotation and second stage filtration divides at least the lower portion of a flotation tank into independent cells. A branched slotted conduit located in a filter medium in each cell collects clarified water. Valves control the flow of clarified water from each branched conduit either to a clarified water ring conduit or to a first filtrate/backwash ring conduit connected to a storage tank. The filter media is preferably a dual media, a layer of anthracite or activated carbon over a layer of sand. High cell walls and inclined baffles in each cell retain the filter media during backwashing. The baffles also slow the flotation process. A decompression valve for pressurized water with dissolved air has a very narrow annular slot in the flow path through the valve to create microscopic air bubbles of optimal size for the flotation. A movable member sets this annular slot at a proper value.

Abstract: A method of treating fluid in a bed of ion exchange resin wherein in one embodiment the resin is of a high kinetic type and water is introduced upwardly through the bed to effect a complete fluidized resin bed. The high kinetic resin is of a fine mesh type and preferably can be monospheric. An apparatus for carrying out the method is devoid of any elements which effect a compacting of the resin during normal operation. The method and apparatus is particularly directed to water treatment. In another embodiment, cocurrent proportional regeneration of a resin bed is effected using resins with nonoverlapping terminal velocities in two different ionic forms.

Abstract: A baffle system is described that significantly reduces media loss caused by turbulence encountered during gas and liquid backwashing of a discrete media filter bed. When positioned about a filter collection trough or outlet, the baffle system deflects rising gas bubbles away from the collection trough and disengages filter media from the backwash liquid.

Abstract: A filter for a machine tool operative to filter one of steel, brass, and copper from a liquid agent is disclosed herein. The filter consists of a cylindrical container having a closed top end and a closed bottom end, an upper duct positioned near the top end of the container, a lower duct positioned near the bottom end of the container and having a lower diffuser fluidly connected thereto, and a filtering element surrounding the lower diffuser. The filter element consists of ilmenite particles having a density (d) of about 6 g/cm.sup.3 and a size ranging between a smallest size of about 0.2 mm and a largest size of about 1.0 mm, the ilmenite particles being in the form of grains having sharp edges and irregular sized faces.

Abstract: A method of washing an upflow filter between service runs employs a filter bed having a non-buoyant particulate filter layer through which influent to be filtered is directed in an upward direction, and through which liquid employed in the washing operation is directed in an upflow direction. A two-stage washing operation includes the steps of first directing a combination of air and liquid in an upflow direction through the filter layer with the velocity of the liquid being less than the minimum fluidization velocity of the filter layer, for disrupting only some floc retained in the filter layer during a previous service run, and thereafter directing only liquid in an upflow direction through the filter layer at a velocity less than the minimum fluidization velocity of the filter layer for removing disrupted floc from the filter layer while leaving some floc attached to said particulate media of the filter layer.

Abstract: An assembly for removing wash water for washing filters containing granular filter material, which are washed simultaneously with water and air, such as those employed especially in water treatment, and recovering the particles of granular filter material entrained by the water during the washing which includes a collecting member having calibrated holes for collecting and removing dirty water, internal and external partitions placed on each side of the collecting member, defining a water recovering zone inside the internal partitions and between the internal and external partitions, tranquil flow zones promoting the separation, by downward concurrent settling of the particles of granular material and of the dirty water to be removed, and a baffle intended to avoid disturbing the preceding zones by the water/air/granular material three-phase mixture formed during the washing, placed under said zones and directing the three phase mixture towards an external degassing zone where the air is removed before the re

Abstract: Underdrain lateral system, which is especially adapted for use in a gravity filter bed, includes, as its preferred embodiment, scallop-shaped laterals having an upper, wrapped wire, slotted screen surface. The screen surface supports and retains the filter media particles directly, without the necessity of an underlying gravel layer, and is itself supported by channel-shaped rod members which are welded to the wires. The web portions of the channel rods perform the function of simultaneously distributing air and water during backwashing, and include small apertures in upper channels and larger apertures in lower channels to cause a plenum to be formed inside the laterals which ensures that the distribution of air and water will be uniform throughout the lateral, even if the lateral is not perfectly level.

Abstract: The filtration system provides a long horizontal flow path through buoyant filter media. The filter media is contained in a vessel and the relationship between the water level in the vessel and the amount of filter media is such that the media extends completely across the horizontal flow path of the water during the filtration mode of operation. The system is configured so that the buoyant media volume expands during a cleansing mode of operation.

Abstract: A filtering system includes a filter vessel containing a movable granular media bed, a feed stream inlet port for flowing a liquid-solid stream through the bed for filtration, a dirtied media outlet and a cleaned effluent outlet. A vertical cleaning section in either a separate stand-alone washing section vessel or in a washing section within the filter vessle, includes a wash path in which a washing liquid typically a portion of the cleaned effluent washes contaminants from the dirtied media resultant from filtration of the feed stream. The resultant contaminants-containing wash water is pumped to waste but a sidestream thereof is recycled at least in part to the filter vessle to a location in the vessel between the feed stream inlet port and the dirtied media outlet so that the liquid ordinarily transported with the dirty media at the bottom of the filter is replaced, at least in part with the recycle liquid.

Abstract: A method of washing an upflow filter between service runs employs a filter bed having a non-buoyant particulate filter layer through which influent to be filtered is directed in an upward direction, and through which liquid employed in the washing operation is directed in an upflow direction. A two-stage washing operation includes the steps of first directing a combination of air and liquid in an upflow direction through the filter layer with the velocity of the liquid being less than the minimum fluidization velocity of the filter layer, for disrupting only some floc retained in the filter layer during a previous service run, and thereafter directing only liquid in an upflow direction through the filter layer at a velocity less than the minimum fluidization velocity of the filter layer for removing disrupted floc from the filter layer while leaving some floc attached to said particulate media of the filter layer.

Abstract: An underdrain lateral for a liquid purification system is described. The lateral has three chambers, a primary chamber, a compensating chamber, and gas chamber. Turbulence is minimized during cleansing of the purification media by isolating the gas from the liquid and the backwash liquid. This is accomplished by feeding gas into the gas chamber so that the chamber is occupied by gas only during cleansing. Orifices in the wall between the primary and compensating chambers and in the baffle between the compensating and gas chambers provide compensation for even distribution of liquid in the lateral. The design also enables the use of cut out in the gas chambers to equalize gas pressures and flow among the laterals and throughout the system bed and cut outs in the primary chambers to equalize liquid pressure and flow along the laterals and throughout the system bed.

Abstract: A flow collector/distributor for a water treatment tank comprises a housing proportioned to communicate through a wall of the water treatment tank to provide flow communication between the tank interior and the tank exterior. The collector/distributor defines an inner end to project inwardly from the tank wall and an outward end to face outwardly from the tank wall. A plurality of slots are defined in the tubular housing, positioned to communicate with the tank interior when the collector/distributor is seated in the tank wall. The slots are of a width which is narrow enough to permit water flow therethrough while substantially preventing passage therethrough of water treatment material present within the tank.

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: 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.

Abstract: A filter system for achieving continuous filtering by the provision of three filter chambers disposed about a common vertical axis, each containing a filter bed comprised of buoyant particles through which the fluid to be filtered is passed in an upward direction and wherein provision is made for rehabbing the beds of particulate material as they become filled with solids, preferably in succession to enable continuous operation.

Abstract: A suction control filter system for swimming pools is provided, in which the vacuum filter of the water recirculation system features positive suction backwash of the filter during cleaning.

Abstract: A granular media filter has an underdrain system for use in a granular media filter comprising perforated lateral conduits arranged for the distribution of air and water for scouring and backwashing of the filter. Each conduit is in the form of a single linear conduit containing two or more separate axially parallel ducts, each duct having an external wall in common with the conduit, which wall is provided with axially spaced apertures for emission of water or air, there being no intercommunication between the ducts. The underdrain system itself also forms a feature of the invention.

Abstract: A system for removing contaminants from water prior to supply to service by entraining a controlled quantity of air into the water to oxidize the contaminant particles and then filtering the contaminants in a combination aeration/filtration tank. The filtration tank includes an adapter which cooperates with a filter tank and the control valve for the filter tank to facilitate precipitation of water through the filter bed and venting of excess gases from the tank in addition to the filtering and backwash functions of the filter tank. The adapter is designed to cooperated with the control mechanism and tank of filter tanks used in currently available water conditioning systems.

Abstract: A coarse media flocculator utilizes buoyant media restrained against upward movement in a flocculator chamber whose cross-sectional area increases uniformly in the direction of vertical flow, thereby providing a uniformly tapering velocity gradient. The height of the media bed within the chamber is alterable, thereby changing its depth and cross-sectional characteristics within the tapered chamber. The velocity gradients of the flocculator can thus be changed independent of flow. The media restrainer comprises interlocked cooperating gratings each respectively joined to an opposite wall of the flocculator housing by a tracking mechainsm. Upon manipulation of a motor device, one grating is horizontally extended or retracted, producing a lowering or raising of the restrainer as its cross-sectional area is respectively enlarged or reduced.

Abstract: An improved unit for removal of tannin and lignin from water is disclosed, which features a cylindrical tank containing a tannin/lignin-adsorbing resin bed and a distributor tube/water distributor assembly. The assembly comprises a distributor tube extending from an orifice in the upper portion of the tank to a lower distributor assembly, and a riser tube having an open end disposed near the lower distributor assembly and communicating with an upper distributor located beneath the surface of the resin. A water flow restrictor is provided in the lower distributor assembly, such that when water is passed downwardly through the distributor tube in a backwash mode, some of the water is injected into the riser tube. This causes the backwash water to flow into the resin bed at its lower portion and to carry resin up through the riser tube to the upper portion of the resin bed.

Abstract: An apparatus for use in conjunction with a pressure vessel, having a tubular conduit extending into the interior of the pressure vessel. The outer end of the conduit is rigidly fixed to one end of the pressure vessel in a pressure-tight connection. The inner end of the conduit is attached to a saddle at the other end of the pressure vessel, where the saddle is adapted to slidably receive the conduit such that upon expansion of the pressure vessel due to pressurization, the conduit will move independently relative to the saddle.

Abstract: A bed of particulate material of varying sizes is located within a vessel. This bed comprises an upper and lower region. Particulate material is supplied continuously to the center of the upper region so as to form a peak shape which descends downwardly and radially outwardly from the center. Liquid to be filtered is introduced to this peak shape and is filtered downwardly through the bed. A majority of the filtered liquid passes through a screen located between the upper and the lower regions into a screen filtrate enclosure. The remaining liquid continues to the lower region. This liquid and dirty particulate material are transported by an air lift tube from the lower region to a position above the upper region. At this position, the particulate material is washed and supplied to the center of the upper region. The remaining liquid and filtered particles are removed from the vessel.