Abstract: An apparatus for collecting and removing solid particles from a flowing fluid (5) includes a grid unit (6) including a plurality of stationary bars (1) being arranged to form a stationary bar unit (3). Each of the stationary bars (1) includes a plurality of steps (8). A plurality of movable bars (2) is arranged to form a movable bar unit (4). Each of the movable bars (2) includes a plurality of steps (8). The stationary bars (1) and the movable bars (2) are arranged side by side to alternate. A first parallelogram unit (11, 12, 13, 14, 17) is connected to stationary bearings (11, 12) to be pivotable in a plane about the pivot axes of the stationary bearings (11, 12) with respect to the stationary first bar unit (3). A second parallelogram unit (15, 16, 18, 19, 20, 21) is operatively connected to the first parallelogram unit and to the movable second bar unit (4).

Abstract: A filtration unit is provided with a self-cleaning mechanism which backflushes a screening element therein when it becomes blinded by solid material. A reservoir enables a head of screened liquid to be built up above the screening element. Upon blinding of the screening element, a subsequent rise in the pressure at the inlet of the filtration unit is detected by way of a rising fluid level in a vertically extending chamber. The above causes the opening of a discharge valve which enables a discharge flow to rapidly empty the reservoir through the screening element in a reverse direction, thereby clearing the screen. The clearing operation is carried out entirely hydraulically by the action of the screened fluid and thus no brushes, rakes or scraping devices are required.

Abstract: A raked bar screen for a storm overflow comprises a grid of parallel spaced-apart bars (1) attached at their ends to a framework (2,3,14). A comb assembly (4,5,6) has teeth (5) which engage in the spaces between the grid bars (1). The comb assembly is longitudinally reciprocable, whereby the comb teeth can sweep longitudinally back and forth between the grid bars. The grid bars are shaped to provide a straight central portion (10) and longitudinal end portions (11, 12) which are angled in relation to the straight portion. In use, sweeping of the comb teeth between the grid bars at the angled end portions drives out entrapped solid matter.

Abstract: A vertical pulp treatment vessel having a top and bottom, such as a continuous or batch digester, has at least a first substantially annular screen assembly disposed within the vessel between the top and bottom. A first substantially annular header is associated with the first screen assembly and first and second withdrawal conduits extend outwardly from the header and are in fluid communication with it. A barrier, such as a radially extending plate, is disposed in the header between the withdrawal conduits, the withdrawal conduits being adjacent each other (typically spaced from each other between about 2-30.degree., e.g. between about 10-20.degree.). A small, compared to the prior art, platform is provided for allowing access to the withdrawal conduits, and automatically controlled valves or like structures in or associated with the conduits, the platform having an arcuate extent of less than 180.degree., typically less than about 110.degree. (e.g. about 90.degree. or less).

Abstract: A screening apparatus (1) for sewage (13) including liquid (4) and debris and flowing in an oncoming tube (23) includes a conveyor assembly (6) and a separation area (2). The conveyor assembly (6) has a tube-like housing (7), an axle (8) driven by a motor, and a screw (9) provided on the axle (8). The conveyor assembly (6) with its axis (10) is arranged substantially vertical to convey the debris in a substantially upward direction. The separation area (2) of cylindrical shape to deposit the debris has an axis (5), an inner surface (41), a circumference, and openings (3) located about the circumference. The separation area (2) with its axis (5) is arranged in alignment with the substantially vertically arranged axis (10) of the conveyor assembly (6). The separation area (2) is connected to the housing (7) of the conveyor assembly (6), and includes an opening (17) serving as an inlet (40) for the sewage (13) into the interior of the separation area (2).

Abstract: An apparatus for separating bodies from a flowing liquid in which the apparatus includes a rotary conveyor helix (3) which is disposed at an angle with the horizontal and has a lower portion (10) which forms a screening device (40) and an upper portion where discharge takes place of material which has been displaced by the conveyor helix (3) from the screening device to the upper portion. At least one extra screening device (70) is disposed adjacent to the first screening device (40) for lateral transport to the first screening device of material which has been entrapped by the extra screening device.

Abstract: A water filter arrangement (10) for trapping gross pollutants flowing in a storm water system is provided in-line or at end-of-line of a storm water pipe. The arrangement comprises an inlet (14) and an inlet area (18) which directs incoming water (16) into a filter (20). The filter traps entrained gross pollutants and filtered water exits the filter via filter outlet (50). The outlet (50) and surrounding walls (58 and 57) are shaped to create a flow of filtered water which forms a water barrier which restrains the flow of water and gross pollutants from the inlet (14) to the outlet (52). The water barrier is located between the inlet (14) and the outlet (52) preferably closer to the outlet than the inlet. As the filter (20) becomes full and the flow of filtered water exiting the filter decreases the water barrier subsides.

Abstract: There is provided a guide roller assembly for use in a wastewater treatment facility comprising a pin and a guide roller, wherein the guide roller directly surrounds the pin and the pin rotates within the roller. There is also provided a guide roller assembly for use in a cog rake bar screen comprising a pin and a guide roller, the guide roller surrounding the pin, wherein the guide roller comprises a low-friction polymeric material and the pin rotates within the guide roller, the guide roller being free to rotate.

Abstract: A device for cleaning a bar rack of the type used as a screen to remove solid objects from the inlet of a water or waste treatment plant. Such devices typically have rake and a motor to drive the rake up and down the screen; the motor being connected to the rake via a rake arm. The disclosed rake arm has a variable length in response to contact between the rake arm or the rake with an object fixed to the screen or resting on the channel floor. This variable length allows the motor to drive the rake without interruption to its normal operation. Such device has particular utility in a front cleaned rack.

Abstract: Improved flow modifier assembly for a water intake system having a cylindrical intake screen prevents damage to fish and other aquatic organisms by providing a controlled velocity profile which causes the average flow velocity to closely approach the peak flow velocity. By extending two or more concentric tubular flow modifiers into one end of the screen, it is possible to achieve flow uniformities of more than 90%, as compared to a maximum of about 72% for a prior art configuration utilizing a single tube flow modifier. In addition, the size, weight and cost of screen required can be greatly reduced for a given peak flow velocity as compared to prior art devices.

Abstract: There is provided a guide track for cog rake bar screens comprising a metallic or nonmetallic guide track. There is also provided a guide track for cog rake bar screens comprising modular sections of guide track being disposed adjacent one another wherein guide rollers are guided within the guide track.

Abstract: A flume system for use with a floor mounted filtration apparatus and a floor mounted in-line machine section is provided. The machine section receives a flow of clean coolant from the filtration apparatus and has a series of machine outlets for outputting dirty coolant carrying particulate generated by the machine section. The system includes an elongated floor mounted flume disposed adjacent the series of machine outlets to receive the machine outputted dirty coolant. The flume has a slope of less than 2% and is coupled at an outlet end to the filtration apparatus. A discharge pipe is mounted adjacent a distal end of the flume for introducing a stream of coolant into the flume in a direction generally toward the outlet end. The stream of coolant introduced into the flume causes the flume to have an efficient hydraulic radius such that a minimal amount of coolant flows within the flume at a sufficient velocity to wash away the particulate from the flume into the filtration apparatus.

Abstract: An endless screen lifts fecal matter and sewer influent debris from an influent channel. The endless screen is powered by an externally positioned air cylinder driving a pawl and rachet to move the screen in an elliptical path. A tank positioned below a top drop point for the screen receives the fecal matter and debris. A paddle mixer breaks up the fecal matter for return to the sewer channel and a conveyor picks up the debris and deposits it in a landfill receptacle.

Abstract: A filter device for removing suspended solids from storm water includes support device removably retainable in an entrance to a drain, a cage cooperating with the support means, filtration devices removably attachable to the support and suspended in the cage for removing suspended solids from storm water entering the drain.

Abstract: A filtration system for storm drain collection boxes includes a helical coil frame, open at both ends, which coil frame is attached at an exit end to a vertical exit side wall of the collection box with the exit end aligned with a collection box outlet opening. The opposite, inlet end of the coil frame is suspended from a ceiling of the collection box, and a filter fabric "sock", which is also open at both ends, is positioned surrounding the coil frame. The inlet end of the coil frame is positioned at a level below the ceiling of the collection box. The filter sock normally filters out silt, sediment and solid materials from storm water run-off before the water enters the storm drainage system but the open inlet end of the coil frame and sock acts as an overflow during flooding conditions to permit storm water to bypass the filtration provided by the filter sock while still filtering out solid materials via a wide mesh screen.

Abstract: A cleaning device for moving debris adjacent a trash rack, the device having a mounting base for mounting the device adjacent the trash rack and a longitudinally extending arm having a first end and a distal end, the arm being capable of being driven in a direction generally parallel to the longitudinal axis of the arm, a debris collecting assembly located at the arm distal end, the debris collecting assembly comprising a fixed jaw mounted on the arm and a mobile jaw moveably connected to the fixed jaw by a jaw connecting structure to allow the mobile arm to both pivot and move inwardly with respect to the fixed jaw.

Abstract: A trash rack for filtering large volumes of intake water generally of the type available to power-generating facilities. The trash rack includes reinforcing rods fabricated of non-metallic materials in a pultrusion fabrication process. The pultruded reinforcing rods are substantially lighter than prior steel reinforcing rods. The pultruded rods are flexible enough to give under impact and high-loading without fracture or permanent distortion, yet are strong enough to withstand the type of loading commonly experienced by such large-volume trash racks.

Abstract: A rain cover 10 prevents leaves and other debris from plugging a conventional gutter G, while rain water from the roof of a building is transmitted to the gutter by surface tension. The cover includes a main plate 14 inclined for allowing water and debris to pass by gravity from an upper portion 30 to a lower portion 32. A front portion 16 of each of a plurality of traversely spaced fins 14 extend laterally beyond an outer wall of the gutter. Pairs of adjacent fins 14 are separated by a uniform traverse gap of less than 0.05 inches to significantly increase the return of water to the gutter by surface tension with the fin walls. The cover may be economically manufactured from plastic or metal, and may be easily installed on an existing gutter system. The separation device of the present invention may be used in other applications to separate solid debris from a fluid.

Abstract: Debris removing screen basket and overflow apparatus embodiments for use in a storm collection sewer. The device has two embodiments, each including a central panel with foldable wings in each side of the central panel. During initial assembly, the wings are folded up around the central panel for insertion through a manhole cover. Each wing can have an optional extension panel. In the first embodiment, the wings, extension panels and the central panel form a single type panel that is inclined at a variable angle so as to suit various floor conditions at a particular location. Both wings and extension panels have angled deflector top portions, while the central panel does not. A screen mesh basket is supported behind the central panel. Storm water and debris fill up the area in front of the apparatus. The rising water when reaching the height of the deflector portions is forced over the central panel and into the basket.

Abstract: A diverter screen for efficiently handling solid and floatable objects in combined sewer overflows and storm water runoff systems is disclosed. The screen is formed of a mechanical bar screen, one or more regulator or overflow chambers, and a deflector plate for diverting the solids and floatables into the outgoing sewage interceptor channel. The bar screen sits on a shelf in a concrete channel, and is sized to capture solids and floatables that must be prevented from entering the rivers, lakes or oceans The bar screen uses a downward rake motion to push solids and some floatables into the outgoing interceptor, while other floatables are allowed to drain out as the regulator channel drains.

Abstract: A method and apparatus for controlling the fluid flow through a waste fluid inlet channel, such as for a sewage treatment plant, includes a weir that may be inserted into the channel. The weir may be one or more plates that serve to reduce the effective cross section of the channel. The plates may be shaped so that the channel is more restricted at greater depths, or may be combined to form such other shape, in order to provide desirable flow patterns. Plates may be added, removed, or exchanged with different sized plates, to accommodate a range of fluid volume at a desired flow rate. The plates may combine with a bar rack, and will not interfere with the cleaning thereof. The plates may be positioned to allow grit to flow through without impediment.

Abstract: A storm drain filter (10) functioning to remove selected substances from water flowing through a municipal storm drain. The storm drain filter (10) has an absorption filter (18) functioning to absorb selectable substances from a liquid. The absorption filter (18) comprises an absorption filter frame (18A) enclosing an absorption filter absorbing material (18B) between pairs of at least two absorption filter longitudinal retainers (18C) and at least two absorption filter transverse retainers (18D). The at least two absorption filter longitudinal retainers (18C) and at least two absorption filter transverse retainers (18D) function to retain the absorption filter absorbing material (18B) within the absorption filter frame (18A). A tray (16) functions to support the absorption filter (18). The tray rear (16B) comprises at least one orifice (16BA) functioning to permit liquid to flow therethrough.

Abstract: The segregating unit of the invention is installed in a sewer pipe section having an upstream end and a downstream end, and a peripheral wall including a floor and a ceiling. The segregating unit comprises a bar screen having two straight panels composed of horizontally disposed, vertically stacked, spaced-apart bars. The two panels span the whole width and height of the pipe in a downstream convergent fashion, thus forming a V at their adjacent edges which open adjacent the pipe floor portion into an elongated, rigid, cylindrical sleeve member radially smaller than the pipe and upwardly inclined, extending through the pipe ceiling. The sleeve member comprises an output mouth located outside the pipe section, which opens into a storage box cart. An endless screw is coaxially installed inside the sleeve member and is driven into rotation by a motor.

Abstract: A screen system for a digester for continuous cooking under raised pressure and temperature of fiber material in a vertical vessel, where input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is circular and which is assembled by means of welding, and which is fitted into the digester shell by means of welding.

Abstract: The screening apparatus of the invention has a main cylindrical chamber linking a waste water inlet pipe to a refuse pipe and to an overflow outlet pipe. The waste water inlet pipe conveys water from a city sewer duct or the like, and this water is destined to be conveyed to a water treatment plant through the refuse pipe. However, during important storm water flow rate conditions in the waste water inlet pipe, the water level in the main chamber will rise since the refuse pipe will overflow due to a too large quantity of water. The screening apparatus includes a coaxial, cylindrical rotor defining a vertical through channel, and an annular grate being located intermediate the top and bottom of the main chamber and extending from the bottom edge of the rotor radially outwardly to the peripheral wall of the main chamber, where the annular grate is fixedly anchored. The rotor carries brooms adjacent the grate underface.

Abstract: A new raw water strainer includes a body having a closed first end and an open second end and defining a chamber therebetween. The chamber has a central axis intersecting the first and second ends. An inlet is provided including an inlet passage in fluid communication with the chamber. An outlet, spaced apart from the inlet, is also provided and includes an outlet passage in fluid communication with the chamber. A cover is included which is sized and adapted to be secured to the body to close the open second end. A screen assembly having first and second sides positioned in the chamber at an angle of about 45.degree. or less relative to the central axis is located so that it is between the inlet and the outlet. A basket assembly is provided which is sized and adapted to be removably placed in the chamber and to carry the screen assembly.

Abstract: A device for removing deposited material from a liquid in flume includes a conveyor for the deposited material that is disposed at an ague with respect to the plume and leads to a discarding point. The device includes a housing which houses a shaft and a conveyor screw mounted to the shaft. The shaft includes a hollow portion therein for housing a heater. The heater heats the conveyor for preventing material from freezing in the conveyor.

Abstract: A method and apparatus for controlling the fluid flow through a waste fluid inlet channel, such as for a sewage treatment plant, includes a weir that may be inserted into the channel. The weir may be one or more plates that serve to reduce the effective cross section of the channel. The plates may be shaped so that the channel is more restricted at greater depths, or may be combined to form such other shape, in order to provide desirable flow patterns. Plates may be added, removed, or exchanged with different sized plates, to accommodate a range of fluid volume at a desired flow rate. The plates may combine with a bar rack, and will not interfere with the cleaning thereof. The plates may be positioned to allow grit to flow through without impediment.

Abstract: An apparatus and method for separating material which includes solid and/or particulate matter from flowing liquid and/or gas. The apparatus includes a separation panel positioned in a fluid flow path, and the separation panel is housed in a separation chamber. Fluid can be introduced into the separation chamber by an inlet to establish a circular flow of the fluid within a confine of the separation panel, so material entrained in the fluid is trapped within the confine of the separation panel. The separation panel, separation chamber and inlet can be dimensioned and disposed such that as the apparatus operates, the flow of the fluid outside the separation panel is in a direction opposite to a direction of the flow of the fluid within the separation panel.

Abstract: A filtering apparatus (1) to filter solid litter from stormwater. The apparatus (1) comprises an inclined filter grate (2) which is located above an outlet (4). The grate (2) extends downwardly from the inlet (3) so that litter is filtered from the stream by the grate 2, with the litter being directed towards a catchment surface (8).

Abstract: An apparatus and method for removing solids from waste water includes a screen trough and screw auger combination. The screw auger's internal edge is connected to and supported by an axle. According to another feature of the invention, a replaceable edge of material can be used at the very edge of the spiral flighting of the screw auger. A still further optional feature can be the use of a spray bar to direct spray onto the faces of the spiral flighting of the screw auger.

Abstract: The water screening apparatus of the invention includes a conduit in which is positioned a discharge pipe opening through which water flowing in the conduit is to be dispatched completely during normal water flow conditions. The discharge pipe opening is positioned adjacent the conduit bottom wall portion so that as long as the water level does not rise above it, the water is completely dispatched therethrough. A bar screen is transversely disposed inside the water conduit and downwardly slopes from the conduit upstream end to the discharge pipe opening and covers the whole conduit width. When the water level rises above the discharge pipe opening, the water flowing above the discharge pipe opening will flow through the bar screen, the latter intercepting any macroparticles beyond a set threshold level carried by the water flow.

Abstract: A strainer for removing particles from a horizontal flow of effluent comprises a plurality of parallel fixed bars adapted to extend angularly downwardly into the flow of effluent and a set of parallel displaceable bars interdigited with the fixed bars. The displaceable bars are interconnected and connected to a drive mechanism to cause the displaceable bars to move in a circuitous path such that the displaceable bars move upwardly relative to the fixed bars to remove material engaged thereon and are thence thereafter lowered, whereby the material is lifted upwardly along the fixed bars. The displaceable bars are supported at their lower ends to the drive mechanism by a flexible connection apparatus so that the path of movement of the displaceable bars is unconstrained to minimize stress on the strainer should debris become lodged beneath the lower end of the displaceable bars.

Abstract: A rain cover 10 prevents leaves and other debris from plugging a conventional gutter G, while rain water from the roof of a building is transmitted to the gutter by surface tension. The cover includes a main plate 14 inclined for allowing water and debris to pass by gravity from an upper portion 30 to a lower portion 32. A front portion 16 of each of a plurality of traversely spaced fins 14 extend laterally beyond an outer wall of the gutter. Pairs of adjacent fins 14 are separated by a uniform traverse gap of less than 0.05 inches to significantly increase the return of water to the gutter by surface tension with the fin walls. The cover may be economically manufactured from plastic or metal, and may be easily installed on an existing gutter system. The separation device of the present invention may be used in other applications to separate solid debris from a fluid.

Abstract: A device for removing material screened or filtered out of a liquid flowing in a channel (3), especially in waste water treatment plants, is described. The device comprises an unpowered cylindrical grating surface (8) being immersed partly in the liquid and being formed by a plurality of substantially semicircular grating bars (10) located with distance to each other. The device further comprises a removing beam (12) rotatably driven about the axis (2) of the grating surface (8) and having removing elements (15) extending between the grating bars (10) from the inside of the cylinder to the outside. A conveying device (17) for the material is provided which is positioned with respect to the grating surface (8) and leads to a point outside the liquid in the channel (3), the device having a tube-like housing (22) with an opening (23) for the entry of the material and a driven screw (20) inside the housing (22).

Abstract: A mechanically raked screen system is used for preliminary waste water treatment. A screen is formed of a multiplicity of mutually parallel screen bars. The screen bars are oriented substantially transversely relative to a flow direction of a flowing liquid and forming screen spaces of a given width therebetween. A rake assembly rakes the screenings from the screen. The rake assembly includes two endless chains which traveling about sprocket wheels disposed laterally of the screen, and a rake attached to and extending between the chains. The rake is oriented substantially perpendicularly to the screen and travels with the chains for repeatedly raking the screen. The tynes of the rake are integrally formed from a single metal piece together with the rake plate. The vertical screen bars have a trapezoidal cross section, such that the leading side facing against the flow of the waste water is about twice as wide as the trailing side.

Abstract: A retractable traversing trash rake is provided for cleaning weedscreens or bar grates at an installation for generating power, filtering water, or the like. The trash rake includes a frame carrying a troney movable from a position inside the frame to a position outside the frame. The trolley carries a trash rake which may be lowered to clean the weedscreen, and the trolley may be moved to a position within the frame, where the trash rake may be opened to deposit collected debris into a hopper. The hopper is pivotally mounted for tilting in opposite direction to provide multiple dumping options. A method of cleaning weedscreen by using a retractable traversing trash rake is also disclosed.

Abstract: A debris removal device for rain gutter downspouts is inserted between the bottom of the downspout and the top of a ground drainpipe into which the downspout empties. The device comprises an elongate tubular housing open on both ends and having an unobstructed third opening formed transversely through the tubular wall between the ends. A partition, having apertures formed therein, extends generally transversely within the tubular housing at an inclination converging toward the third opening so as to divert debris, which enters the tubular housing through the first opening, out the third opening while enabling rainwater associated with the debris to pass through the apertures in the partition and out the second opening. Water flow guides associated with the partition divert rainwater away from the third opening to inhibit it from flowing out the third opening along with the debris. A dam is provided at the bottom of the third opening to likewise inhibit the flow of water out the third opening.

Abstract: An upper end of an outer pipe 16 is connected to a gutter, and a lower end of the outer pipe is connected to a water collecting box communicating with a sewer pipe. An inner pipe 18 which is arranged apart from an inner circumferential surface of a vertical portion 16d of the outer pipe at an outer circumferential edge of an upper portion thereof is connected to a storage-percolating box at a lower end thereof. A ring-like flow-separating piece 24 is disposed on an inner circumferential surface of the vertical portion of the outer pipe above an outer end of the inner pipe by a predetermined distance.

Abstract: The screen comprises a set of spaced parallel grating bars set at an inclination of about 35 degrees. The grating bars retain solids carried by the water flowing between the bars. These solids are automatically pushed down the bars and away into a collecting trough transverse to the bars by water streams flowing within longitudinal grooves formed from the top of the bars. The cross-sectional area of each groove decreases from the upper end to the lower end of the bar, so that the water accelerating down the bar grooves will constantly fill the same.

Abstract: A fish-excluding, self cleaning screen forming at least part of the boundary between a body of water such as a stream, and a bay from which water is to be withdrawn. On the bay side of the screen is a hub with a plurality of rotating wands that discharge water against the bay side of the screen to flush screen apertures and provide a periodic variation in flow through the screen to discourage passage of fish. Optional brushes may periodically brush the bay side of the screen to assist in cleaning the apertures.

Abstract: Debris removing screen basket and overflow apparatus embodiments for use in a storm collection sewer. The device has two embodiments, each including a central panel with foldable wings in each side of the central panel. During initial assembly, the wings are folded up around the central panel for insertion through a manhole cover. Each wing can have an optional extension panel that slidable attached to each wing by bolts/screws and nuts through longitudinal slots. In the first embodiment, the wings, extension panels and the central panel form a single type panel that is inclined at a variable angle so as to suit various floor conditions at a particular location. In the first embodiment the panel and wings have a front edge that sits on the inlet drain floor and a top edge touching an upper ridge of the basket.

Abstract: A device for removing floating and suspended debris from a liquid flow passed through a liquid flow flume (3) is disclosed, the device including a separator (9) positioned within the liquid flow flume at an angle with respect to the flume and extending across the path of the liquid stream for collecting floating and suspended debris thereon. An elongated conveyor assembly (10) having an elongated tubular housing (20) with a first conveyor portion (11) and a second conveyor portion (12) is also provided as a part of the device. The first conveyor portion of the conveyor assembly is positioned within the separator and extends therefrom, the first portion of the conveyor assembly, as well as the conveyor assembly, being independently supported with respect to, and without being formed as a part of, the separator.

Abstract: The device of the present invention is an end of the line sewage filter which comprises a metal framing that supports stainless steel walls, ceiling and floor and is built on and attached to a concrete platform. There is an oil filter mat which is placed on the floor of the structure to absorb some of the oil present in the sewage water. Holes in the floor of the device which align with holes in the concrete platform allow only the water and no trash or debris to exit the filter unit. Additionally, the filter unit is fitted with a door for easy access to the inside of the unit for cleaning.

Abstract: Headworks for preliminary treatment of wastewater in a sewage treatment plant provides for primary filtration of grit and other coarse debris, de-ragging in a flume which carries the water away from the filter, chemical addition in a chemical mixing tank and scum removal in a scum removal tank provided with a scum skimmer. The scum removal tank may also be provided with means for pre-aerating the wastewater, secondary grit removal means, secondary de-ragging means and a partial flume for flow measurement. A debris collection device in the form of a flexible fabric sock is also disclosed.

Abstract: A wire mesh rodent screen is inserted in the end of a corrugated plastic drainage pipe to prevent rodent incursions into the pipe. The screen is formed from two rectangular pieces of wire mesh. One piece is folded to form a cylinder with an in-turned lip at one end. The other piece is stamped to form a shallow dish of corresponding diameter to that of the cylinder. The dish is inserted in the cylinder to engage the lip and is secured to the lip by twisted wire ties.

Abstract: A screw conveyor including a feed screw formed, at least partially, as a shankless screw, a jacket surrounding the feed screw and a brush cooperating with the inner surface of the jacket for cleaning the same, with the feed screw including a plurality of substantially band-shaped screw threads extending along an imaginary helical line and arranged, when viewed in a transporting direction, one behind the other with an ever increasing distance from a screw axis so that each two adjacent screw threads form a step therebetween, and with the brush being arranged on the step formed by two outmost screw threads.

Abstract: A laterally moveable bar rake is provided for cleaning a bar rack installed across a water stream of a water treatment facility, storm water station or the like. The device includes a traveling framework for back and forth movement across the top of the bar rack, a telescoping arm with a rake head mounted on the lower end of the telescoping arm and a tilt mechanism for tilting the telescoping arm between raking and extension position so that the arm can be extended to the bottom of the bar rack or beyond, tilted toward the bar rack and withdrawn along the bar rack to rake debris onto a discharge hopper or conveyor.

Abstract: Apparatus for trapping and collecting debris including an in-line trap contained in a subterranean chamber having an inlet and an outlet for connection to an underground conduit such as a sewer or storm drain conduit. The trap comprises a net being closed on all sides except on an inlet side which faces the inlet to the chamber. The chamber is contained in a vault having a set of upper doors and the bag is attached to a frame structure having suitable supports which may be grasped such that the bag may be lifted upwardly through the doors for replacement. An overflow weir is provided for allow flow past the trap when the bag is full of debris. Sensing systems are further provided for detecting and signalling when the bag is full. A multi-bag system is also disclosed in which at least two bags in parallel are provided such that one bag may accommodate overflow when the other is being serviced.

Abstract: A hydraulic distribution and control unit has a chamber with an inlet (1a) and at least two subchambers. A partition wall (5) separates the subchambers one from another. One edge of the partition wall crosses the inlet to the main chamber, dividing the inlet into layers at different levels. The uppermost subchamber has an overfall edge (4a) and the lowermost subchamber includes an underflow (8).