Abstract: The present invention discloses a landslide experimental device for remotely controlling and simulating a constant seepage flow and weight load and an experimental method thereof in centrifuge test. The landslide experimental device includes a model box, a landslide device, a near-constant water flow control box, remote control devices and a water outlet pipe. The landslide device comprises a landslide model, a load balancing device, a weight storage device, an angle control panel and a tension bar. The remote control devices are arranged at the control box water outlet, at the control box water inlet, on the tension bar, on telescoping control sensors and on the weight storage device, respectively. With the present invention, the influences on the stability of landslide model with different landslide angles under the condition of the seepage flow and weight load can be simulated.

Abstract: Aggregate washing systems are described including mechanisms for slurrying, washing and/or dewatering aggregate material.

Abstract: Vibratory material classifiers are disclosed. Some embodiments include eccentric shaft assemblies having removable eccentric weights. Some embodiments include oil access and indicator conduit extending from the interior to the exterior of a classifier.

Abstract: Systems and methods for separating fluids from drill cuttings. Specifically, the invention relates to shakers that incorporate a vacuum system and methods of operating such systems to effect a high degree of fluid separation. The system and methods are effective across a variety of screen sizes, vacuum flows and vacuum designs.

Abstract: One or more toy pieces can be picked up and collected by various embodiments of a toy piece collection system. The system can consist of a bin operatively connected to a pressure source and an inlet. The bin may house a sorting structure that consists of a plurality of separated members each having at least one sorting aperture arranged to separate and sort materials by size.

Abstract: An assembly and method for gravitationally separating gold from particles, and specifically for separating small components of gold, less than 1 millimeter from small particles. A series of sieves having graduated mesh sizes, and arranged in a sequential, stacked configuration sieves the aggregate of large particles and larger components of gold. The remaining small particles and smaller components of gold fall into a container. A pressurized column of fluid is forced into the container. The fluid has sufficient flow velocity to suspend the lighter small particles, but insufficient flow velocity to support the denser, high specific gravity gold. Gold has a large specific gravity relative to the fluid and particles. Gravity causes the gold to falls into a transparent collection conduit. Manipulation of valves enables gold to redirect to a collection bin. Fluid flow is shut, enabling small particles to be flushed out through gravitational forces and excess fluid momentum.

Abstract: Systems and methods for separating fluids from drill cuttings, specifically, shakers that incorporate modifications including vacuum systems and/or partitions and methods of operating such shakers to affect a high degree of fluid separation. The systems and methods are effective across a variety of screen sizes, vacuum flows and vacuum designs. The systems are also particularly effective in assisting in the separation of gases from drilling fluids.

Abstract: A system for dewatering a stream of slurry has a first and a second separator. The first separator removes objects above a first size, to produce a stream of primary treated slurry. The second separator removes objects above a second size from the primary treated stream, the second size being smaller than the first size. Optionally, a third separator removes objects above a yet smaller third size from the stream of secondary treated slurry. The first separator has a plurality of sieve mat supports alternately connected to a main support frame section and a movable support frame section so that the flexible sieve mat can be agitated by the movable support frame section, a collector being provided for collecting the primary treated slurry passing through the flexible sieve mat. In an optional step, water contained in the separated solids is removed.

Abstract: A system for dewatering a stream of slurry has a first and a second separator. The first separator removes objects above a first size, to produce a stream of primary treated slurry. The second separator removes objects above a second size from the primary treated stream, the second size being smaller than the first size. Optionally, a third separator removes objects above a yet smaller third size from the stream of secondary treated slurry. The first separator has a plurality of sieve mat supports alternately connected to a main support frame section and a movable support frame section so that the flexible sieve mat can be agitated by the movable support frame section, a collector being provided for collecting the primary treated slurry passing through the flexible sieve mat. In an optional step, water contained in the separated solids is removed.

Abstract: A three-stage separator system for separating the solids and liquids from a slurry includes a first stage having an inclined housing defining a liquid channel. A slot sieve is disposed over an open surface of the channel. A mechanical vibrator assembly imparts mechanical vibration to a vibration zone of the slot sieve. A slurry delivery apparatus delivers the slurry to the slot sieve. A second stage includes an inclined conveyer positioned to convey partially-separated solids and includes a drive mechanism driven at a speed to cause the partially-separated solids to tumble as they are transported up the conveyor. A third stage includes a press positioned to accept partially-separated solids passing out of the tunnel press restrictor.

Abstract: A screening apparatus for separating components of a material by vibratory separation which, in certain aspects, includes a vibratable box connected via vibration isolators within a container, the box including screening apparatus thereon or the vibratory separator having replaceable screening cartridges within a container. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Abstract: Methods and systems are disclosed employing a shale shaker for processing a mixture of drilling fluid and solids with multiple screen assemblies and conversion apparatus for switching flow to the screen assemblies between series flow and parallel flow; and in one aspect, a screen or screens for screening lost circulation material.

Abstract: Methods and systems are disclosed employing a quad-tier shale shaker for processing a mixture of drilling fluid and solids which solids include, in one aspect, lost circulation material (and/or material of size similar to the size of the lost circulation material). This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Abstract: A vibrating screen includes a frame, a screen supported by the frame, a vibration device coupled to the frame to vibrate the screen, a pressurized fluid spray assembly operable to discharge a pressurized fluid against the screen, a canopy coupled to the frame and movable between a closed position, in which at least a top side of the screen is covered by the canopy, and an open position, in which at least a portion of the top side of the screen is uncovered, an actuator coupled between the frame and the canopy to move the canopy between the closed and open positions, and a controller operably coupled to the actuator and the pressurized fluid spray assembly. The controller is operable to close the canopy and initiate operation of the pressurized fluid spray assembly in an automated sequence.

Abstract: The present invention provides a vibratory screening apparatus (1) for use in removing solids from a liquid feed, and a basket (4) therefore. The apparatus comprises a static outer housing (2), and a floating basket vibratable by a vibrator device (10). The basket mounts a stack (7) of screen assemblies (8) provided with respective flow directing trays (9) for receiving filtrates from the screen assemblies. A flow distributor (15) divides the feed into at least first and a second feed streams and directs them onto respective screen assemblies, and receives from the flow directing trays, filtrates from respective screen assemblies.

Abstract: A combination of prospecting equipment and apparatus, for the purpose of collecting precious minerals from mineral bearing sand and gravel, located in regions that are arid in nature, have little water or limited water usage, due to environmental concerns. The Wash Plant Unit comprising; A feed hopper for receiving and washing materials. A sluice box and apparatus for collecting precious minerals. A sluice box extension with a filter screen for separating gravel from sand and water. A filtration box with a sediment pan and screening devices for separating sand from water. A receptacle and implement holder for holding miscellaneous prospecting supplies. A water pump with a suction and discharge for drawing and dispensing water. All built upon and attached to its own water reservoir, which is attached to a frame with a hitch, built upon a set of axles with tires, suitable for being transported by an All Terrain Vehicle.

Abstract: A vibratory separator having a basket for supporting screen assembly apparatus, the basket having an interior surface, vibrator apparatus connected to the basket to vibrate it and the screen assembly apparatus releasably secured thereto, seal apparatus connected to the screen assembly for sealing an interface with a part of the interior surface of the basket, the seal apparatus including a seal holder removably holding a seal member, the seal holder having a projection projecting into a recess of the seal.

Abstract: A unibody structure for a screen assembly for a vibratory separator, the unibody structure, in certain aspects having an integral body member with a portion having a plurality of spaced-apart openings in a pattern of a plurality of spaced-apart screening openings and including a pair of spaced-apart integral side members made of folded portions that form the pair of spaced-apart integral side members, a pair of spaced-apart integral end members made of folded end portions, the pair of spaced-apart integral end members each with a first end member and a second end member, the first end member configured with a shoulder support portion for sealingly abutting a screen ledge end of an adjacent screen, and the second end member configured with a ledge portion for sealingly abutting a shoulder portion of an end of an adjacent screen, and the plurality of spaced-apart openings of the integral body member defined by a plurality of spaced-apart strips, each adjacent pair of the plurality of spaced-apart strips definin

Abstract: A flow diverter and a vacuum blower for vibrating screen separator assembly. The flow diverter decelerates and increases the exposed surface of materials. The exhaust blower removes vapors from the materials.

Abstract: A flow diverter and a vacuum blower for vibrating screen separator assembly. The flow diverter decelerates and increases the exposed surface of materials. The exhaust blower removes vapors from the materials.

Abstract: A vibratory separator including basket apparatus for holding screening apparatus, at least one upper screen apparatus in the basket, the at least one upper screen apparatus having a fluid exit end, at least one lower screen apparatus in the basket below the at least one upper screen apparatus, fluid flowable from the at least one upper screen apparatus down onto the at least one lower screen apparatus, flow diffusion apparatus mounted below the fluid exit end of the at least one upper screen apparatus and above the at least one lower screen apparatus, so that fluid flowing down from the at least one upper screen apparatus flows onto the flow diffusion apparatus and is diffused thereby, and vibrator apparatus for vibrating the basket and the screen apparatus therein.

Abstract: An integrated gasket and screen frame for a screen assembly for use with a vibrating shaker. The screen assembly includes a tubular frame having a top side and an under side. At least one screen cloth is affixed to the top side of the frame. A slot in the tubular frame has a width. An elastomeric gasket has at least a portion wider than the width of the slot so that the gasket may be press fit and mechanically locked into the slot and held therein.

Abstract: A screen system employs a resiliently mounted housing, a vibration generator mounted to the housing, a mounting frame fixed to the resiliently mounted housing and a support surface. This system receives a screen including a screen frame and pre-tensioned screen cloth. The frame includes an inwardly extending mounting flange accessible from below the screen when placed in the housing. Clips pivotally mounted relative to the mounting frame include a first rounded lever extending upwardly to selectively engage the inwardly extending mounting flange. Second levers extend downwardly to cooperate with actuators. The actuators include inflatable bodies with contacts which, upon inflation, force the clips to engage the inwardly extending mounting flanges. This engagement retains the screen on a resiliently mounted housing and is able to further tension the screen in place.

Abstract: A vibratory separator for separating components of material introduced to the vibratory separator, the vibratory separator in one particular aspect being a shale shaker, the vibratory separator including a basket for holding screening apparatus, the basket having two sides spaced-apart by a first end at which the material is introduced into the basket and a second end spaced-apart from the first end, components separated from the material exiting the basket from the second end, vibrating apparatus connected to the basket for vibrating the basket, screening apparatus mounted in the basket, the screening apparatus having at least a first portion and a second portion, the first portion at the first end of the screen and the first portion lower in the basket than the second portion, receptacle apparatus below the screening apparatus for receiving material components flowing through the screening apparatus, maintenance apparatus for maintaining height of a portion of the screening apparatus, and a pool of the mate

Abstract: A new and unique design use of directional and re-directional raised ribs on a solids control filtering screen, such as those used in drilling wells for hydrocarbons and other substances, in conjunction with a coordinated system of hanging such screens and directing and redirecting the flow of trapped solids over the surface of such screens, is disclosed for use with a vibratory shaker. The invention counteracts the natural tendency of trapped solids to migrate to and congregate in the lowest areas of a suspended screen and facilitates a dryer fluids discharge, as well as more effectively utilizing the available screening surface area, and therefore the invention reduces the incidence of screen wear and tearing and increases the flow rate conductants and drying capabilities through the screen.

Abstract: A flow diverter and a vacuum blower for vibrating screen separator assembly. The flow decelerates and increases the exposed surface of materials. The exhaust blower removes vapors from the materials.

Abstract: A screen assembly has been invented which has a base, at least one layer of screening material on the base, and at least one ramp formed in the at least one layer of screening material.

Abstract: A vibrating dual deck dewatering unit which includes a lower screen deck and an upper screen deck. Material being processed by the unit is discharged from the upper screen deck onto the lower screen deck in such a manner that excess water is allowed to backflow beneath the upper screen deck, while solids are directed in an opposite direction. The upper screen deck is provided with a jagged discharge lip which creates interruptions or gaps in the flow of discharged solids. The excess water which is discharged from the upper screen deck is allowed to backflow through the interruptions or gaps in the discharged solids that are created by the jagged discharge lip of the upper screen deck.

Abstract: A new screen has been invented for use with vibratory screening apparatuses which has, in certain aspects, a base, a first screen on the base, and a scalping screen on the first screen, the first screen assembly including a corrugated screen having alternating crests and valleys, and the second screen assembly secured to the crests of the corrugated screen, and cushion members disposed between the first and second screen assemblies, the corrugated screen of the first screen assembly having first end openings beneath valleys on two sides thereof, and end plugs within the first end openings to sealingly close off the end openings to fluid flow. The present invention has other embodiments disclosed herein from. A screening apparatus or shale shaker and methods of their use have been invented that use such screens.

Abstract: A mining system and related methods are disclosed by which gold and/or other heavy metals are recovered at multiple sites along a continuously hydrated ore processing route. The gold-bearing ore and primary or carrier water are dynamically and circuitously displaced to segregate the gold, and precipitate the gold particles into predetermined recovery sites along the flow path of the mix. Boil box recovery sites are selectively provided for recovery of nuggets and smaller gold particles. Secondary water churns and disrupts the primary carrier flow of the mix through each boil box.Each trough includes a dynamic segregation box having successive compartments across which a top layer of turbulent flow continuously occurs. Within each compartment, during use, a bottom layer of laminar flow takes place not only within each compartment, but from compartment-to-compartment.

Abstract: A multi-functional linear motion shaker includes a rectangular outer support frame with a tank, often referred to as a "possum belly", for receiving the incoming drilling fluid flow. A set of adjustable louvers and a tray is positioned on the side of the tank. The adjustable louvers and tray serve to screen out the larger and stickier drill cuttings or solids. A vibrating deck assembly is positioned within the outer support frame adjacent the tank and tray assembly. The vibrating deck assembly is of a double deck design whose upper and lower decks include cross members to support the mud screens. The upper and lower decks are vertically spaced apart and connected together into one unit by vertical structural members. A moveable plate is positioned on the upper deck adjacent the adjustable louvers and tray. This moveable plate can be positioned to direct drilling fluid flow to the upper deck or repositioned to redirect fluid flow to the lower deck and bypass the upper deck.

Abstract: A vibrating screen unit for dewatering dredged material. The vibrating screen unit includes a frame and a top screen deck, a middle screen deck and a bottom screen deck. The middle screen deck includes a splitter which extends across the width of the frame and comprises alternating closed channels and screen rows which alternate across the width of the frame.

Abstract: The invention relates to an apparatus in the form of a multi-cell installation, and a method for the recovery of metal values from a liquid medium 16 in the form of a pulp or leach solution in which a continuous supply of a liquid medium 16 is continuously brought into reactive contact with a high concentration of a particulate material 17, and in which the particulate material is continuously separated from the liquid medium. The installation comprises a plurality of vessels 10, 12 for the liquid medium independently driven agitation means 34 for maintaining particulate material 17 in suspension; a screen 22 arranged at an angle to the horizontal and located above the liquid level; and an axial flow impeller 26 for causing an upward flow of the liquid medium 16 to the screen 22.

Abstract: A vibratory screen for a vibratory screening machine consisting of a plate having a plurality of spaced openings therein, a coarse screen located in contiguous relationship to the plate, a fine screen on top of the coarse screen, a finer screen on top of the fine screen, and a topmost screen which is less fine than the finer screen and epoxy binding all of the foregoing screens to the plate at the borders of the openings. A vibratory screening machine having a tank for receiving a liquid-solid mixture, a plurality of screens of the foregoing type mounted to produce a sealed partition in the tank, an inlet conduit for supplying a liquid-solid mixture to the screens at a rate to maintain a head of the liquid-solid mixture above the screens, a vibratory motor attached to the tank to vibrate the tank, an outlet in the tank below the screens, and a liquid trap located at the outlet to thereby prevent air from entering the chamber in the tank below the screens and to draw a slight vacuum in the chamber.

Abstract: A process for the recovery of coal particles having a maximum dimension of less than 2 mm from coal tailings including the steps of forming a slurry (101) of tailings having a pulp density of from 10 to 30% by weight; feeding the slurry into a hydrocyclone (103) to produce an underflow second stream which contains the tailing particles over a predetermined size and some of the gangue particles smaller than that size and an overflow stream containing the coal particles smaller than the predetermined size and the balance of the gangue particles, the hydrocyclone (103) being operated such that the underflow stream has a pulp density of from 40% to 60% by weight; adjusting the pulp density of the second stream, if required, to from 20 to 50% by weight; passing the repulped second stream over a rapped or vibrated sieve screen deck (105) having a wedge wire sieve screen with a radius of less than 2 m, an arc angle of from 45.degree. to 60.degree.

Abstract: A continuous process for the separation of small particles from larger particles in a biological preparation passes a liquid stream of the preparation through a first filter or screen, which retains larger particles, passing smaller particles in the liquid. The large particles have retained on their surfaces wetting water, in which are entrained some of the small particles. The large particles are directed to a liquid having a concentration of smaller particles lower than the concentration of smaller particles in the wetting water, and mixed therein. The smaller particles separate from the larger particles in the mixed suspension, which is then directed to a second filter or screen, for further separation. The smaller particle/liquid stream may be recycled to the biological preparation stage, the liquid suspension for the large particles, or to a separator means where the smaller particles are separated off from the liquid stream.

Abstract: A vibratory filtering screen assembly comprises an upwardly inclined member (12) on which is mounted the main filtering screen (14). At the exit (16) of the main screen is a secondary screen module (20) comprising a plurality of transverse supports (22) of rectangular section on which is mounted a screen (24) held in position by a silicon beading (26). Surrounding the secondary screen is a perimeter border or dam (28) for containing the discharge which is passed on to the secondary screen. In operation slurry is fed onto the main screen (12) where vibration passes it to exit (16). Wet solids components of the slurry drop into the secondary screen (20) where the vibration continues to dry out the solid particles, waste liquid being diverted away by a plate (30).

Abstract: A soil rinsing apparatus includes a rinsing and sieving element with two successive sieve regions for rinsing and sieving the soil. Water is supplied in order to reduce the soil to slime and to separate harmful substances from the soil. In order to reduce the water consumption and to improve the soil processing quality fresh water is supplied to the first sieve section and water leaving the first sieve section is collected and fed to the second sieve section which precedes the first sieve section.

Abstract: A method for sorbing metal values from a slurry containing the same is disclosed. The slurry is advanced through a plurality of vessels arranged in series while countercurrently directing a sorbent through the vessels. Metal values are sorbed from the slurry in each of the vessels by mixing the pulp to achieve homogeneity with the pulp being maintained at a predetermined level in the vessel. A portion of the homogeneous pulp is directed into an interstage screening system disposed within the vessel and at least partially submerged beneath the predetermined pulp level, whereby the sorbent is separated from the slurry. The separated sorbent is primarily returned to the vessel while a portion of the sorbent is removed from the interstage screening system.

Abstract: In carbon-in-pulp (CIP) and carbon-in-leach (CIL) processes, especially those utilizing pure oxygen instead of normal air to increase the overall efficiency of the cyanide leaching-adsorption process in the recovery of gold and/or silver from ores, the screen within each tank which surrounds the slurry outlet is kept clean. The cleaning action is accomplished by linearly reciprocating the screen first slowly in one direction, and then quickly in another (to cause back flushing); or by rotating a cleaning rotor on the inside of a cylindrical screen. The cleaning rotor may be connected to the same shaft as an agitator disposed above a draft tube within the tank. The screen surface is tapered in its direction of movement, and during movement has a tendency to transport and concentrate the carbon (charcoal) particles at the far end of the slow stroke, and the concentrated particles can be withdrawn and recirculated to other tanks in the system.

Abstract: A hopper assembly for uniform distribution of sludge, in which distribution elements on the bottom of the hopper are rotatable about vertical axes to enhance uniformity of distribution of the sludge issuing from the hopper.

Abstract: A sorption vessel including a tank for retaining a pulp of an aqueous slurry and a sorbent at a predetermined liquid pulp level therein; and an interstage screening system disposed within the tank and at least partially submerged beneath the predetermined pulp level. The interstage screening system includes a housing for isolating the system from the pulp, thereby providing a hydraulic differential between the predetermined pulp level and the screening system; a conduit for selectively introducing the pulp onto the screen member, the pulp being urged through the conduit by the hydraulic differential; and at least one screen member disposed within the housing for selectively and continuously separating the sorbent from the pulp.

Abstract: A filter which is particularly useful with biological material is formed of porous piezoelectric material such as PZT or Polyvinylidene fluoride. By an application of a voltage to the piezoelectric material, the filter body is caused to vibrate so as to inhibit fouling. In a modification, the piezoelectric material is not itself porous but is bonded to a filter membrane such that vibrations of the piezoelectric material are transmitted to the membrane. Through suitable control of the vibration, the selectivity of the filter can be controlled. In other modifications the vibratory movement of the filter membrane can be produced in other ways such as electro-mechanically.

Abstract: In carbon-in-pulp (CIP) and carbon-in-leach (CIL) processes, especially those utilizing pure oxygen instead of normal air to increase the overall efficiency of the cyanide leaching-adsorption process in the recovery of gold and/or silver from ores, the screen within each tank which surrounds the slurry outlet is kept clean. The cleaning action is accomplished by linearly reciprocating the screen first slowly in one direction, and then quickly in another (to cause back flushing); or by rotating a cleaning rotor on the inside of a cylindrical screen. The cleaning rotor may be connected to the same shaft as an agitator disposed above a draft tube within the tank. The screen surface is tapered in its direction of movement, and during movement has a tendency to transport and concentrate the carbon (charcoal) particles at the far end of the slow stroke, and the concentrated particles can be withdrawn and recirculated to other tanks in the system.

Abstract: A screen unit for a screening machine comprises a screen layer which is bonded to a screen frame spanning an opening thereof. The screen layer is uniformly heated before such bonding is effected so that cooling after bonding generates a tension in the screen layer to allow it to have a trampoline or drumhead vibratile action. The tension is maintained by a reinforcing frame embedded in the frame body.

Abstract: A vibratory screening device for dressing, sizing, desliming, and dewatering feed streams of fine particulate material is comprised of a vibratory sieve bend screen and a vibratory planar screen deck. The sieve bend screen is positioned at the feed end of the planar screen deck and is arranged so that linear vibratory motion acting on the sieve bend screen is substantially tangential to the arcuate midsection of the sieve bend. Advantageously, the two units can be mounted on a single frame so that only a single vibratory drive is required for imparting linear vibratory motion to both the sieve bend and the planar screen deck. The linear vibratory motion is preferably at an angle of about 40.degree. to the main planar deck and imparts a counter-current force to the fine particulate material flowing across the mid-section of the sieve bend.

Abstract: Separating equipment having a partially submerged vibratory screen in a screening device wherein oversized particles are induced to flow in a spiral direction outwardly from a central submerged area of the screen. A low velocity inlet manifold is employed centrally above the screen and a spray mechanism directs clearing spray to a peripheral area outwardly of the submerged portion of the screen. The screen is submerged by means of a chamber which extends outwardly above the lower most portion of the concaved partially submerged screen. The preferred embodiments specifically contemplates the screening of water borne wood pulp for the paper industry.

Abstract: A novel vibratory screening apparatus particularly adapted for the wet-screening of slurry mixtures containing particles and liquids, and more particularly to the separation of solid particles and liquids utilizes in combination a combined vibratory screening deck having a sieve bend portion upstream of an inclined substantially planar portion to effect substantial dewatering of the slurry mixture as it flows across the screening deck.

Abstract: A sieve screen deck, the screen of which comprises a plurality of horizontal wedge wires connected to an array of backing bars running longitudinally of the screen parallel to its fall line. The screen is connected to a frame at its two ends, at least one end being connected by resilient means such that the screen may vibrate and flex under the influence of rapping or vibrating means. Side walls are provided along sides of the sieve screen, to prevent material flowing over sides of the screen, are also formed of a resilient material in order that they do not substantially impede the ability of the sieve screen to vibrate and flex under the influence of the rapping or vibrating means.

Abstract: A vibratory screening machine for separating particles from fluid includes a fine mesh screen located within a vibratory basket. The machine further includes a supply for delivering fluid having the entrained particles from a source thereof towards the screen. A weir is disposed substantially adjacent the supply and overlies an upstream portion of the screen for directing the flow of fluid onto the screen. The weir includes an upstream end positioned adjacent the supply and a downstream end. A plate forming a dam is attached to the downstream end of the weir to form a pool of fluid on the weir. The weir includes at least one fluid flow opening positioned substantially adjacent the plate forming the dam. A flow directing plate is connected to the weir for directing the fluid flowing through the fluid flow opening towards the upstream portion of the screen underlying the weir.