Abstract: An endless media filtration system includes a housing with a pool forming assembly mounted between a pair of side walls. The pool forming assembly includes a central shaft with two spaced-apart containment discs rotatably mounted on the shaft between the side walls. An endless loop filter media belt is supported on an endless loop carrier belt and includes an upper run which is pressed against the peripheral edges of the discs to form a generally semicircular shaped pool along bottom arcs of the discs. A separation pan is located between upper and lower runs of the carrier belt to direct filtered liquid to one side of the carrier belt and out the bottom of the housing. A backwash assembly includes a first spray rod spraying air through the filter media, a second spray rod spraying water through the filter media, and a third spray rod spraying air through the filter media after the filter media has passed under the second spray rod.

Abstract: A modular filter apparatus is formed from stacked filter modules. Slurry to be filtered flows into the apparatus through a flowmeter and check valve into a header. The flow of slurry then branches off through feeders to each of the filter modules. Connected to the header is a slurry supply source, a cakewash supply source and a header drain. The modules are coupled to a hydraulic jack mechanism and an upper strongback.

Abstract: A method and device for drainage of a fibrous suspension where a converging drainage gap is formed between a first area and a second area. At least one of the first area or the second area is water permeable. A curved drainage zone is connected to the converging drainage gap. The first area moves relative to the second area. A fibrous suspension is introduced into the converging drainage gap. The fibrous suspension is transported by one of the first area and the second area as a layer. The first area and the second area are compressed closer together thereby causing drainage from the fibrous suspension through one of the first area or the second area.

Abstract: Disclosed is a separator that extracts solids from a manure slurry. The separator includes a powered rotating drive cylinder, a plurality of fins radially extending from the drive cylinder, and a flexible conveyor belt driven by the drive cylinder. The conveyor belt has a plurality of grooves positioned so that at least one of the fins contacts a substantial portion of one of the grooves as the drive cylinder drives the flexible conveyor belt.

Abstract: An etching device for preparing flexible blocks which can be used for printing in flexography, typography or dry offset generally includes an etching tank containing a bath (22) and brushes (3), a stirring and heating device, and an overfill system (20) for discharging the solution from the etching tank through an outlet duct (21) to a separation device. The separation device includes a reception vat (14) having an upper part which is equipped with a device (10) for separating the water and the polymer, and at least one filtering membrane (7).

Abstract: A treatment process for recovering protein, fatty and water component products from a float material produced by a waste water treatment system, wherein the protein and fatty components possess improved stability and are suitable for further processing for inclusion in various products, such as animal feed. The recovered water component can also be further processed before discharge into a sewer system.

Abstract: An apparatus and method for filtering particulate materials from a fluid stream wherein a dirty fluid stream is passed through a moveable filter media and the cleaned fluid stream is recirculated in part to form filter media by-pass preventing liquid curtains along the side edges of said filter media.

Abstract: An endless belt for supporting a continuous web of filter media and moving it through liquid filtration apparatus where a pressure differential is applied across the belt and media. The belt may be fabricated at relatively low cost while retaining the required tensile strength. The belt is formed from a plurality of unique, unitary portions termed "hinge members" which are arranged in longitudinal columns and lateral rows, a plurality of links between each pair of laterally adjacent hinge members and connecting rods extending the full width of the belt through aligned openings in looped portions of the hinge members and openings in the links. The hinge members are preferably formed from a continuous strip of sheet metal by stamping and bending operations, with the links providing added tensile strength.

Abstract: A magnetic separator apparatus having a configuration of barium ceramic magnets impregnated into polypropylene bars interspersed onto a conveyor belt which passes through an aqueous solution containing unwanted magnetic particulate. A plurality of spaced-apart magnet pairs embedded in each polypropylene bar are configured to provide maximum field penetration and holding strength of the magnets. Particulate attracted to the plurality of magnet pairs are scraped from the conveyor belt into a collection drawer.

Abstract: An apparatus for filtering machine coolant which includes a filtering belt conveyor having a series of bars on the outer surface of the filtering belt conveyor. The filtering belt conveyor is located inside of a tank along with a separate drag conveyor which removes fines that are sprayed off the filtering belt conveyor. There is a partition in the tank between the filtering belt conveyor and the separate drag conveyor.

Abstract: The present invention pertains to a system for transferring sludge. The system comprises a gravity deck machine having a belt which transports sludge and a first plow and at least a second plow disposed adjacent to the belt for dispersing sludge transported by the belt. The system is also comprised of a mechanism for moving the first plow and at least the second plow simultaneously from a first desired position to a second desired position. The present invention pertains to a method for transferring sludge. The method comprises the steps of placing the sludge on a belt of a gravity deck machine. Next there is the step of moving the sludge with the belt in a first direction so sludge is moved past a first plow and at least a second plow disposed at a first level in the sludge and dispersed by the first and second plows as the sludge moves past the plows. The second plow is positioned downstream of the first plow in regard to the sludge.

Abstract: Process and device for draining a fibrous pulp suspension. The process may include positioning two surfaces to converge in a downstream direction, feeding the fibrous pulp suspension between the two converging surfaces, driving at least one of the two converging surfaces to move the suspension with a relative translational velocity, and draining the fibrous pulp suspension through each of the two surfaces. The device may include two arcuate surfaces positioned to form converging surfaces. One of the two arcuate surfaces may include a drivable, pivotable, and rotatable cylinder having an outer sleeve with openings, the other of the two arcuate surfaces may include a screen positioned to be guided around at least a portion of the outer sleeve. The screen and the openings may form drains for draining the fluid pulp suspension.

Abstract: A filtration apparatus designed to remove solid contaminants from a liquid includes an endless filtration belt located in a liquid tank, so that liquid flows through minute openings in the belt into a liquid collection box located within the belt envelope. Edge areas of the belt are engaged with annular support walls carried by the tank side walls, such that a continuous seal is provided against migration of contaminants around the belt side edges. Contaminants collecting on the belt surface can be periodically removed by moving the belt across a spray system that dislodges the contaminants from the belt into the tank. A drag conveyor removes contaminants from the tank.

Abstract: A device to drain a fibrous pulp suspension including an arched surface that is impermeable. The arched surface, moreover, is surrounded by a permeable belt. The belt and the arched surface are able to be moved such that there exists a relative velocity between the belt and the arched surface. The arched surface includes recesses that are able to take up quantities of fluid.

Abstract: A bypass diverter box disposed upstream from conventional solids control equipment of a mud system of a drilling rig contains a drilling mud separation unit having a continuous-loop scalper screen that is driven in a continuous loop to separate, convey and discharge large amounts of gumbo, heavy clays and drill solids at the end of the separation unit. The flow divider box is a box-like housing with a verter plate, upper and lower baffle plates and a grate that allows drilling fluid or drilling mud to be selectively directed to the mud separation unit to be separated prior to passing to the conventional downstream solids control equipment or allows the fluid to bypass the separation unit and flow directly to the conventional solids control equipment.

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 filtering apparatus and filtering system where a hinge belt 10 of a hinge-belt type filtering apparatus 100 is continuously rotated by driving of a drive motor 65 such that hinge scrapers are rotated along a bottom plate 6b of the hinge filtering apparatus main body, from a horizontal part to a slope part of the hinge filtering apparatus main body.

Abstract: An oil skimmer of the endless belt type which is transportable as a unit is disclosed. The unit has an adjustment for adjusting the location of the axis of head pulley rotation and a floating tail pulley to assure accurate tracking of the belts on the pulleys and consistent and appropriate tension on the belt. The tail pulley features L-shaped spokes having legs that provide limited pulley-to-belt contact, minimizing oil transfer from the belt to the tail pulley, and also providing a mechanism for forcing oil against a descending belt reach to provide enhanced oil pick-up.

Abstract: A method for concentrating a suspension comprises the steps of providing a first surface; providing a second surface; introducing a suspension; moving the second surface relative to the first surface; and applying suction to the second surface. The first surface is relatively liquid-tight and includes a feature for increasing friction. The second surface is relatively liquid-pervious, faces the first surface, and is moveable relative to the first surface. Introduction of the suspension between the first and second surfaces forms a suspension web. Moving the second surface relative to the first surface and applying suction through the second surface causes dewatering of the suspension web and increased friction between the suspension web and the second surface.

Abstract: An apparatus for recovering an oil-based liquid from a body of liquid including the oil-based liquid. The apparatus includes a pair of cooperating rollers defining a nip therebetween, an endless loop of oil-based liquid absorbent material that passes through the nip and extends from the cooperating rollers along a path into the oil-based liquid in the body to absorb the oil-based liquid from the body, and a diverter engaged with the material and spaced from the cooperating rollers along the path. The material is conveyed by the cooperating rollers along the path from the body and squeezed at the nip by the cooperating rollers to force the oil-based liquid to flow along the material. The diverter guides the oil-based liquid away from the material as the oil-based liquid flows along the material from the cooperating rollers. A scraper is engaged with the material ahead of the cooperating rollers along the path to remove debris from material prior to the material passing through the cooperating rollers.

Abstract: An oil-water separator system and method to separate contaminated oil and water into clean water and free coalesced oil for collection and removal. The system includes a process tank for the oil and water, a pump to pump the oil and water through first and second stage oil-coalescing filters and through a full depth, fibrous filter under back pressure to provide filtered clean water of selected purity; typically, less than 20 ppm. The coalesced and filtered oil-water is returned and recycled to the process tank wherein a free coalescing oil layer forms on the surface, which free coalesced oil is removed by a belt skimmer for collection and removal.

Abstract: A pool cleaner floats on the surface of a pool. The cleaner includes a pump and filter, the filter being connected downstream of the pump. A vacuum head, connected by a hose to the pump, is moved around the pool, to direct water from the pool through the pump and filter. Due to the absence of any filter on the upstream side of the pump, the cleaner maintains its efficiency for a longer time than comparable cleaners of the prior art. The cleaner may also include a rotary strainer, placed upstream of the pump, for removing large pieces of debris. The strainer includes a slidable, transparent access cover which allows visual monitoring of the condition of the strainer, and permits easy access to the interior of the strainer, for removal of debris. In another embodiment, the cleaner includes a filter unit having a continuous sheet of filter material which advances automatically when the filter material previously exposed to the water has become clogged.

Abstract: The invention relates an apparatus for the dewatering of sludge and similar substances with a sludge chamber (20) provided with filter areas (25) having at least one sludge inlet being connected to a device (3) creating a hydrostatic filtration pressure. The sludge chamber is formed by pressure plates (22, 23) which can be pressed against each other to create an additional mechanical dewatering pressure by high pressure generators (33). Further there is provided a predewatering stage (2) containing filter areas which is forming a compensation container (5) and which is connected to a continuous sludge feed (6). The device (3) for creating the hydrostatic filtration pressure is formed as one or more syringe-like piston cylinder units (14) of preferably as one or more containers being changeable in volume.

Abstract: An improved filter apparatus includes an upper tank for holding dirty liquid and has a perforated plate. A lower compartment is beneath the plate for receiving liquid from the upper tank. A permanent filter belt for filtering particulate from the dirty liquid is arranged in a first circulating path across the plate. A first pair of drive loops are attached on respective sides of the belt. A drag conveyor having flights is arranged in a second circulating path across the plate. The belt is positioned between the plate and the flights of the conveyor across the plate. A second pair of drive loops are attached on respective sides of the flights. A driving mechanism is operable with the drive loops for indexing the belt and the conveyor along the circulating paths such that a fresh segment of the belt is periodically indexed over the plate while a dirty segment of the belt is being cleaned and the flights of the conveyor carry away accumulated particulate filtered by the belt.

Abstract: A method and an apparatus for the purification and treatment of liquids which are used for cooling and/or lubricating and contain impurities of metal and other materials, particularly for separating scale from the process water of cooling cycles in the metallurgical industry, wherein the liquid to be purified flows through intermediate spaces between plates arranged parallel next to each other in a container, and wherein the plates are arranged horizontally and are moved upwardly and/or downwardly transversely of the flow direction of the liquid. The solid particles are removed from the process water by sedimentation on the plates and additionally by a magnetic force which emanates from the upper sides of the plates.

Abstract: A method of separating particulate material suspended in a liquid from that liquid is described. The method includes the steps of: providing at least one upright tubular filter unit having a top end and a lower end; introducing a flow of the suspension into the tubular filter unit at one end thereof; and allowing the suspension to pass through the tubular filter unit trapping particulate material on an inside surface thereof. Apparatus in which the method of the invention is performed is also described.

Abstract: A gumbo separator has a continuous, inclined, moving screen belt which rides on and is supported by a perforated backing plate. The desirable portion of drilling fluids fed to the gumbo separator passes through the screen belt and backing plate and may be further processed to remove drill cuttings. The gumbo, containing gummy hydrated clays, are conveyed off the screen belt to the reserve pit. The gumbo separator provides a self cleaning screen belt, using a counter-rotating belt cleaning brush. A spray bar back-washes the screen belt with high pressure drilling mud to remove any gumbo lodged in the screen belt openings.

Abstract: A continuous-belt drilling mud separation unit is removably mounted in a box-like housing disposed in the flow path of drilling mud or drilling fluids and is operated by a motor on the housing. The separation unit includes a generally rectangular frame, a tensioning system, and a wide continuous belt in the form of a mesh screen, chain, self-cleaning chain link belt, or combination chain link belt and wire mesh screen which extends around rollers or sprockets and is driven in a continuous loop moving along the longitudinal axis of the frame. As drilling mud or drilling fluids are conducted onto the moving belt, liquids and particles smaller than the openings in the belt pass through the openings and liquids and particles larger than the openings are transported on the moving belt and are discharged off of one end as the belt completes its path.

Abstract: A separating device comprises an endless carrier belt which supports a filter belt. Suction boxes for drawing off filtrate are placed on the side of the carrier belt. The carrier belt protrudes laterally into the continuous slot of the vacuum box. In a large separating installation with long carrier belts and filter belts lateral displacements of the carrier belt occur during operation, whereby sealing becomes a problem. These problems are resolved according to the invention in that the suction box has a sealing member connecting onto the side edge of the carrier belt and this sealing member is displaceable laterally.

Abstract: A self-cleaning filter apparatus for use in removing particulate matter from a transport fluid, such as air, which includes a housing having a pair of spaced pulleys over which an endless filter belt is positioned to present two generally straight filter reaches and two generally curved filter reaches. The endless filter belt includes a permeable substrate formed as an endless belt and a plurality of pleats of filter media extending outwardly from the surface of the substrate so that the transport fluid can pass inwardly therethrough and deposit the particulate material on the exterior surface of the pleats. A suction nozzle and/or an air discharge device is positioned adjacent the outer surface of the endless filter at one of the curved reaches thereof for removing particulate matter deposited on the pleats as they pass along such curved reach.

Abstract: A filter press for reducing the water content in a starting material including a pressure chamber with a stationary lower plate and five hydraulically mobile chamber walls for applying pressure to the starting material.

Abstract: This invention relates to a belt press for dewatering sludge, such as sewage sludge. The press includes a camera to monitor physical operation of a gravity belt section of the press. A numerical control device uses electromagnetic radiation received from the gravity belt section to control the physical operation of the gravity belt section. An actuator device may be used to control a height of a weir for distribution of the sludge over the gravity belt section, and another actuator device may be used to control positions of ploughs which plough the sludge.

Abstract: A tracking system for a flexible moving belt wherein an adjustable protuberance arrangement on the belt support structure having a preselected removable and replacable frictional surface which serves to engage against an adjacent face of the belt to align and center such flexible moving belt.

Abstract: In a method and apparatus for removing water from sludge the sludge is introduced into an intermediate chamber from which it is fed into at least one sludge chamber having a filter surface. A hydrostatic pressure is built up in the sludge chamber to remove the water. The sludge chamber is then opened and the filter surface moved out of the sludge chamber to remove the filter cake. The hydrostatic pressure is generated by the sludge being transferred out of the intermediate container, after the continuous feed of sludge thereto has been cut off, by positive displacement of the volume of sludge from the intermediate container into the sludge chamber. The feed of sludge into the sludge chamber may occur simultaneously at a plurality of points from a corresponding number of intermediate containers.

Abstract: A continuous-belt drilling mud separation unit is removably mounted in a box-like housing disposed in the flow path of drilling mud or drilling fluids and is operated by a motor on the housing. The separation unit includes a generally rectangular frame, a tensioning system, and a wide continuous belt in the form of a mesh screen, chain, self-cleaning chain link belt, or combination chain link belt and wire mesh screen which extends around rollers or sprockets and is driven in a continuous loop moving along the longitudinal axis of the frame. As drilling mud or drilling fluids are conducted onto the moving belt, liquids and particles smaller than the openings in the belt pass through the openings and liquids and particles larger than the openings are transported on the moving belt and are discharged off of one end as the belt completes its path.

Abstract: A coolant reclamation device for use in conjunction with a conveyor of a first width wherein the conveyor receives solid contaminants and coolant from a machine tool operation. The conveyor transports the solid contaminants and coolant to the coolant reclamation device. The coolant reclamation device includes an elongate body which defines a chamber and contains an elongate opening which provides direct access to the chamber. The device also includes an elongate screen located over the opening. The coolant reclamation device is positioned relative to the conveyor so that the solid contaminants and coolant discharged from the conveyor impinge the screen whereby the solid contaminants remain on the surface of the screen and the coolant passes through the screen into the chamber. The elongate body contains a return port through which the chamber is in fluid communication with the coolant reservoir via a conduit.

Abstract: In a device for filtering, washing and drying a solid material-liquid mixture, using a liquid permeable filter cloth the mixture is first subjected to a pressure difference above and below the filter cloth, whereafter liquid is supplied to the mixture. The mixture present above the filter cloth is then dried according to the invention using radiation sources, the radiation from which has differing, preferably increasing, wavelengths in the processing direction. The wavelength lies in the infrared range. The applied wavelength is chosen subject to the product for filtering.

Abstract: The present invention entails a hog sewage separator for separating solids within the hog sewage from the water or liquid therein. The sewage separator includes a conveyor having a perforated solids retainer extending thereover so as to define an open channel through which the separated solids are conveyed by the conveyor. Hog sewage directed into the separator unit is separated as the water or liquid flows through the perforated retainer and spills over into an underlying lagoon. The separated solids are conveyed by the separator to a holding tank.

Abstract: An endless filter chain for filtering a liquid, such as sewage, which flows along a drainage duct is provided. The filter chain comprises strainer elements and connecting links interconnected to allow the strainer elements to pivot about respective axes of the connecting links while maintaining a small clearance between the leading edge of each strainer element and the trailing edge of the respective adjacent preceding element while the filter chain is trained about an upper and a lower turning roller. the filter chain does not comprise conveyor chains and the strainer elements can be sized to a width where they cover practically the entire width of the drainage duct. A method and an apparatus for filtering liquid as well as a strainer element and a connecting link are provided.

Abstract: A drum filter system includes a tank in which a rotary drum is disposed with liquid to be filtered entering inside the drum and exiting peripherally of the drum. The drum consists of a plurality of individual filter elements that are removable in a direction parallel to the axis of rotation of the drum. Each filter element is mounted using a unique mounting bracket assembly. A backwashing sub-system is provided that allows backwashing of individual filter elements as they are indexed into alignment with the backwashing sub-system. A conveyor conveys material removed from the filter elements by the backwashing sub-system to a point of discharge.

Abstract: A traveling water and fish screen device is provided for separating debris from channels of flowing of water. The device includes a carriage that is placed in the water flow and a screen mounted in the carriage which utilizes a continuous band of specially constructed rigid grate panels pivotally attached to and separated by support members in the form of cross bars between each panel. Special hinges are used which provide an extremely small gap between each panel and the adjacent cross bars, which gap is maintained as the as the band rotates around upper and lower cylinders in the carriage. Flaps are provided on the outward, upstream edges of the carriage to prevent debris from coming into contact with the cylinders, support chains or sprockets of the device. The rigid grate panels each have a first set of parallel cross members, and a second set of parallel cross members that are perpendicular to the first set.

Abstract: The invention provides a multi-stage apparatus for continuous waste water filtration, comprising a first tank provided with a waste water inlet pipe to supply waste water containing suspended solids to the tank, means for adding a coagulant to the waste water and an outlet pipe, a second tank receiving the mixture of waste water and coagulant from the outlet pipe, the second tank being sufficiently large to allow larger suspended solids to settle and being provided with a lower, openable port for discharge of the settled solids and having an upper weir for discharge of partially-cleared water, a continuously-driven, non-taut perforated belt, having a surface positioned to receive, at a first location, a stream of the discharged, partially-cleared water, the belt perforations being sized to enable the passage of clear water therethrough while retaining fine and coagulated solids on the surface for subsequent discharge at a second location, and the belt being non-taut to form a trough for retaining a body of wa

Abstract: Article conveyor apparatus and method are disclosed having fluid containment, and particularly for conveying of articles such as cans having an oily liquid thereon when transported from a processing or forming station. The articles are mass transported along a predetermined path that is closed to the atmosphere except for infeed and discharge of articles, with the articles being transported by engagement with a moving belt having openings therein. The inlet of a chamber, otherwise closed to the atmosphere and having negative fluid pressure maintained therein during normal operation, is positioned adjacent to the belt so that the negative pressure maintains articles in contact with the belt during transport along the predetermined path regardless of path orientation and also draws fluid from the transported articles and belt into the chamber through the openings in the belt and the chamber inlet.

Abstract: An apparatus for filtering a liquid slurry is described. The apparatus uses a pair of filter chambers formed by a pair of fixed plates, and a pair of opposed moveable plates. The moveable plates are moved into engagement with the fixed plates by the downward movement of a wedge member disposed between the plates and, the plates are bias so that when the wedge member is withdrawn, the plates will be drawn together opening the filter chambers. The chambers are sealed by opposed arcuate gaskets so that the sealing action is achieved by internal pressure rather than the pressure driving the plates together. A filter media is provided on a continuous roll which extends between the gaskets and is intended to carry the filter cake out of the chamber when the plates are separated whereupon the cake will be dropped from the filter media into a collection area so that the filter media can be reused.

Abstract: A filter or dust collector which includes a housing for supporting a filter media formed as an endless belt to move along said housing as dirty air passes inwardly through the moving filter media. The surfaces of the housing which support the moving filter media are formed with suction channels, and the filter media is provided with a sealing strip that includes a slack portion of flaccid material that can be drawn partially into the suction channel by the suction therein to enhance the seal along the side edges of the moving filter media.

Abstract: Methods and apparatus for concentrating a liquid suspension of solid particles are disclosed including providing a screening web moving in an endless path, folding the screening web into a tubular configuration at a first location along that path, unfolding the screening web from that tubular configuration at a second location along that path, introducing the liquid suspension into the tubular configuration of the screening web proximate to the first location so that liquid can pass outwardly through the tubular configuration of the screening web and a concentrate of the solid particles can be formed therein, and removing the concentrate from the screening web proximate to the second location.

Abstract: A screen assembly is described which comprises a flow channel along which sewage is intended to flow, in use, a continuous flexible belt entrained around roller or wheel means and projecting into the channel, and means for driving the belt. The belt is perforated such that relatively large solids carried along the flow channel in the sewage are trapped by the belt adhering thereto due to a pressure differential across the belt. Movement of the belt lifts such solids from the flow channel. The belt is of thickness less than or equal to 1 mm.

Abstract: The invention relates to a device for separating liquids and solids. An endless filter belt is used, beneath which a suction box is placed which can generate underpressure relative to the ambient pressure. The suction box is bounded on at least one of the sides by a stationary underpressure box, wherein the suction box is provided with a connecting element co-acting with the underpressure box. This enables embodying of the connection between the suction box and this underpressure box without for example rubber connecting hoses. This is important because rubber material cannot for instance withstand high temperatures.

Abstract: A dewatering apparatus of filter belt type has a guide member having a guide surface whose radius of curvature becomes smaller in the direction of belt travel. An endless roller chain travels along the guide member. A restricting sprocket has a pair of engaging tooth surfaces for engaging with rollers of said roller chain and is rotatably supported near one end portion of the guide member. Endless filter belts hold sludge between an upper filter belt and a lower filter belt. The filter belts are arranged to partly overlap on the rollers from a side of the guide surface of a larger radius of curvature and to depart from the rollers at a side of the guide surface of a smaller radius of curvature, whereby the upper filter belt and the lower filter belt are separated from each other to discharge the sludge. Driving rollers give a traction to the filter belts at a side at which the filter belts are separated from the roller chain.

Abstract: An apparatus for recovering oil-based liquid from a body of liquid including a first layer of the oil-based liquid and a second layer of a second liquid having an interface with the first layer is disclosed. The apparatus includes an endless loop of oil-based liquid absorbent material extending downward a vertical distance into the first layer for absorbing the oil-based liquid therefrom and a drive conveying the absorbent material in a substantially vertical path from the first layer. The apparatus also includes a guide submerged in the body of liquid directing the absorbent material through the first layer. The guide has a buoyancy selected to maintain the absorbent material in the first layer by varying the vertical distance in response to a variation in the level of the interface.