Abstract: A filtration system for handling an array of filter wells which are open at the top and closed by a filter membrane at the bottom. The system includes a manifold chamber defined by side and bottom walls and having a support for the wells which carries the filter membranes above the bottom walls so that filtrate may be drawn through the membranes. A vacuum fitting is connected to the chamber so that a low pressure source may be applied thereto, and a sealing sheet extends over the wells and having holes aligned with the open tops of the wells so that when the low pressure is applied to the chamber, filtrate may be drawn through the membrane.

Abstract: Filter apparatus and method for separating contaminants from a liquid stream through at least a partially submerged liquid pervious rotatable drum under negative pressure and having a flexible filtering web fed therearound with that portion of the drum not contacted by the filtering web being covered by a cover means with the filtering web being guided to enter and exit the liquid stream to contact the pervious rotatable drum at preselected angles to make optimum contact with the rotatable drum.

Abstract: Disclosed is an improved method and apparatus for creating a more uniform filter cake on a vacuum filter belt. A weir box for depositing a slurry on the filter belt has an outlet in the form of a plurality of slots spaced transversely of the filter belt with each slot being in the form of a truncated triangle with the base of the triangle being located closer to the filter belt than the truncated portion of the triangle.

Abstract: Apparatus for treating a pulp suspension with a treatment liquid is disclosed, comprising a continuous pervious belt for receiving the pulp suspension and moving it through a treatment zone in a predetermined direction. A treatment liquid supply is located above the continuous belt for supplying the treatment liquid onto the pulp suspension as it travels through the treatment zone, and a collector is located below the continuous belt for receiving liquid passing through the pulp suspension.

Abstract: A vacuum filter for the separation of solids from liquids, comprising an endlessly circulating array of troughs which constitute a common horizontal filter surface, on which an endless filter cloth is laid, in which each trough has an elastic sealing strip on that rimless edge which extends along the trough bottom transversely to the direction of movement. A good vacuum seal between two successive troughs with easy replaceability of the sealing strip is provided wherein the sealing strip is releasably clamped by a spring-loaded movable clamping bracket against the leading and/or rear edge of one of the adjacent troughs.

Abstract: An apparatus for separating liquids and solids from a mixture thereof comprises a trough structure (12) in which is suspended a filter means (14) on which the mixture can be placed. A vacuum mechanism (16) draws a vacuum beneath the filter means to draw the liquids downwardly from the solids, and a oscillating mechanism (20) causes the remaining solids on the filter to move in a conveying direction. A flexible perforated sheet (60) is provided beneath and in generally continuous contact with the filter means (14) and which can be intermittently flexed to maintain the filter means unobstructed by solids.

Abstract: The present invention concerns a device for generating negative pressure inside a cylindrical roll mantle of a revolving roll. The roll has a roll mantle provided with through-holes, grooves or equivalent apertures and confining a suction chamber in the interior thereof, in which a negative pressure can be generated by suctioning air out of the suction chamber. A suction flow directed towards the suction chamber thereby prevails in the holes, grooves or equivalent apertures of the roll mantle. At least one rotor blower or equivalent is attached to the roll to revolve along with the roll, with an intake side of the rotor being connected to the suction chamber of the roll. The movement of rotation of the roll thereby produces rotary movement of the rotor or equivalent, which in turn generates negative pressure in the suction chamber. Thus, in the arrangement in accordance with the present invention, external equipment of negative pressure or a separate piping system is not needed.

Abstract: A disposable diagnostic plasma filter dispenser includes a low cost disposable container and a rotor drive for rotationally energizing a rotor within the container. The disposable container is particularly suitable for drawing and dispensing blood samples for clinical analysis and includes a tube shaped outer wall having a frangible dispenser outlet cover, a close fitting inner tube supporting a filter membrane and a unitary rotor disposed for axel free rotation and axial translation within the inner tube in response to energization from the rotor driver. The rotor produces vortex enhanced filtration while maintaining a flow of filter fluid through the filtration gap and creating a transmembrane pressure.

Abstract: A method and apparatus wherein a conventional vacuum operated filter unit which generates a positive pressure on the particulates in a suspension against a filter membrane is converted into an anti-clogging filter unit through addition of a supplemental device which generates a counteracting negative pressure on the suspension as it is being filtered, thereby pulling the particulates in the suspension away from the filter membrane.

Abstract: Battery powered vacuum unit, useful for suction filtration of water samples in the field. The vacuum unit comprises a miniature piston type air suction pump, driven by a small direct current (DC) motor which in turn is powered by a battery or other 12 volt DC power source. The motor may be controlled by a timer. The motor has a maximum power requirement of about 75 Watts and the suction pump has the ability to produce a vacuum of at least about 12.5 mm of mercury. The entire unit is preferably self-contained in a single housing, and preferably weighs no more than about 5 kilograms (11 pounds).

Abstract: A double valve arrangement is installed in intermittently operating vacuum filter apparatus in a pipeline connecting the filter means to a vacuum source to vent the line to atmosphere whenever the vacuum is shut off. This valve arrangement comprises a pipe section provided with a lateral opening, connected to the filter means, and with internal mutually facing annular shoulders disposed at respective sides of the lateral opening, and a piston-mounted sealing disc which is of smaller diameter than the pipe section and is reciprocable inside same to abut sealingly the one or the other of the shoulders and thereby bring the lateral opening into communication with the respective opposing end of the pipe section, which is connected, respectively, either to the vacuum source or to atmosphere. An annular gap is always present between the peripherly of the disc and the internal surface of the pipe section so that movement of the disc, e.g. at a frequency of 5 to 20 cycles per minute, is not impeded by rubbing.

Abstract: A virus-infected body fluid is decontaminated as it is being collected, before it has had an opportunity to clot or thicken and before attending personnel are exposed to it, by introducing a suitable viricidal into the tubing through which the fluid is transported from the fluid source to a collection receptacle in an amount and concentration sufficient to substantially reduce the virus population in the collected fluid. In applications where suction is used to pull the fluid through the tubing, a venturi is used to draw a metered amount of liquid viricidal from a container into the tubing, and in cases when the fluid is transported by gravity, an in-line filter containing a suitable viricidal is connected in line with the tubing, the viricidal being leached from the filter by the fluid flowing through it. In both cases, the viricidal is thoroughly mixed with the fluid and continues to act on the collected fluid until its disposal.

Abstract: A filter has an endless filter cloth, which passes under a slurry feed and over a suction box, through which suction is applied to the cloth to remove liquid from the slurry. The cloth is driven by a roller, around which the cloth is trained, linked to a motor. The operation of the motor is controlled by a central device so that the cloth is advanced incrementally, the length of advance of an increment being predetermined and selected to satisfy operating requirements. The control device can also provide for regular acceleration and deceleration.

Abstract: A fluid-operated, time delay control and system embodying same are set forth. The time delay control includes an accumulator chamber communicating with a source of fluid under negative pressure or vacuum and a second chamber having a partition dividing it into two parts, a first of which communicates with the accumulator chamber. The second part communicates with a vacuum-sensitive switch which is energized when sensing a vacuum of a predetermined value. The partition has a check valve for maintaining the vacuum switch in communication with a vacuum after the vacuum is released at the source and the pressure rises in the first part of the second chamber. An adjustable flow control valve in the partition slowly releases the vacuum which the switch senses. The switch then reverts to a de-energized condition when a predetermined value is reached. A filtering system incorporates the time delay control with the control controlling a vacuum break valve and a motor for moving a strip of filter media.

Abstract: In order to remove liquid from a slurry of water and powdered material, and particularly from a slurry containing spent powdered ion exchange resins and other media used to decontaminate water in nuclear power plants, a vessel is filled with the slurry. The vessel contains filters, particularly panels which are arrayed in the upper portion of the vessel and through which water is filtered leaving a body ("cake") of the powdered material in the vessel. The filters are surrounded on at least their sides and top by a bag of pliant material. This bag defines a variable volume region and may be evacuated to compress the cake against the filters, prevent breaking suction at the filters and enabling them to continue to remove the water remaining in the cake so that additional water may be removed from the cake and discharged from the vessel, leaving a compact mass which efficiently utilizes the volume of the vessel, thereby preparing the vessel and the dewatered slurry for disposal.

Abstract: Filter cake produced from a slurry is compressed in an enclosure (6) having a pair of opposed flexible walls (5) at least one of which is constituted by a filter and drainage medium. The filter cake is cyclically deformed while under compression with the filter cake supported at least one position (14, 52) within its periphery whereby the unsupported parts of the filter cake are cyclically deformed about the periphery and the position or positions of support. All parts of the filter cake are thus subjected to substantially uniform bending whereby drying of the filter cake is improved.

Abstract: A method for assay of an analyte and assay device therefor. The assay device includes an assay component affixed to a permeable membrane. The membrane preferably rests on a permeable membrane support and covers an opening through a receptacle for holding a liquid. The support is adjacent the open upper end of a double ended needle, the lower end of which is adapted to puncture a plug inserted in an open end of a preevacuated container. Puncturing of the plug establishes fluid communication between the prevacuated interior of the container and the opening in the receptacle whereby liquid in the receptacle is passed through the membrane. The membrane has a bubble point sufficient to prevent passage of air through the membrane after all of the liquid has been pulled through as long as the membrane remains wet so that vacuum in the tube is not lost. The device may be part of an assay workstation which comprises a canister and various utensils useful in performing the assay.

Abstract: The present invention relates generally to improvements in an apparatus for effecting solvent extractions using liquefied gas or gases in the supercritical state as the solvents and specifically to an apparatus for separating solids from fluids at high pressures.

Abstract: An apparatus having a liquid-permeable belt for receiving cellulose pulp, a liquid supply device for discharging treatment liquid on the cellulose pulp, and a container extending across the entire width of the belt for collecting treatment liquid penetrating the belt. The container is adapted to maintain a treatment liquid level at such a distance from the belt so that the formation of foam from treatment liquid is reduced. The container includes a liquid outlet for discharging the treatment liquid and a vapour outlet for discharging vapours and gases from the bottom of the container. The vapour outlet communicates with a passageway within the container, which passageway is formed as a pipe or is partially defined by a container wall. A deflector can be provided on the container for operatively deflecting treatment liquid away from the passageway.

Abstract: A manual liquid filtration device includes a housing having an open lower end providing access to an internal vacuum chamber, and defining a liquid specimen receiving chamber at its upper end adapted for flow communication with the vacuum chamber. An elastic diaphragm extends across the lower open end of the housing and upwardly along its outer peripheral surface so as to cooperate with air orifices in the housing to define valve means enabling unidirectional air flow from the vacuum chamber. A porous membrane filter element is interposed between the specimen receiving chamber and the vacuum chamber and when dry enables air to pass therethrough from the vacuum chamber upon flexing of the diaphragm into the vacuum chamber. When wetted by water, the filter element maintains vacuum in the vacuum chamber but enables liquid from a liquid specimen to be drawn through the filter element so as to retain solid particulate on the filter element for diagnosis or further reagent washing.

Abstract: A method and apparatus for the simultaneous filtering of samples contained in a plurality of test tubes includes a test tube block, a vacuum manifold, base manifold and vacuum base. The vacuum manifold is provided with a plurality of recesses complementary with barrels in the block defining chambers to receive the test tubes. The base manifold and vacuum base are assembled as a unit including recesses to receive filter screens and passages leading from the recesses to a vacuum source. The vacuum manifold is positioned onto the block with a filter medium placed over the vacuum manifold and secured in place by attaching the base manifold/vacuum base unit to the block. When vacuum is applied to the vacuum base the entire assembly is inverted whereby the contents of the test tubes are drawn through passages in the vacuum base to the filter medium. Passages in the base provide a wash solution to the barrels which is drawn through the device by the vacuum.

Abstract: An apparatus used to separate solid-phase materials from rinse water containing soluable constituents dissolved from rock or ore bodies by percolation of water therethrough is described. The apparatus includes an upper funnel and a bottom receptacle as well as a central passage member disposed therebetween. The upper funnel includes a perforated bottom and a central standpipe. The bottom receptacle includes a pair of vacuum tubes. The central member includes a plurality of filter members. When in use, filtration through some or all of the filters can be aided by applying a suction to the vacuum tubes.

Abstract: A complete filter system mounted on a support platform that can be supported on a flat bed truck and transported over a highway including a vacuum receiver having a plurality of flat wall portions so that each cross-sectional configuration thereof is generally rectangular in shape.

Abstract: A fat collection syringe is shown which has a barrel with an open end and a closed end with nipples for connection respectively to a source of high suction vacuum and to a collection needle. A plunger is longitudinally movable in the barrel to facilitate receiving collected material and has a longitudinal central passage for connection to a low suction vacuum for drawing a washing liquid through the material collected therein. The plunger central passage extends from end to end and has a scraper mounted on its inner end wall. A suction tube extends through the passage with a filter on its inner end and is positioned in engagement with the scraper. The outer end of the tube has a cap positioned thereon when vacuum is being applied to the nipple connected to high suction vacuum.

Abstract: Apparatus for separating relatively large undesirable particles from a slurry includes an endless movable filter belt mounted for movement along a horizontal path and supply means depositing slurry carrying large particles on the upper surface of the filter means. Pressurized gas jets are positioned beneath the lower surface of the filter means in the area beneath which the slurry and relatively large particles are deposited to agitate same and suction means beneath the filter belt to separate the slurry from the relatively large particles to provide purified slurry. Gas from the slurry is separated by a degasser having a spiral floor partition which slurry comprises drilling mud and said large particles comprise earth cuttings comprises a common wall between gas and slurry outflow conduits in a space-saving manner.

Abstract: For the separation of suspensions in the form of liquid solid component mixtures with the aid of porous filter membranes or for the separation of suspensions free of solid components into the liquid components with the aid of solution diffusion membranes, a reduced pressure is produced on the permeate side of the membrane. For this purpose the permeate is sucked off by a jet pump and is transferred into a closed circuit flow in which it serves as a drive medium for the jet pump. The apparatus for performing the method includes a membrane filter arrangement (6) with a closed circuit conduit (11) connected to the permeate discharge conduit. A conveying pump (13) and a jet pump (10) as well as a collecting container (12) is arranged in the closed circuit conduit. The permeate discharge conduit is connected with the jet pump.

Abstract: Drill cuttings, and similar slurries or mixtures oily solid particles, are treated by a dryer apparatus which vaporizes the liquid and discharges relatively large solid particles for disposal. Vapor and entrained solid fines are conveyed from the dryer to a condenser and then to a rotary drum vacuum filter having a precoated filter media disposed thereon. The solid fines are filtered by the filter media comprising diatomaceous earth or perlite and the clarified condensed liquid is conveyed to separator means for separating oil, water and any other liquids present. The filter media stripped from the filter and contaminated with entrapped solid fines is conveyed through the dryer means and disposed with the solids particles being discharged from the dryer.

Abstract: A filter apparatus and method is provided wherein a tank is adapted to receive unfiltered liquid. An outlet chamber is located adjacent the bottom wall of the filter tank and is separated therefrom by a perforated plate. A filter media is movable across the rear, bottom and front walls of the filter tank and accordingly, unfiltered liquid must pass through the filter media as well before entering the outlet chamber. A chain flight assembly is provided which is movable across the filter media along the rear, bottom and front walls of the filter tank. As the chain flight assembly is continuous, a return path is across the top of the tank above the unfiltered liquid. A baffle plate is provided near the rear wall within the filter tank.

Abstract: A disposable vacuum assisted filter funnel for filtering fluids into bottles. The bottle top filter forms a vacuum dependent seal with the mouth of the bottle. When fluid is introduced into the bottle top filter, the evacuated bottle draws the fluid through the filter into the bottle. The bottle top filter lacks a vacuum plenum between the vacuum source and the bottle. The bottle top filter may be manufactured from one molded piece.

Abstract: A belt filter device mounted on a frame carrying an endless conveyor belt has a casing arranged below an upper run of the belt, and application of subatmospheric pressure to interior regions of the casing causes liquid to be withdrawn from material lying on the conveyor belt through drainage holes provided in the belt. The casing is pivotal with respect to the frame between a first, operational position and a second, cleaning position, and a separating means shifts the casing away from a cover or support means simultaneously with movement of the casing from its operational position toward its position for cleaning.

Abstract: A filter unit is provided for separating solids from a liquid including a receiving tank and a vacuum chamber located beneath the tank and separated therefrom by a perforate septum. A closed loop filter media is trained about the tank and a length thereof is disposed beneath a flight conveyor assembly including chains which overlie the side margins and flights which engage ridges provided in the filter media. A filter media cleaning arrangement is provided at one end of the tank for removing solids from the filter media and transporting the solids for disposal.

Abstract: A method and apparatus for rejuvenating oil well drilling mud is provided by an endless filter which is supported by a pair of spaced driven drums; drilling mud is distributed onto a moving flight of the filter at spaced locations so as to provide layers of the drilling mud on the filter. Passage of the drilling mud through the filter is assisted by spraying the drilling mud with drilling mud which has passed through the system (filtrate) and by applying suction to the underside of the filter. The drilling mud, after passing through the filter is degassed in a second stage degasser. The filter is cleaned by a solution spray, and by back washing with air and either water or diesel oil.

Abstract: A drum filter is disclosed mounted vertically within a tank which receives the liquid to be filtered. The drum is provided with inside and outside filter media layers and intermediate axially extending passages receiving filtered liquid flow, which is collected in a central tube extending vertically upward and adapted to be connected to a suction pump.A backwash arrangement includes a backwash flow passage directing flow successively through each of the axial passages as the drum is incrementally rotated about its axis.Collection troughs are positioned extending axially along the inside and outside periphery of the drum member so as to receive the backwashing flow and contaminants, with a flushing flow carrying off the contaminants from the tank for secondary filtration.The rotary indexing drive consists of a cylinder actuated ratchet drive with a sprocket wheel in engagement with a chain track located about the interior diameter of the drum member at its upper end.

Abstract: New and improved, liquid level adjusting and filtering device is provided, and is operable upon insertion into a container to automatically adjust the level of a liquid as contained in the container to a predetermined, precisely repeatable location, and to filter the thusly level-adjusted liquid. The device is particularly adapted for use in conjunction with test tube-like devices, in the nature of those marketed under the Trademark "Vacutainer" by the Becton-Dickinson Company of East Rutherford, NJ, containing whole blood samples which have been separated as by centrifugation into respective blood cell, buffy and blood serum layers; and is operable in that context to present blood serum samples to automated sample analysis systems at the same predetermined and precisely repeatable location relative to the aspirating probe means of such systems.

Abstract: A horizontal endless belt vacuum filter comprises an endless belt pierced, in its central part, with holes moving above the upper opening of a longitudinal vacuum and extending beneath the upper side of the conveyor belt. An endless filtering medium passes over guide rollers and is applied on the upper side of the conveyor belt, in order to receive the mass to be filtered. The vacuum box is mounted to pivot, as a whole, about a longitudinal axis offset laterally on one side of the conveyor belt. This vacuum box is borne by the inner ends of transverse bars which are articulated on horizontally aligned bearings materializing the pivot axis and which bear, at their outer ends, a manifold. This manifold is connected on the one hand to the vacuum box, via at least one connecting pipe, and on the other hand to the source of vacuum, by at least one dismountable coupling member.

Abstract: A removable baffle insert for positioning in a filtrate compartment of a rotary drum vacuum filter comprising an elongated C-shaped member positioned between a pair of compartment walls and having one arm thereof providing the ceiling of the compartment to prevent filtrate run-back during the filtration cycle.

Abstract: A filter system and method are provided utilizing a filter tank separated into an inlet compartment and a filtrate compartment by a filter media. Under normal filter operation, the liquid to be filtered enters the inlet compartment, is passed through the filter media and out the filtrate compartment by a pressure differential created across the filter media by a pump device. When the need arises to move the filter media as a result of the buildup of contaminents on it, it is necessary to alleviate the pressure differential across the filter media. Such pressure differential is alleviated by the controlled flowing of filtered liquid through an orifice in a closed valve into the filtrate compartment.

Abstract: Improved belt filter in which the belt comprises transverse channels provided with draining holes issuing into a draining trough. The end of a suction pipe connected with a vacuum-creating device, issues into the upper part of said trough.

Abstract: Apparatus for manufacturing a series of samples of a mixture comprises a continuous filter strip on a roll and means for advancing the filter strip along a predetermined guide path. A suction head is located below the guide path and a bell member above the guide path at a point opposite to that of the suction head. The bell member is capable of being raised and lowered so that a portion of the filter strip is sealed between the bell member and suction head when the bell member is in the lowered position. Feeding means are provided through which samples of the mixture are conveyed from a sample vessel, through the bell member and onto the filter strip when the bell member is in the lowered position. A stamping device is located downstream the bell member whereby portions of the filter strip supporting the sample are stamped out in disc form. The disc is received within a receiving vessel. Reagent fluid supplied to the disc through a needle.

Abstract: A semi-automatic quantitative filtration assembly is disclosed having a measuring means to measure and present a known quantity of fluid for filtering and a fluid holding means adjacent to a filter medium. The fluid holding means is adapted to receive and hold excess fluid during filtering and to prevent intermixing with a known quantity of fluid to be presented to filtering. The filtering apparatus is designed to filter a quantitative amount of fluid and receive fluid in the fluid holding tank which is excess sample fluid or fluid unwanted as a result of error or operational failure and which drains to a common vacuum/waste means for filtered fluid. A variety of features are also provided to insure proper operation and minimize operator error.

Abstract: A universal infusion apparatus for use with sterile, sealed bottles of infusion liquid has a hydrophobic filter for stopping possible loss of liquid through the air duct, that is used for letting air into the vessel to take the place of the liquid run off therefrom. The air filter is furthermore used for stopping bacteria from the outside air being taken up into the vessel. For decreasing the degree of vacuum necessary for starting operation of the filter when there is liquid on the inside face of it so that there is no danger of the bottle collapsing, there is an air trap or storage space in which air will be kept when liquid makes its way through the air duct.

Abstract: A drum structure for a rotary drum vacuum filter wherein the drum comprises a pair of conical shaped support members having concentrically arranged interconnected peripheral base portions with the apexes of the support members carried by spaced cylindrical end plates which form the end walls of the drum. Filtrate compartments are formed beneath the outer filtration surface of the drum by adjacent pairs of a plurality of spaced panels having edge portions fixed to both the support members and the end plates.

Abstract: An all-TEFLON filter-degasser for removing solids and gases from a solvent. The filter-degasser has a filtering portion, a vacuum application portion downstream of the filtering portion, and a solvent bottle connecting portion. The vacuum application portion includes an externally tapered male member, and the solvent bottle connecting portion includes an internally identically tapered female member. The male member can be inserted into and withdrawn from the female member without requiring any relative rotation therebetween, so that the filter-degasser can be connected hermetically airtight to the solvent bottle likewise without any rotation being required therebetween. This abstract is not to be taken either as a complete exposition or as a limitation of the present invention, however, the full nature and extent of the invention being discernible only by reference to and from the entire disclosure.

Abstract: In a filtration apparatus for fluids and liquids having an external vessel, in particular a centrifuge tube and a filter unit disposed in the liquid, the medium to be filtered is under excess pressure and in contact with the filter element of the filter unit and for the static membrane filtration on the outer side of the filtration unit facing the vessel bottom a filter membrane is arranged with the filtration-active layer towards the outside.

Abstract: Concurrent operation of a sizable number of vacuum filtration units is facilitated by a rotatable carrier stand. Any selected one of the units may readily be turned to a position convenient to the operator without interruption of the vacuum connections and without entanglement of vacuum lines. Components of the filtration units may then be manipulated with a reduced risk of breakage, spillage or inadvertent disconnection of vacuum lines. Installation and removal of a filtration unit may be accomplished very quickly and simply with the use of only one hand in some cases. Simultaneous filtering operations may be performed more efficiently particularly within enclosures such as fume hoods, glove boxes or the like which otherwise restrict access to the filtration units by an operator.

Abstract: A solid, fiberglass-reinforced plastic rotary drum filter includes a first solid fiberglass-reinforced head at one end and a second solid fiberglass-reinforced head at the other end. A central solid fiberglass-reinforced plastic pipe extends from one plastic head a predetermined distance into the plastic drum. A plurality of radial, solid fiberglass-reinforced plastic drainage conduits extends from the solid fiberglass-reinforced plastic deck of the plastic drum to the central pipe. The longitudinal separation between the radial plastic drainage conduits and the first plastic head is carefully chosen and the dimensions of the first plastic head are such that the first plastic head is strong enough to withstand the head-bending force due to radial force, drive torque, and hydraulic end force.

Abstract: A filter belt is progressed stepwise over successive vacuum boxes by a guide roller at the forward end of the upper run being extended from its retracted position to its full line position while vacuum to the boxes is shut off. A displaceable roller permits this by taking up any slack in the belt and return movement of the belt upon retraction of the foremost guide roller is prevented by a unidirectional arrangement in at least one of the rollers guiding the lower return run of the belt. Slurry is fed onto the belt by a first nozzle, optional wash liquor is fed onto the resultant filter cake by a second nozzle and optional recirculated wash liquor is fed by a third nozzle all under the influence of a control which provides for such feed only for a predetermined period of time during the actual movement of the belt.

Abstract: A filtering apparatus is used to continuously separate a large quantity of a substance such as a slurry, sludge or other suspension into a liquid component and a solid component in such a manner that the separated solid component is obtained as a cake in a semi-dried condition, and comprises a rotary drum including a perforated cylindrical member and a filter cloth provided on the outer peripheral surface. The drum is supported for rotation so that a portion thereof is immersed into the substance to be filtered. The pressure within the drum is reduced by a vacuum pump so that the liquid component of the substance is drawn into the drum through the portion thereof is immersed into the substance while the solid component of the substance is accumulated on the filter cloth of the rotating drum and is held as a cake thereon. The cake is continuously removed by a doctor blade in the portion of the drum which is exposed to the atmosphere.

Abstract: A rotary filter drum in which the drum is a single cell having a perforated cylindrical wall and solid end walls. A hollow central shaft extends through the drum and its opposite ends extend axially from the end walls. The drum contains a plurality of relatively narrow elongated open-top pans that are equally spaced radially from and angularly about the central shaft. Each pan is defined by a bottom, spaced apart inner and outer sidewalls which extend the full length of the drum and the drum end walls. The pan walls are secured to the ends of the drum. The pans are located so the open tops face the direction of drum rotation and the entire leading edge of the outer sidewall of the pan is secured to the perforated cylindrical wall. A closed conduit connects the bottom portion of each pan to the central shaft which in turn connects to the vacuum source so the filtrate is removed from and vacuum applied to the interior of the drum solely through the central shaft but via the pans and connecting conduits.

Abstract: A bench for vacuum filtration of fluid samples includes a stand having at least one aperture for receiving and supporting a filter device. A vacuum distribution conduit is rigidly mounted on the stand and a vacuum branch conduit extends between the vacuum distribution conduit and the filter device. An isolating valve is provided in the vacuum branch conduit.