Rotating Drum Patents (Class 210/784)
  • Patent number: 6042735
    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.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: March 28, 2000
    Assignee: Voith Sulzer Stoffaufbereitung GmbH
    Inventors: Axel Gommel, Herbert Holik, Josef Schneid
  • Patent number: 6004468
    Abstract: An apparatus for processing a solid-liquid material comprises a housing formed with a series of interconnected chambers defined by chamber walls with at least two drums mounted in series within the chambers. Each chamber receives one of the at least two drums for rotatable movement therein. Each chamber and the associated drum are dimensioned to define a region therebetween to retain the solid-liquid material. The regions of adjacent chambers communicate with each other to define a continuous passage from drum to drum through the apparatus. An inlet in the housing admits the solid-liquid material to the passage, and an outlet permits extraction of a processed solid-liquid material from the passage. Each drum rotates in a direction opposite to the adjacent drum to advance the solid-liquid material through the passage from drum to adjacent drum in a sinuous path such that the curvature of the solid-liquid material changes when passing from drum to adjacent drum.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: December 21, 1999
    Inventors: Adrian Barbulescu, Joana Barbulescu
  • Patent number: 5985159
    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.
    Type: Grant
    Filed: May 12, 1997
    Date of Patent: November 16, 1999
    Inventors: Kent Strid, Rolf Oswaldsson, Lars Horlyk
  • Patent number: 5972229
    Abstract: A method for filtering out particles from a fluid is disclosed, wherein unfiltered fluid is guided into a filter housing of a filter apparatus and filtered fluid is guided from the filter housing, and wherein a rotary filter element, which has a filter structure and is arranged in the filter housing and is rotatable about an axis thereof, is rotated at a speed which is sufficiently high that all particles passing in a fluid flow into the area of the rotary filter element are affected by its structure and are ejected therefrom, whereas the fluid passes the structure of the rotary filter element substantially freed from the particles and flows off from the filter housing.
    Type: Grant
    Filed: May 14, 1998
    Date of Patent: October 26, 1999
    Assignee: Nyfotek AS
    Inventor: Eric Gustaf Lundin
  • Patent number: 5968372
    Abstract: A high pressure automatic lime mud precoat filter cake heel removal system provides for steady kiln operation. The system provides multiple points of washing located such that washing of the entire filter can be accomplished in a short period of time. Each washing point comprises preferably two nozzles at predetermined angles to optimize washing of the filter media. The system is reciprocatively driven by a fractional horsepower gear motor connected to a torque converting coupling which is, in turn, connected to a threaded jack shaft or lead screw. The gear motor is controlled by a dual speed reversing variable frequency drive; limit switches automatically control cycling of the system in conjunction with logic circuits and sensors. This system is variably controlled so that cycle times may range optionally from approximately one to approximately five hours in length.
    Type: Grant
    Filed: December 16, 1997
    Date of Patent: October 19, 1999
    Assignee: Baker Hughes Incorporated
    Inventors: Johan Martensson, Bal K. Sethi, Donald Brown
  • Patent number: 5951861
    Abstract: A device for filtering a liquid substance comprising a container (1) having an inlet (2), a rotor (6), an inner rotor part (7), at least one disc filter (8). Spray nozzles are provided for releasing material filtered away from the substance and deposited on the filter disc. Furthermore there are conveyors (17) for removing the material released.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: September 14, 1999
    Assignee: Kvaerner Pulping AS
    Inventor: Kent Strid
  • Patent number: 5897788
    Abstract: A method and apparatus to clean a filter drum used for thickening lime mud. The drum is rotated about a horizontal axis in a first direction so that the circumferential surface of the drum moves into contact with lime mud in a vat and a precoat layer formed on the drum, as well as an external layer of lime mud which forms a thickened lime mud cake when a vacuum is applied to the drum withdrawing liquid from the lime mud. The thickened external layer of lime mud cake is scraped from the drum at a second side of the vat, and at a first opposite side of the vat a first jet of liquid is directed onto the drum surface (e.g. at a pressure of about 30-100 bar) to remove a strip of the precoat layer, a third jet of liquid cleans the drum after removal of the precoat layer, and a second jet of liquid is directed onto the drum with sufficient intensity (e.g. a pressure of about 2-20 bar) to remove, by spreading and partially detaching, a strip from the thickened lime mud cake.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: April 27, 1999
    Assignee: Ahlstrom Machinery Oy
    Inventors: Vesa Ketolainen, Pekka Ruokolainen, Juba Titoff
  • Patent number: 5882529
    Abstract: The invention relates to a reverse centrifugal filter and a method of separating solids particles suspended in a liquid. The reverse centrifugal filter of the invention contains a rotatable filter screen in a filter vessel. As the filter screen rotates, solid particles in a liquid which may accumulate on the filter screen are thrown away from it, thus keeping the filter screen alway clean for efficient operation.
    Type: Grant
    Filed: May 12, 1997
    Date of Patent: March 16, 1999
    Inventor: Rajendra P. Gupta
  • Patent number: 5874006
    Abstract: A process for the aseptic concentration of collagen from about 0.25% (w/w) suspensions to gels of 15% using vortex flow filtration with a variety of membrane types--ultrafiltration and microfiltration and polymeric and stainless steel is provided. The resulting gels are suitable for use in medical products and/or pharmaceutical formulations. This process achieves high degree of concentration in a closed system and at high flux with minimal trans-membrane pressure drop.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: February 23, 1999
    Assignee: Matrix Pharmaceutical, Inc.
    Inventors: Richard Lee, Daniel Prows, Louis Fries
  • Patent number: 5855800
    Abstract: A centrifugal separator includes a chip bowl for receiving a fluid-particulate mix and delivering the mix onto the screening surface of a cylindrical separator screen disposed around the bowl. A canopy portion of the bowl overlaps the separator screen and is axially positionable therealong such that a variable length of the separator screen may extend beyond the forward edge of the bowl. A separator drive shaft has an axial bore for housing a bowl drive column and an adjusting rod. The bowl drive column is mounted to the separator drive shaft and adjusting rod such that axial movement of the adjusting rod causes axial movement of the bowl drive column but not the separator drive shaft and rotation of the separator drive shaft causes rotation of the bowl drive column but not the adjustment rod.
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: January 5, 1999
    Assignee: National Conveyors Company
    Inventor: Arnold B. Serenkin
  • Patent number: 5851392
    Abstract: The present invention provides a self cleaning doctor blade which is a floating blade containing beveled edges or "relief gaps" comprising beveled mitered leading edges on each blade. This arrangement allows for the blades as a whole to remain free from build-up of fine particulate matter. The invention further provides a doctor blade made of replaceable units allowing for fine adjustment of blade-to-drum surface distance as well as replacement of small damaged segments rather than the whole blade.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: December 22, 1998
    Inventor: C. Lamar Brady, Jr.
  • Patent number: 5849202
    Abstract: A process and device for the filtration of solid-liquid mixtures, in particular, solid-liquid suspensions with readily sedimenting substances, uses a filtration device such as a rotary filter optionally operating at an overpressure and in a pressure vessel. The process primarily comprises producing a movement in addition to the natural or usual filtration movement of the or in the mixture. Conveniently, a filtration device and, in particular, with rotary filters in a pressure vessel, includes a partly open feeding device, in particular, a feeding pipe for the supply of mixture or suspension, and a device for additionally influencing the natural or usual filtration movement of or in the mixture or suspension for generating an additional flow of the mixture.
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: December 15, 1998
    Assignee: Andritz-Patentverwaltungs-Gesellschaft M.B.H.
    Inventors: Manfred Koch, Hubert Riemer
  • Patent number: 5705031
    Abstract: In a kraft pulp mill, a process and apparatus for removing and washing dregs from green liquor so that the pH of the dregs is below "hazardous waste" levels. Specifically, green liquor clarifier underflow is filtered using a simple non-precoat cassette filter to form a first dregs cake. The dregs cake is diluted, preferably with water. The diluted dregs cake is then filtered in a precoat dregs filter to produce a dregs cake that is at least 50% solid and has a pH of about 12.0 or less.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: January 6, 1998
    Assignee: Kvaerner Pulping Technologies AB
    Inventor: Peter A. Angevine
  • Patent number: 5676847
    Abstract: A method for recovering crystals from a crystal-containing slurry, which comprises supplying the slurry to a rotary filter having a rotating cylindrical filter medium, filtering the supplied slurry in a filtering region to retain the crystals on the filter medium and washing the filter cake formed on the rotating filter medium repeatedly in a plurality of washing regions by spraying a washing liquid onto the cake in each region by supplying any one of washing regions on the aft side in the rotating direction of the filter medium with the spent washing liquid of the washing region adjacent to said one washing region on the fore side in the rotating direction.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: October 14, 1997
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Ryoichi Yamamoto, Toshiyuki Sakata, Hiroshi Suzuki, Etsuro Okamoto
  • Patent number: 5637213
    Abstract: Filter apparatus for filtering contaminants from a fluid, such as machine tool coolant, are disclosed. One filter apparatus includes a filter drum unit having a generally cylindrical open perforated support sheet with a cylindrical screen element mounted thereabout. Circumference varying mechanisms, such as turnbuckles, are connected relative to the support plate to vary the circumference of the support plate and the tautness of the screen element. A disc filter assembly having a mandrel and fluidly attached annular disc filter elements is also described. Each annular disc filter element has an inner structure with concentric ribs forming concentric grooves therebetween which are connected to radially extending grooves. A screen element is supported by the ribs so that the microscreen will not tear while allowing filtering of fluid into the grooves which are in fluid communication with the mandrel.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: June 10, 1997
    Assignee: Henry Filters, Inc.
    Inventors: Stephen N. McEwen, Jay M. Creps, Scott M. McEwen, Richard A. Hallet, Robert F. Benschoter, Barry Benschoter
  • Patent number: 5628912
    Abstract: A method and apparatus for efficiently separating solids from liquid/solid slurries are disclosed. The slurry to be separated is retainably placed within a container having one or more lift paddles secured within its inner cavity. The container is supported for rotation about an axis and has drive means for slowly rotating the container. As the container rotates, the lift paddles lift a portion of the retained slurry, allowing the liquid portion to fall back into the primary slurry pool to be separated, and lifting the solids toward the top of the rotation path of the paddles. The separated solids slide by gravity off of the lift paddles as they approach the top of their rotation paths and into a collection hopper and transport means that carry them away from the container. The liquids returned to the primary retained slurry within the container assist in washing the slurry for facilitating solids separation without required increase in the retained slurry volume.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: May 13, 1997
    Assignee: NTH, Inc.
    Inventor: Clinton A. Nesseth
  • Patent number: 5624578
    Abstract: A nozzle assembly (1) for use in a separation apparatus for separation of liquid suspensions the separation including such nozzle assembly, and a method for its use. In the nozzle assembly, the outlet end of the nozzle is biasable towards the inner surface of the rotatable screening drum (7) of the separation process, and a roller or pad is provided on the nozzle to contact the drum and maintain a substantially constant distance between the the nozzle outlet and the drum surface. The outlet end of the nozzle can be swivable relative to the feed means of the nozzle.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: April 29, 1997
    Assignee: Andritz Sprout-Bauer, Inc.
    Inventor: George Burgess
  • Patent number: 5611926
    Abstract: Described is a water treatment device which comprises a) a treatment tank with an inlet and an outlet for the treatment water, and a rotating drum used for forced generation of a primary current and a secondary current accompanying the primary current in the treatment water in the treatment tank. The device can be used for the collection and removal of oil and/or other suspended matter in the treatment water through the rotating action of the rotating drum.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: March 18, 1997
    Inventor: Tetsuo Nishida
  • Patent number: 5607596
    Abstract: Process for the treatment of the combustion residues and for the purification of the combustion fumes, in which the residues are washed and then rinsed to reduce the leachable fraction both in respect of the trace elements and in respect of the total soluble fraction, with a low consumption of water and of optional reactants.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: March 4, 1997
    Assignee: Lab S.A.
    Inventor: Jean-Francois Vicard
  • Patent number: 5603846
    Abstract: A fractional filtration apparatus, used for obtaining cutting oils fractionally cleaned by using one filtration apparatus so as to reuse the separated cutting oils in accordance with the types of machining operations, includes a plurality of liquid tanks for fractionally storing the cleaned cutting oils, a filtration target cutting oil storage tank for temporarily storing a filtration target cutting oil charged through a charge port, rotatably driven filtration drums, dividing the liquid level of the cutting oil and being pivotal in the filtration target cutting oil storage tank, each drum having a side-surface opening in at least one surface thereof in order to let a filtered cleaned cutting oil flow into the cutting oil tanks, and each drum being provided with filters of different mesh sizes, injection nozzles for reversely washing the filters provided on the outer circumferential surfaces of the filtration drums, and dip-up members, disposed at a predetermined intervals, for continuously conveying the cutt
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: February 18, 1997
    Assignee: Kabushiki Kaisha SYST
    Inventors: Tadao Uchiyama, Koji Tomizama
  • Patent number: 5589079
    Abstract: An assembly for recovering crystals from a slurry comprises a filtration unit including a rotatably mounted cylindrical filter, a slurry input for receiving slurry pressurized by a pump. The filtration unit has an outlet for discharging crystalline material separated from the slurry by the filtration unit. A first hopper connected to the filtration unit at the discharge outlet thereof is provided at a downstream side with a first valve unit which is in turn connected to a second hopper on a downstream side. A second valve unit is coupled to the second hopper at a downstream side thereof. Each of the valve units includes a rotatably mounted dome shaped valve member. The second hopper is provided with a vent extending to a gas storage tank. A conduit links the hoppers to one another for substantially equalizing pressure in the hoppers prior to an opening of the upstream valve during a discharge procedure.
    Type: Grant
    Filed: May 17, 1995
    Date of Patent: December 31, 1996
    Assignee: Baker Hughes Incorporated
    Inventors: David B. Park, Michael F. Crawley
  • Patent number: 5565110
    Abstract: A method and apparatus for improving the operation of a vacuum drum filter. A hollow and perforated shower roll is located at the top of a vacuum drum apparatus for drying and cleaning paper pulp. The interior of the shower roll is provided with a liquid distribution pipe having a plurality of spaced openings therealong, the pipe also having a substantially vertically extending dam which extends radially to adjacent the lower interior surface of the shower roll. In operation, rotation of the vacuum drum in a vat of paper pulp to be dewatered results in the continuous formation of layer of pulp on its exterior surface, the layer being compressed by the shower roll at the nip between the vacuum roll and the shower roll. Concurrently, the shower roll discharges or exudes water onto and into the pulp layer at the nip.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: October 15, 1996
    Assignee: International Paper
    Inventors: C. Lamar Brady, Gary E. Keller
  • Patent number: 5531889
    Abstract: A method for removing polymer particles from the stripping solution used in the treatment of printed wireboards comprises passing a solution having resist particles dispersed therein over a screen having openings of 100 microns, where the screen is maintained at an angle of from 40 to 70.degree. to the horizontal. The apparatus comprises a curtain tube consisting of an inner concentric tube with a plurality of holes and an outer concentric tube with a slot wherein the position of the slot is adjustable, filter means comprising a screen, and a pump for circulating the solution. In one embodiment, the filter means comprises a cylindrical screen.The stripping solution comprises an aqueous solution of an organoamine, ionic nitrogen compound or alkali or alkaline-earth hydroxide, or mixtures thereof.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: July 2, 1996
    Assignee: Atotech USA, Inc.
    Inventors: David T. Baron, Alexander R. Taylor, Kuldip S. Johal
  • Patent number: 5464542
    Abstract: A method for filtering and backwashing solid particles out of liquids is illustrated, with a filter drum (5) positioned completely below the liquid level (6) having a cylindrical surface (7) coated with a filter medium (8), the liquid flown through the outside of the filter drum to the inside. A backwashing device for removal of the filter cake from the filter medium is provided. At the beginning of each cycle of backwashing an air cushion (15) is introduced in the filter drum (5) and liquid in the filter drum (5) is displaced in such a manner so that liquid jets from an ejetion apparatus (19) containing a spraying head (17) and being arranged in the interior of the filter drum without being sealed on the filter drum penetrate through the air cushion (15) to the backside of the cylindrical surface (7) of the filter drum (5). The filter cake so removed from the filter drum is withrawn at the outside of filter drum (5) in a stream of liquid.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: November 7, 1995
    Assignee: Hans Huber GmbH Maschinen-und Anlagenbau
    Inventors: Johann Grienberger, Rudolf Bogner, Christian Frommann
  • Patent number: 5421997
    Abstract: A sleeve filter centrifuge comprises between the closed end wall of a centrifugal drum and a base portion movable relative to this end wall a flexible, extendible dividing wall, for example in the form of a bellows or a folded membrane. This dividing wall provides a seal between a displacing shaft bearing the base portion and the inner chamber of the centrifugal drum accommodating the suspension and prevents any exchange of substances, which, for example, impairs sterilization, between the process area of the centrifugal drum and the machine frame side of the sleeve filter centrifuge.
    Type: Grant
    Filed: July 7, 1993
    Date of Patent: June 6, 1995
    Assignee: Heinkel Industriezentrifugen GmbH & Co. KG
    Inventor: Hans Gerteis
  • Patent number: 5409618
    Abstract: A fluid classifier for separating particles from a lading for operation with a lading tank including a filter unit for mounting in the tank and having capillary passages for fluid flow from the tank externally of the filter unit to the interior of the filter unit for providing a pressure differential across the capillary passages resulting from a difference in fluid level in the tank and within the filter unit, a drive for rotating the filter unit in the tank, and a pump for pumping fluid from filter unit interior to the outlet. Ultrasonic transducers positioned along the filter unit for agitating the lading adjacent the capillary passages. A method of controlling fluid flow through the capillary passages.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: April 25, 1995
    Assignee: Kenneth E. Price
    Inventor: Paul D. Price
  • Patent number: 5407587
    Abstract: A method and apparatus for removing solids from the porous surface of a rotating vacuum drum. Such drums are used to separate the solid and liquid phases of a slurry, such as a calcium carbonate containing mud slurry. Doctor blades are often used to scrape the drum exterior surface of excess mud to minimize the build up of solids thereon. Nonetheless a cake eventually forms on the drum and clogs the porous surface and stops the vacuum action. The drum is stopped and the drum backwashed by water to dislodge the cake. According to this invention, a jet of water from a nozzle is substantially tangentially directed against the drum surface to thereby eliminate stopping the drum for cake dislodgement. The nozzle is located beneath and moves with a reciprocating secondary doctor blade, the secondary doctor blade being of a length less than the width of the drum. A stationary, main doctor blade spans the entire width of the drum.
    Type: Grant
    Filed: August 17, 1993
    Date of Patent: April 18, 1995
    Assignee: International Paper Company
    Inventor: J. Lennart Westerberg
  • Patent number: 5360620
    Abstract: This invention is directed to an apparatus and method for wetting and dissolving finely divided dry particles, including hygroscopic particles such as coffee fines, in a liquid, including viscous liquids such as concentrated coffee liquor, in a manner in which foaming, the presence of wet lumps and liquor degradation are minimized. The apparatus includes a dissolving tank containing at least one pair of counter-rotating drums partially submerged in a body of the dissolving liquid. The tank includes a liquid inlet and a discharge conduit which maintain a predetermined level of liquid in the tank. A powder feeding device mounted above the tank discharges a falling curtain of particles onto a thin layer of liquid on the surface of one of the drums in each counter-rotating pair.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: November 1, 1994
    Assignee: Nestec S.A.
    Inventor: Sheng H. Hsu
  • Patent number: 5306433
    Abstract: An improved solvent dewaxing process in which a method and apparatus for continuous hot wash of a dewaxing filter is disclosed. A hot wash solvent is continuously sprayed below the doctor blade followed by a cold solvent spray below the hot solvent spray. Additionally, a solvent management process for changing the proportions of the solvent in response to different viscosity feedstocks thereby increasing filtration efficiency is also disclosed.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: April 26, 1994
    Assignee: Mobil Oil Corporation
    Inventor: Lyle A. Leach
  • Patent number: 5305685
    Abstract: A disposal device for disposing of spent beverage brewing substances for use with a beverage brewing apparatus. The beverage brewing apparatus is the type which uses a beverage brewing substance which is disposed in a brewing chamber and infused with a liquid to produce a brewed beverage. A drain conduit extends from the brewing chamber and communicates with the substance disposal device for removing a slurry of moist beverage brewing substance and liquid waste from the brewing chamber of the apparatus into the disposal device. The disposal device includes a housing which houses a strainer basket. The strainer basket is rotatably retained in the housing. The drain conduit from the beverage brewing apparatus deposits the spent beverage brewing substance inside of the strainer basket. The strainer basket is rotated to centrifugally remove a liquid component of the spent beverage brewing substance and drain such liquid out through a drain port in the housing.
    Type: Grant
    Filed: May 4, 1993
    Date of Patent: April 26, 1994
    Assignee: BUNN-O-MATIC Corporation
    Inventor: William E. Midden
  • Patent number: 5300233
    Abstract: Displacement washing of slurry body is provided in a centrifuge filter (peeler centrifuge) by introducing wash liquid along the inner surface of the drum while the drum is rotating. The wash liquid moves through the filter into the slurry body in a broad front to displace the mother liquor of the slurry body toward the axis of rotation of the drum. The mother liquor is removed by an overflow pipe or dip tube to a point outside the centrifuge filter for disposal.
    Type: Grant
    Filed: February 9, 1993
    Date of Patent: April 5, 1994
    Assignee: Dorr-Oliver Incorporated
    Inventors: Chie-Ying Lee, Win-Chin Chiang
  • Patent number: 5290454
    Abstract: A process is for removal of suspended solids including resin and fatty acids from pulp mill effluents including Chemi-Thermo-Mechanical Pulp (CTMP) mill effluents. The process involves filtration of untreated or primary treated effluents through a mat of primary sludge, pulp or woodroom sludge. A sludge mat is formed on a wire screen or punched drum and the effluent to be treated is filtered through the mat. Most of the suspended solids and a part of colloidal material and dissolved solids are retained by the mat. Following the filtration stage, the sludge is dewatered and removed. A portion of the sludge is recycled to form the mat for the next filtration cycle, while the excess sludge is purged. The filtration is achieved by the application of vacuum below the filter mat or pressure over mat.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: March 1, 1994
    Assignee: Pump and Paper Research Institute of Canada
    Inventors: Joseph Dorica, Steven Prahacs, Pritham Ramamurthy
  • Patent number: 5281343
    Abstract: A method and apparatus for filtering pulp fibers from a pulp slurry, using a combination of vacuum, hydrodynamic and hydrostatic forces in order to achieve a more effective deposition of pulp fibers onto the filter surface and enhanced flow of filtrate through the cylinder. The apparatus is in the form of an improved vacuum filtration system, in which the filtrate outlet tube is disposed along the axis of rotation of the rotary cylinder and the filtrate inlet and outlet ports of each filtrate conduct are radially offset from one another in the direction of intended rotation of the cylinder. During various phases of filter operation, vacuum forces generated by the vacuum source cooperate with either hydrodynamically or hydrostatically generated forces, which together act upon columns of filtrate in the filtrate conduits as the cylinder rotates.
    Type: Grant
    Filed: April 20, 1993
    Date of Patent: January 25, 1994
    Assignee: Ingersoll-Rand Company
    Inventors: Frederick S. Lewis, Lewis F. Empie, Rollin E. Brown
  • Patent number: 5264138
    Abstract: A method and apparatus for fibrous suspensions in the wood processing industry and more specifically to a so-called drum cylinder, the basic construction of which comprises a vessel, into which suspension being thickened is supplied and a wire-surface cylinder rotating in the vessel. The drum filter is characterized in that the closure member of the drum filter has a channel for leading gas from the filtrate tubes through the compartments of the distribution chamber to the outside of the closing member. The method is characterized in that the operation phase of the filter cylinder is divided into five separate stages. In the first stage, when the cylinder descends on to the vessel, air and the initial filtrate are discharged from the filtrate components and the formation of the pulp web on the wire surface begins. In the second stage, filtrate is discharged with vacuum and the formation of the pulp web continues.
    Type: Grant
    Filed: May 1, 1991
    Date of Patent: November 23, 1993
    Assignee: A. Ahlstrom Corporation
    Inventors: Jukka Heino, Raimo Kohonen, Erkki Savolainen
  • Patent number: 5262069
    Abstract: Disclosed are a filter cake scraping method which can scrape a filter cake layer deposited on the surface of a filter drum with a scrape blade even if the particles of the cake are fine, and a rotary drum filter using this method. When pressure inside a suspension vessel rises above a predetermined value, a control means quickly reduces the pressure. Accordingly, precoated material or the like, which has been deposited on the filter drum, expands to push a layer of filter cake outward, thus permitting a scrape blade provided beside the filter drum to scrape the expanded cake layer.
    Type: Grant
    Filed: February 5, 1992
    Date of Patent: November 16, 1993
    Assignee: FSK, Inc.
    Inventor: Sakae Kato
  • Patent number: 5250198
    Abstract: An improved method for separating solid particles from liquids, such as dewatering and thickening of sludge collected in a container (1), involves the use of at least one drainage unit (9) having doubled screened jacket walls (25, 26) defining a dewatering chamber (10). The liquid relieved of solids within the chamber is subjected to a turbulent motion acting against said screened jacket walls for obstruction of the solids deposition at the wall surfaces of the chamber facing the sludge in the container. The turbulent motion is obtained by a forced fluid F introduced in the chamber through one or more tubes (30, 31). The fluid may favorably be in form of compressed air or water returned from the reject system (14, 16).
    Type: Grant
    Filed: August 16, 1991
    Date of Patent: October 5, 1993
    Inventor: Hans Stedfeldt
  • Patent number: 5227075
    Abstract: The invention relates to a continuous-working process and apparatus for replacing the liquid in a liquid suspension of a fibrous material with another liquid by forming of this material a bed on a moving filter surface and by displacing the liquid present in this bed with the other liquid. The bed of material is formed on a cylindrical filter surface installed in a vertical orientation below the liquid surface in a container and conveys it continuously forward filtration and several successive liquid displacements effected by maintaining a hydrostatic pressure difference across the formed bed, which is conveyed continuously horizontally forward, and through it there flow liquids horizontally during the filtration and liquid displacement.
    Type: Grant
    Filed: December 5, 1991
    Date of Patent: July 13, 1993
    Assignee: Salomans Oy Hackman Process Ltd.
    Inventor: Hakan Ostman
  • Patent number: 5202034
    Abstract: An apparatus for dewatering aqueous sludge is disclosed. A porous drum is partially immersed in a sludge pond. A porous belt is connected between the drum and a roller which moves the belt. As the belt moves, the sludge adheres to the belt. A vacuum is drawn on the interior of the drum, removing some of the water. Sludge which is conveyed on the belt is frozen as it approaches the roller. The frozen sludge is broken into smaller cakes as it leaves the roller. The frozen cakes are subsequently dethawed providing a solid residue which is disposed.
    Type: Grant
    Filed: July 12, 1991
    Date of Patent: April 13, 1993
    Inventor: Courtland J. Martel, Jr.
  • Patent number: 5192454
    Abstract: A method of treating a fiber suspension in a disc-type pulp treatment apparatus, wherein the apparatus includes a pressure-proof casing with an inlet for the fiber suspension and a discharge for treated suspension and filtrate, a shaft rotating inside the casing an a plurality of discs arranged on the shaft, and wherein the discs are formed of sectors having filter surfaces between which surfaces is a liquid compartment communicating with the liquid discharge. The method includes feeding the fiber suspension to be treated overpressurized into the casing, filling the casing up with the fiber suspension, carrying out the treatment in a closed airless space and discharging the pulp from the casing.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: March 9, 1993
    Assignee: A. Ahlstrom Corporation
    Inventors: Pasi Immonen, Ramio Kohonen
  • Patent number: 5190673
    Abstract: An improved solvent dewaxing process in which a method and apparatus for continuous hot wash of a dewaxing filter is disclosed. A hot wash solvent is continuously sprayed below the doctor blade followed by a cold solvent spray below the hot solvent spray. Additionally, a solvent management process for changing the proportions of the solvent in response to different viscosity feedstocks thereby increasing filtration efficiency is also disclosed.
    Type: Grant
    Filed: June 12, 1991
    Date of Patent: March 2, 1993
    Assignee: Mobil Oil Corp.
    Inventor: Lyle A. Leach
  • Patent number: 5182031
    Abstract: The device comprises a closed chamber (1) equipped with an inlet pipe (3) for the aerated liquid, an outlet pipe (4) for the deaerated liquid, and an air evacuation pipe (5); and a rotor having a shaft extending into the chamber. The shaft carries means (7) for centrifugation of the liquid and means (8,9,10) for intensive agitation of the centrifuged liquid.The device works according to the following process: continuously, the liquid is introduced into the closed chamber and it is vigorously centrifuged there in with the aid of mechanical means (7) and simultaneously subjected to intensive agitation with the aid of second mechanical means (8,9,10).The released air gathers freely at the center of the chamber whence it is evacuated, as the deaereated liquid is evacuated through the outlet pipe.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: January 26, 1993
    Assignee: E & M Lamort (Societe Anonyme)
    Inventor: Jean-Pierre Lamort
  • Patent number: 5167839
    Abstract: An improved conveyor system for machine tool cleaning applications comprises a sump internal to a machine tool, a recirculating system in fluid communication with the sump, a hinge belt conveyor, portions of which are interposed between the sump and the recirculating system for removing coarse solids from the fluid, and a fine filter interposed between the sump and the recirculating system for removing fine solids from the fluid.
    Type: Grant
    Filed: July 23, 1991
    Date of Patent: December 1, 1992
    Assignee: H & W Systems Corporation
    Inventors: Kemble Widmer, II, George F. Coogan, Bobby L. Heffner, Bryce E. Bairey
  • Patent number: 5158691
    Abstract: A filter apparatus (10) for filtering machine tool coolant is disclosed as including a filter assembly (12) including a foraminous non-reticulated metal screen (30) having minute openings and a smooth planar surface for providing improved scrape cleanability and preventing movement of machining chips, particulate and also elongate contaminants from one side of the filter (12) to the other side thereof.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: October 27, 1992
    Assignee: Henry Filters, Inc.
    Inventors: Stephen N. McEwen, Jay M. Creps, Scott M. McEwen
  • Patent number: 5149448
    Abstract: A drum filter for thickening lime sludge in which the lime sludge is thickened on a filter layer (precoat) formed by the lime sludge on the filter periphery. The filter is provided with high pressure liquid nozzles continuously reciprocating in the longitudinal direction of the drum in such a way that, during each rotation of the drum, part of the filtering layer is continuously detached and drops into a vat containing the lime sludge.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: September 22, 1992
    Assignee: A. Ahlstrom Corporation
    Inventor: Esko Mattelmaki
  • Patent number: 5143627
    Abstract: An apparatus and method provide automated collection and transfer of particles from a liquid suspension to a glass slide for visual examination. A solution which contains particles, for example cells, is drawn through a filter element so that particles too large to pass through the filter element collect against a first surface of the filter element. A transfer fluid, such as alcohol, is applied from a second surface of the filter element to the first surface, to transfer cells from the filter element to a glass slide positioned adjacent the filter element. An alternative transfer mechanism applies a selected pneumatic signal to the filter element for transferring collected cells to the viewing slide. The apparatus includes a device for dispersing the liquid suspension of particles prior to the collection process and particles collect against the filter element with a spatial distribution advantageous for visual examination. The transfer operation maintains this spatial distribution.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: September 1, 1992
    Assignee: Cytyc Corporation
    Inventors: Stanley N. Lapidus, Lewis T. Polk, Jr., Fredric L. Farber, J. Morgan Barlas, Anne A. Hurley
  • Patent number: 5143555
    Abstract: A method and apparatus for doctoring (cutting) the solids off a precoat filter. A stationary doctor blade continuously doctors mud (from a mud bath) from the surface of a rotating porous surface vacuum drum. A traveling doctor blade, located upstream of the stationary doctor blade, moves back and forth along the drum. The stationary blade extends the width of the rotating vacuum drum while the traveling blade is shorter and is also located nearer to the drum surface.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: September 1, 1992
    Assignee: International Paper Company
    Inventor: C. Lamar Brady
  • Patent number: 5078903
    Abstract: A pressure-fed apparatus for the separation of solids and liquids from a suspension has a fine-apertured rotatable screening drum, inlet means to introduce a flow of suspension into the interior of the screening drum under pressure. Feed means comprising a plurality of nozzles eject the suspension tangentially onto the inner surface of the screening drum and from a position directly adjacent the said inner surface. Suspension may be ejected with or against the direction of rotation of the drum.
    Type: Grant
    Filed: November 21, 1989
    Date of Patent: January 7, 1992
    Assignee: Contra-Shear Holdings Ltd.
    Inventor: George Burgess
  • Patent number: 5055205
    Abstract: This invention increases the efficiency and flow rate of rotary drum filtration and makes possible the use of such filtration for volatile and high temperature materials. According to the invention a rotary drum filter unit operates continuously in a pressure vessel and solids are intermittently discharged from the vessel. The filtered solids are scraped from the drum periphery and dropped into a trough in the vessel communicating with a discharge passageway. When the passageway is filled with solids, a shroud, driven by a reciprocating ejector traps the solids in the passageway. The ejector compacts the trapped solids forming plugs which are sequentially discharged from the pressure vessel.
    Type: Grant
    Filed: May 24, 1989
    Date of Patent: October 8, 1991
    Assignee: Alar Engineering Corporation
    Inventor: Harold R. White
  • Patent number: 5051195
    Abstract: Method and equipment for filtration of a suspension so that the suspension to be filtered is fed from a feed part (4) onto the filter face of a filter member (5), which moves relative the feed part. The pulp layer is formed on the outer face of the filter member and the filtrate flows into the interior of the filter member, and the pulp layer is removed from the filter member at the removing point. After the pulp removing point (17), before the feed point (4), one or several cleaning points (12) are provided wherein liquid is made to flow through the filter member (5) from the inner face of the filter member to the outer face. The flow rate of the liquid that flows through the cleaning point or points is adjusted higher than the rate of any liquid flow that may flow through the rest of the filter member from the inside-face side to the outside-face side.
    Type: Grant
    Filed: October 13, 1989
    Date of Patent: September 24, 1991
    Assignee: Sunds Defibrator Rauma Oy
    Inventors: Pertti Haapamaki, Aaro Ahlgren, Lassi Suoninen, Juho Eriksson
  • Patent number: RE36297
    Abstract: A method and apparatus for fibrous suspensions in the wood processing industry and more specifically to a so-called drum cylinder, the basic construction of which comprises a vessel, into which suspension being thickened is supplied and a wire-surface cylinder rotating in the vessel. The drum filter is characterized in that the closure member of the drum filter has a channel for leading gas from the filtrate tubes through the compartments of the distribution chamber to the outside of the closing member. The method is characterized in that the operation phase of the filter cylinder is divided into five separate stages. In the first stage, when the cylinder descends on to the vessel, air and the initial filtrate are discharged from the filtrate components and the formation of the pulp web on the wire surface begins. In the second stage, filtrate is discharged with vacuum and the formation of the pulp web continues.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: September 14, 1999
    Assignee: A. Ahlstrom Corporation
    Inventors: Jukka Heino, Raimo Kohonen, Erkki Savolainen