By Gas Contact Patents (Class 210/771)
  • Patent number: 6638429
    Abstract: Method and apparatus for processing a watery substance, such as sludge or manure, wherein in a mixer-drier (33) the watery substance to be processed, which may or may not be mechanically partly dewatered (in 31) and/or preheated (in 32), is mixed with zeolites of type A, which adsorb water from the watery substance while releasing adsorption heat which causes an amount of moisture to evaporate, while from the mixer-drier vapor and a mixture of zeolites and dried matter are discharged, whereafter the zeolites are regenerated in an oven (35) through heating, and are returned to the mixer-drier after being separated from dry matter residue formed by the heating, such as ash, and released moisture. Prior to the supply to the oven, at least a part of the dried matter can be extracted by a separation device (34) the mixture formed in the mixer-drier.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: October 28, 2003
    Assignee: Nederlandse Organisatie voor toegepast-natuurwetenschappelijk Onderzoek TNO
    Inventors: Paulus Josephus Theodorus Bussmann, Jacob Boot
  • Publication number: 20030155158
    Abstract: Hydrocarbon contaminants in drill cuttings generated in an oil drilling operation are removed by mixing the drill cuttings with an agglomerant to produce a pre-treatment mixture; heating to vaporize the hydrocarbon contaminants under a condition in which vapor entrainable particles of the drill cuttings are agglomerated by the agglomerant, and caking of drill cuttings is inhibited; drill cuttings having a reduced content of the contaminant are removed, and vaporized hydrocarbons having a reduced content of vapor entrainable particles are recovered. In this way, the particulate content of vapors escaping from the drill cuttings is reduced.
    Type: Application
    Filed: February 20, 2002
    Publication date: August 21, 2003
    Inventors: Kazimierz S. Szymocha, Barry E. McIntyre
  • Publication number: 20030136746
    Abstract: An apparatus for treating a multi component liquid substrate while leaving particulate matter therein as a skein of hollow fiber filtering membranes immersed in the substrate which is contained in a non-pressurized reservoir. A pumping fluid communication with the lumens of the membranes draws a component of the substrate as permeate through the membranes by applying a section to the lumens of the membranes. In various embodiments, an aeration system as a gas distributor for discharging air directly into the substrate within the skein, upper and lower headers of the skein are spaced apart by a gas tube, and a gas distribution system has through passages through the lower header to discharge bubbles into the substrate above the lower header.
    Type: Application
    Filed: May 4, 2001
    Publication date: July 24, 2003
    Inventors: Henry Behmann, Mailvaganam Mahendran, Pedersen Steven, Wayne Henshaw
  • Publication number: 20030127401
    Abstract: A pressure-filter apparatus includes at least one filtration chamber coupled with a source of slurry. The filtration chamber is also coupled with a source of fluid at an elevated pressure, which may be arranged in series or in parallel with a source of wash fluid. The pressure-filter apparatus may also include a source of fluid at a conventional pressure.
    Type: Application
    Filed: February 14, 2003
    Publication date: July 10, 2003
    Inventor: Steve C. Benesi
  • Patent number: 6585900
    Abstract: A process for the treatment of sludge which produces a dry sludge free of pathogenic and non-pathogenic microorganisms enriched with nitrogen which can be used as a fertilizer, and which uses as raw materials: elemental sulfur, formaldehyde, ammonia, urea, chlorine, and sulphuric acid, and comprises the steps of feeding the sludge into a pre-dryer into which is fed a hot gas stream containing sulfur trioxide produced by the combustion and catalytic oxidation of sulfur with air and finally completely drying the sludge by feeding it into an ammoniator.
    Type: Grant
    Filed: January 31, 2001
    Date of Patent: July 1, 2003
    Inventor: José Cabello-Fuentes
  • Patent number: 6555013
    Abstract: A method and apparatus for treating an aqueous-containing sludge in which the sludge is filtered on an elongate moving sheet of a water permeable unwoven fabric on paper. The moving sheet is folded and compressed between rollers whereby to express water therefrom. The folded moving sheet and contained sludge is dried, and the dried sheet and sludge is incinerated. Combustion heat from the incineration step is used in the drying step.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: April 29, 2003
    Assignee: Omega Co., Ltd.
    Inventors: Shinichi Nakamura, Kunihiko Fukuzuka, Kenji Nagayoshi
  • Patent number: 6526675
    Abstract: A method of dewatering fine particulate materials is disclosed. In this method, an aqueous slurry of fine particles is treated with appropriate hydrophobizing reagents so that the particulate material becomes moderately hydrophobic. A lipid of vegetable or animal origin is then added to the slurry in solutions of light hydrocarbon oils and short-chain alcohols, so that the hydrophobic lipid molecules adsorb on the moderately hydrophobic surface and, thereby, greatly enhance its hydrophobicity. By virtue of the enhanced hydrophobicty, the water molecules adhering to the surface are destabilized and more readily removed during the process of mechanical dewatering. The moisture reduction can be further improved using appropriate electrolytes in conjunction with the lipids, spraying surface tension lowering reagents onto the filter cake, subjecting the cake to a suitable vibratory means, and using combinations thereof.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: March 4, 2003
    Inventor: Roe-Hoan Yoon
  • Patent number: 6521135
    Abstract: A pressure-filter apparatus includes at least one filtration chamber coupled with a source of slurry. The filtration chamber is also coupled with a source of fluid at an elevated pressure, which may be arranged in series or in parallel with a source of wash fluid. The pressure-filter apparatus may also include a source of fluid at a conventional pressure.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: February 18, 2003
    Inventor: Steve C. Benesi
  • Patent number: 6502326
    Abstract: A method and apparatus for reducing the moisture content bound by capillarity in fiber cells of solid materials containing carbon. The material is ground and screened to form a loose sheet of the solid materials and/or sludges. The material is processed by screening and grinding methods for a plurality of hoppers for different grain sizes and grain size distributions. A thin layer of fines is spread as a first layer onto the spreading, feeding and filter belt, and a substantially thicker coarse material layer is formed as a second layer to form a sandwich of the material. The fines layer depth HF and coarse material depth HG of the sandwich correspond to the consistency and the proportion of the fines of the material. The sandwich formed is then carried by a belt into the pressure chamber of the filter press according to the dewatering cycle, while simultaneously the squeezed-out dry material is carried away.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: January 7, 2003
    Assignee: Maschinenfabrik J. Dieffenbacher GmbH & Co.
    Inventor: Friedrich B. Bielfeldt
  • Patent number: 6440316
    Abstract: Methods of improving the efficiency of solid-liquid separation during centrifugal filtration have been developed. They consist of increasing the pressure drop across the filter cake using extraneous means such as increasing the gas pressure inside a filter chamber and/or applying vacuum on the outside. The extraneous means of increasing the pressure drop is designed to increase the rate of removing liquid (water) during the drainage period of the centrifugal filtration process and, hence, lower the amount of the residual liquid (water) left in the filter cake.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: August 27, 2002
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Roe-Hoan Yoon, Ramazan Asmatulu
  • Patent number: 6409929
    Abstract: Apparatus and a method are presented for the mechanical removal of moisture from a filter cake. Differential pressure causes the flow of a treatment fluid through the filter cake. The treatment fluid displaces liquid originally present in the filter cake to prevent cracking of the filter cake.
    Type: Grant
    Filed: March 11, 1997
    Date of Patent: June 25, 2002
    Assignee: BOKELA Ingenieurgesellschaft fur Mechanische Verfahrenstechnik mbH
    Inventors: Reinhard Bott, Robert Kern, Thomas Langeloh
  • Publication number: 20020070183
    Abstract: In order to produce pellets or agglomerates in an economically feasible manner from clarified sludge which contains disease-causing bacteria and which is dewatered in a solid mantle worm-gear centrifuge (11) and is subsequently thermally dried in the centrifuge housing (14), and which satisfy the conditions of being hygienically unremarkable and also storage-stable, according to the invention it is proposed that the clarified sludge pellets (25), still hot or warm due to thermal clarified sludge drying, are held at their temperature in a sanitizing apparatus (26) for a dwell time of at least 10 min and thus sanitized and additionally dried.
    Type: Application
    Filed: November 21, 2001
    Publication date: June 13, 2002
    Inventor: Wilfried Schnabel
  • Publication number: 20020066703
    Abstract: The invention relates to a process for preparing trimethylolpropane with simultaneous formation of formate salts of the formula
    Type: Application
    Filed: August 22, 2001
    Publication date: June 6, 2002
    Inventors: Paul Wagner, Alexander Klausener
  • Patent number: 6256902
    Abstract: An apparatus and method for drying and deagglomerating substances of finely-divided solids suspended in a fluid medium. The apparatus includes the basic components of a phenumatic friction dryer, a flash dryer and a ring dryer.
    Type: Grant
    Filed: June 10, 1999
    Date of Patent: July 10, 2001
    Inventors: John R. Flaherty, Bradley P. Gehring
  • Publication number: 20010003330
    Abstract: Apparatus and a method are presented for the mechanical removal of moisture from a filter cake. Differential pressure causes the flow of a treatment fluid through the filter cake. The treatment fluid displaces liquid originally present in the filter cake to preent cracking of the filter cake.
    Type: Application
    Filed: March 11, 1997
    Publication date: June 14, 2001
    Inventors: REINHARD BOTT, ROBERT KERN, THOMAS LANGELOH
  • Patent number: 6205675
    Abstract: A dehydration machine includes a stuff tank, a stuff inlet provided at a lower portion of the stuff tank, a stuff outlet provided at an upper portion of the stuff tank, and a pair of drums each having a circumferential wall with a plurality of water passage apertures, the pair of drums being juxtaposed in the stuff tank. The pair of drums rotate adversely about its respective axis so as to introduce stuffs in the stuff tank therebetween from a lower side thereof. One of the drum is rotatable in an immovable manner, and the other of the drums is rotatable in an inclinable manner while being urged toward the one of the drums by an air spring. Each of the drums is provided with a metal net on an outer surface of the circumferential wall.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: March 27, 2001
    Assignee: Taizen Company Limited
    Inventors: Tetsuo Ide, Takefumi Ide
  • Patent number: 6090360
    Abstract: A method for recovering particulate silicon essentially free of silicon containing compounds from a by-product stream containing metal salts and high-boiling silicon containing compounds having a boiling point higher than the sublimation temperature of the metal salts. The method comprises first separating the particulate silicon and other solids from the by-product stream by a method such as filtration. The particulates are then washed with a solvent having a boiling point lower than the sublimation temperature of the metal salt, thereby separating residual high-boiling silicon containing compound from the particulate silicon and other solids. The particulate silicon and other solids are then recovered in a dried form, essentially free of silicon containing compounds, by spray drying at a temperature lower than the sublimation temperature of the metal salt.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: July 18, 2000
    Assignee: Dow Corning Corporation
    Inventor: John Eric Herman
  • 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: 5972228
    Abstract: A filtering apparatus comprises: a pressure vessel; a plurality of filter elements arranged within the pressure vessel, the filter elements each having an upper end, a lower end and a side wall; filling bodies positioned within the filter elements; a first conduit for introducing compressed gas into the pressure vessel; a second conduit for transporting unfiltered liquid to and from the pressure vessel; and a third conduit for removing filtrate from the pressure vessel and transporting back-flushing liquid to and from the filter elements, the third conduit positioned proximate to a bottom portion of the pressure vessel and attached to the lower ends of the filter elements, such that the third conduit provides a support structure for the filter elements and the back-flushing liquid introduced via the third conduit fills the filter elements in a direction from the lower ends toward the upper ends, the volume of back-flushing liquid introduced into the filter elements limited by the filling bodies.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: October 26, 1999
    Assignee: Kvaerner Pulping Technologies AB
    Inventors: Magnus Ingelman, Hans-.ANG.ke Karlsson, Per Larsson, Martin Wimby, Anita Markusson
  • Patent number: 5928522
    Abstract: Refinery waste feedstock is screened to remove large particles and is diluted to less than 5% solids weight percent to form a slurry. The slurry is agitated and heated to 180.degree. F. or higher for a time sufficient to melt waxy petroleum solids, reduce the viscosity of the slurry, reduce the density of petroleum fractions within the slurry, and begin to break surface adhesion of petroleum to residual fines. The conditioned slurry is passed through a first disc/bowl centrifuge which separates more than 80% of the waste volume as a first liquid effluent containing most of the petroleum fractions from the original waste and which may be returned to the refinery for processing. The residual cake is diluted with hot water to form a second slurry and is treated with an amount of hydrogen peroxide for a time sufficient to lyse and/or liberate residual petroleum bound to inert fine particles and to oxidize toxic polycyclic aromatic hydrocarbons to non-toxic derivatives.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: July 27, 1999
    Assignee: Continuum Invironmental, Inc.
    Inventor: Lawrence M. Conaway
  • Patent number: 5879566
    Abstract: A method and system for processing waste dries and reforms a sludge stream of the waste with a first reformed effluent stream to produce a gas effluent stream and a solids effluent stream. The gas effluent stream is reformed further to produce the first effluent stream, which is then directed back to the sludge stream.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: March 9, 1999
    Assignee: The Scientific Ecology Group, Inc.
    Inventors: Thomas Stephen Snyder, Matthew Reed Cage, John Gregorie Wagner, Bryan Arthur Roy
  • Patent number: 5853590
    Abstract: A method of treating sludge to provide a stable product for use as a beneficial soil or fertilize for agricultural lands is disclosed which includes the steps of:(a) mixing sludge with at least one alkaline material in an amount sufficient to raise pH of the mixture to a level of at least 12 and to increase percent of solids in the mixture to at least 40% by weight, and such that odorant sludge organics and inorganics are bound to adsorbent particles of the alkaline material,(b) aerating and drying the mixture by agitation and heating to stabilize the mixture and increase the percent solids to at least 50% by weight, and(c) pasteurizing the dried mixture at a temperature at or above 52.degree. C.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: December 29, 1998
    Assignee: Medical College of Ohio
    Inventor: Jeffrey C. Burnham
  • Patent number: 5840187
    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.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: November 24, 1998
    Assignee: Pannevis B. V.
    Inventors: Ulrich Derenthal, Karel Antoon Thissen
  • Patent number: 5736007
    Abstract: Liquor removal from particulate solids such as wet wood pulp is achieved by applying a pneumatic or vapor pressure force through a pad of the wood pulp to compress the solids and to expel liquor from the solids. If air is used as a displacing medium, no wash liquor is added and the solids are simply compressed and some of the liquor is replaced by the gas passing through the suspension. If steam is used, not as a heating medium but as a pressure medium, an increase in liquor removal occurs over and above that removed by gas only due to the condensation of the steam to form a liquid front travelling before the steam through the solid suspension. Hence, in principle, a combination of pressure washing and displacement occurs resulting in a high efficiency in washing. Gas or steam could therefore simply be applied to any conventional operation to increase the washing efficiency both by compression and by displacement.
    Type: Grant
    Filed: March 15, 1995
    Date of Patent: April 7, 1998
    Assignee: Auckland UniServices Limited
    Inventor: Geoffrey Graeme Duffy
  • Patent number: 5700378
    Abstract: The invention relates to a method and an apparatus for the gravitational separation of fine particles out of a liquid. The liquid containing the particles which are to be separated is conducted with laminar flow through the gaps between a plurality of closely separated, essentially horizontally orientated surface-forming elements (16). The liquid flow through the gaps is interrupted when the particle concentration in the liquid which has flowed through the gaps exceeds a predetermined value. The surface-forming elements (16) are repositioned to an essentially vertical discharging position in order to remove the particle collection present on the surface-forming elements. The surface-forming elements (16) are then returned to the essentially horizontal working position and a new gravitational separation cycle begins.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: December 23, 1997
    Assignee: Vivex AB
    Inventors: Hyosong Lee, Lars Ehnstrom
  • Patent number: 5670061
    Abstract: Process for the partial oxidation of a hydrocarbon feedstock, comprising the steps of gasification, partial oxidation and removal of the carbon by forming a soot water slurry containing the unburned carbon and ash and filtration of the soot water slurry to form a filtercake of carbon and ash, wherein the filter cake is dried by means of a fluid bed and the dried filtercake is burned at temperatures between 600.degree. C. and 1000.degree. C. Preferably The fluid bed is operated by means of a fluidizing gas at a temperature of at least 150.degree. C. The dried filtercake is burned under circumstances that carbon is left in the resulting ash.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: September 23, 1997
    Assignee: Norsk Hydro a.s.
    Inventors: Wolfgang Kowallik, Hans Jurgen Maaz, Werner Soyez
  • Patent number: 5670056
    Abstract: Small, wet particulate material is effectively dried by adding a hydrophobizing agent to coat the surfaces of the particulates, and then mechanically removing water droplets from the surfaces of the particulates. Once on the surface of the particulates, the hydrophobizing reagent makes the particulates relatively more hydrophobic and increases the water contact angle on the particulates. The moisture content of the particulate material can easily be reduced to levels below 20%, below 10%, and even below 5%. The process can be used to dewater a wide variety of constituents including coal particles, clays, sulfides, phosphorous compounds, minerals, metals, waste sludge, etc. Particularly preferred hydrophobizing reagents include mono unsaturated fatty esters and polysiloxane polymers.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: September 23, 1997
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Roe-Hoan Yoon, Cesar Indiongco Basilio
  • Patent number: 5656179
    Abstract: The device for continuous filtration and drying of a solid suspension comprises a belt filter (1) and downstream a belt drier (2). By means of a porous conveyor belt (3) the filter cake generated in the belt filter (1) is conveyed further into the belt drier (2) in which there are provided heating devices for heating and drying the filter cake (7) which is on the conveyor belt (3). After leaving the belt filter (1), the filter cake (7) is present on the conveyor belt (3) in the form of a gas-permeable bed of solids in layer form having a maximum layer thickness of 50 mm, preferably a maximum of 20 mm. The heating devices in the belt drier comprise, on the one hand, a hot gas chamber (8) disposed above the conveyor belt (3) to generate a hot gas which flows through the bed of solids downwardly from above and, on the other hand, one or more contact heating elements (10, 15, 18, 19, 20, 22) disposed above and/or below the conveyor belt (3).
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: August 12, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Dietrich Gehrmann, Norbert Schweigler
  • Patent number: 5656157
    Abstract: In apparatus for separating the components of a mixture, the mixture is admitted to a first inlet which communicates with a working region which may be defined by a cylindrical tube. A fluid under pressure is admitted to a chamber through a second inlet. The chamber also communicates with the working region. The fluid forms a spiralling flow which draws the mixture into the working region in the form of a vortex. In the apparatus, the chamber communicates with the working region by way of a throat, and the mixture is conveyed from the working region along an outlet.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: August 12, 1997
    Assignee: Precision Stainless, Inc.
    Inventors: Brooks A. Robertson, C. Patrick McKee, Alex R. Carra
  • Patent number: 5643468
    Abstract: A slurry is subjected to a filtration and washing process in order to separate the liquor from the solids. The filtration and washing process is carried out in a housing (101) enclosing an inert gaseous atmosphere which also passes through the filter cake and may be recycled, after treatment, to remove contaminants therefrom. To prevent recontamination of the filter cake as a result of the recycled gas entraining contaminant vapors within the housing (101), the gas is introduced into the housing (101) at a downstream location (152a, 166) relative to the direction of travel of the filter cake on a movable filter medium (100) and in such a way as to develop a contaminant concentration gradient whereby the cleanest cake is contacted by gas having the lowest contaminant level.
    Type: Grant
    Filed: July 20, 1995
    Date of Patent: July 1, 1997
    Assignee: Imperial Chemical Industries PLC
    Inventor: Alan Macpherson Ure
  • Patent number: 5615494
    Abstract: An apparatus for detaching a filter cake created by a suction dryer from off the filter surface of a filter medium and for an essentially simultaneous treatment of the cake to a form advantageous for further processing. The apparatus comprises a suction dryer (1, 11, 27), a connected filter surface (4, 14, 28) and a basin (2, 13, 27) for the material to be filtered. According to the invention, in the vicinity of the filter surface (4, 14, 28) of the filter medium, there is installed a blowing member (7, 17, 21) with at least one part, the blowing effect whereof can advantageously be extended over the whole width of the filter surface (4, 14, 28) of the filter medium, on which surface the filter cake can be formed.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: April 1, 1997
    Assignee: Outokumpu Mintec Oy
    Inventor: Bjarne Ekberg
  • Patent number: 5614107
    Abstract: A method for processing sewage eliminates chemical "treatment", or, the addition of chemicals that are as harmful or more so to the environment as raw sewage. The method of processing sewage disintegrates the generally solid components of sewage into a highly de-moisturized powder via alternative processes of either (i) a freeze-drying process, or (ii) a combination centrifugal separation and an evacuated "bake-out" process, both which substantially drive out the vaporizable components of the sewage. In consequence, there are no resultant effluent and/or exhausting vapors from this method which would impact the environment.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: March 25, 1997
    Assignee: Enviro-Tech-2000, Inc.
    Inventor: Albert T. Mallia, Jr.
  • Patent number: 5611261
    Abstract: A spent beverage brewing substance disposal device for use with a beverage brewing apparatus. The disposal device is connected to the beverage brewing apparatus for receiving a slurry of spent beverage brewing substance and liquid. The disposal device includes a housing having a delivery port communicating with a drain conduit of the beverage brewing apparatus for receiving the slurry therethrough. A foraminous structure is retained in the housing and positioned for receiving the slurry. The foraminous structure allows a liquid portion to drain therethrough while retaining the solid or particulate matter of the slurry. A pressurizing apparatus is coupled to the housing of the disposal device so as to pressurize the interior chamber defined by the housing to expedite the separation of the liquid portion from the solid portion. Liquid which is drained from the slurry passes through the foraminous structure and into a drain.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: March 18, 1997
    Assignee: Bunn-O-Matic Corporation
    Inventor: Randy D. Pope
  • Patent number: 5611935
    Abstract: A method for treating sludge by dewatering to form thick sludge and drying to form dry sludge includes the steps of mechanically predewatering thick sludge to produce predewatered thick sludge and mixing the predewatered thick sludge with non-cooled dry sludge to produce a sludge mixture. The temperature of the sludge mixture to be dried is measured and the dry substance contents of the dry sludge based on the measured temperature is determined. Fluctuations in the dry substance contents of the dry sludge are compensated by controlling the amount of recirculated dry sludge to be mixed with the predewatered thick sludge as a function of the temperature of the sludge mixture to be dried. The sludge mixture is dried to produce dry sludge and a portion of the dry sludge is recirculated to be mixed with the predewatered thick sludge.
    Type: Grant
    Filed: August 18, 1995
    Date of Patent: March 18, 1997
    Assignee: Steag Aktiengesellschaft
    Inventors: Heinz Thiemann, Helmut Brauweiler, Ivan Rupert, J org Bublies, Burkhard M oller
  • Patent number: 5609733
    Abstract: System and method for treating toxic washwater from ink, paint, pesticides and the like. The wash water is heated to a temperature on the order of 100.degree. F. in a sump positioned beneath a bed of horse manure media containing aerobic fungi and bacteria. Washwater is foam lifted from the sump to a level above the media and allowed to filter down through the media. Hot dry air is blown into the media from the side to maintain the media at a temperature on the order of 100.degree. F. and thereby promote microbiological activity and evaporation of the water in the media. Warm moist air from the media is cooled to condense the moisture, and the condensed moisture is collected as distilled water. A prefilter removes excessive amounts of solids from the washwater before it is introduced into the sump, and a Carnot cycle system provides the necessary heating and cooling for the water, media and air.
    Type: Grant
    Filed: April 27, 1995
    Date of Patent: March 11, 1997
    Assignee: Advanced Bio-Gest, Inc.
    Inventor: R. Edward Burton
  • Patent number: 5575923
    Abstract: An improved salt basket for dewatering solids, particularly salts resulting from evaporation of industrial wastewaters. The salt basket system includes a pressurizable vessel having a screen floor situated above a bottom liquid collection head, an inlet for the brine/solids slurry from which solids are to be separated and dried, an inlet for air, an inlet for steam (the latter two inlets may be combined, where convenient), an inlet for solids free feed, and a drain outlet (these two may be combined where convenient into a combination feed/drain connection). Preferably, an automated system for introducing feed brine and for removing the solids product is provided. For safety, a pivotally attached lower door has a hydraulic failsafe closure mechanism and locking safety latches to prevent the door from inadvertently opening.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 19, 1996
    Assignee: Ionics, Incorporated
    Inventors: Robert L. Solomon, Ferris C. Standiford, Joseph Bostjancic, Dan Peterson, George R. Jones
  • Patent number: 5562832
    Abstract: Secondary sludge produced in the papermaking process is dewatered by adding a material capable of absorbing water together with dry fibers to the secondary sludge, and mixing the secondary sludge with the dried fibers to produce a modified secondary sludge which has sufficient structure and low enough moisture that it may be further dewatered by mechanical means. The preferred fiber adding materials are those readily produced in the papermaking process, particularly dry primary sludge, dried fines and bark and fly ash from boilers.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: October 8, 1996
    Assignee: Beloit Technologies, Inc.
    Inventors: Robert W. McOnie, John E. Rude
  • Patent number: 5556232
    Abstract: A method for recovering solid waste from a non-hazardous, non-septic liquid waste stream which includes the steps of: powering a drying gas heating mechanism, such as a furnace, using aerobically generated biogas as a power source for the liquid drying mechanism; passing at least a portion of the liquid waste stream through a mixer, such as an inline static mixer, prior to drying the at least portion of the liquid waste stream; substantially atomizing the waste stream output from the mixer; drying the atomized waste stream using a liquid drying mechanism, such as a spray dryer; and passing waste particulate, produced by the step of drying, through a particulate collector to produce solid waste particulate. Preferably, the process includes tapping the aerobically generated biogas from a landfill.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 17, 1996
    Assignee: Land & Lakes Company
    Inventor: Raymond J. Malmgren
  • Patent number: 5540846
    Abstract: The invention relates to a process for the separation, in particular filtration of liquids and solids from solid-liquid mixtures, such as from a mineral, ore, coal or sludge suspensions of contaminated earth. The processing space of the filtration apparatus is submitted to overpressure and includes a collector container for solid-liquid mixture, a pressure filter, a discharge system and container for condensate and solid matter. The separation or filtration takes place at an overpressure and at an elevated temperature, preferably 40.degree. C. to 300.degree. C., conveniently 60.degree. C. to 200.degree. C., preferably about 150.degree. C. The pressure filter device communicates with a source for a heated medium.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: July 30, 1996
    Assignee: Andritz-Patentverwaltungs-Gesellschaft m.B.H.
    Inventors: Manfred Koch, Reinhard Pinter
  • Patent number: 5525239
    Abstract: There is disclosed a heated aeration method of completing the processing of a partially treated mixture of wastewater sludge and alkaline materials to produce a biologically active but pathogenetically clean fertilizer which can safely and easily be spread on agricultural lands. Also disclosed are a product made by the method and an apparatus for carrying out the method. The mixture is loaded into a forceful stream of heated air which carries the mixture through a rotating, internally vaned drum which has an internal, longitudinal, vaned core which rotates with the drum. The core and the vanes impart paths to the mixture particles which allow smaller particles to exit quicker than larger and thereby avoid sterilization and which breaks up larger mixture particles and otherwise enhances the spreadability of the resultant fertilizer. A vane on the core is bent and its portion beyond the bend is pronged to facilitate showering rather than dumping mixture particles.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: June 11, 1996
    Assignee: Duske Design & Equipment Co., Inc.
    Inventor: Wilfried P. Duske
  • Patent number: 5520822
    Abstract: An apparatus for hyperbaric filtration includes a sealable filtering vessel including an internal filtering cavity. A porous filtering plate is mounted in the vessel. The filtering plate divides the cavity into a first chamber wherein the filter cake is held by the filtering plate and a second chamber. A pressurized fluid source is connected by a delivery conduit to the filtering vessel so as to allow the delivery of pressurized fluid to the first chamber. An exhaust conduit is connected to the filtering vessel in communication with the second chamber. A rotary flow control valve in the exhaust conduit is connected to a drive motor so that fluid pressure may be released in a pulsating manner. This serves to vibrate the filter cake and filtering plate freeing moisture for removal with the passage of the pulsating pressurized fluid from the vessel. A circuit is also provided for supplying an electric current to the filter cake during filtering so as to further improve filtering efficiency.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: May 28, 1996
    Assignee: University of Kentucky Research Foundation
    Inventor: Fuhua Sun
  • Patent number: 5514286
    Abstract: An improved method and apparatus for removing chemical contaminants from soil. Contaminated soil is loaded and hydraulically sealed in the treatment vessel. A vacuum is placed on the material, which is indirectly heated through the heat transfer plate from a natural gas of propane fired burner located under the plate. As the material is heated, contaminants are vaporized and flow through the vacuum discharge pipe toward the condenser unit. Vapors are cooled in the condenser through a series of refrigerated condensing coils where the vaporized material is converted back to a liquid and discharged to a liquid recovery vessel. After treatment, material is downloaded into a roll-off type container for post-treatment analysis and cool down prior to recycling or backfilling. Recovered liquids are recycled or sent to an appropriate facility. Process time is typically 45 minutes to an hour for a six cubic yard batch. The system is self-contained, mobile, and operable by a two-person crew.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: May 7, 1996
    Assignee: ETG Environmental
    Inventor: Richard A. Crosby
  • Patent number: 5474686
    Abstract: In a continuous process for drying a sludge composed of combustible material and water, the wet sludge is first mixed with a proportion of material which has been dried in the process and is then fed into a hot gas stream from a burner. The hot gas stream carries the mixture along and dries it, and a proportion is tapped off and mixed with the incoming wet sludge. A part of the remainder is fed, with supplementary fuel, if necessary, to the burner to create the hot gas stream. The rate of fuel supply is varied in dependence on a temperature of the hot gas stream when it exhausts from the mixture drying operation.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: December 12, 1995
    Inventor: Derek J. Barr
  • Patent number: 5472622
    Abstract: An improved salt basket for dewatering solids, particularly salts resulting from evaporation of industrial wastewaters. The salt basket system includes a pressurizable vessel having a screen floor situated above a bottom liquid collection head, an inlet for the brine/solids slurry from which solids are to be separated and dried, an inlet for air, an inlet for steam (the latter two inlets may be combined, where convenient), an inlet for solids free feed, and a drain outlet (these two may be combined where convenient into a combination feed/drain connection). Preferably, an automated system for introducing feed brine and for removing the solids product is provided. For safety, a pivotally attached lower door has a hydraulic failsafe closure mechanism and locking safety latches to prevent the door from inadvertently opening.
    Type: Grant
    Filed: April 20, 1993
    Date of Patent: December 5, 1995
    Assignee: Ionics, Incorporated
    Inventors: Robert L. Solomon, Ferris C. Standiford, Joseph Bostjancic, Dan Peterson, George R. Jones
  • Patent number: 5466383
    Abstract: A process and apparatus for treating dried sludge comprising organic material, inorganic material and heavy mertals. The process comprises indirectly heating the sludge in the absence of oxygen to a temperature of from 300.degree. to 550.degree. C. for volatilization of organic material and heating the residual char in the absence of oxygen to a temperature of from 750.degree. C. to 1000.degree. C. together with injecting steam for gasifying non volatile organic carbons in theresidual char, whereby the organic material in the sluge is converted into energy-containing products. The heavy metals remain in the ash as metal-sulfide complexes which are not soluble in acdidic water.
    Type: Grant
    Filed: January 6, 1994
    Date of Patent: November 14, 1995
    Assignee: Samsung Engineering & Construction Co., Ltd.
    Inventor: Kunmo Lee
  • Patent number: 5462676
    Abstract: A system and process for treating solid and liquid wastes, where the solid waste is separated from the liquid waste in a chamber, the liquid waste is passed out of the chamber, the solid waste is converted to ash, a fluid such as liquid waste is introduced into the chamber and combined with the ash, and the ash and fluid are exhausted out of the chamber together. Preferably, the system includes the use of hot air to agitate the solids during their conversion to ash. Desirably, the system also includes a filter and means to swirl the liquid waste as it exits the chamber, so that the liquid waste evenly distributes the solid waste within the filter as the liquid waste is exhausted.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: October 31, 1995
    Assignee: Envirowaste Systems, Inc.
    Inventor: John Pitts
  • Patent number: 5426866
    Abstract: In order to considerably reduce expenditures for the dewatering of sludges, particularly from sewage treatment facilities, and thereby perform the step from a sticky, wet solid to a flowable solid granulate practically without the re-admixture of material, it is proposed to employ a solid bowl sludge centrifuge as the dispersing member in a subsequently connected convection dryer for further dewatering of the wet solids particles that are ejected with a dry substance content of approximately 25-35 weight percent. The wet solids particles that are ejected at high speed in the form of a film of particles from the outlet of the solid bowl sludge centrifuge are surrounded by the hot drying gas while still on their trajectory and are pre-dried to a dry substance content of approximately 65 weight percent (FIG. 5).
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: June 27, 1995
    Assignee: Lucia Baumann-Schilp
    Inventor: Andrzej Rumocki
  • Patent number: 5372653
    Abstract: A method of cleaning metal filters of a solvent spun fibre production plant. The method comprises the step of (a) dissolving dope from the filters using a hot solvent for the dope, (b) washing the solvent from the filters using hot water, (c) pyrolysing remnants of dope or solvent in the filters, (d) ultrasonically washing the pyrolysed particles from the filters, (e) reheating the filters to dislodge pyrolysed particles, (f) ultrasonically rewashing the filters and (g) drying the filters.
    Type: Grant
    Filed: May 28, 1993
    Date of Patent: December 13, 1994
    Assignee: Courtaulds Fibres (Holdings) Limited
    Inventor: Gary E. G. Gray
  • Patent number: 5330642
    Abstract: Apparatus for filtering cellulose acetate solutions, including a backflush filter to effect filtration so as to avoid solvent losses and filtering aids that must be dumped, dilution means including solvent supply means for diluting the backflush liquid, separation means for eliminating solid insoluble components, and means for recycling backflush liquid freed from solids to a plant for producing new cellulose acetate spin solution.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: July 19, 1994
    Assignee: Lenzing Aktiengesellschaft
    Inventor: Walter Klein
  • Patent number: 5288434
    Abstract: A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: February 22, 1994
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Ken N. Brewer, James A. Murphy