Washing With A Fluid Other Than The Prefilt Patents (Class 210/772)
  • Patent number: 4686048
    Abstract: A process is disclosed for treating cat cracker bottoms sludge to remove the cat cracker bottoms hydrocarbons from the catalyst fines in the sludge to provide treated fines which are environmentally safe for landfill. The process involves mixing the sludge with a hydrocarbon diluent, separating the fines from the diluent-sludge mixture, then mixing the separated fines and remaining diluent with water and distilling off the remaining diluent to obtain the treated fines.
    Type: Grant
    Filed: December 23, 1981
    Date of Patent: August 11, 1987
    Assignee: Exxon Research & Engineering Co.
    Inventors: George A. Atherton, Ghazi B. Dickakian, Edward D. Grant, Jr.
  • Patent number: 4684512
    Abstract: The invention is a process for recovering phosphorus value from magnesium pyrophosphate containing filter media in the wet superphosphoric acid purification process. The invention comprises treating the filter cake with a salt to remove the adhering phosphoric acid without solubilizing magnesium acid pyrophosphate. The filter cake, after phosphoric acid removal, can be utilized as commercial or technical grade magnesium acid pyrophosphate.
    Type: Grant
    Filed: August 25, 1986
    Date of Patent: August 4, 1987
    Assignee: Stauffer Chemical Company
    Inventors: John M. Stewart, Teddy R. Clark, Thomas E. Edging
  • Patent number: 4684494
    Abstract: Process and apparatus for ultrafiltration of the cooling water of a pressurized water nuclear reactor, during operation of the reactor. A fraction of the flow of pressurized water is withdrawn continuously in at least one cold branch (8) of the primary circuit (2). This withdrawn water is circulated, while it is still at the temperature and pressure of the primary circuit (2), in contact with the entry face of an ultrafiltration wall (40). The filtrate is withdrawn at a pressure which is less than 15 bars lower than the primary water pressure. The concentrate is kept in circulation with the entry face of the wall (40). The wall (40) can consist of an assembly of tubes maintained between two tube plates. The invention applies to pressurized water nuclear reactors whatever the number of primary circuit loops.
    Type: Grant
    Filed: September 24, 1984
    Date of Patent: August 4, 1987
    Assignee: Framatome & Cie.
    Inventor: Philippe Dagard
  • Patent number: 4668384
    Abstract: A washing unit has a receptacle for receiving at least one half of the length of a cylindrical cartridge filter for swimming pool filtration systems. An orifice, disposed in the side of the receptacle, directs water against at least the lower half of the external cylindrical surface of the filter to wash off and entrain foreign matter collected thereon upon flow of the water intermediate the filter and the receptacle. A discharge outlet downstream of the filter discharges the water and entrained foreign matter. An upwardly extending mouth at the inlet of the receptacle accommodates manual insertion, withdrawal and manipulation of the filter during washing while containing water splash. A pair of legs extending from proximate the inlet maintain the receptacle inclined to encourage downward water flow along the filter from the orifice to the discharge outlet.
    Type: Grant
    Filed: May 3, 1985
    Date of Patent: May 26, 1987
    Inventor: Paul D. Holman
  • Patent number: 4664813
    Abstract: A method and apparatus for dewatering and drying sludge. A pair of upper and lower members form a closed chamber into which sludge is poured. Sidewalls of the upper member are pressed against the lower member to seal the chamber. Compressed air supplied at a pressure P.sub.1 to a continuous groove in the lower edge of the sidewalls flows across the sloped inside surfaces of the sidewalls and supplements air supplied to the chamber at a somewhat lower pressure level P.sub.2, the combined pressures P.sub.1 and P.sub.2 in said chamber forcing liquid from said sludge through porous media in the bottom of the chamber. Air from the continuous groove aids in releasing the dried sludge from the chamber when the upper and lower members are separated.
    Type: Grant
    Filed: September 26, 1985
    Date of Patent: May 12, 1987
    Inventor: John R. Schneider
  • Patent number: 4655937
    Abstract: Disclosed is an improved rotary drum vacuum filter that is especially useful in the filtration of particulates that form an easily eroded cake. The improved filter utilizes sprayers and a spray blocking means to achieve an unexpectedly efficient rinse of the cake.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: April 7, 1987
    Assignee: BASF Corporation
    Inventor: David C. Hendrix
  • Patent number: 4652380
    Abstract: Filter cake waste media from a phosphoric acid purification process containing contaminating amounts of arsenic is treated in the process of this invention to remove the arsenic therefrom and to render the filter media suitable for reuse. The process of the invention comprises separating the arsenic contaminant from the filter material by treating the material with sufficient amount of a base, such as soda ash, to dissolve the contaminating arsenic compounds into solution and separating and recovering the filter media from the arsenic-containing solution. The separated arsenic can be recovered by reprecipitation utilizing an acid and a source of soluble sulfide ions.
    Type: Grant
    Filed: July 5, 1985
    Date of Patent: March 24, 1987
    Assignee: Stauffer Chemical Company
    Inventor: Donald R. Wheeler
  • Patent number: 4623631
    Abstract: The filtration of zeolites, for example sodium alumino silicates, from aqueous slurries containing the zeolites is improved by washing the filter cake with an aqueous solution of any salt which has the capacity to produce a stabilized slurry of the zeolite. Suitable salts include alkali metal carbonates, bicarbonates, sulphates and salts of organic acids.
    Type: Grant
    Filed: April 19, 1984
    Date of Patent: November 18, 1986
    Assignee: J. M. Huber Corporation
    Inventor: John A. Kostinko
  • Patent number: 4619770
    Abstract: A method and apparatus for recovering a product fluid from a filter, wherein a wash fluid is passed through the filter so as to yield a mixture of product fluid and wash fluid. The mixture is then phase separated in a phase separator into a first phase substantially comprising product fluid, and a second phase substantially comprising wash fluid.
    Type: Grant
    Filed: January 7, 1985
    Date of Patent: October 28, 1986
    Assignee: Phillips Petroleum Company
    Inventor: Ernest B. Boston
  • Patent number: 4614597
    Abstract: A process for recovering oil containing dissolved alkaline earth metal sulfonate from siliceous filter cakes containing such oils by mixing the filter cake with sufficient 0.5 to 16N sulfuric acid or phosphoric acid to bring the pH of the mixture to a level in the range about 2 to 7, settling the acid-filter cake mixture to separate an upper oil-sulfonate phase and recovering the upper phase.
    Type: Grant
    Filed: December 17, 1984
    Date of Patent: September 30, 1986
    Assignee: Claypro U.S.A.
    Inventors: Frank A. Stuart, William H. Tyson, Jr.
  • Patent number: 4608122
    Abstract: The washing efficiency of removal of cooking and bleaching chemicals from cellulose paper pulp on horizontal belt washing filters is improved by disrupting the filter mat adjacent the belt intermediately of soft, displacement wash liquor applications to the filter mat topside. The objective may be achieved by directing a line of low volume, high pressure jets of filtrate or wash liquor against the belt underside. Alternatively, sonicly vibrated foils extended transversely of and adjacent to the belt are effective to disrupt the filler mat pursuant to the invention objective.
    Type: Grant
    Filed: October 19, 1984
    Date of Patent: August 26, 1986
    Assignee: Westvaco Corporation
    Inventors: Edward P. Klein, Alfred H. Nissan
  • Patent number: 4578197
    Abstract: A method of and an arrangement for thickening of suspensions includes filtering of a suspension through candlelike filter elements in a filter container, backwashing the filter elements individually without interrupting the filtration process by applying pressure impulses of gaseous backwash medium to the pressure elements in a direction opposite to the filtration direction, wherein the gaseous backwash medium forms a gas chamber over the filter elements separated from the suspension fluid and having an adjustable pressure.
    Type: Grant
    Filed: July 23, 1982
    Date of Patent: March 25, 1986
    Assignee: DrM Dr. Muller AG
    Inventor: Hans Muller
  • Patent number: 4547226
    Abstract: The sugar content of citrus press liquor is enhanced by separating citrus solids, extracting fructose, glucose, and sucrose from the solids, and recombining the aqueous extract to increase the sugar content thereof. By inversion of the sucrose present in the sugar-enhanced press liquor, a high fructose syrup can be readily obtained which is indistinguishable from high fructose corn syrup. When separation is effected by centrifugation, a biocidally active colloidal phase is formed from which citrus terpenes and limonene can be extracted, resulting in a press liquor suitable for fermentation. The solid residue remaining after extraction can also be recycled with the remaining press cake.
    Type: Grant
    Filed: August 3, 1983
    Date of Patent: October 15, 1985
    Assignee: IGI Biotechnology, Inc.
    Inventors: Robert A. Milch, Patricia Guerry-Kopecko, Carol Koeble-Smith, Edward M. Sybert
  • Patent number: 4544491
    Abstract: A process for recovering hydrocarbon oils and hydrocarbon oils containing dissolved additives from filter cakes produced by filtering such oils using a siliceous filter aid.A small amount of a release agent, up to 2 cc per gram of filter cake, is slowly added to the filter cake with agitation to prevent formation of a release agent phase and then a further quantity of release agent is added to the resultant mixture with gentle stirring and the final mixture is then held quiescent at elevated temperature until an oil phase separates. The oil phase is removed and the remainder of the mixture is filtered to separate a release agent filtrate and a filter cake consisting mainly of filter aid.
    Type: Grant
    Filed: August 24, 1983
    Date of Patent: October 1, 1985
    Assignee: Claypro Associates
    Inventors: William H. Tyson, Frank A. Stuart
  • Patent number: 4541840
    Abstract: The invention relates to a process and a device for the discharge of residues of ash-containing fuels occurring during gasification of coal. The hot mixture of residues and water is separated in a separating chamber, whereby the residues enter a lock vessel situated under the separating chamber. The hot water is recycled to the water bath situated under the gasification reactor. After the lock vessel has been filled with residue, the hot water in the separating chamber is cooled or replaced by cold water. The discharge of the residues is pressureless and is effected by a stream of water flowing through the separating chamber into the lock vessel. Separating chamber and lock vessel remain filled with water at all times.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: September 17, 1985
    Assignee: Ruhrchemie Aktiengesellschaft
    Inventors: Josef Hibbel, Ulrich Gerhardus, Volkmar Schmidt, Bernhard Lieder, Heinrich Scheve, Erwin Zerres
  • Patent number: 4501670
    Abstract: A process for treating filter cakes, obtained by filtering oils containing oil soluble alkaline earth metal sulfonates employing siliceous filter aids in the filtration, to release oil and sulfonate from the filter cakes is disclosed. The filter cakes are mixed with hot aqueous solutions of materials selected from the group consisting of alkali metal hydroxides, alkali metal salts of acids having ionization constants less than 1.5.times.10.sup.-4 and mixtures of said salts and alkali metal hydroxides and held at a temperature above 160.degree. F. to separate oil and sulfonate.
    Type: Grant
    Filed: June 20, 1983
    Date of Patent: February 26, 1985
    Inventors: William H. Tyson, Frank A. Stuart
  • Patent number: 4488912
    Abstract: The sugar content of citrus press liquor is enhanced by separating citrus solids, extracting fructose, glucose, and sucrose from the solids, and recombining the aqueous extract to increase the sugar content thereof. By inversion of the sucrose present in the sugar-enhanced press liquor, a high fructose syrup can be readily obtained which appears indistinguishable from high fructose corn syrup. When separation is effected by centrifugation, a colloidal phase is formed from which limonene and biocidal flavanoids can be extracted, resulting in a press liquor suitable for fermentation to alcohol. The solid residue remaining after extraction can also be recycled with the remaining press cake.
    Type: Grant
    Filed: August 4, 1982
    Date of Patent: December 18, 1984
    Assignee: IGI Biotechnology, Inc.
    Inventors: Robert A. Milch, Patricia Guerry-Kopecko, Carol Koeble-Smith, Edward M. Sybert
  • Patent number: 4486315
    Abstract: A particle washing system and method of use provides for the placement of the fluid containing the desired particles within an inner tube having near the bottom thereof an orifice plugged with a material for sealing the particulate containing fluid from a wash fluid under forces substantially equal to 1G. The inner tube is positioned within an outer tube which contains a wash fluid having a density at least equal to that of the particle containing solution but less than that of the particles. Application of centrifugal force, substantially greater than 1G, and directed toward the bottom of the outer tube, causes the sealing material to be dislodged thereby permitting the particles to move through the orifice and through the outer solution. Thus the particles are collected from the inner solution, washed by the outer solution, and pelleted at the bottom of the outer tube.
    Type: Grant
    Filed: March 11, 1982
    Date of Patent: December 4, 1984
    Assignee: Ortho Diagnostic Systems Inc.
    Inventor: John W. Teipel
  • Patent number: 4439327
    Abstract: A backwashing alluvial filter has a vertical filter container, a plurality of collecting pipes removably mounted in the container, a plurality of filter elements suspended on the collecting pipes, separating walls subdividing the interior of the filter container into at least two chambers, and communicating with one another via vertical overflow shafts. Washing off of solid matter is performed by supplying a washing liquid via pipes directly under the overflow shafts.
    Type: Grant
    Filed: June 29, 1982
    Date of Patent: March 27, 1984
    Assignee: Dr. Muller AG
    Inventor: Hans Muller
  • Patent number: 4436631
    Abstract: A particle washing system and method of use is described wherein in a preferred embodiment the fluid containing the desired particles is placed within an inner tube having near the bottom thereof an orifice with a diameter at least equal to that of the diameter of the particles, and wherein the inner tube is positioned within an outer tube having a fluid with a density at least equal to that of the solution containing the particles to be separated but less than that of the particles. The application of centrifugal force to the particles directed toward the bottom of the outer tube causes the particles to move through the orifice and through the outer solution contained within the outer tube so that the particles are collected from the inner solution, washed by the outer solution, and subsequently sedimented at the bottom of the outer tube.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: March 13, 1984
    Assignee: Ortho Diagnostic Systems Inc.
    Inventors: Henry A. Graham, Jr., Johnna B. Hawk, Rosemary K. Chachowski
  • Patent number: 4435293
    Abstract: A particle washing system and method of use is described wherein in a preferred embodiment the fluid containing the desired particles is placed within an inner tube having near the bottom thereof an orifice with a diameter at least equal to that of the diameter of the particles, an air vent and, wherein the inner tube is positioned within an outer tube having a fluid with a density at least equal to that of the solution containing the particles to be separated within the inner tube but less than that of the particles. The application of centrifugal force to the particles directed toward the bottom of the outer tube causes the particles to move through orifice and through the outer solution contained within the outer tube so that the particles are collected from the inner solution, washed by the outer solution, and subsequently sedimented at the bottom of the outer tube.
    Type: Grant
    Filed: August 5, 1981
    Date of Patent: March 6, 1984
    Assignee: Ortho Diagnostic Systems Inc.
    Inventors: Henry A. Graham, Jr., Johnna B. Hawk, Rosemary K. Chachowski
  • Patent number: 4426295
    Abstract: A process is provided which permits the rapid concentration and collection of cells in body fluid with minimal need for centrifugation and without filtration or sediment flotation, while also permitting the collection of cells from the fluid in an essentially monolayer arrangement with essentially no cell distortion. The apparatus used in this process comprises an elongated receptacle or chamber having, at one end, an outlet opening through which body fluid containing cells to be collected can be introduced, e.g., by means of a syringe, and, interposed between the inlet opening and an outlet opening at the other end of the chamber, a filter, e.g., a microporous filter.
    Type: Grant
    Filed: September 28, 1981
    Date of Patent: January 17, 1984
    Inventors: Deborah A. Evans, Lisbeth E. Shelley
  • Patent number: 4406796
    Abstract: A mixture of oil, mostly finely divided solids, and water (a typical example would be steel rolling mill scale mixture) is one of the feed materials for this process. Most of the water is first drawn off. Then the material is fed through a plurality of mixers, and after each mixer the entire composition is passed through a separator, herein described as a dewetting apparatus, which separates the fine solids from the oil and solvent and returns the expended solvent upstream toward the feed point. The diminished volume of material then passes through a final dewetting screen where the solids are washed by a small stream of fresh solvent and the fine solids then pass through a dryer. All expended solvent is collected and passed through a fractionating still which separates the recovered oil, for storage, and the solvent vapors pass through a condenser to a regenerated solvent storage tank. All of the expended solvent is saved and used over repeatedly.
    Type: Grant
    Filed: September 3, 1981
    Date of Patent: September 27, 1983
    Inventor: Leonard A. Duval
  • Patent number: 4404106
    Abstract: A filter apparatus has an elongated shaft, a plurality of filtering elements mounted on the shaft and spaced from one another in direction of elongation of the latter, and means for cleaning the filtering elements. The cleaning means includes a source of cleaning medium under elevated pressure and a plurality of nozzle elements communicating with this source. The nozzle elements face toward surfaces of filtering material provided on the filter elements and are turnable relative to these surfaces. The cleaning medium is ejected from the nozzle elements at a pressure between substantially 5 and 100 bar toward the surfaces of the filtering material of the filter elements so that the cleaning medium removes a cake deposited during a filtering process from the surfaces of the filtering material and thereupon also cleans the filtering material of the filter elements.
    Type: Grant
    Filed: June 2, 1980
    Date of Patent: September 13, 1983
    Assignee: Chemap AG
    Inventors: Hans Muller, Bruno Guazzone
  • Patent number: 4402834
    Abstract: A process of dewatering sludge in which raw sludge and a flocculating agent are first mixed by suitable means, then fed into a rotary filter drum or similar device to effect thickening of the sludge and partial dewatering thereof. The now thickened sludge is then conveyed through a filtering assembly in which the sludge is subjected to further dewatering forces, which could be vacuum, centrifugal, static pressure, or pressure while moving along the filter surfaces, thereby further dewatering the sludge. The filtrate discharged from the filter drum and the filtering assembly and also wash water used for cleaning the filter surfaces in the filter drum and the filtering assembly are at least partly returned to the filter drum to effect total flocculation and recapture of sludge particles contained in the filtrate and the wash waters.
    Type: Grant
    Filed: April 6, 1981
    Date of Patent: September 6, 1983
    Assignee: Albert Klein KG
    Inventors: Wendel Bastgen, Helmut Schreiber, Eugen Grumbel
  • Patent number: 4385903
    Abstract: An aqueous slurry of a water-insoluble or slightly water-soluble metal hydroxide can be effectively filtrated and dehydrated by adding an anionic surfactant of the following formula (I):R--O--AO--.sub.n X (I)wherein R represents an alkyl or alkenyl group of 8-24 carbon atoms, A represents an alkyene group of 2-4 carbon atoms, X represents SO.sub.3 M (M being H, K, Na or NH.sub.4), PO.sub.3 M (M being K or Na) or CH.sub.2 COOM (M being K or Na), and n represents an interger of 1-100,to the aqueous slurry of the metal hydroxide or to the washing water.
    Type: Grant
    Filed: October 29, 1981
    Date of Patent: May 31, 1983
    Assignee: Kao Soap Co., Ltd.
    Inventors: Noboru Moriyama, Takeshi Inoue
  • Patent number: 4374735
    Abstract: Oil polluted water or solid adsorbents are treated with microbially produced glycolipids to separate the oil phase. The treatment may be carried out in an apparatus which can be taken to the site and which comprises a mixing vessel supported by an undercarriage and provided with a storage container to supply the glycolipids, filling means, overflow discharge means and outlet means at its base.
    Type: Grant
    Filed: June 11, 1980
    Date of Patent: February 22, 1983
    Assignees: Wintershall Aktiengesellschaft, Gesellschaft fur Biotechnologische Forschung
    Inventors: Walter Lindorfer, Walther Schulz, Fritz Wagner, Wilhelm Jahn-Held
  • Patent number: 4358383
    Abstract: Cleaning a filter surface (16) in situ in a filer housing (10) forming part of a pressure filtering apparatus for liquids is carried out by drying the coating deposited on the filter surface by means of hot air which is caused to flow at a moderate rate through the suspension chamber (5) of the filter housing in a direction over and substantially parallel to the sludge-coated filter surface. The dried coating is detached from the filter surface and removed from the suspension chamber by means of compressed air which alternately with the hot air and at a substantially higher rate than the latter also is caused to flow in a direction over and substantially parallel to the filter surface.
    Type: Grant
    Filed: March 1, 1981
    Date of Patent: November 9, 1982
    Inventor: Hans E. Asp
  • Patent number: 4350597
    Abstract: An apparatus and a process are provided which are particularly suited for treatment of sludge eminating from a metal finishing solution regeneration process, especially aluminum finishing solution. The sludge is washed on a horizontal belt vacuum filter from which a majority of the washing fluid is returned to the regeneration process. A portion of the washing water is wasted. After washing, the sludge is reslurried. Thereafter, the reslurried sludge is pumped to a reaction vessel in the presence of carbon dioxide under pressure. Sufficient carbon dioxide is provided to react with excess lime in the sludge to produce calcium carbonate and a substantially neutral pH. The sludge after carbonation is dewatered in a rotary drum vacuum filter and thereafter is suitable for placement in a landfill.
    Type: Grant
    Filed: October 31, 1980
    Date of Patent: September 21, 1982
    Assignee: Wilson & Company
    Inventors: Robert P. Selm, Leland M. Shepard
  • Patent number: 4342638
    Abstract: An apparatus arrangement and method of operation for treatment of the residue from a coal liquifaction and hydrogenation reactor, which residue contains 5% to 10% solids and is at elevated temperature (f.i. above 700.degree. F.) and pressure of 150-200 psi. Said apparatus comprising a continuous pressure precoat filter sealed against pressure loss, a sealed repulper associated with said pressure filter for repulping filter cake in relatively cooler solvent while maintaining the pressure thereon at about 150-200 lbs/in..sup.2 to yield a slurry, then utilizing the pressure to force the slurry into and through a second pressure filter wherein to effect liquid solids separation; and separately discharging the filtrate and cake from the second filter.
    Type: Grant
    Filed: December 30, 1980
    Date of Patent: August 3, 1982
    Assignee: Envirotech Corporation
    Inventor: Donald A. Dahlstrom
  • Patent number: 4338201
    Abstract: A method of separating solids and liquid material in a slurry. The solids are continuously purged, washed, dried and removed with a minimum amount of mechanical handling. The slurry is continuously deposited on a moving horizontal rotary screen and condensible vapor is introduced above the layer while the pressure is reduced below the layer. Liquid is withdrawn from underneath the slurry layer with the vapor passing through the layer becoming superheated upon passage to evaporate further liquid from the solids. A stream of gas, which may be the same condensible vapor, is directed at the solids to entrain them and remove them from the screen.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: July 6, 1982
    Assignee: Fabcon
    Inventor: Joseph C. V. Ducasse
  • Patent number: 4299806
    Abstract: The invention is a process for purifying elemental yellow phosphorus by contacting the yellow phosphorus with an aliphatic alcohol-tetraalkyl ammonium halide solution which effectively removes impurities and produces a colorless product.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: November 10, 1981
    Assignee: Stauffer Chemical Company
    Inventors: Mark A. Kuck, Gary K. Miller
  • Patent number: 4297164
    Abstract: An improved displacement washing process for recovering processing chemicals from a porous medium, particularly wood pulp, is described. The effective mobility of a displacing solution, typically a more dilute solution of the chemical sought to be recovered, is reduced such that it is less than the mobility of the solution to be recovered. In a pulp mill washing system, consumption of wash water may be reduced 0.6 tons of water per ton of pulp produced without reducing chemical recovery. Conversely, chemical effluent from the washer could be reduced by 50% without increasing wash water requirement. Mobility is proportional to the permeability of the porous medium with respect to the solution of interest and inversely proportional to the viscosity of that solution. Mobility of the wash solution relative to the solution to be displaced is preferrably reduced by the addition of a soluble, high molecular weight polymer, greater than 10.sup.
    Type: Grant
    Filed: March 10, 1980
    Date of Patent: October 27, 1981
    Assignee: Weyerhaeuser Company
    Inventor: Peter F. Lee
  • Patent number: 4288329
    Abstract: A mixture of solids, mostly finely divided, and oil, such as usually mixed with mill scale, and water is the feed material for this process. Most of the water is first drawn off. Then the material is fed through a plurality of mixers, and after each mixer the entire composition is passed through a separator, herein described as a dewetting apparatus, which separates the fine solids from the oil and returns the expended solvent upstream toward the feed point. The diminished volume of material then passes through a final dewetting screen where the solids are washed by a small stream of fresh solvent and the fine solids then pass through a dryer. All expended solvent is collected and passed through a fractionating still which separates the recovered oil, for storage, and the solvent vapors pass through a condenser to a regenerated solvent storage tank. All of the expended solvent is saved and used over and over.
    Type: Grant
    Filed: November 9, 1979
    Date of Patent: September 8, 1981
    Inventor: Leonard A. Duval
  • Patent number: 4269693
    Abstract: A process is disclosed for recovering re-usable bitumen from waste bituminous roofing felt and the like. The waste material is cooled, preferably to 0.degree. C. to 5.degree. C., and then comminuted to a particle size less than 5 mm, for example using a flail. The comminuted material is added to water and the material which floats is collected, melted and then filtered to remove particulate or fibrous impurities. Additives may be added to the molten material to adjust its melting point, according to the eventual use of the recovered bitumen. Any fibrous impurities filtered out may be treated with white spirit or kerosene to extract further bitumen, which is then recovered from the solvent.
    Type: Grant
    Filed: May 23, 1979
    Date of Patent: May 26, 1981
    Inventor: Anthony M. B. Hastie
  • Patent number: 4267061
    Abstract: Solids and a clear liquid phase are separated and recovered wherein the solids are suspended in high boiling liquids. The sludge phase is separated from the liquid phase. A separate liquid phase which has a higher density than the liquid content of the sludge phase is added to the dispersion to be separated or to the sludge phase and the resulting mixture is centrifuged to separate the solids from the liquid phase.
    Type: Grant
    Filed: January 4, 1979
    Date of Patent: May 12, 1981
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Thomas Simo, Roland Rammler
  • Patent number: 4260495
    Abstract: Zeolites are prepared by hydrothermal crystallization of alkaline aqueous synthesis mixtures. Normally the zeolites are filtered and washed with water until the filtrate shows a pH of about 9 to 12. Sometimes, especially if the resulting zeolite consists of very fine particles, the zeolite filter cake shows thixotropic properties.If the filter cake is washed with diluted sodium hydroxide or only small amounts of water this thixotropy can be avoided.
    Type: Grant
    Filed: July 24, 1979
    Date of Patent: April 7, 1981
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Horst Bennoit, Dieter Schmid
  • Patent number: 4260489
    Abstract: Oily sludge is treated by filtering it through a precoated surface filter, treating the filtration residue with a hydrocarbon solvent and/or steam stripping the extracted residue.The residual oil content of the treated sludge is very low and it can be used for land fill operations.
    Type: Grant
    Filed: July 19, 1979
    Date of Patent: April 7, 1981
    Assignee: The British Petroleum Company Limited
    Inventors: George Greig, Michael P. Broadribb
  • Patent number: 4250032
    Abstract: The invention relates to a process for the disposal of bauxite processing wastes comprising the steps of:(a) filtering the bauxite muds in suspension coming from the washing decanter,(b) continuously washing the dehydrated filtration cake on the filter with hot water with recycling of the liquid phase containing the greater part of the soda into the basic chemical process of the bauxite treating plant.
    Type: Grant
    Filed: March 5, 1979
    Date of Patent: February 10, 1981
    Assignee: Eurallumina S.p.A.
    Inventor: Giuseppe Costa