For Scale Inhibiting Or Corrosion Preventing Patents (Class 203/7)
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Patent number: 4444675Abstract: Formation of alkaline scale in water distillation equipment is reduced or substantially eliminated without a significant increase in equipment corrosion rate by dissolving an effective amount of carbon dioxide in brine which is boiling or flashed or which has been boiled or flashed and which contains an effective amount of a high temperature threshold effect chemical scale control additive.Type: GrantFiled: February 18, 1982Date of Patent: April 24, 1984Assignee: Mechanical Equipment Company, Inc.Inventor: Richard W. Goeldner
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Patent number: 4434059Abstract: Industrial process cooling water systems are stabilized against iron precipitation by adding thereto an effective amount of an acrylic acid-acrylamide copolymer having specific weight ratios.Type: GrantFiled: November 18, 1982Date of Patent: February 28, 1984Inventors: Donald A. Johnson, Baker N. Nimry
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Patent number: 4430156Abstract: In a multiphase flow tube for drying pumpable suspensions to form solids having low residual moisture contents, the process uses brief increases in the pressure of the gas stream to prevent blockages.Type: GrantFiled: August 6, 1981Date of Patent: February 7, 1984Assignee: Bayer AktiengesellschaftInventors: Clemens Casper, Dieter Grenner, Gerd-Rudiger Klette, Edzard Tholema
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Patent number: 4430196Abstract: Methods and compositions are disclosed for neutralizing acidic components in petroleum refining units. The neutralizing agent comprises a member selected from the group of dimethylaminoethanol and dimethylisopropanolamine. The neutralizing agent may be added directly to the charge, in a reflux line, or directly to the overhead line of the refining unit. In those instances in which sour crude is to be refined, it is desirable that dimethylisopropanolamine be used in conjunction with the dimethylaminoethanol. The neutralizing agents are added in an amount sufficient to elevate the pH of the condensate (as measured at the accumulator) to within the pH range of 4.5-7.Type: GrantFiled: March 28, 1983Date of Patent: February 7, 1984Assignee: Betz Laboratories, Inc.Inventor: Joseph H. Y. Niu
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Patent number: 4422953Abstract: This invention relates to a method of inhibiting corrosion in halohydrocarbon systems such as haloethylene or other corrosive systems, which comprises treating such system with alkyl, alkenyl, or alkyl-X succinic acids or derivatives thereof, for example, salts thereof, where X is an oxygen, sulfur, amino, etc. containing group.Type: GrantFiled: April 21, 1982Date of Patent: December 27, 1983Assignee: Petrolite CorporationInventors: Mark T. Grace, Michael I. Naiman, Eddie C. French
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Patent number: 4415542Abstract: The scaling of autoclave and leaching-equipment surfaces during the high pressure leaching of nickeliferous oxide and silicate ores is controlled during leaching to favor the formation of scale containing substantial amounts of magnesium sulfate that is more easily removed by chemical dissolution using water or dilute sulfuric acid at temperatures ranging from about 50.degree. C. to 250.degree. C. than scale containing substantial amounts of alunite.Type: GrantFiled: June 21, 1982Date of Patent: November 15, 1983Assignee: Compagne Francaise D'Entreprises Minieres, Metallurgiques et D'InvestissementsInventors: Paul B. Queneau, Robert E. Doane, Mark H. Berggren, Mark W. Cooperrider
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Patent number: 4399109Abstract: A method is provided for inhibiting the formation of silica scale on flash-pot surfaces during the multi-stage flashing of sulfuric acid pressure-leach slurry obtained following the continuous autoclave leaching of nickel lateritic ore at elevated temperature and pressure during which silica is dissolved, wherein the leach slurry is subjected to a high-temperature flash stage such that the slurry at the flash temperature is supersaturated in soluble silica, and wherein the slurry is thereafter subjected to at least one additional flash at an intermediate-temperature flash stage at which silica precipitates and tends to form a scale accompanied by a decrease in said supersaturation.Type: GrantFiled: February 26, 1982Date of Patent: August 16, 1983Assignee: Compagnie Francaise d'Entreprises Minieres, Metallurgiques et d'InvestissementsInventors: Ralph K. Iler, Paul B. Queneau, Mark W. Cooperrider
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Patent number: 4396492Abstract: This invention is directed to a method of reducing the amount of corrosion resulting in a petroleum process operation wherein N-methyl pyrrolidone is utilized as one of the components by adding an effective corrosion inhibiting amount of an ester additive formed from a polycarboxylic acid and glycol or glycerol, preferably a dimer acid of linoleic acid and diethylene glycol.Type: GrantFiled: November 3, 1981Date of Patent: August 2, 1983Assignee: Exxon Research and Engineering Co.Inventor: Ewa A. Bardasz
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Patent number: 4374101Abstract: In the high-pressure sulfuric acid leaching of nickeliferous oxide and silicate ore, there is a tendency for the formation of scale on autoclave surfaces. The scale comprises oxides and sulfates of metals selected from the group consisting of aluminum, iron, silicon and magnesium. The scale is chemically removed by flushing the autoclave following completion of a leaching regime with a sulfuric acid solution containing about 20 to 100 gpl H.sub.2 SO.sub.4 at a temperature of about 150.degree. C. to 250.degree. C. and a pressure ranging from about 54 psig to 562 psig for a time sufficient to effect substantial removal of the scale.Type: GrantFiled: June 21, 1982Date of Patent: February 15, 1983Assignee: Amax Inc.Inventors: Guy W. Lussiez, Mahesh C. Jha
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Patent number: 4366066Abstract: Apparatus and a method of adding CO.sub.2 to softened water flowing through a series of interconnected flash chambers after the softened water has been directed out of a settler. The inlet of the settler receives preheated hard water after the hard water has passed through a series of interconnected preheating chambers, there being a preheating chamber for each flash chamber, respectively. Each preheating chamber and the corresponding flash chamber comprise a stage of a multi-stage water softening system, the preheating and flash chambers of each stage being separated by a partition defining an opening near the top portion of the stage to place the respective first and second chambers of each stage in fluid communication with each other and to allow flashed, heated water vapor from the flash chamber to pass into direct, admixing contact with cooler, hard water sprayed into the preheating chamber to preheat the hard water.Type: GrantFiled: March 27, 1981Date of Patent: December 28, 1982Assignee: Bechtel International CorporationInventors: Alfred N. Rogers, Leon Awerbuch, Sherman C. May
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Patent number: 4349412Abstract: A method of concentrating and drying water-containing fluent media, especially waste water concentrates, wherein an additive is incorporated in the water-containing fluent media for separating the solids thereof without the formation of scale and the liquid is evaporated. The additive comprises precipitates containing hydroxides, phosphates or arsenates of magnesium, calcium, zinc, aluminum or iron.Type: GrantFiled: December 18, 1978Date of Patent: September 14, 1982Assignee: Osterreichische Studiengesellschaft fur Atomenergie Ges.m.b.H.Inventors: Karl Knotik, Peter Leichter, Johann Glock
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Patent number: 4343658Abstract: Metal substrate surfaces are protected against carbon accumulation when exposed to an environment wherein carbon-containing gases are decomposed. The protection is accomplished by the use of tantalum and/or tungsten entities deposited and/or diffused into the surface of the substrate.Type: GrantFiled: April 14, 1980Date of Patent: August 10, 1982Assignee: Exxon Research & Engineering Co.Inventors: Rees T. K. Baker, James J. Chludzinski
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Patent number: 4342652Abstract: An effective amount of a copolymer of maleic acid or anhydride and allyl sulfonic acid when added to the water to be treated provides increased inhibition of scale formation in evaporative desalination units.Type: GrantFiled: January 22, 1981Date of Patent: August 3, 1982Assignee: American Cyanamid CompanyInventors: Arthur M. Schiller, James S. Balcerski
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Patent number: 4335072Abstract: Apparatus for determining the corrosion rate of petroleum distillation equipment so that corrosion inhibitors may be effectively utilized to control corrosion. The apparatus includes a water box having a coil arranged in the box through which hydrocarbon vapors are directed. Cooling water is forced through the box in a counterflow direction to cool the vapors and simulate cooling that will take place in heat exchange units. Corrosion and temperature probes are arranged along the coil to determine corrosion rates at the various temperature levels of the hydrocarbons so that a corrosion profile can be established and related to the temperature of the vapors at various locations in the heat exchange units of the equipment.Type: GrantFiled: August 17, 1981Date of Patent: June 15, 1982Assignee: Nalco Chemical CompanyInventors: Jack W. Barnett, Roy D. Sawyer
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Patent number: 4323430Abstract: A process for the substantially complete removal of acid gases and ammonia from aqueous solutions is disclosed, which comprises a two stage distillation operation wherein the pressure in the first distillation stage is substantially less than the pressure in the second stage, the ammonia concentration in this stage decreases downwardly so that an aqueous bottoms stream has a pH less than 8, this aqueous bottoms stream is treated with alkali and then distilled in the second stage. A portion of the aqueous bottoms can be vaporized by indirect heat exchange with vapors evolving from the second stage. The improvement lies in adding ammonia to the overhead vapor from the first stage to reduce corrosion of the condenser and preferably, the amount of vapor condensed is controlled to further minimize corrosion.Type: GrantFiled: March 16, 1981Date of Patent: April 6, 1982Assignee: United States Steel CorporationInventors: Donald Glassman, Edward E. Maier
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Patent number: 4312633Abstract: 1,1,1-trichloroethane is recovered in an excellent yield from textile material without deterioration in quality of the textile material by a method in which a textile material is introduced into a hot water bath having a temperature of 64.degree. C. or more and a pH of 4.0 or more, so as to allow 1,1,1-trichloroethane to vaporize together with water, the mixture of vapors of 1,1,1-trichloroethane and water is condensed by cooling it, and then, the condensed 1,1,1-trichloroethane is separated from the condensed water.Type: GrantFiled: December 14, 1979Date of Patent: January 26, 1982Assignee: Asahi-Dow LimitedInventors: Ken Kazama, Ikuo Muramoto, Yasunaga Katsumata
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Patent number: 4311562Abstract: Deposit formation in distillation units, particularly column reboiler units, associated with the separation and purification of dialkyl phosphorochloridothioates from a crude material containing oxygenated compound impurities, is inhibited by incorporating in the feed stock a minor proportion (generally about 0.05 to about 15.0 weight percent) of the condensation product of phenol, and preferably a high molecular weight alkylphenol, an aldehyde and an amine having a H--N< group.Type: GrantFiled: November 17, 1980Date of Patent: January 19, 1982Assignee: Ethyl CorporationInventor: Ellis B. Rifkin
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Patent number: 4311597Abstract: A method of removing ammonia from a wastewater containing free and fixed ammonia said process comprising the steps of: distilling the wastewater to remove the free ammonia; treating the distilled wastewater with soda ash to decompose the fixed ammonia; and distilling the treated wastewater to remove the decomposed ammonia.An apparatus for removing ammonia from a wastewater containing free and fixed ammonia comprising: an ammonia still for removing free and fixed ammonia; a source of soda ash solution; and means for feeding the soda ash solution from said soda ash source to the ammonia still to decompose the fixed ammonia.Type: GrantFiled: February 21, 1979Date of Patent: January 19, 1982Assignees: Republic Steel Corporation, The Hanna Furnace CorporationInventor: Aniruddha Bhattacharyya
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Patent number: 4302682Abstract: A power generation system and method of operation for generating electricity by utilizing temperature differences inherently present in the ocean between water near the surface and water from the ocean's depths. A pump provides relatively warm, surface ocean water to a flash evaporator where a portion of the water is flashed into steam. The steam is expanded through a subatmospheric pressure range turbine which exhausts into a condensing enclosure. The steam exhausting into the enclosure is condensed by relatively cold ocean water pumped thereinto. The turbine drives a generator and thus produces the electricity. The turbine speed and generator output are controlled by selectively introducing atmospheric air and relatively warm water into the exhausted motive steam flow. Such selective introduction into the exhausted steam flow of air and/or relatively warm water increases the absolute pressure at the turbine's exhaust end and thus reduces steam flow through the turbine.Type: GrantFiled: August 10, 1979Date of Patent: November 24, 1981Assignee: Westinghouse Electric Corp.Inventor: Bernard L. LaCoste
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Patent number: 4302328Abstract: A process is provided for treating spent geothermal brine to remove silica. The process includes introducing the brine into the reaction zone of a reactor-clarifier and allowing the brine to flow therefrom into the clarification zone of the reactor-clarifier. In the clarification zone, particles settle from the brine and are urged to the center of the tank beneath the reaction zone, and the settled particles are drawn upwardly into the reaction zone by an impeller. The particles mix with the brine in the reaction zone to form a substantially uniform distribution therein to provide nuclei for silica precipitation from the brine. A stream of sludge is removed from the bottom of the reactor-clarifier and disposed of.Type: GrantFiled: April 27, 1979Date of Patent: November 24, 1981Assignee: Envirotech CorporationInventor: Robert H. Van Note
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Patent number: 4282178Abstract: The addition of a small amount of hydrazine or a derivative or salt thereof serves to inhibit the corrosive effect of caustic such as sodium hydroxide on metal surfaces during the manufacture of the caustic or in processes using same. For instance, aqueous sodium hydroxide solutions having hydrazine or a derivative or salt thereof added thereto in an effective concentration in the range of from as little as about 2 ppm or less and up to about 1000 ppm, preferably of from about 2 to about 200 ppm, and most preferably from about 3 to about 40 ppm, can be concentrated by evaporation in nickel or nickel alloy equipment at temperatures as high as 150.degree.-175.degree. C. without causing undue corrosion.Type: GrantFiled: July 25, 1980Date of Patent: August 4, 1981Assignee: Vulcan Materials CompanyInventor: Gyaneshwari P. Khare
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Patent number: 4276124Abstract: A distillation system for sea water is provided with a fan to force air under pressure through a heating chamber having a heat exchanger to heat the air, a passageway from the heating chamber for directing the heated and pressurized air to an evaporator in which a reservoir of sea water is maintained at a predetermined level and in which cylindrical horizontally disposed brushes are partially submerged in the sea water and rotated as the heated air from the heating chamber passes over the rotating brushes with the brushes rotated at a sufficiently high speed to keep the brushes wet thereby preventing the formation of scale on the brushes. The moisture laden heated air then flows through a condenser which includes a heat exchanger utilizing sea water as the cooling medium and includes an outlet valve which permits the condensed water to be withdrawn for use.Type: GrantFiled: July 17, 1975Date of Patent: June 30, 1981Assignee: Haakon HaakonsenInventor: Arthur E. Mock
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Patent number: 4265701Abstract: An evaporator for increasing the solids content of a liquid-solids mixture employs vapor compressor means to recycle superheated vapors that are boiled off the mixture by a heat transfer fluid. The super-heated vapors are forced into the mixture before the mixture is heated by passage over a heat transfer surface, and the vapors cause the mixture to flow past such heat transfer surface at sufficient velocity to prevent excessive solids from depositing on the heat transfer surface.Type: GrantFiled: January 7, 1980Date of Patent: May 5, 1981Assignee: Ecodyne CorporationInventor: Henry G. Lankenau
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Patent number: 4263092Abstract: A method is disclosed for inhibiting soft scale precipitation in black liquor systems by adding thereto polyacrylic acid.Type: GrantFiled: August 16, 1979Date of Patent: April 21, 1981Assignee: Betz Laboratories, Inc.Inventors: Frederick C. Klaessig, Donald F. Jacques
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Patent number: 4260461Abstract: A vapor compression distillation apparatus and method are provided wherein scaling tendencies are eliminated. The raw feedwater has acid added to it in an amount sufficient to convert the carbonates and/or bicarbonates therein to carbon dioxide. The heated acidified feedwater is then deaerated to remove the carbon dioxide and other non-condensible gases. The deaerated water flows to the evaporator through a line having a valve therein controlled by the liquid level in the deaerator to maintain such level constant even though the tube side of the evaporator is being operated at a pressure less than that of the deaerator. This permits the evaporation to take place under a partial vacuum and at a boiling temperature of less than 212.degree. F. even though the deaerator is operated at atmospheric pressure. Vent steam from the evaporator is added to the deaerator to further preheat the feedwater, and as a sparging or stripping agent to aid in the elimination of carbon dioxide and other non-condensible gases.Type: GrantFiled: December 21, 1978Date of Patent: April 7, 1981Inventor: John E. Pottharst, Jr.
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Patent number: 4255309Abstract: A method is disclosed for inhibiting soft scale precipitation in black liquor systems by adding thereto a treatment comprising in combination polyacrylic acid and methyl vinyl ether/maleic anhydride copolymer.Type: GrantFiled: August 16, 1979Date of Patent: March 10, 1981Assignee: Betz Laboratories, Inc.Inventors: Frederick C. Klaessig, Donald F. Jacques
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Patent number: 4247371Abstract: Water containing dissolved compounds is preheated, and is then pressurized in stages of water pressure, while receiving a quantum of steam. Scale-forming compounds in the water are thermally precipitated, and clarified post-thermal water is formed. This is flash vaporized in stages corresponding to the stages of water pressure, and the flashed vapors are compressed to form each said quantum of steam. Alternately, the flashed vapors themselves comprise each said quantum of steam, by being induced into the water as it flows through an eductor means. Flash-cooled, post-thermal water, substantially devoid of scale-forming compounds, is employed as such, or more generally is evaporated to form fresh water and an end concentrate of dissolved compounds.Type: GrantFiled: December 20, 1978Date of Patent: January 27, 1981Inventor: Paul S. Roller
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Patent number: 4229284Abstract: A method of inhibiting corrosion in separation units of water-free petroleum and petrochemical hydrocarbon processing systems which comprises adding a compound corresponding to Formula I below either alone or in combination with a film-forming amine corrosion inhibitor to the hydrocarbon being processed:Formula IR--O--(CH.sub.2)nNH.sub.2,wherein n is 2 or 3 and R is a lower alkyl radical of not more than 4 carbon atoms.Type: GrantFiled: May 15, 1978Date of Patent: October 21, 1980Assignee: Nalco Chemical Co.Inventors: James A. White, Thomas C. Maynard
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Patent number: 4223120Abstract: Terpolymers of maleic anhydride, acrylamide or methacrylamide and a third monomer consisting of octene, styrene and the like.Copolymers of maleic anhydride and acrylamide or methacrylamide.Use of the hydrolyzed form of the terpolymer as a scale control agent.Novel process employing a mixture of aromatic and ketonic solvent and a temperature of at least 120.degree. C. which renders the polymers of the invention insoluble in water at ambient temperature.Type: GrantFiled: December 8, 1978Date of Patent: September 16, 1980Assignee: Pfizer Inc.Inventor: Stephen R. Kurowsky
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Patent number: 4200501Abstract: Silicate fouling on the reboilers and trays and the distillation train used for the production of dihydric alcohols is arrested by the addition of caustic to the feed stream.Type: GrantFiled: March 24, 1978Date of Patent: April 29, 1980Assignee: BASF Wyandotte CorporationInventors: Edward J. Panek, Werner O. Moll, Lee H. Bergman, Siegfried P. Kersten
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Patent number: 4200500Abstract: The reaction product of long-chain unsaturated hydrocarbons (fatty derivatives) with maleic acid anhydride and/or maleic acid is added to the salt-containing water of a thermal desalination installation to increase the solubility of the calcium and magnesium salts and prevent encrustation of heating surfaces thereby.Type: GrantFiled: November 7, 1977Date of Patent: April 29, 1980Assignees: Grillo-Werke Aktiengesellschaft, Ludwig Taprogge Reinigungsanlagen fur RohrenwarmeaustauscherInventor: Natvarlal B. Desai
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Patent number: 4191615Abstract: In order to prevent corrosion of the apparatus in extraction and extractive distillation processes where N-substituted morpholine is employed as the selective solvent an additive is added to the solvent which additive consists of (a) phosphoric acid, (b) a salt thereof, (c) a vanadium compound, (d) a molybdenum compound or (e) a mixture of two or more of these compounds, the addition being effected in an amount of about 0.005 to 0.02% by weight of the morpholine solvent.Type: GrantFiled: December 23, 1977Date of Patent: March 4, 1980Assignee: Krupp-Koppers GmbHInventors: Martin Schulze, Gerhard Preusser
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Patent number: 4188291Abstract: A method is disclosed for processing industrial waste waters and, in particular, blow down water from thermal electric plants. The water is processed to concentrate the salts contained therein and to obtain a concentrated brine which can then be passed to a thermal evaporator and/or solar evaporation ponds. The water is processed by the addition of magnesium hydroxide and carbon dioxide in amounts sufficient to precipitate the calcium as calcium carbonate, thereby obtaining a water reduced in calcium content and increased in magnesium content from the industrial waste water. The treated water is processed to recover a purified water from a brine, preferably by reverse osmosis. Calcium hydroxide is added to the brine generated by the reverse osmosis process in an amount sufficient to precipitate magnesium hydroxide therefrom which can be recycled to supply the magnesium hydroxide used in pre-treatment of the water prior to the reverse osmosis process.Type: GrantFiled: April 6, 1978Date of Patent: February 12, 1980Inventor: Donald R. Anderson
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Patent number: 4147627Abstract: Magnesium hydroxide scale formation in evaporative desalination units is inhibited by adding to the saline water being processed a mixture of certain polycationic and polyanionic polymers.Type: GrantFiled: February 7, 1977Date of Patent: April 3, 1979Assignee: American Cyanamid CompanyInventor: Richard M. Goodman
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Patent number: 4145393Abstract: Gray cast iron can be protected against corrosion in boiling concentrated sulfuric acid if the acid contains precious metals such as gold or the metals of the platinum group. It is possible to add small amounts of compounds of the precious metal to the acid or to bring both the gray cast iron and the acid into contact with metal sheets or wires of the precious metal. It is also possible to use small amounts of the precious metal as an alloying element of the gray cast iron.Type: GrantFiled: June 16, 1977Date of Patent: March 20, 1979Assignee: Hoechst AktiengesellschaftInventors: Helmold von Plessen, Edmund Bassler
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Patent number: 4111759Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantially all of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantially all of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia. In the second distillation, the amount of fixed ammonia is substantially reduced.Type: GrantFiled: July 8, 1976Date of Patent: September 5, 1978Assignee: United States Steel CorporationInventors: William J. Didycz, Donald Glassman, Edward E. Maier, George T. Saniga
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Patent number: 4108734Abstract: The fouling of ammonia stills which results from the clogging, particularly of the lower plates of the stills, with sludge and precipitates is eliminated by use of a calcium compound precipitation step followed by a clarification step prior to initiation of actual distillation.Type: GrantFiled: June 14, 1976Date of Patent: August 22, 1978Assignee: Bethlehem Steel CorporationInventors: Daniel Kwasnoski, Charles J. Sterner, Russel J. Horst, Kenneth R. Burcaw, Jr.
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Patent number: 4108735Abstract: Fouling of an ammonia still, used for removal of ammonia from weak ammonia liquor derived from a coal coking operation, is alleviated by pre-precipitating insoluble calcium salts from the ammonia liquor by treatment of the liquor with lime prior to introduction into a single-leg still.Type: GrantFiled: June 14, 1976Date of Patent: August 22, 1978Assignee: Bethlehem Steel CorporationInventors: Kenneth R. Burcaw, Jr, Daniel Kwasnoski, Eugene M. Rudzki
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Patent number: 4104131Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantial amounts of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantial amounts of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia and is conducted at a pH of more than 9. In the second distillation, the amount of fixed ammonia is substantially reduced.Type: GrantFiled: July 8, 1976Date of Patent: August 1, 1978Assignee: United States Steel CorporationInventors: William J. Didycz, Donald Glassman, Edward E. Maier, George T. Saniga
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Patent number: 4096085Abstract: An aqueous organic amine acid gas scrubbing system, particularly an aqueous N-methyldiethanolamine or diethanolamine acid gas scrubbing system having incorporated therein (1) a compound or mixture of compounds having the formula ##STR1## wherein n is an integer from 1 to 3, m is an integer from 2 to a number sufficient to yield a molecular weight of about 800, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from the group consisting of --H, --C.sub.n' H.sub.2n' OH, --C.sub.n' H.sub.2n'+1, --C.sub.n' H.sub.2n' N(R.sub.3)R.sub.4 wherein n' is an integer from 1 to 2 and wherein R.sub.1 -R.sub.3 and R.sub.2 -R.sub.4 may be joined to form cyclic amines when n is 2; said compound being present in about 10 to about 2000 parts per million parts of treating solution; (2) copper or a copper ion yielding compound in from 0 to 1000 ppm; and (3) sulfur or a sulfur atom yielding compound in from 0 to 1000 ppm.Type: GrantFiled: October 29, 1976Date of Patent: June 20, 1978Assignee: The Dow Chemical CompanyInventors: Smallwood Holoman Jr., Robert G. Asperger, Leroy S. Krawczyk
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Patent number: 4086146Abstract: A method of inhibiting the deposition of scale on the heat exchange surfaces of evaporators by adding 0.1 to 15 part per million quantities of maleic-furan copolymers or salts thereof to the evaporators.Type: GrantFiled: March 3, 1977Date of Patent: April 25, 1978Assignee: W. R. Grace & Co.Inventor: Jacob Block
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Patent number: 4072607Abstract: An anionic polymer of acrylamide having a skewed molecular weight distribution such that about 60% of said polymer has a molecular weight of about 500 to 2,000 and about 10% of said polymer has a molecular weight of about 4,000 to 12,000 has been discovered. The process of manufacturing this skewed molecular weight distribution anionic polymer is described. Its use as a scale inhibitor for controlling the deposition of adherent scales on the walls of vessels or pipes, and as an anti-precipitant for keeping alkaline earth cations in solution is also described. The use of the anionic polymer of acrylamide consisting of a skewed molecular weight could be used in recirculating water systems, boilers, and in evaporative and reverse osmosis desalination systems.Type: GrantFiled: October 26, 1976Date of Patent: February 7, 1978Assignee: American Cyanamid CompanyInventors: Arthur Maurice Schiller, Richard Martin Goodman, Roger Edgar Neff
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Patent number: 4065607Abstract: Terpolymers of maleic anhydride, acrylamide or methacrylamide and a third monomer consisting of octene, styrene and the like.Copolymers of maleic anhydride and acrylamide or methacrylamide.Use of the hydrolyzed form of the terpolymer as a scale control agent.Novel process employing a mixture of aromatic and ketonic solvent and a temperature of at least 120.degree. C. which renders the polymers of the invention insoluble in water at ambient temperature.Type: GrantFiled: March 23, 1977Date of Patent: December 27, 1977Assignee: Pfizer Inc.Inventor: Stephen R. Kurowsky
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Patent number: 4062764Abstract: A method of neutralizing acidic components in petroleum refining units in which distillation is taking place, which method comprises adding a compound corresponding to Formula I below either alone or in combination with a film-forming amine to the petroleum product being distilled:Formula Ir--o--(ch.sub.2).sub.n NH.sub.2wherein n is 2 or 3 and R is a lower alkyl radical of not more than 4 carbon atoms.Type: GrantFiled: July 28, 1976Date of Patent: December 13, 1977Assignee: Nalco Chemical CompanyInventors: James A. White, Thomas C. Maynard
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Patent number: 4054493Abstract: Preheated saline water, typically sea or brackish water, is further heated by quanta of steam, passed to it at differential temperatures and pressures and condensed in the saline water. Scale compounds are precipitated and scale-forming bicarbonates decomposed, with the evolution of carbon dioxide, which is gathered and expelled by steam accessory to the quanta of steam. Post-thermal saline water, which is formed, is multistage flash vaporized while self-cooling. The flashed vapors are compressed to form said quanta of steam. After being further cooled while preheating saline water, post-thermal saline water is evaporated in a multistage vapor compression evaporator, producing brine at a high concentration factor. Relative to equilibrium in scale-compound precipitation between 302.degree. F and 347.degree. F, the recovery of fresh water is 70% to 80% for sea water, and 80% to 90% for brackish waters over a wide range of salinity.Type: GrantFiled: July 1, 1976Date of Patent: October 18, 1977Inventor: Paul S. Roller
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Patent number: 4048021Abstract: In a method of obtaining purified 2,6-naphthalenedicarboxylic acid dimethyl ester by vacuum distilling crude 2,6-naphthalenedicarboxylic acid dimethyl ester under conditions of application of heat, the improvement which comprises vacuum distilling a crude 2,6-naphthalenedicarboxylic acid dimethyl ester having an acid value (A.sub.f), as expressed in milligrams of KOH required for neutralizing the carboxyl groups contained in one gram of said crude 2,6-naphthalenedicarboxylic acid dimethyl ester, of from 1.0 to 50.Type: GrantFiled: September 23, 1976Date of Patent: September 13, 1977Assignee: Teijin LimitedInventors: Hiromitsu Takamoto, Kiyoshi Yamamoto, Nobuo Taneda, Toru Matsubayashi, Gentaro Yamashita
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Patent number: 4043873Abstract: Process for the separation of trioxane from aqueous solutions containing it together with formaldehyde, which comprises subjecting the said solutions to evaporation at temperatures of 100.degree. C or lower, at pressures lower than atmospheric, and with residence times of less than 1 minute under the evaporation conditions, with vaporization of a quantity of from about 5 to about 15% by weight of the solution introduced, and recovering the trioxane from the products evaporated in this way.Type: GrantFiled: April 19, 1976Date of Patent: August 23, 1977Assignee: Societa' Italiana Resine S.I.R. S.p.A.Inventors: Jacob Ackermann, Pierino Radici, Umberto Santini, Paolo Colombo
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Patent number: 4036749Abstract: There is disclosed a treatment of water that greatly reduces the scaling tendency of the water during its subsequent use or processing. The treatment comprises precipitation and separation of the calcium values of the water as calcium carbonate by the addition of magnesium hydroxide precipitant thereto, with, as needed, a carbonate source, e.g., carbon dioxide. During subsequent use or processing, salts dissolved in the water are concentrated in a residual portion thereof and the residual portion is processed by the addition of calcium hydroxide to precipitate the dissolved magnesium values from the residual portion and supply the magnesium hydroxide that is employed as the precipitant in the treatment of the raw water. The treatment can be applied to any of a variety of water treating processes such as reverse osmosis, distillation, electrodialysis, freezing, vapor compression, ion exchange, evaporative cooling and/or boiler feed water treatment.Type: GrantFiled: November 8, 1976Date of Patent: July 19, 1977Inventor: Donald R. Anderson
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Patent number: 4024050Abstract: Phosphate and phosphite mono- and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100.degree. to 1500.degree. F. and which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled refining systems.Type: GrantFiled: October 23, 1975Date of Patent: May 17, 1977Assignee: Nalco Chemical CompanyInventors: Don C. Shell, Edward C. Hayward
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Patent number: 4024049Abstract: Thio-phosphate and -phosphite mono- and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100.degree. to 1500.degree. F and which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled refining systems.Type: GrantFiled: November 20, 1975Date of Patent: May 17, 1977Assignee: Nalco Chemical CompanyInventors: Don C. Shell, Edward C. Hayward