By Distilling, Or Liquefying Vapors Of, Used Agent Patents (Class 134/12)
  • Patent number: 5037572
    Abstract: Azeotropic mixtures of n-perfluorobutylethylene and trans-1,2-dichloroethylene with methanol or ethanol or isopropanol are disclosed. The azerotropic mixtures are useful as: cleaning agents, blowing agents, refrigerants, aerosol propellants, heat transfer media and power cycle working fluids.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: August 6, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5037573
    Abstract: The azeotropic mixture of 1,1-dichloro-1-fluoroethane and n-perfluorobutylethylene is disclosed. The azeotropic mixture is useful as: a cleaning agent, a blowing agent, a refrigerant, an aerosol propellant, a fire extinguishing agent, a heat transfer medium and a power cycle working fluid.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: August 6, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5035830
    Abstract: Azeotropic mixtures of hexafluoropropylene/ethylene cyclic dimer with methanol or ethanol, the azeotropic mixtures being useful as: cleaning agents, blowing agents, refrigerants, aerosol propellants, heat transfer media and power cycle working fluids.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: July 30, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5035831
    Abstract: Stable azeotrope-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane, nitromethane, 1,2-dichloroethylene and an alkanol which are useful in a variety of industrial cleaning applications.
    Type: Grant
    Filed: October 6, 1989
    Date of Patent: July 30, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Hillel Magid, Ian R. Shankland, David P. Wilson, Kane D. Cook, Earl A. E. Lund
  • Patent number: 5034149
    Abstract: Azeotropic mixtures of 3-chloro-1,1,1-trifluoropropane (HCFC-253fb) with methanol, ethanol, or trans-1,2-dichloroethylene (t-HCC-1130) are useful in solvent cleaning applications.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: July 23, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5026499
    Abstract: An azeotropic mixture of hexafluoropropylene/ethylene cyclic dimer (dimer) with trans-1,2-dichloroethylene and methanol is useful in solvent cleaning applications and as refrigerants, aerosol propellants and blowing agents.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: June 25, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5026497
    Abstract: Azeotropic mixtures of perfluoro-1,2-dimethylcyclobutane, methanol and either 1,1-dichloro-1-fluoroethane or dichlorotrifluoroethane, are useful in solvent cleaning applications, and as refrigerants, aerosol propellants and polymer blowing agents.
    Type: Grant
    Filed: March 12, 1990
    Date of Patent: June 25, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5026498
    Abstract: Azeotropic mixtures of 1,1,1,2,3,3-hexafluoro-3-methoxypropane with one of trans-1,2-dichloroethylene (t-HCC-1130), cis-1,2-dichloroethylene (c-HCC-1130), 1,1-dichloro-1,2-difluoroethane (HCFC-132c), or 1,2-dichloro-1,2-difluoroethane (HCFC-132), and the use of such azeotropic mixtures in solvent cleaning applications is disclosed.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: June 25, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5026501
    Abstract: Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane; dichlorotrifluoroethane; and dichloromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: June 25, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Peter B. Logsdon, Leonard M. Stachura, Rajat S. Basu
  • Patent number: 5026502
    Abstract: Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane; dichlorotrifluoroethane; and alkane or cycloalkane having 5 carbon atoms are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning and as blowing agents.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: June 25, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Peter B. Logsdon, Ellen L. Swan, Leonard M. Stachura, Rajat S. Basu
  • Patent number: 5024781
    Abstract: Stable azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane, dichlorotrifluoroethane, methanol, and a mono- or di-chlorinated C.sub.2 or C.sub.3 alkane which are useful in a variety of industrial cleaning applications.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: June 18, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Peter B. Logsdon, Leonard M. Stachura, Ellen L. Swan, Rajat S. Basu
  • Patent number: 5023009
    Abstract: The azeotropic mixture of 1,1,1,2,3,3-hexafluoro-3-methoxypropane and 2,2,3,3,3-pentafluoropropanol-1, and the use of such azeotropic mixture as: a cleaning agent, a blowing agent, a refrigerant, an aerosol propellant, a heat transfer medium, a fire extinguishing agent, a gaseous dielectric and a power cycle working fluid is disclosed.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: June 11, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5023010
    Abstract: Azeotropic mixtures of 1,1,1,2,3,3-hexafluoro-3-methoxypropane with methanol or isopropanol or n-propanol, the azeotropic mixtures being useful in solvent cleaning applications.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: June 11, 1991
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5011542
    Abstract: In a method, especially for stripping enamel and removing coatings from objects, the advantages of a solvent treatment are to be retained, without having to put up with the disadvantages of contaminating the environment. This is accomplished essentially by using in a closed treating vessel a treating mixture with at least a preponderance of a solvent with a proportion of water in excess of that required for an azeotropic mixture and carrying out the treatment while boiling the treating mixture. After the treating mixture is removed from the vessel, any solvent components still present are distilled off azeotropically from the system with water and removed before the vessel is opened.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: April 30, 1991
    Inventor: Peter Weil
  • Patent number: 4999127
    Abstract: Azeotropic mixtures of 2-chloro-1,1,2-triflurorethyl-2-difluoromethyl ether and trans-1,2-dichloroethylene with methanol, the azeotropic mixtures being useful in solvent cleaning applications.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: March 12, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 4997589
    Abstract: Novel azeotrope-like compositions comprising 1,2-difluoroethane and dichlorotrifuoroethane which are useful in a variety of industrial applications including refrigerant applications, solvent applications, and blowing agent applications.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: March 5, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Earl E. A. Lund, Ian R. Shankland, Ellen L. Swan
  • Patent number: 4994201
    Abstract: Stable azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane, dichlorotrifluoroethane, methanol and cyclopentane which are useful in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: February 19, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Leonard M. Stachura, Peter B. Logsdon, Ellen L. Swan, Rajat S. Basu
  • Patent number: 4994202
    Abstract: Azeotropic mixtures of perfluoro-dimethylcyclobutane with 1,1-dichloro-1-fluoroethane or dichlorotrifluoroethane, are useful in solvent cleaning applications, and as refrigerants, aerosol propellants and polymer blowing agents.
    Type: Grant
    Filed: March 12, 1990
    Date of Patent: February 19, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 4988455
    Abstract: Azeotrope-like compositions consisting essentially of 1,1-dichloro-1,2,2-trifluoropropane and alkanol having 1 to 4 carbon atoms are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: October 6, 1989
    Date of Patent: January 29, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Hillel Magid, Richard E. Eibeck, Michael Van Der Puy, Richard M. Hollister, Dennis M. Lavery
  • Patent number: 4986928
    Abstract: Azeotropic mixtures of 1-chloro-1,2,2-trifluorocyclobutane and methanol are useful in solvent cleaning applications and as refrigerants, aerosol propellants and polymer blowing agents.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: January 22, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 4983222
    Abstract: A method for decontaminating PCB containing transformers. The transformer is initially cleaned using a vapor degreasing solvent. The internal parts are removed and given a second cleaning which combines vapor degreasing with mechanical tumbling. The transformer and its parts are cleaned to less than 10 .mu.g/100 cm.sup.2 PCB. These cleaned parts are reclaimed rather than disposed of as toxic waste.
    Type: Grant
    Filed: April 14, 1988
    Date of Patent: January 8, 1991
    Assignee: Union Carbide Chemicals and Plastics Company Inc.
    Inventors: Gregory R. Green, George R. Green
  • Patent number: 4980032
    Abstract: An apparatus and method for reprocessing waste piranha containing contaminated H.sub.2 SO.sub.4 from, for example, a semiconductor processing operation is described. The apparatus and method include a first distillation flask which are maintained under a substantial vacuum. The first distillation flask includes a first column with a column packing means and a reflux means to retard loss of H.sub.2 SO.sub.4 in the first distillation. The second distillation flask boils off substantially pure H.sub.2 SO.sub.4 through a column which is coupled to a condenser which condenses substantially pure H.sub.2 SO.sub.4.
    Type: Grant
    Filed: August 12, 1988
    Date of Patent: December 25, 1990
    Assignee: Alameda Instruments, Inc.
    Inventors: Jesse C. Dobson, Marshall McCormick
  • Patent number: 4975198
    Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises the steps of separating the material into a solid fraction and a liquid fraction when liquid is present leaching the solid fraction with a leaching solvent to obtain contaminated leaching solvent and a mixture of decontaminated solids and leaching solvent and stripping the contaminant, from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants. When liquid is present in the material, adsorbing residual contaminants from the liquid fraction are adsorbed onto decomtaminated solids to produce decontaminated liquids and contaminated solids.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: December 4, 1990
    Inventor: Werner Steiner
  • Patent number: 4970013
    Abstract: Azeotropic mixtures of 2,3-dichloro-1,1,1,3,3-pentafluoropropane and methanol, the azeotropic mixtures being useful in solvent cleaning applications.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: November 13, 1990
    Assignee: E. I. duPont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 4965011
    Abstract: Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane, dichlorotrifluoroethane, and nitromethane are stable and have utility as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: October 4, 1989
    Date of Patent: October 23, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, Joel E. Rodgers
  • Patent number: 4961870
    Abstract: Azeotrope-like compositions comprising 1,1,2-trichloro-1,2,2-trifluoroethane; 1,2-dichloroethylene; and alkanol having 3 to 7 carbon atoms have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing a printed circuit boards.
    Type: Grant
    Filed: December 14, 1989
    Date of Patent: October 9, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Kane D. Cook, Chien C. Li, Rajat S. Basu, David P. Wilson
  • Patent number: 4960535
    Abstract: Stable azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane, dichlorotrifluoroethane and a mono- or di-chlorinated C.sub.2 or C.sub.3 alkane which are useful in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: October 2, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Peter B. Logsdon, Leonard M. Stachura, Ellen L. Swan, Rajat S. Basu
  • Patent number: 4954290
    Abstract: Azeotropes of 1,1-dichloro-2,2,2-trifluoroethane with pentanes and their use as cleaning agents and foam blowing agents.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: September 4, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Philip L. Bartlett, Joseph A. Creazzo, Robert A. Gorski
  • Patent number: 4954222
    Abstract: A dry cleaning solvent recovery and filtering system includes a dry cleaning solvent tank containing solvent for use in a dry cleaning machine. A filtration path from the tank includes a centrifugal separator for removing coarse debris and a filter element for removing fine debris from the solvent fluid. The filter element includes a perforated metal cylinder, having an open mouth, with a Teflon.RTM. coated screen forming the interior debris collection surface. A rinsing spray nozzle situated at the mouth of the filter element directs a fluid spray under pressure against the collection surface in the same direction that debris contaminated solvent fluid flows therethrough. The pressure of the fluid spray is sufficient to dislodge fine debris adhered to the collection surface without forcing the debris into the perforations of the filter element.
    Type: Grant
    Filed: November 18, 1988
    Date of Patent: September 4, 1990
    Inventors: Larry L. Durr, B. Jan Clay, Larry J. Durr
  • Patent number: 4954289
    Abstract: Azeotropes of 1-chloro-1,2,2,2-tetrafluoroethane or 1-chloro-1,1-difluoroethane with n-butane or isobutane and their use as propellants and foam blowing agents.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: September 4, 1990
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Philip L. Bartlett, Joseph A. Creazzo, Robert A. Gorski
  • Patent number: 4929312
    Abstract: A solvent recovery system is provided which is characterized by improved efficiency and safety. The system includes an evaporator unit having a heat source for vaporizing contaminated solvent. The resulting vapors are subsequently liquified in a condensing unit. During evaporation and condensation of the solvent, a negative pressure is maintained within the system using a vacuum generator. After condensation, the liquid solvent passes into at least one accumulator which is periodically drained. The accumulator and vacuum generator operate in synchronization so that a vacuum is maintained in the system while drainage of the accumulator occurs. Since the evaporation and condensation systems of the invention are maintained at a negative pressure, any leaks therein do not result in the escape of flammable vapors.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: May 29, 1990
    Inventor: Robert D. Westcott
  • Patent number: 4917042
    Abstract: An apparatus for degreasing plastic automobile parts has a degreasing tank with a liquid degreasing agent reservoir in the bottom thereof and a degreasing vapor space thereabove, a heater in the reservoir for heating degreasing agent for vaporizing it, and a parts conveyor extending through the tank and having a downwardly inclined portion extending downwardly into the degreasing vapor space from one end to a nadir within the degreasing vapor space and an upwardly inclined portion extending out of the degreasing vapor space. Several cooling coils extend around the inside of the tank with an uppermost cooling coil at a level corresponding to the top of the degreasing vapor space and the remaining coils being spaced downwardly into said degreasing vapor space at intervals.
    Type: Grant
    Filed: August 31, 1988
    Date of Patent: April 17, 1990
    Assignee: Mazda Motor Manufacturing (USA) Corporation
    Inventors: Tadayoshi Kuronaga, Yuji Tanaka, Kikuo Kato
  • Patent number: 4913178
    Abstract: Disclosed is a process for removing polychlorinated biphenyls from electrical apparatus, particularly transformers, to achieve concentration levels of 50 ppm or less as required by the EPA. A dielectric fluid having a relatively low boiling point as compared to polychlorinated biphenyls and other contaminants and in which PCB's are soluble is selected. There is an external cooling loop through which the dielectric fluid is circulated maintaining the temperature and pressure of the transformer within its design limits. There is an external distillation loop where the liquid removed from the transformer is heated to boiling point of the selected dielectric fluid thereby vaporizing the dielectric fluid and leaving the polychlorinated biphenyls in liquid phase in the distillation vessel. The dielectric fluid vapor is then condensed and returned to solubilize remaining PCB's in the transformer.
    Type: Grant
    Filed: August 18, 1988
    Date of Patent: April 3, 1990
    Assignee: Quadrex HPS Inc.
    Inventor: David E. Fowler
  • Patent number: 4909898
    Abstract: A process for removing substantial quantities of volatile liquid e.g. hydrocarbon from a mixture of polymer and such liquid is provided. This process includes the initial step of introducing the mixture, and a liquid which is immiscible with the polymer, into a mixing/kneading zone provided with heated heat transfer surfaces having a temperature higher than the boiling point of the lowest boiling liquid component in the mixing/kneading zone. The mixture and the immiscible liquid are subjected to a period of continuous mixing and kneading within the mixing/kneading zone, to bring the mixture into continuously moving contact with the heat transfer surfaces. During this period of continuous mixing/kneading, the heated heat transfer surfaces are repeatedly mechanically cleaned to prevent buildup of solid polymer thereon.
    Type: Grant
    Filed: October 1, 1986
    Date of Patent: March 20, 1990
    Assignee: Polysar Limited
    Inventors: Dilipkumar Padliya, Kenneth C. Shepherd, Jeffrey T. Reed
  • Patent number: 4904407
    Abstract: Azeotrope-like compositions comprising 1,1,2-trichloro-1,2,2-trifluoroethane, methanol, nitromethane, 1,2-dichloroethylene and 1-chloropropane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including the defluxing of printed circuit boards.
    Type: Grant
    Filed: December 1, 1988
    Date of Patent: February 27, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, David P. Wilson, Earl A. E. Lund
  • Patent number: 4900470
    Abstract: Azeotrope-like compositions comprising 1,1,2-trichloro-1,2,2-trifluoroethane, methanol, nitromethane and 1-chloropropane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including the defluxing of printed circuit boards.
    Type: Grant
    Filed: December 1, 1988
    Date of Patent: February 13, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Earl A. E. Lund, Ellen L. Swan, Rajat S. Basu, David P. Wilson
  • Patent number: 4899798
    Abstract: Method of and apparatus for continuously reducing oxides which form on the surface of copper bar and rod during casting including means for collecting cleaning mixture vapors; means for raising the temperature and pressure of the collected vapor; means for lowering the temperature of the collected vapor below the temperature at which the vapor will condense without lowering the system pressure; and means for separating condensed cleaning mixture from uncondensed vapor as the uncondensed vapor is being conveyed to a furnace or other means for oxidizing residual vapor.
    Type: Grant
    Filed: November 28, 1988
    Date of Patent: February 13, 1990
    Assignee: Southwire Company
    Inventors: Ronald R. Martin, Vernon J. Miller, Sr.
  • Patent number: 4900365
    Abstract: Azeotrope-like compositions comprising trichlorofluoromethane, a dichlorotrifluoroethane selected from the group consisting of 1,1-dichloro-2,2,2-trifluoroethane and 1,2-dichloro-1,1,2-trifluoroethane and isopentane are novel compositions particularly useful as blowing agents in the preparation of polyurethane and polyisocyanurate foams.
    Type: Grant
    Filed: September 6, 1988
    Date of Patent: February 13, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Earl E. A. Lund, Robert G. Richard, Ian R. Shankland
  • Patent number: 4898601
    Abstract: An aftercooker device for reducing the solvent content of drycleaning solid residues is disclosed as is its application in dry cleaning processes. The aftercooker is adapted for use with fouled disposable filters as well as with the solids which result from the flashing of soil-containing filter backwash. The aftercooker and its use are characterized by the use of ambient to moderately elevated temperatures and low velocity flows of air to remove solvent from residues and to the use of a vent scrubber to recover the solvent so removed.
    Type: Grant
    Filed: June 1, 1989
    Date of Patent: February 6, 1990
    Inventor: Michael E. Casey
  • Patent number: 4894176
    Abstract: Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane, dichlorotrifluoroethane and methanol are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: January 16, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, Ian R. Shankland
  • Patent number: 4885099
    Abstract: A closed circuit solvent stripping and reclaiming apparatus for recovering solvent from filters used in dry cleaning machines comprising a steam cabinet (2), and condenser (3), a water solvent separator (4), a recirculating tank (5), a blower (6) and a carbon bed adsorber (7). Dry cleaning filters are disassembled and their constituents separated and placed in foraminous trays (9) inside the steam cabinet (2). The filter material is agitated with a shaker and alternately subjected to dry heat, vaporized recycled solvent saturated water, and live steam. Steam and solvent vapors derived from the filters are conducted to a condenser (3) for liquification followed by separation in the water solvent separator (4). Solvent is thereby reclaimed and solvent saturated water is collected and stored in the recycling tank for reintroduction into the steam cabinet for subsequent stripping cycle.
    Type: Grant
    Filed: October 31, 1986
    Date of Patent: December 5, 1989
    Assignee: J.A.C. Corporation
    Inventor: George H. Kelly
  • Patent number: 4879004
    Abstract: In order to dissolve oil or PCB which exists in the electrical insulation of parts to be cleaned, a solvent is evaporated during a heating phase by an evaporator located with the parts in an autoclave. The solvent vapor condenses on the parts and penetrates into the electrical insulation to form an oil or PCB-solvent mixture. In the heating phase, a plurality of intermediate pressure reductions are carried out in the autoclave, and during each intermediate pressure reduction the solvent is simultaneously distilled out of the oil or PCB-solvent mixture, directly from the autoclave. That is, during each of the pressure reductions, the solvent supply is discontinued and the mixture circulated through a circulating line. Following the completion of each intermediate pressure reduction, the pure oil or PCB present in a condensate vessel is pumped out by an intermediately located feed pump through a connecting line and into a reservoir.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: November 7, 1989
    Assignee: Micafil AG
    Inventors: Gustav Oesch, Paul Gmeiner, Urs Hofer
  • Patent number: 4877545
    Abstract: Azeotropic mixtures of 1,1,2-trichlorotrifluoroethane (CFC-113) with trans-1,2-dichloroethylene and ethanol, n-propanol, isopropanol or acetone. Also, Azeotropic mixtures of 1,1,2-trichlorotrifluoroethane (CFC-113), trans-1,2-dichloroethylene and ethanol or acetone with nitromethane are disclosed. The azeotropic mixtures are useful in solvent cleaning applications.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: October 31, 1989
    Assignee: E. I. Du Pont De Nemours and Company
    Inventors: Abid N. Merchant, Robert A. Gorski, Kenneth C. Burke
  • Patent number: 4873015
    Abstract: Azeotrope-like compositions comprising 1,1,2-trichloro-1,2,2-trifluoroethane, methanol, nitromethane and dimethoxymethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including the defluxing of printed circuit boards.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: October 10, 1989
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, Earl A. E. Lund, David P. Wilson
  • Patent number: 4869825
    Abstract: A process for the decontamination of materials such as soil, sediments and sludges contaminated with organic contaminants such as PCB's. The process comprises leaching a mixture of solids, water and contaminant in a three step process with solvents to obtain contaminated solvent and water and a mixture of decontaminated solids and solvent. The contaminant is stripped from the contaminated leaching solvent with a stripping solvent to concentrate the contaminants.
    Type: Grant
    Filed: April 15, 1988
    Date of Patent: September 26, 1989
    Inventor: Werner Steiner
  • Patent number: 4863630
    Abstract: Azeotrope-like compositions comprising 1,1-dichoro-1-fluoroethane, dichlorotrifluoroethane and ethanol are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: March 29, 1989
    Date of Patent: September 5, 1989
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu
  • Patent number: 4855023
    Abstract: An improved wafer cleaning process wherein a novel oxidant solution comprising ultrapure sulfuric acid, peroxydisulfuric acid, and ultrapure water used in a semiconductor wafer cleaning process is continuously withdrawn after use. The withdrawn oxidant is reprocessed continuously by contacting with alumina to remove fluoride ions. Water is continuously separated or stripped from the oxidant solution by heating the solution and bubbling an inert gas therethrough. The separated oxidant is continuously distilled and condensed to form a purified stream of sulfuric acid. The major portion of this stream is continuously returned to the wafer cleaning process. The remaining minor portion is continuously cooled, subjected to analysis for purity, and diluted with ultrapure water prior to electrochemical treatment in the anode compartment of an electrochemical cell. This converts at least a portion of the dilute sulfuric acid to peroxydisulfuric acid.
    Type: Grant
    Filed: April 19, 1988
    Date of Patent: August 8, 1989
    Assignee: Athens, Inc.
    Inventors: R. Scot Clark, Joe G. Hoffman, John B. Davison, Alan W. Jones, Allen H. Jones, Jr., David W. Persichini, Wallace I. Yuan, Bruce A. Lipisko
  • Patent number: 4853040
    Abstract: Substrates polluted with toxic substances are treated at their location of contamination, in-situ with solvated electrons prepared chemically or electrochemically. The process is useful in detoxifying inert, non-reducible solvents contaminated with chemically reducible substances.
    Type: Grant
    Filed: March 30, 1987
    Date of Patent: August 1, 1989
    Assignee: A. L. Sandpiper Corporation
    Inventors: Duane J. Mazur, Norman L. Weinberg, Albert E. Abel
  • Patent number: 4844745
    Abstract: Removal and/or clean-up of polychlorinated biphenyls (PCBs) from contaminated surfaces with novel compositions of petroleum distillates and wetting agents.
    Type: Grant
    Filed: October 12, 1988
    Date of Patent: July 4, 1989
    Assignee: Integrated Chemistries, Inc.
    Inventors: James E. Nash, Kurt E. Heikkila
  • Patent number: 4842764
    Abstract: Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane and methanol are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: May 3, 1988
    Date of Patent: June 27, 1989
    Assignee: Allied-Signal Inc.
    Inventors: Earl A. E. Lund, Robert G. Richard, Ian R. Shankland, David P. Wilson