Patents Assigned to The BOC Group, Inc.
  • Patent number: 5620501
    Abstract: Selected strongly adsorbed gaseous impurities are removed from a gas stream by pressure swing adsorption in an adsorption system which includes a single adsorption vessel, a gas storage vessel and a single gas pump. Feed gas is pumped at a selected adsorption pressure cocurrently through the adsorption vessel, which contains an adsorbent that selectively adsorbs the selected impurity or impurities. The less strongly adsorbed components of the gas mixture pass out the adsorption vessel through the nonadsorbed gas outlet end of the adsorption vessel. When the adsorbed gas front reaches a certain point in the adsorption vessel, the adsorption step is terminated and gas is countercurrently transferred from the adsorption vessel to a gas storage vessel, optionally with use of the gas pump. The adsorption vessel is then countercurrently evacuated by use of the pump and a selected gas-enriched product is recovered and sent to storage or further processed in downstream treatment operations.
    Type: Grant
    Filed: August 15, 1995
    Date of Patent: April 15, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Satish S. Tamhankar, Ramakrishnan Ramachandran
  • Patent number: 5617742
    Abstract: A distillation apparatus having applicability to an air separation plant in which a distillation column is suspended within a containment sleeve from a main heat exchanger or a head condenser of the distillation column. The suspension of the distillation column is flexible so that the distillation column can assume a vertical orientation under influence of gravitational force to be self-leveling.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: April 8, 1997
    Assignee: The BOC Group, Inc.
    Inventor: Karl O. Toppel
  • Patent number: 5616170
    Abstract: Chabazite, offretite, erionite, levyne, mordenite, gmelinite, zeolite A, zeolite T, EMC-2, ZSM-3, ZSM-18, ZK-5, zeolite L, and beta zeolite whose exchangeable cations are composed of 95 to 50% lithium ions, 4 to 50% of one or more of aluminum, cerium, lanthanum and mixed lanthanides and 0 to 15% of other ions are prepared by ion-exchanging the base zeolite with water-soluble trivalent ion salts and with water soluble lithium salts. The zeolites preferentially adsorb nitrogen from gas mixtures.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: April 1, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Adeola F. Ojo, Frank R. Fitch, Martin Bulow
  • Patent number: 5616225
    Abstract: In one group of embodiments, two or more small anodes are spaced apart from one another in a magnetron, with some aspect of their electrical power being individually controlled in a manner to control a density profile across a plasma. In another group of embodiments, the same effect is obtained by mechanically moving one or more small anodes or anode masks. When used in a magnetron having either a rotating cylindrical cathode or a stationary planar cathode and designed to sputter films of material onto a substrate, the uniformity of the rate of deposition across the substrate is improved. Also, adverse effects of sputtering dielectric materials are reduced.
    Type: Grant
    Filed: March 23, 1994
    Date of Patent: April 1, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Peter A. Sieck, Richard Newcomb, Terry A. Trumbly, Stephen C. Schulz
  • Patent number: 5615573
    Abstract: A level detector for detecting a level of a liquid is provided with an elongated probe having opposed proximal and distal ends. In use, the distal end of the elongated probe is submerged beneath the level of the liquid with an unwetted length of the elongated probe located above the level of the liquid. A thermal conductor or an electrical heater is provided for maintaining a temperature difference between the proximal end of the elongated probe and the liquid so that at an intermediate location of the elongated probe, located above the level of the liquid, the temperature will be dependent upon the unwetted length of the elongated probe. A thermocouple or the like can be provided for generating a signal referable to the temperature at the intermediate location and the level of the liquid can thereby be correlated with such signal.
    Type: Grant
    Filed: July 8, 1994
    Date of Patent: April 1, 1997
    Assignee: The BOC Group, Inc.
    Inventor: Ron C. Lee
  • Patent number: 5614039
    Abstract: Method for heat treating a metal in which argon gas is selectively injected into the cooling zone of a heat treating apparatus when the temperature therein is above the level at which significant nitriding will occur.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: March 25, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Harbhajan S. Nayar, John J. Dwyer, Jr., Neeraj Saxena
  • Patent number: 5611366
    Abstract: Method and apparatus for producing a vaporized fuel stream from a liquid fuel in which an inert gas is injected into a pressurized storage container containing the liquid fuel to provide a vaporized fuel stream having a substantially constant pressure, flow rate and composition.
    Type: Grant
    Filed: June 19, 1995
    Date of Patent: March 18, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Geoffrey K. Creffield, Ian F. Chapman, Janice C. Aitken, Mark Cole, George R. White, III, Harbhajan S. Nayar
  • Patent number: 5611218
    Abstract: A method and apparatus for generating nitrogen from the separation of air in a single column nitrogen generator. Nitrogen rich vapor is condensed to form reflux through the vaporization of an oxygen-rich liquid stream produced as column bottoms. The vaporized oxygen-rich stream is in part recompressed in a recycle compressor, cooled and reintroduced back into the column to increase nitrogen production. The vaporized oxygen-rich stream is also in part expanded with the performance of work. The work of expansion is applied to the compression. A supplemental refrigerant stream produced by a nitrogen liquefaction unit allows the nitrogen to be taken as a liquid and increases the amount of work of expansion able to be applied to the compression.
    Type: Grant
    Filed: December 18, 1995
    Date of Patent: March 18, 1997
    Assignee: The BOC Group, Inc.
    Inventor: Joseph P. Naumovitz
  • Patent number: 5609104
    Abstract: An incinerator in which halogenated organic compounds are burned in the presence of oxygen or oxygen enriched air to produce combustion products. The combustion products potentially include unreacted oxygen and halogenated organic compounds which can react with oxygen to produce halogenated furans and dioxins. The formation of the halogenated furans and dioxins is minimized by firing a burner, burning a hydrogen containing fuel at a fuel-rich stoichiometry, into the combustion products so that the fuel will react with the unreacted oxygen. This will reduce formation of the halogenated furans and dioxins. Any of the halogenated furans and dioxins that are formed are substantially eliminated by the reaction of hydrogen supplied by the fuel with the halogenated furans and dioxins.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: March 11, 1997
    Assignee: The BOC Group, Inc.
    Inventor: Loo T. Yap
  • Patent number: 5601634
    Abstract: High purity argon is produced by subjecting a two-phase liquid-vapor mixture containing up to 3 volume % of nitrogen and/or up to 5 volume % oxygen to cryogenic temperature swing adsorption in an adsorption bed containing one or more adsorbents selective for nitrogen and/or oxygen at a temperature between the bubble point and the dew point of the two-phase mixture.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: February 11, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Ravi Jain, Sidney S. Stern
  • Patent number: 5591308
    Abstract: An oxygen delignification method and apparatus in which a charge of heated wood pulp is reacted with oxygen in the presence of a charge of caustic soda in a plurality of reaction stages located between mixing stages in which caustic is mixed with the wood pulp. The use of the plurality of mixing stages reduces peak pH exposure of the wood pulp that would otherwise occur if the charges of caustic and wood pulp were mixed all at once. Moreover, the caustic mixed in such manner replenishes neutralized caustic and ensures that the average pH level is increased above that in conventional oxygen delignification. The increase in average pH level favors an increase in the delignification. Filtrate from a washing stage is introduced into the mixing stages to prevent wood pulp degradation.
    Type: Grant
    Filed: June 28, 1995
    Date of Patent: January 7, 1997
    Assignee: The BOC Group, Inc.
    Inventors: Mark J. Kirschner, Rustam H. Sethna
  • Patent number: 5587003
    Abstract: Carbon dioxide is removed from a gas stream by passing the gas stream through a bed of natural or synthetic clinoptilolite or their chemically-modified derivatives. The process is particularly advantageous when applied to the removal of ppm levels of carbon dioxide from gas streams at temperatures above 20.degree. C.
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: December 24, 1996
    Assignee: The BOC Group, Inc.
    Inventors: Martin Bulow, Loc Dao, Frank R. Fitch
  • Patent number: 5582034
    Abstract: A method of producing nitrogen is a single column nitrogen generator in which first and second coolant streams are used to condense nitrogen-rich tower overhead to provide reflux for the distillation column. One of the coolant streams is composed of liquid having a higher nitrogen content than oxygen-rich liquid produced in a bottom region of the distillation column. This coolant stream is compressed, cooled and recycled to the bottom of the distillation column in order to increase nitrogen recovery.
    Type: Grant
    Filed: November 7, 1995
    Date of Patent: December 10, 1996
    Assignee: The BOC Group, Inc.
    Inventor: Joseph P. Naumovitz
  • Patent number: 5579646
    Abstract: A cryogen delivery apparatus for delivering cryogen in a saturated state includes a vessel to contain the cryogen in liquid and vapor phases. The vessel has a headspace region and a heat exchanger located within the headspace region for indirectly exchanging heat between the vapor located within the headspace region and a liquid stream composed of the liquid phase of the cryogen. In case the cryogen is introduced into the vessel as a subcooled liquid, the vapor will condense into the liquid phase and the subcooled liquid will be converted into a saturated liquid. The saturated liquid will then be discharged from a liquid outlet connected to the heat exchanger. In the event the liquid enters the vessel as two-phase flow, the vessel will act as a phase separator. A branched supply line is provided having a liquid inlet branch connected to a bottom liquid inlet of the vessel so that a supply stream composed of the cryogen flows into the vessel.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: December 3, 1996
    Assignee: The BOC Group, Inc.
    Inventor: Ron C. Lee
  • Patent number: 5578147
    Abstract: Process and apparatus for the heat treating of a part suspected of containing a lubricant in which the part is preheated to a temperature at which the lubricant vaporizes, the vaporized lubricant is converted to at least one gaseous by-product, the concentration of at least one of the by-products is then measured and heat treating of the part is conducted when the concentration of the measured by-product or total C--H bonds thereof reaches a predetermined value.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: November 26, 1996
    Assignee: The BOC Group, Inc.
    Inventors: Harbhajan S. Nayar, George R. White, III
  • Patent number: 5570582
    Abstract: A cryogenic refrigeration method for use in connection with a cryogenic temperature swing adsorption process. The cryogenic temperature swing adsorption process has a discontinuous production cycle during which production of a purified vapor stream ceases or is reduced through use of purified vapor to purge a regenerating adsorption bed. Additionally, the purified vapor stream in part of the production cycle is superheated through use of the purified vapor stream to cool the regenerating adsorption bed. A heat exchange stream is liquefied against the vaporization of at least part of an impure liquid stream to produce an impure vapor stream to be purified by the adsorption process. Process liquid is continually produced from the liquefaction of the process stream. The process liquid is used to in turn liquefy the purified vapor stream at varying flow rates that are sufficient to liquefy the purified vapor stream throughout the production cycle.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: November 5, 1996
    Assignee: The BOC Group, Inc.
    Inventors: Paul Sweeney, Colleen Prince, Andrew P. Owen
  • Patent number: 5571309
    Abstract: An adsorption process in which high and low pressure feed streams are introduced into a plurality of beds to produce product streams by adsorbing one or more preferentially adsorbed components within the beds. Each bed is subjected to a low pressure feed stage to produce a low pressure product stream followed by a high or higher pressure feeding stages to produce one or more high pressure product streams. Thereafter the beds are regenerated through depressurization and purge stages. The cycle is conducted out of phase so that one of the beds is producing the high pressure product stream while another bed is producing a low pressure product stream.
    Type: Grant
    Filed: July 28, 1995
    Date of Patent: November 5, 1996
    Assignee: The BOC Group, Inc.
    Inventor: Ravi Kumar
  • Patent number: 5571231
    Abstract: An apparatus for storing a multi-component cryogenic liquid in which headspace vapor in a storage tank is condensed in an external condensation tank through indirect heat exchange with liquid being vented from the storage tank. The resulting condensate can then be re-introduced into the storage tank through a pressure building circuit applied to the external condensation tank. In such manner, the pressure within the storage tank is regulated and the composition of the liquid stored within the storage tank is held with some degree of consistency. The use of an external condensation tank allows prior art cryogenic storage tanks and dewars to be retrofitted to store a multi-component cryogenic liquids.
    Type: Grant
    Filed: October 25, 1995
    Date of Patent: November 5, 1996
    Assignee: The BOC Group, Inc.
    Inventor: Ron C. Lee
  • Patent number: 5565089
    Abstract: Coke deposits are removed from particulates by combustion in a regenerator by a process in which air is initially used as the oxidant. The combustion gas is subjected to a separation process to remove nitrogen therefrom, and the remaining carbon dioxide-enriched gas stream is recycled to the regenerator together while substantially pure oxygen is introduced into the regenerator. As the level of carbon dioxide in the system increases, the amount of air being introduced into the regenerator is gradually reduced and, in compensation, the amount of oxygen flowing to the regenerator is gradually increased. Eventually, part or all of the air is replaced by oxygen and carbon dioxide recycle gas, and the level of oxygen and carbon dioxide are regulated to maintain the desired temperature in the regenerator.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: October 15, 1996
    Assignee: The BOC Group, Inc.
    Inventors: Ramakrishnan Ramachandran, Raghu K. Menon
  • Patent number: 5563734
    Abstract: An infrared reflecting interference filter capable of transmitting a desired proportion of visible radiation while reflecting a large portion of incident solar radiation is provided. The filter comprises a transparent substrate onto which is deposited a dielectric layer, followed by metal and dielectric layers. In between each of the dielectric and metal layers is deposited a precoat layer that promotes adhesion between the dielectric and the metal. One aspect of the invention is the use of a film comprising nickel and chromium nitride for each of the metal precoat layers. These precoat layers are thin so that there is less absorption of visible light but yet maintains good adhesive properties. Another aspect of the invention is the use of silver as the metal layer. Specifically, silver is sputtered in an atmosphere containing a mixture of nitrogen and argon or other inert gas.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: October 8, 1996
    Assignee: The BOC Group, Inc.
    Inventors: Jesse D. Wolfe, Abraham I. Belkind, Ronald E. Laird