Vacuum Applied Patents (Class 95/101)
  • Patent number: 5370728
    Abstract: A single bed, air separation PSA system utilizes an external product surge tank to supply product oxygen and purge gas to the adsorbent bed. An equalization tank supplies void space gas to the bed for repressurization purposes.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: December 6, 1994
    Assignee: Praxair Technology, Inc.
    Inventors: Kimberly A. LaSala, Herbert Schaub
  • Patent number: 5354360
    Abstract: The present invention is directed to a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium at ambient temperatures or above by use of a magnesium exchanged, sodium A-zeolite in a preferred level of magnesium exchange and an appropriate pressure range for adsorption and desorption of bulk gases which provides improved recovery and reduced bed size factor.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: October 11, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Charles G. Coe, James E. MacDougall, Scott J. Weigel
  • Patent number: 5354346
    Abstract: A pressure swing adsorption process is set forth for the recovery of two gas products at high recovery and high purity using the steps of adsorption, depressurization, low pressure purge, evacuation and repressurization. The purge effluent and a portion of the depressurization effluent are used to partially accomplish the repressurization step.
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: October 11, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Ravi Kumar
  • Patent number: 5330561
    Abstract: A process for separating a feed gas mixture into a more strongly adsorbable component and a less strongly adsorbable component in a plurality of adsorbent beds containing an adsorbent selective for the more strongly adsorbable component using pressure equalization between beds after initial depressurization to provide a purge gas, using countercurrent evacuation wherein at least two adsorption beds are countercurrently evacuated simultaneously in overlapping countercurrent evacuation steps in the plurality of adsorption beds, and using a combination of less strongly adsorbable component and feed gas mixture to repressurize the adsorbent bed. Oxygen product can be recovered from air at high recovery using the process.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: July 19, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Ravi Kumar, Tarik Naheiri, Charles F. Watson
  • Patent number: 5328503
    Abstract: A process for separating a feed gas mixture into a more strongly adsorbable component and a less strongly adsorbable component in a plurality of adsorbent beds containing an adsorbent selective for the more strongly adsorbable component using pressure equalization between beds after initial depressurization to provide a purge gas and using a combination of less strongly adsorbable component and feed gas mixture to repressurize the adsorbent bed. Oxygen product can be recovered from air at high recovery using the process.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: July 12, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Ravi Kumar, Tarik Naheiri, Charles F. Watson
  • Patent number: 5296017
    Abstract: A method and an apparatus for concentrating/purifying a chlorine gas are disclosed in which a pressure swing adsorption method for alternately repeating an adsorbing operation and a desorbing operation employing one or more adsorption towers packed with an adsorbent for adsorbing the chlorine gas are used to obtain a high-purity concentrated/purified chlorine gas and an exhaust gas containing virtually no chlorine gas is obtained from the chlorine gas containing impurities by terminating the adsorption operation when the rate of temperature rise near the outlet end of an adsorption tower due to adsorption of chlorine therein rises above a predetermined amount.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: March 22, 1994
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Yoshitsugu Kono, Masaaki Ura, Hiroyuki Itoh, Satoshi Tsuruda
  • Patent number: 5294247
    Abstract: The present invention is a process for recovering hydrogen from dilute refinery off gases using a vacuum swing adsorption process having a simultaneous cocurrent depressurization to provide purge gas for another bed under the influence of a vacuum and countercurrent depressurization to vent void space gas and/or adsorbed gas to ambient.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: March 15, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Eric W. Scharpf, Ravi Kumar
  • Patent number: 5275640
    Abstract: Process for obtaining nitrogen from air or nitrogen-containing gases by pressure exchange adsorption and desorption on two alternately operated adsorbers filled with carbon molecular sieves, whereby air is passed through the adsorber so that the oxygen is adsorbed and enriched nitrogen is obtained, while at the same time the other adsorber is regenerated by pressure relief, whereby in a first carbon molecular sieve layer (on the air intake side) of the two adsorbers, making up 1/20 to 1/2 of the entire carbon molecular sieve layer, a carbon molecular sieve A is introduced which serves simultaneously for the adsorption of the residual humidity and gas separation, and that in a second (on the air-outlet side) carbon molecular sieve layer a carbon molecular sieve B is introduced serving exclusively for gas separation, and that the carbon molecular sieve A has a relative volume of 3.0 to 3.4 and the carbon molecular sieve B has a relative volume of 2.3 to 2.95.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: January 4, 1994
    Assignee: Bergwerksverband GmbH
    Inventors: Hans J. Schroter, Alfons Schulte-Schulze Berndt, Heinrich Heimbach, Ferdinand Tarnow
  • Patent number: 5261947
    Abstract: The selective adsorption of nitrogen from air is used in a system including a number of adsorbers, to give oxygen enriched gas at elevated pressure, the adsorber is regenerated by depressurization under atmospheric pressure with a pump and by repressurization with oxygen enriched gas. The pumping duration is at most equal to the duration of the production step.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: November 16, 1993
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Leon Hay, Sylvie Eteve
  • Patent number: 5258060
    Abstract: The present invention is directed to adsorptive separation of nitrogen with active adsorbent phases with high N.sub.2 capacity and high heats of adsorption when diluted with inert material at levels ranging from 5% to 80%. The presence of diluent reduces the temperature swings in the adsorbent bed, which increases the utilizable effective N.sub.2 working capacity and decreases the relative amount of O.sub.2 left unrecovered on the active adsorbent phase. The net result is equal or better process performance allowing utilization of a lower amount of active adsorbent phase. Use of a diluent having a higher heat capacity than that of the active adsorbent phase increases these benefits, but dilution effects are beneficial even for diluents with heat capacities equal to or lower than that of the active adsorbent phase.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: November 2, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Thomas R. Gaffney, John F. Kirner, Ravi Kumar, Robin J. Maliszewskyj
  • Patent number: 5248322
    Abstract: A pressure swing adsorption process is set forth for the recovery of two gas products at high recovery and high purity using the steps of adsorption, depressurization, evacuation and repressurization. A portion of the depressurization effuent is used to partially accomplish the repressurization step.
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: September 28, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Ravi Kumar