Patents by Inventor Bowie G. Keefer

Bowie G. Keefer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6406523
    Abstract: Gas separation by pressure swing adsorption (PSA) is performed within an apparatus having a plurality of adsorbers cooperating with first and second valves in a rotary PSA module, with the PSA cycle characterized by multiple intermediate pressure levels between the higher and lower pressures of the PSA cycle. Gas flows enter or exit the PSA module at the intermediate pressure levels as well as the higher and lower pressure levels, under substantially steady conditions of flow and pressure. The PSA module comprises a rotor containing laminated sheet adsorbers and rotating within a stator, with ported valve faces between the rotor and stator to control the timing of the flows entering or exiting the adsorbers in the rotor.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: June 18, 2002
    Assignee: QuestAir Technologies, Inc.
    Inventors: Denis J. Connor, David G. Doman, Les Jeziorowski, Bowie G. Keefer, Belinda Larisch, Christopher McLean, Ian Shaw
  • Publication number: 20020066367
    Abstract: Disclosed embodiments of the apparatus address the challenges of rotary PSA systems, both axial and radial flow, with M>1 by providing interpenetrating, layered manifolds to accommodate all of the steps of a complex PSA cycle, suitable with equal compactness for any value of “M”. This approach extends readily to accommodate a plurality of rotary PSA modules and their cooperating compression machinery within a single layered manifold assembly for a single PSA plant train. Described embodiments of the rotary PSA apparatus include stators that define fluid ports. In particular embodiments of the described apparatus, a second stator defines pressure swing adsorption cycle sectors, each sector being defined by a light product delivery port, light product withdrawal ports, and light reflux return ports. The adsorber elements may directly contact one or more of the stators in a fluidly sealing manner (i.e., have a clearance gap of from about 0 to about 50 microns) using described reinforced adsorbers.
    Type: Application
    Filed: September 25, 2001
    Publication date: June 6, 2002
    Inventors: Bowie G. Keefer, Matthew Babicki, Brian Sellars, Ian Spencer Parker, David G. Doman, Alain Carel, Surajit Roy
  • Publication number: 20020056375
    Abstract: A gas separation system includes a stator, and a rotor rotatably coupled to the stator, and at least one surge absorber in communication with the stator. The stator includes a stator valve surface and a plurality of function compartments opening into the stator valve surface. The rotor includes a rotor valve surface in communication with the stator valve surface, and a plurality of flow paths for receiving adsorbent material therein. The rotor also includes a plurality of apertures provided in the rotor valve surface and in communication with the flow paths for cyclically exposing the flow paths to the function compartments. The surge absorbers are configured to reduce pressure variations in the function compartments and to maintain each function compartment at one of a plurality of discrete pressure levels. In this manner, substantially uniform gas flow can be maintained through the function compartments and the flow paths without recourse to multistage compression machinery.
    Type: Application
    Filed: December 3, 2001
    Publication date: May 16, 2002
    Inventor: Bowie G. Keefer
  • Publication number: 20020056374
    Abstract: A gas separation system for separating a feed gas mixture into a first gas component and a second gas component comprises a stator, and a rotor rotatably coupled to the stator. The stator includes a first stator valve face, a second stator valve surface, and a plurality of function compartments opening into the stator valve surfaces. The rotor includes a first rotor valve surface in communication with the first stator valve surface, and a second rotor valve surface in communication with the second stator valve surface. The rotor also includes a plurality of rotor flow paths for receiving gas adsorbent material therein for preferentially adsorbing the first gas component in response to increasing pressure in the rotor flow paths in comparison to the second gas component. Each rotor flow path includes a pair of opposite ends opening into the rotor valve faces for communication with the function compartments.
    Type: Application
    Filed: June 22, 2001
    Publication date: May 16, 2002
    Inventors: Bowie G. Keefer, Kevin A. Kaupert
  • Publication number: 20020035924
    Abstract: A pressure swing adsorption system for separating components of a gas mixture includes a first adsorbent module, and a second a adsorbent module coupled to the a first adsorbent module. The first adsorbent module includes a first gas inlet for receiving the gas mixture, at least one bed of first adsorbent material in communication with the first gas inlet for adsorbing a gas mixture component from the gas mixture, and a first gas outlet in communication with the first adsorbent beds for receiving a first product gas therefrom. The second adsorbent module includes a second gas inlet coupled to the first gas outlet for receiving the first product gas, at least one second bed of adsorbent material in communication with the second gas inlet for adsorbing a first product gas component from the first product gas, and a second gas outlet in communication with the second adsorbent beds for receiving a second product gas therefrom.
    Type: Application
    Filed: December 3, 2001
    Publication date: March 28, 2002
    Inventor: Bowie G. Keefer
  • Publication number: 20020022146
    Abstract: Methods for forming adsorbent laminate structures particularly for use in pressure swing adsorption processes and devices are disclosed. One disclosed embodiment comprises providing a metal or alloy support and depositing adsorbent material onto the support by electrophoretic deposition. Adsorbent material has been deposited on just one planar surface, and on both first and second planar surfaces, of the support. Adsorbent material also may be deposited on plural strips, which are then assembled into a laminate structure along the support. Adsorbers also are described comprising first and second wire mesh sheets having adsorbent material deposited on a first major planar surface thereof. The first and second sheets are placed adjacent one another and spaced sufficiently to define a flow channel.
    Type: Application
    Filed: April 20, 2001
    Publication date: February 21, 2002
    Inventors: Bowie G. Keefer, Alain Carel, Brian Sellars, Ian Shaw, Belinda Larisch
  • Publication number: 20020004157
    Abstract: An electrical generating system consists of a fuel cell, and an oxygen gas delivery. The fuel cell includes and anode channel having an anode gas inlet for receiving a supply of hydrogen gas, a cathode channel having a cathode gas inlet and a cathode gas outlet, and an electrolyte in communication with the anode and cathode channel for facilitating ion exchange between the anode and cathode channel. The oxygen gas delivery system is coupled to the cathode gas inlet and delivers oxygen gas to the cathode channel. The electrical current generating system also includes gas recirculation means couple to the cathode gas outlet for recirculating a portion of cathode exhaust gas exhausted from the cathode gas outlet to the cathode gas inlet.
    Type: Application
    Filed: March 14, 2001
    Publication date: January 10, 2002
    Inventors: Bowie G. Keefer, Christopher R. McLean, Michael J. Brown
  • Publication number: 20010023640
    Abstract: Gas separation by pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA), to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed with an apparatus having a plurality of adsorbers. The adsorbers cooperate with first and second valve means in a rotary PSA module, with the PSA cycle characterized by multiple intermediate pressure levels between the higher and lower pressures of the PSA cycle. Gas flows enter or exit the PSA module at the intermediate pressure levels as well as the higher and lower pressure levels, under substantially steady conditions of flow and pressure. The PSA module comprises a rotor containing laminated sheet adsorbers and rotating within a stator, with ported valve faces between the rotor and stator to control the timing of the flows entering or exiting the adsorbers in the rotor. Feed gas is compressed prior to entry to the first valve means.
    Type: Application
    Filed: December 8, 2000
    Publication date: September 27, 2001
    Applicant: QUESTAIR TECHNOLOGIES INC.
    Inventors: Bowie G. Keefer, Julie C. Scott, Christopher McLean
  • Patent number: 6176897
    Abstract: Pressure swing adsorption separation of a feed gas mixture, to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed in a plurality of preferably an even number of adsorbent beds, with each adsorbent bed communicating at its product end directly to a variable volume expansion chamber, and at its feed end by directional valves to a feed compressor and an exhaust vacuum pump. For high frequency operation of the pressure swing adsorption cycle, a high surface area layered support is used for the adsorbent. The compressor and vacuum pump pistons may be integrated with the cycle, reciprocating at twice the cycle frequency. Alternative configurations of the layered adsorbent beds are disclosed.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: January 23, 2001
    Assignee: Questor Industries Inc.
    Inventor: Bowie G. Keefer
  • Patent number: 6056804
    Abstract: Pressure swing adsorption separation of a feed gas mixture, to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed with a cooperating set of "N" adsorbers in a rotary assembly, with each adsorber communicating at its product end directly to a rotary cyclic displacement chamber, and at its feed end by rotary distributor valve ports to a rotary piston feed compressor and a rotary piston exhaust vacuum pump. The compressor and vacuum pump are integrated with the cycle, and rotate at "N" times the cycle frequency. Alternative adsorber configurations for high frequency operation are disclosed.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: May 2, 2000
    Assignee: Questor Industries Inc.
    Inventors: Bowie G. Keefer, Christopher R. McLean
  • Patent number: 6051050
    Abstract: Pressure swing adsorption (PSA) separation of a feed gas mixture is performed within an apparatus having typically a single prime mover powering a feed compressor for one or multiple rotary PSA modules in parallel, each module including a rotor with a large number of angularly spaced adsorber elements, with valve surfaces between the rotor and a stator so that individual adsorber elements are opened to compartments for staged pressurization and blowdown, with thermally boosted energy recovery from staged expansion of countercurrent blowdown and light reflux gases, and a plurality of adsorber elements opened at any instant to each compartment so that each compressor and expander stage operates under substantially steady conditions of flow and pressure.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: April 18, 2000
    Assignee: Questor Industries Inc.
    Inventors: Bowie G. Keefer, David G. Doman
  • Patent number: 5256172
    Abstract: Pressure swing adsorption separation of a gas mixture is performed in an apparatus with a plurality of adsorbent beds cooperating to exchange energy from an adsorbent bed undergoing a depressurization step to an adsorbent bed undergoing a pressurization step, and with provision for thermal coupling in order to improve process efficiency. Thermal coupling is provided as heating to augment expansion energy recovery, and as a temperature gradient imposed in adsorbent beds to provide the function of a thermal regenerator in a regenerative thermodynamic cycle. The invention provides improved techniques for recovery of expansion energy in pressure swing adsorption, and for direct application of thermal energy to power pressure swing adsorption processes.
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: October 26, 1993
    Inventor: Bowie G. Keefer
  • Patent number: 5096469
    Abstract: Pressure swing adsorption separation of a gas mixture is performed in first and second working spaces, with each working space having a flow path contacting adsorbent beds and variable displacement chambers. The volumes of the first and second working spaces are cyclically varied in opposite phase by oscillations of a liquid column whose movements change the volume of variable displacement chambers, so as to achieve cyclic pressure changes in each working space as required for the pressure swing process, while the inertia of the oscillating liquid column exchanges energy between the first and second working spaces.
    Type: Grant
    Filed: November 13, 1990
    Date of Patent: March 17, 1992
    Inventor: Bowie G. Keefer
  • Patent number: 5082473
    Abstract: Pressure swing adsorption separation of a gas mixture, containing a first component and also a second component which may be at low or trace concentrations, is performed to extract the second component from the gas mixture so that a first product stream containing the first component may be substantially purified with respect to the second component, while the second component is concentrated to a high degree in a second product stream. Gas mixtures containing three components may also be separated. The apparatus of the invention performs the separation within a single working space.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: January 21, 1992
    Inventor: Bowie G. Keefer
  • Patent number: 4973408
    Abstract: Apparatus and process for reverse osmosis or other pressure-driven membrane fluid separations, with a free rotor booster pump to increase the pressure of a feed fluid from an initial feed pressure to a working pressure at which perm-selective membranes separate the feed fluid into permeate and concentrate fluid fractions. The free rotor booster pump is powered solely by expansion of the concentrate fluid, thus recovering pressure energy from the concentrate fluid to amplify the pressure of the feed fluid. The free rotor booster pump is self-starting, provides desirable self-regulating characteristics to the apparatus, and simplifies the process since auxiliary valves that were required with prior art energy recovery turbines for starting procedures and running adjustments may be eliminated.
    Type: Grant
    Filed: February 23, 1989
    Date of Patent: November 27, 1990
    Inventor: Bowie G. Keefer
  • Patent number: 4968329
    Abstract: Pressure swing adsorption separation of a gas mixture containing a more readily adsorbed component and a less readily adsorbed component is performed to concentrate one of the components as a relatively purified product, within an apparatus which includes an adsorbent bed and cyclically operated variable volume displacement means associated with the adsorbent bed to vary the working pressure of the gas contacting the adsorbent bed. The invention provides means to generate flow over the adsorbent bed and achieve recovery of expansion energy, while enabling large exchanges of fresh feed gas for depleted feed gas during each cycle.
    Type: Grant
    Filed: October 1, 1988
    Date of Patent: November 6, 1990
    Inventor: Bowie G. Keefer
  • Patent number: 4816121
    Abstract: Gas or vapor phase chemical reactions are conducted inside an open loop Stirling cycle apparatus which may operate as a heat engine or as a heat pump. Adsorbent surfaces are associated with the thermal regenerators of the Stirling cycle apparatus, so that pressure swing adsorption separation of reactant and product gas species may be achieved in response to cyclic variations of flow and pressure within the apparatus. Flow control means are provided to introduce the feed gas into the working space of the apparatus and to remove separated product fractions. The feed gas is chemically reactive in a reaction zone of the working space, with reactant and product species separated by the apparatus to remove desired product(s) from the reaction zone while retaining reactant(s) in the reaction zone, so that conversion and selectivity objectives can be achieved.
    Type: Grant
    Filed: November 12, 1986
    Date of Patent: March 28, 1989
    Inventor: Bowie G. Keefer
  • Patent number: 4801308
    Abstract: Pressure swing adsorption separation of a gas mixture containing a more readily adsorbed component and a less readily adsorbed component is performed within an apparatus containing an adsorbent bed with cyclically varied geometry, such that the bed volume can be expanded or contracted. Variable volume displacement means at either end of a flow path through the adsorbent bed are operated cyclically to generate flow of a gas mixture along the flow path, in a first direction when the more readily adsorbed component is preferentially adsorbed during the high pressure portion of the cycle while the bed volume is relatively contracted, and in a second reverse direction during the low pressure portion of the cycle while the bed volume is relatively expanded.
    Type: Grant
    Filed: November 12, 1986
    Date of Patent: January 31, 1989
    Inventor: Bowie G. Keefer
  • Patent number: 4702903
    Abstract: Pressure swing adsorption gas separations are conducted inside an open loop Stirling cycle apparatus which may operate as an engine, refrigerator or heat pump. Adsorbent surfaces are associated with the thermal regenerators of the Stirling cycle apparatus, so that a preferentially adsorbed gas fraction is concentrated by parametric pumping into a colder end of an engine or into a warmer end of a refrigerator or heat pump, while a less readily adsorbed gas fraction is concentrated into warmer end of an engine or into colder end of a refrigerator or heat pump. Flow control means are provided to introduce the feed gas into the working space of the apparatus and to remove separated product fractions. Feed gases may be chemically reactive within a portion of the working space, with reactant and product species of the reaction separated by the apparatus to drive the reaction off equilibrium.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: October 27, 1987
    Inventor: Bowie G. Keefer
  • Patent number: RE32144
    Abstract: Reverse osmosis, particularly for water desalination, is achieved using semipermeable membranes which selectively permeate purified water from a feed solution pressurized by reciprocating piston or diaphragm pump. Pump action is assisted by returning pressurized concentrate fluid acting on reverse side of the pump piston or diaphragm. Directional valves controlling alternating admission and venting of concentrate fluid to and from pump cylinder are actuated mechanically by reversal of force applied to the piston rod. Mechanical dwell is provided in the piston or diaphragm motion during directional valve actuation. Pump may be operated by a manual lever or by a crank mechanism on a low speed rotary shaft. An optional differential surge absorber provides continuity of feed solution circulation past membrane surfaces during the return pump stroke, thus minimizing detrimental salt concentration build-up on the membranes.
    Type: Grant
    Filed: February 5, 1982
    Date of Patent: May 13, 1986
    Inventor: Bowie G. Keefer