Patents by Inventor David L. Kraft

David L. Kraft 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: 8327809
    Abstract: A tri-sector regenerative oxidant preheater apparatus, method and arrangement for utilization with oxy-fired pulverized coal combustion power plants. The preheater includes a stationary housing and a rotor rotatably mounted in the housing. Sector plates are located at the axial ends of the rotor and divide the preheater into a flue gas sector, two primary oxidant sectors, and a secondary oxidant sector interposed between the two primary oxidant sectors. A primary oxidant fan is located downstream of the preheater to create a negative environment in the primary oxidant sectors. During operation of the preheater, the environments of the two primary oxidant sectors and the flue gas sector are at about the same negative pressure, and thus there is very limited leakage between the oxidant side and the flue gas side of the preheater.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: December 11, 2012
    Assignee: Babcock & Wilcox Power Generation Group, Inc.
    Inventors: Kiplin C. Alexander, David L. Kraft, Dennis K. McDonald
  • Patent number: 8136544
    Abstract: A sealing apparatus adapted for use in a pressure vessel such as a synthesis gas cooler. The sealing apparatus is of a segmented plate construction formed around an outer wall section of a conduit means of the pressure vessel that defines at least part of a passage for receiving effluent from a gasification process. Pressure responsive mechanisms are provided on the plate segments to maintain the pressure difference across the sealing apparatus within the acceptable operating limits as well as to permit instantaneous pressure release to prevent damage to the pressure part assembly or cage. The seal is also maintained continuously through the differential growth movement between the conduit means and the pressure vessel during heat up and cool down cycles.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: March 20, 2012
    Inventors: Rickey A. Wilson, David L. Kraft, Steven R. Fry
  • Publication number: 20110073049
    Abstract: A circulating fluidized bed (CFB) boiler comprising a reaction chamber. A bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. At least one non-mechanical valve, which includes an opening between the CFB and BFB and independently controlled fluidizing means located both upstream and downstream of the opening, is used to control the heat transfer to the IBHX by controlling the solids discharge from the BFB to the CFB. The elevation of the bottom of the opening is at or above the elevation of the fluidizing means. A flow control barrier may be located downstream of the opening.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Inventors: Mikhail Maryamchik, Kiplin C. Alexander, Mark C. Godden, David L. Kraft
  • Publication number: 20110073050
    Abstract: A circulating fluidized bed (CFB) boiler includes a reaction chamber, where a bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. A plurality of in-bed secondary air nozzles comprise a plurality of tubes which are grouped together and run across the width of the BFB between the BFB enclosure wall and an outside wall of the CFB. The nozzles are positioned to prevent the deflection of solids falling onto the BFB from the CFB by the secondary air jets while avoiding a complicated structure that would interfere with gas and/or solids movement in the furnace. The nozzles' exit openings are flush, or almost flush, with the BFB enclosure wall.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Inventors: MIKHAIL MARYAMCHIK, Kiplin C. Alexander, Mark C. Godden, David L. Kraft
  • Publication number: 20110073022
    Abstract: A system for feeding a primary oxidant to an oxy-fired circulating fluidized bed (CFB) boiler. The system includes a plurality of bubble cap assemblies each comprising a stem and a bubble cap with at least one exit hole, each bubble cap connected via a stem to at least one windbox, the windbox containing at least one manifold. A plurality of pipes are provided, each pipe located within a bubble cap assembly with an open end located either at, above or below the exit holes of the bubble caps and an opposite end connected to the manifold located inside each windbox. Recycle gas is piped into the windbox, to the stem, and exiting from the exit holes located in the bubble cap into the CFB. Oxygen is piped into the manifold, through the pipes and exiting through the exit holes located in the bubble cap.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Inventors: MIKHAIL MARYAMCHIK, KIPLIN C. ALEXANDER, MARK C. GODDEN, DAVID L. KRAFT
  • Publication number: 20100101564
    Abstract: A shop-assembled solar receiver heat exchanger having an arrangement of heat transfer surfaces and a vertical steam/water separator structurally and fluidically interconnected thereto. A vertical support structure is provided to support the vertical separator and the heat transfer surfaces. The vertical support structure is bottom supported, while the vertical steam/water separator and heat exchanger heat transfer surfaces are top supported from the vertical support structure. The vertical support structure provides structural support and rigidity for the heat exchanger and a means by which the heat exchanger can be picked up and lifted for placement at a desired location. A fabrication/transport/lifting fixture is provided which facilitates fabrication, assembly, transportation and erection of the heat exchanger from the shop to the field. The fixture supports two trunnion shafts attached to the support structure of the receiver. Lifting lugs would be located on the top end of the support structure.
    Type: Application
    Filed: October 23, 2009
    Publication date: April 29, 2010
    Inventors: STEVEN P. IANNACCHIONE, DENNIS R. SHIFFER, DAVID T. WASYLUK, JASON M. MARSHALL, DAVID L. KRAFT, GEORGE GRANT, KIPLIN C. ALEXANDER, RICKEY A. WILSON, JUSTIN A. PERSINGER, ADAM N. DePIZZO, MELVIN J. ALBRECHT
  • Publication number: 20090013941
    Abstract: A tri-sector regenerative oxidant preheater apparatus, method and arrangement for utilization with oxy-fired pulverized coal combustion power plants. The preheater includes a stationary housing and a rotor rotatably mounted in the housing. Sector plates are located at the axial ends of the rotor and divide the preheater into a flue gas sector, two primary oxidant sectors, and a secondary oxidant sector interposed between the two primary oxidant sectors. A primary oxidant fan is located downstream of the preheater to create a negative environment in the primary oxidant sectors. During operation of the preheater, the environments of the two primary oxidant sectors and the flue gas sector are at about the same negative pressure, and thus there is very limited leakage between the oxidant side and the flue gas side of the preheater.
    Type: Application
    Filed: July 8, 2008
    Publication date: January 15, 2009
    Inventors: Kiplin C. Alexander, David L. Kraft, Dennis K. McDonald
  • Publication number: 20080041572
    Abstract: A radiant synthesis gas (syngas) cooler used to contain and cool the synthesis gas produced by a coal gasification process used in an IGCC power plant employs a compact radial platen arrangement which is less prone to fouling and/or plugging issues.
    Type: Application
    Filed: August 15, 2007
    Publication date: February 21, 2008
    Applicant: THE BABCOCK & WILCOX COMPANY
    Inventors: Richard A. Wessel, David L. Kraft, Steven R. Fry
  • Publication number: 20080042373
    Abstract: A sealing apparatus adapted for use in a pressure vessel such as a synthesis gas cooler. The sealing apparatus is of a segmented plate construction formed around an outer wall section of a conduit means of the pressure vessel that defines at least part of a passage for receiving effluent from a gasification process. Pressure responsive mechanisms are provided on the plate segments to maintain the pressure difference across the sealing apparatus within the acceptable operating limits as well as to permit instantaneous pressure release to prevent damage to the pressure part assembly or cage. The seal is also maintained continuously through the differential growth movement between the conduit means and the pressure vessel during heat up and cool down cycles.
    Type: Application
    Filed: August 15, 2007
    Publication date: February 21, 2008
    Applicant: THE BABCOCK & WILCOX COMPANY
    Inventors: Rickey A. Wilson, David L. Kraft, Steven R. Fry
  • Publication number: 20080041322
    Abstract: An embodiment in accordance with the present invention provides a device and method for removing ash from an interior surface of a radiant synthesis gas cooler. The device for removing ash includes a rapper actuator, a striker pin coupled to the rapper actuator including a proximal end and a distal end, and a striker target assembly disposed such that a proximal surface of the striker target assembly is in contact with the distal end of the striker pin and a distal surface is in contact with the surface of the radiant synthesis gas cooler.
    Type: Application
    Filed: August 14, 2007
    Publication date: February 21, 2008
    Applicant: THE BABCOCK & WILCOX COMPANY
    Inventors: Steven R. Fry, Harry E. Hillegass, David L. Kraft
  • Patent number: 5526938
    Abstract: A system for classifying and cooling particulate material produced by a fluid bed boiler comprises a vertical housing having an inlet for incoming particulate material and a first outlet for discharging exhaust and a second outlet for discharging solids. A fluidized bed of material is contained within the housing and is located directly above a bed of material. A gas distribution grid provides air to both beds for cooling the particulate material, and temperature measurement is used along with flow measurement to control gas velocity through the beds.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: June 18, 1996
    Assignee: The Babcock & Wilcox Company
    Inventors: David L. Kraft, Michael J. Szmania
  • Patent number: 5078182
    Abstract: An insulated pipe construction avoids deterioration of the refractory due to thermal cycling by supporting the refractory material against the force of gravity without restraining movement of the refractory material due to thermal expansion thereof. Excessive hoop stresses in the shell of the conduit due to thermal expansion of the refractory material can be prevented by providing a crushable layer of insulating fiber board inbetween the refractory material and the inner surface of the shell.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: January 7, 1992
    Assignee: The Babcock & Wilcox Company
    Inventor: David L. Kraft