Patents by Inventor Douglas A. Keller

Douglas A. Keller 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: 7563071
    Abstract: An apparatus for mounting a refractory component such as a turbine shroud ring segment (32) with a ceramic core (42) onto a combustion turbine engine structure (34). The ring segment has a ceramic matrix composite skin (40), and optionally, a thermal insulation layer (46). A pin (60) is inserted through a bore (48) in the core and through an attachment bar (54) with ends received in wells (50) in the core. The attachment bar may be attached to a backing member, or tophat (64), by a biasing device (76) that urges the refractory component snugly against the backing member to eliminate vibration. The backing member and refractory component have mating surfaces that may include angled sides (52S, 70). The backing member is attached to the engine structure. Turbine shroud ring segments can be attached by this apparatus to a surrounding structure to form a shroud ring.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: July 21, 2009
    Assignee: Siemens Energy, Inc.
    Inventors: Christian X. Campbell, Douglas A. Keller, Malberto F. Gonzalez
  • Patent number: 7534086
    Abstract: Aspects of the invention are directed to a multi-layer ring seal segment that can incorporate a plurality of material systems. The ring seal segment can include an inner layer, a central layer and an outer layer. The inner layer can be attached to one side of the central layer, and the outer layer can be attached to an opposite side of the central layer. The inner and outer layers can be made of a ceramic matrix composite, such as a hybrid oxide ceramic matrix composite or an oxide-oxide ceramic matrix composite. The central layer can be made of a material that has high shear strength relative to the inner and outer layers. The ring seal segment according to aspects of the invention can take advantage of the benefits of the different materials so as to better withstand the operational loads of the turbine.
    Type: Grant
    Filed: May 5, 2006
    Date of Patent: May 19, 2009
    Assignee: Siemens Energy, Inc.
    Inventors: Stefan Mazzola, Douglas A. Keller, Anthony L. Schiavo, David C. Radonovich
  • Publication number: 20090071160
    Abstract: A ceramic hybrid structure (207, 502, 602, 608) that includes a wavy ceramic matrix composite (CMC) wall (214, 532, 603, 609) bonded with a ceramic insulating layer (230, 538, 604, 610) having a distal surface (242) that may define a hot gas passage (250, 550, 650) or otherwise be in proximity to a source of elevated temperature. In various embodiments, the waves (216, 537, 637) of the CMC wall (214, 532, 603, 609) may conform to the following parameters: a thickness (222) between 1 and 10 millimeters; an amplitude (224) between one and 2.5 times the thickness; and a period (226) between one and 20 times the amplitude. The uninsulated backside surface (218) of the CMC wall (214) provides a desired stiffness and strength and enhanced cooling surface area. In various embodiments the amplitude (224), excluding the thickness (222), may be at least 2 mm.
    Type: Application
    Filed: September 14, 2007
    Publication date: March 19, 2009
    Applicant: SIEMENS POWER GENERATION, INC.
    Inventors: Douglas A. Keller, Anthony L. Schiavo, Jay A. Morrison
  • Patent number: 7494317
    Abstract: A system for attaching a ring seal to a vane carrier in a turbine engine can allow the ring seal to radially expand and contract at least partially independently of the vane carrier. The system can also be configured to substantially restrict axial and/or circumferential movement of the ring seal. In one embodiment, the ring seal can include a plurality of radial slots circumferentially spaced about the ring seal. A pin can extend substantially through each of the slots and into operative engagement with isolation rings, which are connected to the vane carrier. In another embodiment, the ring seal and the isolation rings can include a series of axially-extending protrusions extending substantially circumferentially about each component. The protrusions on the ring seal can substantially matingly engage the protrusions on the isolation rings. The protrusions can be configured as a Hirth coupling.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: February 24, 2009
    Assignee: Siemens Energy, Inc.
    Inventors: Douglas A. Keller, David C. Radonovich
  • Publication number: 20090010755
    Abstract: An attachment method and flange for connecting a ceramic matrix composite (CMC) component, such as a gas turbine shroud ring (36, 68), to a metal support structure. A CMC flange (20A) may be formed by attaching a wedge-shaped block (26) of a ceramic material to a CMC wall structure (22), and wrapping CMC layers (24) of the wall structure (22) at least partly around the block (26), forming the flange (20A) with an inner oblique face (34) and an outer face (35) normal to the wall structure. An adjacent support structure, such as a metal support ring (40A), may abut the outer face (35) of the CMC flange (20A) and be clamped or bolted to the CMC flange (20A).
    Type: Application
    Filed: July 3, 2007
    Publication date: January 8, 2009
    Inventors: Douglas A. Keller, Jay A. Morrison
  • Publication number: 20080273967
    Abstract: A turbine engine ring seal for sealing gaps between turbine engine outer seal segments and turbine blade tips. The turbine engine ring segment may have an inner radial surface that defines a portion of a gap gas flow path where the inner radial surface may be formed of an abradable ceramic coating and includes a plurality of gas flow protrusions that are oriented transverse to the gap gas flow path. The gas flow protrusions may induce vortices in the gas flow in the gap gas flow path. Additionally, the gas flow protrusions may be series of peaks and depressions between two adjacent peaks, where the depressions have an approximate semicircular shape. The distance between two adjacent peaks may be equal or greater than a width of the depression and the height of a single peak may be six percent or greater than the distance between two adjacent peaks.
    Type: Application
    Filed: February 15, 2007
    Publication date: November 6, 2008
    Inventors: Bonnie D. Marini, Douglas A. Keller
  • Publication number: 20080199661
    Abstract: An insulated CMC structure (20A) formed of a CMC layer (22A), a thermal insulation layer (24A) applied to a front surface (30A) of the CMC layer (22A), and cooling channels (28A) formed along the interface (26A) between the CMC layer and the thermal insulation layer, thus directly cooling the thermally critical area of the interface. Embodiments include cooling channels in direct contact with both layers (FIG. 1); cooling channels in one layer and tangent to the other layer (FIGS. 4, 5 and 9); cooling channels in the CMC layer with an intervening wall (36D, 36E) that bulges into the thermal insulation layer for improved bonding thereof (FIGS. 6, 7); and cooling channels formed in ceramic tubes (38F of FIG. 8).
    Type: Application
    Filed: February 15, 2007
    Publication date: August 21, 2008
    Inventors: Douglas A. Keller, Malberto F. Gonzalez, Gary B. Merrill
  • Publication number: 20080199307
    Abstract: A ceramic seal element (200) for use in a turbo-machine comprises a first, rigid portion (210) comprising ceramic fibers (212) bound within a ceramic matrix binder (214), a second, flexible portion (220) comprising ceramic fibers (222), and a third, rigid portion (230) comprising ceramic fibers (232) bound within a ceramic matrix binder (234). Ceramic fibers (222) retain a desired flexibility because they are not bound in ceramic matrix binder. In some embodiments the ceramic fibers (212, 222, 232) are stacked as horizontally disposed layers (225). Also, the fibers (212, 222, 232) of any layer (225) comprise bundles of fibers wherein some of the bundles extend continuously across portions (210, 220, 230). An alternative sealing element (300) comprises a first, rigid portion (310) comprising ceramic fibers (312) that are bound within a ceramic matrix binder (314), and a second, flexible portion (320) that comprises ceramic fibers (313) that retain a desired flexibility. Methods of manufacture are disclosed.
    Type: Application
    Filed: February 15, 2007
    Publication date: August 21, 2008
    Inventor: Douglas A. Keller
  • Publication number: 20080178465
    Abstract: A CMC wall (20F) may be attached to a metal wall (22F) by a plurality of bolts (28A, 28B, 28C) passing through respective holes (24A, 24B, 24C) in the CMC wall (20F) and holes in the metal wall (22F), clamping the walls (20F, 22F) together with a force that allows sliding thermal expansion but does not allow vibrational shifting. Distal ones of the holes (24A, 24B) in the CMC wall (20F) or in the metal wall (22F) are elongated toward a central one of the bolts (24C) or at alternate angles to guide differential thermal expansion (20T) of the CMC wall (20F) versus the metal wall (22F) between desired cold and hot geometries. A second CMC wall (20R) may be mounted similarly to a second metal wall (22R) by pins (39A, 39B, 39C) that allow expansion of the CMC component (201) in a direction normal to the walls (20F, 20R).
    Type: Application
    Filed: January 25, 2007
    Publication date: July 31, 2008
    Inventors: Anthony L. Schiavo, Douglas A. Keller, Malberto F. Gonzalez, David C. Radonovich
  • Publication number: 20080174041
    Abstract: A method for manufacturing decorative concrete blocks for decorative garden walls is presented, along with a machine suitable for practicing the method.
    Type: Application
    Filed: January 23, 2007
    Publication date: July 24, 2008
    Inventors: Douglas Keller Firedman, Joseph Francis McLaughlin
  • Patent number: 7393183
    Abstract: A trailing edge attachment for a composite turbine airfoil. The trailing edge attachment may include an attachment device for attaching the trailing edge attachment to the airfoil. The attachment device may include a plurality of pins extending through the attachment device and into the trailing edge blade. The trailing edge attachment may also include a spanwise cooling channel for feeding a plurality of cooling channels extending between a leading edge of the trailing edge attachment and a trailing edge of the attachment device. The attachment device may be configured to place the leading edge of the composite airfoil in compression, thereby increasing the strength of the composite airfoil.
    Type: Grant
    Filed: June 17, 2005
    Date of Patent: July 1, 2008
    Assignee: Siemens Power Generation, Inc.
    Inventor: Douglas A. Keller
  • Patent number: 7371043
    Abstract: Fabricating a refractory component for a gas turbine engine, such as a turbine shroud ring segment, by arranging refractory fiber tows (24) in a flaired tubular geometry (20) comprising a stem portion (21) and a funnel-shaped portion (22); impregnating the refractory fibers (24) with a ceramic matrix to form a flaired tube (20) of ceramic composite matrix material; at least partially filling the funnel-shaped portion (22) with a ceramic core (30) extending beyond the end of the funnel-shaped portion to provide a working gas containment surface (31); curing the flaired tube (20) and the ceramic core (30) together; cutting the funnel-shaped portion (22) to provide rectangular edges (27); and providing an attachment mechanism (34, 36, 38, 40) on the stem portion (21) for attaching the component to a surrounding support structure. Additional tows (24) may be introduced at intermediate stages to maintain a desired fabric density.
    Type: Grant
    Filed: January 12, 2006
    Date of Patent: May 13, 2008
    Assignee: Siemens Power Generation, Inc.
    Inventor: Douglas A. Keller
  • Publication number: 20080025838
    Abstract: Aspects of the invention are directed to a ceramic matrix composite ring seal segment. The ring seal segment according to aspects of the invention includes a relatively simple body that is circumferentially curved. At least a portion of the hot gas path surface of the ring seal segment can be coated with a thermal insulating. material. In one embodiment, each ring seal segment can be operatively connected to a stationary support structure, such as by way of isolation rings. The ring seal segments and/or the isolation rings can be configured so as to restrain the ring seal segments in the axial, radial and/or circumferential directions. The ring seal segments can be attached to the isolation rings so that the support points act opposite the operating pressure loads. Thus, the ring seal segments carry these loads in compression, a strong direction of the CMC fibers.
    Type: Application
    Filed: July 25, 2006
    Publication date: January 31, 2008
    Inventors: Bonnie D. Marini, Douglas A. Keller, David C. Radonovich, Gary B. Merrill, Steven J. Vance, Anthony L. Schiavo
  • Publication number: 20070258809
    Abstract: Aspects of the invention are directed to a multi-layer ring seal segment that can incorporate a plurality of material systems. The ring seal segment can include an inner layer, a central layer and an outer layer. The inner layer can be attached to one side of the central layer, and the outer layer can be attached to an opposite side of the central layer. The inner and outer layers can be made of a ceramic matrix composite, such as a hybrid oxide ceramic matrix composite or an oxide-oxide ceramic matrix composite. The central layer can be made of a material that has high shear strength relative to the inner and outer layers. The ring seal segment according to aspects of the invention can take advantage of the benefits of the different materials so as to better withstand the operational loads of the turbine.
    Type: Application
    Filed: May 5, 2006
    Publication date: November 8, 2007
    Inventors: Stefan Mazzola, Douglas Keller, Anthony Schiavo, David Radonovich
  • Publication number: 20070237476
    Abstract: An optical fiber sensor having a central core, a cladding layer disposed about the central core, and a thin film of lithium niobate positioned between the core and the cladding layer. Each of the cladding layer and the central core are made from glass materials having different indices of refraction. The refractive index of the lithium niobate film changes when stress is applied to the optical fiber sensor. Accordingly, stress may be detected and measured by detecting and measuring the modulation of light passing through the optical fiber sensor while the stress is occurring.
    Type: Application
    Filed: October 20, 2006
    Publication date: October 11, 2007
    Inventors: Tracer Jamison, Douglas Keller, Philipp Kornreich, James Flattery
  • Patent number: 7278820
    Abstract: Aspects of the invention are directed to systems for reducing the cooling requirements of a ring seal in a turbine engine. In one embodiment, the ring seal can be made of a ceramic material, such as a ceramic matrix composite. The ceramic ring seal can be connected to metal isolation rings by a plurality of pins. The hot gas face of the ring seal can be coated with a thermal insulating material. In another embodiment, the ring seal can be made of metal, but it can be operatively associated with a ceramic heat shield. The metal ring seal can carry the mechanical loads imposed during engine operation, and the heat shield can carry the thermal loads. By minimizing the amount of ring seal cooling, the ring seal systems according to aspects of the invention can result in improved engine performance and emissions.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: October 9, 2007
    Assignee: Siemens Power Generation, Inc.
    Inventor: Douglas A. Keller
  • Publication number: 20070206911
    Abstract: An optical fiber having a thin layer of gold positioned between the core and cladding. The gold layer is vacuum deposited on a rotating clean glass rod which will become the fiber core. The rod is inserted into a tube that will form the cladding of the fiber. The tube is sealed and placed in a hot tin bath inside a stainless steel pressure chamber that is pressurized and heated to collapse the cladding around the gold-coated core, thereby forming a fiber perform that may be pulled to form the gold metal cylinder fiber of the present invention. The fiber may be cleaved at one end and etched to expose a gold cylinder, thereby forming a highly responsive sensor.
    Type: Application
    Filed: September 11, 2006
    Publication date: September 6, 2007
    Applicant: FANASYS, LLC
    Inventors: Philipp Kornreich, Douglas Keller, James Flattery
  • Publication number: 20070160466
    Abstract: Fabricating a refractory component for a gas turbine engine, such as a turbine shroud ring segment, by arranging refractory fiber tows (24) in a flaired tubular geometry (20) comprising a stem portion (21) and a funnel-shaped portion (22); impregnating the refractory fibers (24) with a ceramic matrix to form a flaired tube (20) of ceramic composite matrix material; at least partially filling the funnel-shaped portion (22) with a ceramic core (30) extending beyond the end of the funnel-shaped portion to provide a working gas containment surface (31); curing the flaired tube (20) and the ceramic core (30) together; cutting the funnel-shaped portion (22) to provide rectangular edges (27); and providing an attachment mechanism (34, 36, 38, 40) on the stem portion (21) for attaching the component to a surrounding support structure. Additional tows (24) may be introduced at intermediate stages to maintain a desired fabric density.
    Type: Application
    Filed: January 12, 2006
    Publication date: July 12, 2007
    Inventor: Douglas Keller
  • Publication number: 20070077141
    Abstract: Aspects of the invention are directed to systems for reducing the cooling requirements of a ring seal in a turbine engine. In one embodiment, the ring seal can be made of a ceramic material, such as a ceramic matrix composite. The ceramic ring seal can be connected to metal isolation rings by a plurality of pins. The hot gas face of the ring seal can be coated with a thermal insulating material. In another embodiment, the ring seal can be made of metal, but it can be operatively associated with a ceramic heat shield. The metal ring seal can carry the mechanical loads imposed during engine operation, and the heat shield can carry the thermal loads. By minimizing the amount of ring seal cooling, the ring seal systems according to aspects of the invention can result in improved engine performance and emissions.
    Type: Application
    Filed: October 4, 2005
    Publication date: April 5, 2007
    Inventor: Douglas Keller
  • Publication number: 20070031258
    Abstract: An apparatus for mounting a refractory component such as a turbine shroud ring segment (32) with a ceramic core (42) onto a combustion turbine engine structure (34). The ring segment has a ceramic matrix composite skin (40), and optionally, a thermal insulation layer (46). A pin (60) is inserted through a bore (48) in the core and through an attachment bar (54) with ends received in wells (50) in the core. The attachment bar may be attached to a backing member, or tophat (64), by a biasing device (76) that urges the refractory component snugly against the backing member to eliminate vibration. The backing member and refractory component have mating surfaces that may include angled sides (52S, 70). The backing member is attached to the engine structure. Turbine shroud ring segments can be attached by this apparatus to a surrounding structure to form a shroud ring.
    Type: Application
    Filed: August 4, 2005
    Publication date: February 8, 2007
    Inventors: Christian Campbell, Douglas Keller, Malberto Gonzalez