Patents by Inventor David J. Mitchell

David J. Mitchell 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: 7969323
    Abstract: An instrumented component (18, 19) for use in various operating environments such as within a combustion turbine engine (10). The component (18, 19) may have a substrate, a sensor (50, 94, 134) connected with the substrate for sensing a condition of the component (18, 19) during operation of the combustion turbine (10) and a connector (52, 92, 140) attached to the substrate and in communication with the sensor (50, 94, 134) for routing a data signal from the sensor (50, 94, 134) to a termination location (53). The component (18, 19) may include a wireless telemetry device (54, 76, 96) in communication with the connector (52, 92, 140) for wirelessly transmitting the data signal. Recesses (114, 116) may be formed with a root portion (112, 132) of components (18, 19) within which wireless telemetry device (54, 76, 96) may be affixed.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: June 28, 2011
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch
  • Publication number: 20110133950
    Abstract: A telemetry system for use in a combustion turbine engine (10) having a compressor (12), a combustor and a turbine (16) that includes a sensor (306) in connection with a turbine blade (301) or vane (22). A telemetry transmitter circuit (312) may be affixed to the turbine blade with an electrical connecting material (307) for routing electronic data signals from the sensor (306) to the telemetry transmitter circuit, the electronic data signals indicative of a condition of the turbine blade. A resonant energy transfer system for powering the telemetry transmitter circuit may include a rotating data antenna (314) affixed to the turbine blade or on a same substrate as that of the circuit. A stationary data antenna (320) may be affixed to a stationary component such as a stator (323) proximate and in spaced relation to the rotating data antenna for receiving electronic data signals from the rotating data antenna.
    Type: Application
    Filed: January 28, 2011
    Publication date: June 9, 2011
    Inventors: Ramesh Subramanian, Anand A. Kulkarni, David J. Mitchell, Bjoern Karlsson, Rod Waits, John R. Fraley
  • Publication number: 20110133949
    Abstract: A telemetry system for use in a combustion turbine engine (10) that includes a first sensor (306) in connection with a turbine blade (301) or vane (22). A first telemetry transmitter circuit (312) is affixed to the turbine blade and routes electronic data signals, indicative of a condition of the blade, from the sensor to a rotating data antenna (314) that is affixed to the turbine blade or is on a same substrate as that of the circuit. A stationary data antenna (333) may be affixed to a stationary component (323) proximate and in spaced relation to the rotating data antenna for receiving electronic data signals from the rotating data antenna. A second sensor (335) transmits electronic data signals indicative of the stationary component to a second telemetry circuit (332), which routes the signals to the stationary antenna. The stationary antenna transmits the electronic data signals to a receiver (338).
    Type: Application
    Filed: January 28, 2011
    Publication date: June 9, 2011
    Inventors: Ramesh Subramanian, Anand D. Kulkarni, David J. Mitchell, Bjoern Karlsson, Rod Waits, John R. Fraley
  • Publication number: 20100226756
    Abstract: An instrumented component (18, 19) for use in various operating environments such as the hot gas path section of a combustion turbine engine (10). The component (18, 19) may have a substrate, a sensor (50, 204, 210) connected with the substrate for sensing a condition of the component (18, 19) within the casing during operation of the combustion turbine (10) and a connector (52, 202) attached to the substrate and in communication with the sensor (50, 204, 210) for routing a data signal from the sensor (50, 204, 210) to a termination location (53). The component (18, 19) may include a wireless telemetry device (54, 202) in communication with the connector (52, 202) for wirelessly transmitting the data signal outside the casing. A transceiver (56) may be located outside the casing for receiving the data signal and transmitting it to a processing module (30) for developing information with respect to a condition of the component (18, 19) or a coating (26) deposited on the component (18, 19).
    Type: Application
    Filed: September 14, 2006
    Publication date: September 9, 2010
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch
  • Publication number: 20100226757
    Abstract: An instrumented component (18, 19) for use in various operating environments such as within a combustion turbine engine (10). The component (18, 19) may have a substrate, a sensor (50, 94, 134) connected with the substrate for sensing a condition of the component (18, 19) during operation of the combustion turbine (10) and a connector (52, 92, 140) attached to the substrate and in communication with the sensor (50, 94, 134) for routing a data signal from the sensor (50, 94, 134) to a termination location (53). The component (18, 19) may include a wireless telemetry device (54, 76, 96) in communication with the connector (52, 92, 140) for wirelessly transmitting the data signal. Recesses (114, 116) may be formed with a root portion (112, 132) of components (18, 19) within which wireless telemetry device (54, 76, 96) may be affixed.
    Type: Application
    Filed: September 14, 2006
    Publication date: September 9, 2010
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch
  • Publication number: 20100117859
    Abstract: An integrated, self-powered, sensing and transmitting module (300) that can be placed within an operating environment, such as by being affixed to a gas turbine engine component, in order to sense the local operating environment and to deliver real-time operating environment data to a location outside of the environment. Such a module may integrate a power element (302); a sensing element 9304); and a transmitting element (308) on a single substrate (320) within a single housing (310). Both sensors and circuitry components are formed directly on or in the substrate in novel configurations to decrease the size and weight of the module.
    Type: Application
    Filed: August 31, 2009
    Publication date: May 13, 2010
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian
  • Publication number: 20100078202
    Abstract: A printed circuit board (PCB 22) capable of withstanding ultra high G forces and ultra high temperature as in a gas turbine (11). The PCB includes a substrate having a plurality of cavities (30A, 36A) formed therein for receiving components of a circuit, and conductors embedded in the PCB for electrically connecting the components together to complete the circuit. Each of the cavities has a wall (36A?) upstream of the G-forces which supports the respective component in direct contact in order to prevent the development of tensile loads in a bonding layer (37A). When the component is an integrated circuit (50), titanium conductors (63) are coupled between exposed ends of the embedded conductors and contact pads on the integrated circuit. A gold paste (51) may be inserted into interstitial gaps between the integrated circuit and the upstream wall.
    Type: Application
    Filed: December 3, 2008
    Publication date: April 1, 2010
    Applicant: SIEMENS ENERGY, INC.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Andrew J. Burns
  • Publication number: 20100068508
    Abstract: A structure and method for instrumenting a component for monitoring wear in a coating. The method includes depositing a first thin layer of electrically insulating material, depositing a thin electrically conductive layer over the first electrically insulating layer, depositing a second thin layer of electrically insulating material over the electrically conductive layer. An overlying thickness of the coating material is deposited over the second thin layer of electrically insulating material. The thicknesses of the insulating and conducting layers is controlled to be small enough such that the overlying coating surface exposed to mechanical wear retains a desired degree of smoothness without the necessity for a separate planarization step.
    Type: Application
    Filed: September 15, 2008
    Publication date: March 18, 2010
    Inventors: Sachin R. Shinde, Anand A. Kulkarni, David J. Mitchell
  • Publication number: 20100039290
    Abstract: In a telemetry system for use in an engine, a circuit structure (34) affixed to a moving part (20) of the engine is disposed for amplifying information sensed about a condition of the part and transmitting the sensed information to a receiver external to the engine. The circuit structure is adapted for the high temperature environment of the engine and includes a differential amplifier (102, 111) having an input for receiving a signal from a sensor (101, 110) disposed on the part. A voltage controlled oscillator (104, 115) with an input coupled to the output of the amplifier produces an oscillatory signal having a frequency representative of the sensed condition. A buffer (105, 116) with an input coupled to the output of the oscillator buffers the oscillatory signal, which is then coupled to an antenna (26) for transmitting the information to the receiver.
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Applicants: Siemens Power Generation, Inc., Arkansas Power Electronics International, Inc.
    Inventors: DAVID J. MITCHELL, ANAND A. KULKARNI, RAMESH SUBRAMANIAN, EDWARD R. ROESCH, ROD WAITS, ROBERTO SCHUPBACH, JOHN R. FRALEY, ALEXANDER B. LOSTETTER, BRICE MCPHERSON, BRYON WESTERN
  • Publication number: 20100039288
    Abstract: A circuit affixed to a moving part of an engine for sensing and processing the temperature of the part. The circuit generates a signal representative of the temperature sensed by a thermocouple (110) and amplified by an amplifier (112). A square wave oscillator (113) with a temperature sensitive capacitor (C8) varies its frequency in response to changes of a local temperature of the circuit. A chopper (114, J27) converts the output of the amplifier into an alternating current signal. The chopper is gated by the square wave oscillator and a second input is coupled to an output of the amplifier. Thus, the chopper has an output signal having a frequency representative of the local temperature and an amplitude representative of the thermocouple temperature, whereby the combined signals represent the true temperature of the part.
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Applicants: Siemens Power Generation, Inc., Arkansas Power Electronics International, Inc.
    Inventors: DAVID J. MITCHELL, ANAND A. KULKARNI, RAMESH SUBRAMANIAN, EDWARD R. ROESCH, ROD WAITS, ROBERTO SCHUPBACH, JOHN R. FRALEY, ALEXANDER B. LOSTETTER, BRICE MCPHERSON, BRYON WESTERN
  • Publication number: 20100039289
    Abstract: A circuit assembly (34) affixed to a moving part (20) of a turbine for receiving information about a condition of the part and transmitting this information external to the engine. The circuit assembly includes a high-temperature resistant package (34A) that attaches to the part. A high temperature resistant PC board (42) supports both active and passive components of the circuit, wherein a first group of the passive components are fabricated with zero temperature coefficient of resistance and a second group of the passive components are fabricated with a positive temperature coefficient of resistance. The active components are fabricated with high temperature metallization. Connectors (40) attached to the PC board pass through a wall of the package (34A) for communication with sensors (30) on the part and with an antenna (26) for transmitting data about the condition of the part to outside the turbine.
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Applicants: Siemens Power Generation, Inc., Arkansas Power Electronics International, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, Roberto Schupbach, John R. Fraley, Alexander B. Lostetter, Brice McPherson, Bryon Western
  • Publication number: 20100039779
    Abstract: A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Applicants: Siemens Power Generation, Inc., Arkansas Power Electronics International, Inc.
    Inventors: DAVID J. MITCHELL, ANAND A. KULKARNI, RAMESH SUBRAMANIAN, EDWARD R. ROESCH, ROD WAITS, ROBERTO SCHUPBACH, JOHN R. FRALEY, ALEXANDER B. LOSTETTER, BRICE MCPHERSON, BRYON WESTERN
  • Publication number: 20100027584
    Abstract: A thin-film thermocouple (12) is disclosed for use with a gas turbine component. The thermocouple may be formed on a non-planar substrate (22) having formed thereon an electrically insulating layer (34) capable of maintaining its insulating properties at gas turbine operating temperatures. A first thermocouple leg (26) made of pure platinum is then deposited on the dielectric layer (34). A second thermocouple leg (28) made of another pure metal or a transparent ceramic oxide is also formed on the dielectric layer (34) wherein the first and second thermocouple legs make ohmic contact at a first end of each leg to form a hot junction (30) for conversion of heat into an electrical signal. The thermocouple may be deposited on a surface of a thermal barrier coating or between a thermal barrier coating and an underlying metal substrate.
    Type: Application
    Filed: December 3, 2008
    Publication date: February 4, 2010
    Applicant: Siemens Energy, Inc.
    Inventors: Anand A. Kulkarni, David J. Mitchell, Edward R. Roesch
  • Publication number: 20090219040
    Abstract: A wear sensor (30, 50, 60) installed on a surface area (24) of a component (20, 21) subject to wear from an opposing surface (74, 75). The sensor has a proximal portion (32A, 52A, 62A) and a distal portion (32C, 52C, 62C) relative to a wear starting position (26). An electrical circuit (40) measures an electrical characteristic such as resistance of the sensor, which changes with progressive reduction of the sensor from the proximal portion to the distal portion during a widening reduction wear of the surface from the starting position. The measuring circuit quantifies the electrical changes to derive a wear depth based on a known geometry of the wear depth per wear width. In this manner, wear depth may be measured with a surface mounted sensor.
    Type: Application
    Filed: May 21, 2009
    Publication date: September 3, 2009
    Inventors: Sachin R. Shinde, Anand A. Kulkarni, David J. Mitchell, Ramesh Subramanian
  • Publication number: 20090121896
    Abstract: A telemetry system for use in a combustion turbine engine (10) having a compressor (12), a combustor and a turbine (16) that includes a sensor (50, 74) in connection with a turbine blade (18) or vane (22). A telemetry transmitter circuit (210) may be affixed to the turbine blade (18) with a first connecting material (52, 152) deposited on the turbine blade (18) for routing electronic data signals from the sensor (50, 74) to the telemetry transmitter circuit (210), the electronic data signals indicative of a condition of the turbine blade (18). An induction power system for powering the telemetry transmitter circuit (210) may include a rotating data antenna (202) affixed to the turbine blade (18) with a second connecting material (140) deposited on the turbine blade (18) for routing electronic data signals from the telemetry transmitter circuit (210) to the rotating data antenna (202).
    Type: Application
    Filed: November 8, 2007
    Publication date: May 14, 2009
    Applicants: SIEMENS POWER GENERATION, INC., ARKANSAS POWER ELECTRONICS INTERNATIONAL, INC.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, John R. Fraley, Roberto M. Schupbach, Alexander B. Lostetter
  • Publication number: 20090017260
    Abstract: A ceramic thermal barrier coating (TBC) (18) having first and second layers (20, 22), the second layer (22) having a lower thermal conductivity than the first layer for a given density. The second layer may be formed of a material with anisotropic crystal lattice structure. Voids (24) in at least the first layer (20) make the first layer less dense than the second layer. Grooves (28) are formed in the TBC (18) for thermal strain relief. The grooves may align with fluid streamlines over the TBC. Multiple layers (84, 86,88) may have respective sets of grooves (90), Preferred failure planes parallel to the coating surface (30) may be formed at different depths (A1, A2, A3) in the thickness of the TBC to stimulate generation of a fresh surface when a portion of the coating fails by spalling. A dense top layer (92) may provide environmental and erosion resistance.
    Type: Application
    Filed: September 26, 2008
    Publication date: January 15, 2009
    Inventors: Anand A. Kulkarni, David J. Mitchell, Ramesh Subramanian, Andrew J. Burns
  • Publication number: 20080093264
    Abstract: The present invention provides for steam generation replacing natural gas with a selected refined product of a feedstock of bitumen, asphaltines or heavy oil using locally produced surplus bitumen, asphaltine or heavy oil, separating the asphaltines and other components of the feedstock for use in providing a liquid fuel for steam generation. The lighter products from the separation equipment not used for liquid fuel may be blended into the produced bitumen, asphaltines or heavy oil, to increase its API gravity and reduce the diluent required for transportation. This technology may be employed in open pit mining operations for the generation of steam and power. The refined components of the feedstock used to provide liquid fuel are selected to optimize energy output balancing planned energy demand against the value of the components of the feedstock used.
    Type: Application
    Filed: October 24, 2006
    Publication date: April 24, 2008
    Inventors: Sujit K. Sarkar, David J. Mitchell
  • Patent number: 5106916
    Abstract: This invention relates to a process for the catalytic grafting of an ethylenically unsaturated monomer onto a copolymer in the presence of a catalyst. The monomer is selected from the group consisting of ethylenically unsaturated carboxylic acids, anhydrides esters and other derivatives thereof. The copolymer is selected from the group consisting of certain copolymers of ethylene and ionomers of such copolymers. The catalyst is a mixture of (a) a certain amount of water and (b) at least one of certain phosphorus-containing compounds. The process comprises admixing copolymer, monomer, catalyst and an organic peroxide at a temperature above the melting point of the copolymer for a period of time so as to obtain a uniform distribution of monomer, catalyst and peroxide in the copolymer. The resultant grafted copolymer has improved color, and is useful in adhesive systems and as a compatibilizer for polymers and other materials.
    Type: Grant
    Filed: October 16, 1989
    Date of Patent: April 21, 1992
    Assignee: Du Pont Canada Inc.
    Inventor: David J. Mitchell
  • Patent number: 4859733
    Abstract: A method is disclosed for the reduction of the extractability of trialkanolamines from polyolefins containing such compounds e.g. as a result of the use of trialkanolamines as catalyst deactivators in processes for the polymerization of olefins. Zinc oxide and/or zeolite molecular sieves are incorporated into the polyolefin, either during the process for the manufacture of the polyolefin or subsequent to such manufacture. Zinc oxide may be used in amount of 0.01-4 parts by weight and zeolite molecular sieves in amounts of 0.05-1 parts by weight, per 100 parts of polyolefin. The resultant compositions may be more acceptable for use in the fabrication of articles intended for the packaging of e.g. foodstuffs.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: August 22, 1989
    Assignee: Du Pont Canada Inc.
    Inventors: David J. Mitchell, Vaclav G. Zboril
  • Patent number: 4803259
    Abstract: A solution polymerization process for the preparation of high molecular weight polymers of alpha-olefins is disclosed. In the process, the coordination catalyst is deactivated using a solution of at least one trialkanolamine deactivating agent of the formula N(ROH)(R'OH).sub.2 where R is isopropyl and R' is alkyl of 2-4 carbon atoms, especially ethyl or isopropyl. The process is capable of producing polyers of improved color.
    Type: Grant
    Filed: April 22, 1987
    Date of Patent: February 7, 1989
    Assignee: Du Pont Canada Inc.
    Inventors: Vaclav G. Zboril, David J. Mitchell