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Sample records for hot gas ceramic

  1. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  2. Process for making ceramic hot gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    2001-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  3. Method of making a continuous ceramic fiber composite hot gas filter

    Science.gov (United States)

    Hill, Charles A.; Wagner, Richard A.; Komoroski, Ronald G.; Gunter, Greg A.; Barringer, Eric A.; Goettler, Richard W.

    1999-01-01

    A ceramic fiber composite structure particularly suitable for use as a hot gas cleanup ceramic fiber composite filter and method of making same from ceramic composite material has a structure which provides for increased strength and toughness in high temperature environments. The ceramic fiber composite structure or filter is made by a process in which a continuous ceramic fiber is intimately surrounded by discontinuous chopped ceramic fibers during manufacture to produce a ceramic fiber composite preform which is then bonded using various ceramic binders. The ceramic fiber composite preform is then fired to create a bond phase at the fiber contact points. Parameters such as fiber tension, spacing, and the relative proportions of the continuous ceramic fiber and chopped ceramic fibers can be varied as the continuous ceramic fiber and chopped ceramic fiber are simultaneously formed on the porous vacuum mandrel to obtain a desired distribution of the continuous ceramic fiber and the chopped ceramic fiber in the ceramic fiber composite structure or filter.

  4. Mechanical behavior of ceramic composite hot-gas filters after exposure to severe environments

    Energy Technology Data Exchange (ETDEWEB)

    Pysher, D.J.; Weaver, B.L.; Smith, R.G. [Ceramic Technology Center, St. Paul, MN (United States)] [and others

    1995-08-01

    A novel type of hot-gas filter based on a ceramic fiber reinforced ceramic matrix has been developed, as reported at previous Fossil Energy Materials Conferences, through research activities at Oak Ridge National Laboratory (ORNL) and at the 3M Company. Simulated testing has been done at the Westinghouse Science and Technology Center. This filter technology has been extended to full size, 60 mm OD by 1.5 meter long candle filters and a commercially viable process for producing the filters has been developed filters are undergoing testing and demonstration use throughout the world for applications in pressurized fluidized-bed combustion (PFBC) and integrated gasification combined cycle (IGCC) plants. Demonstration tests of this ceramic composite filter along with other filters are in progress at the Tidd PFBC plant Mechanical tests were performed on the 3 M brand Ceramic Composite Candle Filter after exposure to various corrosive environments in order to assess its ability to function as a hot gas filter in coal-fired applications. Due to the different construction of ceramic composite filters and the thin composite wall versus the typical thick-walled monolithic filter, standard mechanical property tests had to be refined or modified to accurately determine the filters properties. These tests and filter property results will be described Longitudinal tensile and diametral O-ring compression tests were performed on as-produced candle filters as well as on filters which had been exposed to various environments. The exposures were for 1000 hrs at 850{degrees}C in wet air, in wet air containing Na{sub 2}CO{sub 3}, and in wet air containing NaCl. In addition, a filter which bad been coated with ash (Old Grimethorpe) was exposed to wet air at 850{degrees}C for 1000 hours.

  5. Automated nondestructive evaluation method for characterizing ceramic and metallic hot gas filters.

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, W. A.; Koehl, E. R.; Deemer, C.; Pastilla, P.; Wheeler, B.; Forster, G. A.

    2002-06-03

    In advanced coal-fired power generation, one technology under development to clean up hot gases before their use as fuel for gas turbines is rigid ceramic candle filters. These porous filters are typically 1.5 m long and 60 mm in diameter and are made of various ceramic materials, including clay-bonded SiC. The high costs of downtime in a large utility demands that nondestructive evaluation/characterization (NDE/C) methods be available. At shutdowns, data from such analysis are needed to decide which filters are still usable and which need to be replaced, and if possible, to estimate the remaining lifetimes. Thus our objective was to develop reliable low-cost NDE technology for these filters. Our approach was to develop NDE/C technology, referred to as acousto-ultrasonics (AU), for application to hot gas filters. Lamb waves generated by the AU method were analyzed to derive a stress wave factor (SWF). This technology was tested by comparing SWF data with the measured strength for a variety of rigid ceramic filters and was shown to work on iron-aluminide filters as well but no strength data have been obtained on the iron-aluminides at this time.

  6. High temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Crossland, C.E.; Shelleman, D.L.; Spear, K.E. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1996-08-01

    A vertical flow-through furnace has been built to study the effect of corrosion on the morphology and mechanical properties of ceramic hot gas filters. Sections of 3M Type 203 and DuPont Lanxide SiC-SiC filter tubes were sealed at one end and suspended in the furnace while being subjected to a simulated coal combustion environment at 870{degrees}C. X-ray diffraction and electron microscopy is used to identify phase and morphology changes due to corrosion while burst testing determines the loss of mechanical strength after exposure to the combustion gases. Additionally, a thermodynamic database of gaseous silicon compounds is currently being established so that calculations can be made to predict important products of the reaction of the environment with the ceramics. These thermodynamic calculations provide useful information concerning the regimes where the ceramic may be degraded by material vaporization. To verify the durability and predict lifetime performance of ceramic heat exchangers in coal combustion environments, long-term exposure testing of stressed (internally pressurized) tubes must be performed in actual coal combustion environments. The authors have designed a system that will internally pressurize 2 inch OD by 48 inch long ceramic heat exchanger tubes to a maximum pressure of 200 psi while exposing the outer surface of the tubes to coal combustion gas at the Combustion and Environmental Research Facility (CERF) at the Pittsburgh Energy and Technology Center. Water-cooled, internal o-ring pressure seals were designed to accommodate the existing 6 inch by 6 inch access panels of the CERF. Tubes will be exposed for up to a maximum of 500 hours at temperatures of 2500 and 2600{degrees}F with an internal pressure of 200 psi. If the tubes survive, their retained strength will be measured using the high temperature tube burst test facility at Penn State University. Fractographic analysis will be performed to identify the failure source(s) for the tubes.

  7. High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1997-12-11

    This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

  8. Evaluation of an all-ceramic tubesheet assembly for a hot gas filter

    Energy Technology Data Exchange (ETDEWEB)

    Bitner, J.L. [Mallett Technology, Inc., Canonsburg, PA (United States); Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Eggerstedt, P.M. [Industrial Filter and Pump Mfg. Co., Cicero, IL (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    A 10-inch thick, all-ceramic tubesheet design is evaluated for differential pressure and thermal conditions. Primary stresses from differential pressure are well within a safe allowable. The calculated peak thermal stresses at local discontinuities approach the modules of rupture for the ceramic material. Kiln tests were performed to demonstrate differential temperatures between hot center and cooler rim do not cause failures or visible tensile cracks. There appear to be mitigating mechanisms and design features in the Industrial Filter and Pump (IF and P) Mfg. Co. all-ceramic tubesheet design concept that add forgiveness in accommodating differential pressure and thermal loading stresses. A material characterization program on the ceramic materials is recommended.

  9. Hot gas cleanup using ceramic cross flow membrane filters. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ciliberti, D.F.; Smeltzer, E.E.; Alvin, M.A.; Keairns, D.L.; Bachovchin, D.M.

    1983-12-01

    The single unresolved technical issue in the commercialization of pressurized fluid-bed combustion (PPBC) for electric power production is the hot gas cleaning problem. In this technology, high-temperature and -pressure (HTHP), dust-laden flue gases from the combustor must be cleaned enough to reduce expansion turbine blade erosion to an economically acceptable level. Additionally, the level of particulate emission must be compatible with the New Source Performance Standards (NSPS) for environmental acceptability. The Department of Energy (DOE) has sponsored a wide range of research and development programs directed at the solution of this problem. These programs were divided into two classifications, one dealing with more advanced concepts where testing was to be done at relatively large scale and a second group of less advanced, novel concepts where the testing was to be carried out at a bench scale. The cross-flow ceramic membrane filter program described in this report is a member of the small-scale, novel concept group.

  10. Ceramic stationary gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Roode, M. van [Solar Turbines Inc., San Diego, CA (United States)

    1995-10-01

    The performance of current industrial gas turbines is limited by the temperature and strength capabilities of the metallic structural materials in the engine hot section. Because of their superior high-temperature strength and durability, ceramics can be used as structural materials for hot section components (blades, nozzles, combustor liners) in innovative designs at increased turbine firing temperatures. The benefits include the ability to increase the turbine inlet temperature (TIT) to about 1200{degrees}C ({approx}2200{degrees}F) or more with uncooled ceramics. It has been projected that fully optimized stationary gas turbines would have a {approx}20 percent gain in thermal efficiency and {approx}40 percent gain in output power in simple cycle compared to all metal-engines with air-cooled components. Annual fuel savings in cogeneration in the U.S. would be on the order of 0.2 Quad by 2010. Emissions reductions to under 10 ppmv NO{sub x} are also forecast. This paper describes the progress on a three-phase, 6-year program sponsored by the U.S. Department of Energy, Office of Industrial Technologies, to achieve significant performance improvements and emissions reductions in stationary gas turbines by replacing metallic hot section components with ceramic parts. Progress is being reported for the period September 1, 1994, through September 30, 1995.

  11. High temperature corrosion of advanced ceramic materials for hot-gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Kupp, E.R.; Trubelja, M.F.; Spear, K.E.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States)

    1995-08-01

    Experimental corrosion studies of hot gas filter materials and heat exchanger materials in oxidizing combustion environments have been initiated. Filter materials from 3M Co. and DuPont Lanxide Composites Inc. are being tested over a range of temperatures, times and gas flows. It has been demonstrated that morphological and phase changes due to corrosive effects occur after exposure of the 3M material to a combustion environment for as little as 25 hours at 800{degrees}C. The study of heat exchanger materials has focused on enhancing the corrosion resistance of DuPont Lanxide Dimox{trademark} composite tubes by adding chromium to its surfaces by (1) heat treatments in a Cr{sub 2}O{sub 3} powder bed, or (2) infiltrating surface porosity with molten chromium nitrate. Each process is followed by a surface homogenization at 1500{degrees}C. The powder bed method has been most successful, producing continuous Cr-rich layers with thicknesses ranging from 20 to 250 {mu}m. As-received and Cr-modified DuPont Lanxide Dimox{trademark} samples will be reacted with commonly encountered coal-ash slags to determine the Cr effects on corrosion resistance.

  12. Thermal-shock behavior of advanced ceramic/composite hot-gas filters

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.P.; Sutaria, M.; Bielke, W.

    1997-02-01

    The thermal shock/fatigue behavior of monolithic and composite hot-gas candle filters obtained from various manufacturers was evaluated. The composite filters were made of both oxide and nonoxide materials; the monolithic filters were made only of nonoxide materials. During single-cycle thermal shock tests, composite filters show little or no strength degradation when quenched from temperatures between 900 and 1000{degrees}C. At higher quenching temperatures, slow strength degradation was observed. Regular monolithic SiC filters showed no strength degradation when quenched from temperatures up to {approx}700-900{degrees}C, whereas at higher quenching temperatures, the strength decreased at a relatively sharper rate. On the other hand, recrystallized monolithic SiC filters showed higher initial strength and retained this strength to higher quenching temperatures when compared with regular SiC filters. This finding may be related to the difference in the strength of grain boundary phases in the two filters. For thermal cycles between room temperature and 800-1000{degrees}C, composite filters show little (18-24%) strength degradation up to three cycles, beyond which the strength remains unchanged. Similar behavior, with an initial strength drop of 15-28%, was observed for monolithic filter specimens that were thermally cycled between room temperature and 800{degrees}C.

  13. Evaluation of mechanical properties and structural changes of ceramic filter materials for hot gas cleaning under simulated process conditions

    OpenAIRE

    Westerheide, R.; Wehd, C. von der; Rehak, P.; Adler, J.

    2002-01-01

    In the combined cycle technology for advanced coal fired power plants at high temperatures up to 950 °C the removal of particles from the stream to the gas turbine is carried out with ceramic filter elements. These elements consist often of siliceous bonded coarse grained silicon carbide. A stable long term operation of the filter elements leads to the demands on good resistance towards thermal, mechanical and chemical loading. The structure of ceramic filter elements consists usually of a hi...

  14. Ceramic gas turbine shroud

    Science.gov (United States)

    Shi, Jun; Green, Kevin E.

    2014-07-22

    An example gas turbine engine shroud includes a first annular ceramic wall having an inner side for resisting high temperature turbine engine gasses and an outer side with a plurality of radial slots. A second annular metallic wall is positioned radially outwardly of and enclosing the first annular ceramic wall and has a plurality of tabs in communication with the slot of the first annular ceramic wall. The tabs of the second annular metallic wall and slots of the first annular ceramic wall are in communication such that the first annular ceramic wall and second annular metallic wall are affixed.

  15. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    1998-12-22

    Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the filter elements in these systems will have to be made of ceramic materials to withstand goal service temperatures of 1600 F or higher. Recent demonstration projects and pilot plant tests have indicated that the current generation of ceramic hot gas filters (cross-flow and candle configurations) are failing prematurely. Two of the most promising materials that have been extensively evaluated are clay-bonded silicon carbide and alumina-mullite porous monoliths. These candidates, however, have been found to suffer progressive thermal shock fatigue damage, as a result of rapid cooling/heating cycles. Such temperature changes occur when the hot filters are back-pulsed with cooler gas to clean them, or in process upset conditions, where even larger gas temperature changes may occur quickly and unpredictably. In addition, the clay-bonded silicon carbide materials are susceptible to chemical attack of the glassy binder phase that holds the SiC particles together, resulting in softening, strength loss, creep, and eventual failure.

  16. Development and characterization of Textron continuous fiber ceramic composite hot gas filter materials. Final report, September 30, 1994--October 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    DiPietro, S.G.; Alvin, M.A.

    1997-12-31

    Uncertainties about the long-term ability of monolithic ceramics to survive in the IGCC or PFBC hot gas filter environment led DOE/METC to consider the merits of using continuous fiber reinforced ceramic composites (CFCCs) as potential next-generation high temperature filter elements. This seems to be a logical strategy to pursue in light of the fact that properly-engineered CFCC materials have shown much-improved damage tolerance and thermal shock behavior as compared to existing monolithic ceramic materials. Textron`s Advanced Hot Gas Filter Development Program was intended to be a two year, two phase program which transitioned developmental materials R and D into prototype filter element fabrication. The first phase was to demonstrate the technical feasibility of fabricating CFCC hot gas filter elements which could meet the pressure drop specifications of less than ten inches of water (iwg) at a face velocity of ten feet per minute (fpm), while showing sufficient integrity to survive normal mechanical loads and adequate environmental resistance to steam/alkali corrosion conditions at a temperature of approximately 870 C (1600 F). The primary objective of the second phase of the program was to scale up fabrication methods developed in Phase 1 to produce full-scale CFCC candle filters for validation testing. Textron encountered significant process-related and technical difficulties in merely meeting the program permeability specifications, and much effort was expended in showing that this could indeed be achieved. Thus, by the time the Phase 1 program was completed, expenditure of program funds precluded continuing on with Phase 2, and Textron elected to terminate their program after Phase 1. This allowed Textron to be able to focus technical and commercialization efforts on their largely successful DOE CFCC Program.

  17. Ceramic membranes for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Vincente-Mingarro, I.M. de; Pitarch, J.A. [Tecnologia y Gestion de la Innovacion, Madrid (Spain)

    1998-11-01

    The project is being carried out jointly by TGI, S.A., CIEMAT and CSIC-ICM to develop and evaluate new inorganic membranes of a ceramic type, with nanometric pore size for separation of contaminants and fuel enrichment, in gas mixtures from coal gasification. In order to achieve both the highest active and selective surface, a candle (150 mm length and 60 mm in diameter), with 30-40 % porosity and pore sizes of {lt}1 {mu}m was developed. The processing steps include the slip-casting of the first layer (porous support) in a way than after thermal treatment (1400-1600{degree}C) the desirable shape dimensions, strength, porosity and pore size were obtained. Then the support was dipped successively (colloidal filtration over the casting porous piece) in an appropriate suspension of alumina with lower grain size. The top layer was obtained by the sol-gel process so that through successive setting and heat treatment the pores were reduced to the nanometre size. CVD and CVI techniques were set up to develop membranes for gas separation with a high selectivity level. Experimental chemical infiltration `Membranes Development` on porous substrates has been achieved on disk and candle-shaped materials. Characterisation was by spectrophotometry (IRS). Kinetic studies of coating in order to find out reproducible conditions at low temperature were also carried out. Uniform recovery over the whole membrane surface is wanted. The CIEMAT`s Hot Gas Separation Plant (HGSP) works with gas mixtures at a maximum design temperature 773 K and pressures up to 50 bar. It comprises: a gas supply unit equipped with flow, temperature and pressure measuring and control systems; a heating system within the membrane which must be leak proof for high pressures; and an in-line gas chromatography system thus allowing the chemical composition of the gas entering, permeated and retained to be measured. 7 figs.

  18. Gas Separations using Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Paul KT Liu

    2005-01-13

    This project has been oriented toward the development of a commercially viable ceramic membrane for high temperature gas separations. A technically and commercially viable high temperature gas separation membrane and process has been developed under this project. The lab and field tests have demonstrated the operational stability, both performance and material, of the gas separation thin film, deposited upon the ceramic membrane developed. This performance reliability is built upon the ceramic membrane developed under this project as a substrate for elevated temperature operation. A comprehensive product development approach has been taken to produce an economically viable ceramic substrate, gas selective thin film and the module required to house the innovative membranes for the elevated temperature operation. Field tests have been performed to demonstrate the technical and commercial viability for (i) energy and water recovery from boiler flue gases, and (ii) hydrogen recovery from refinery waste streams using the membrane/module product developed under this project. Active commercializations effort teaming with key industrial OEMs and end users is currently underway for these applications. In addition, the gas separation membrane developed under this project has demonstrated its economical viability for the CO2 removal from subquality natural gas and landfill gas, although performance stability at the elevated temperature remains to be confirmed in the field.

  19. Development of iron-aluminide hot-gas filters

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.; Wright, I.G.; Judkins, R.R.

    1996-06-01

    Removal of particles from hot synthesis gas produced by coal gasification is vital to the success of these systems. In Integrated [Coal] Gasification Combined Cycle systems, the synthesis gas is the fuel for gas turbines. To avoid damage to turbine components, it is necessary that particles be removed from the fuel gas prior to combustion and introduction into the turbine. Reliability and durability of the hot-gas filtering devices used to remove the particles is, of course, of special importance. Hot-gas filter materials include both ceramics and metals. Numerous considerations must be made in selecting materials for these filters. Constituents in the hot gases may potentially degrade the properties and performance of the filters to the point that they are ineffective in removing the particles. Very significant efforts have been made by DOE and others to develop effective hot-particle filters and, although improvements have been made, alternative materials and structures are still needed.

  20. Catalytic hot gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland)

    1996-12-31

    Gasification gas that contains particulates can be purified from tars and ammonia by using nickel monolith catalysts. Temperatures over 900 deg C are required at 20 bar pressure to avoid deactivation by H{sub 2}S and carbon. Dolomites and limestones are effective tar decomposing catalysts only when calcined. Tar decomposition in gasification conditions can take place by steam or dry (CO{sub 2}) reforming reactions. These reactions follow apparent first order kinetics with respect to hydrocarbons in gasification conditions. (author) (16 refs.)

  1. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Matthew R. June; John L. Hurley; Mark W. Johnson

    1999-04-01

    Iron aluminide hot gas filters have been developed using powder metallurgy techniques to form seamless cylinders. Three alloys were short-term corrosion tested in simulated IGCC atmospheres with temperatures between 925 F and 1200 F with hydrogen sulfide concentrations ranging from 783 ppm{sub v} to 78,300 ppm{sub v}. Long-term testing was conducted for 1500 hours at 925 F with 78,300 ppm{sub v}. The FAS and FAL alloys were found to be corrosion resistant in the simulated environments. The FAS alloy has been commercialized.

  2. Particulate Hot Gas Stream Cleanup Technical Issues

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-08-31

    This is the fifteenth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data bank of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on May 18 to the Department of Energy / Southern Company Services Power Systems Development Facility (PSDF) and a particulate sample collected in the Westinghouse filter at Sierra Pacific Power Company's Piñon Pine Power Project. Analysis of this Piñon Pine sample is ongoing: however, this report contains the results of analyses completed to date. Significant accomplishments were achieved on the HGCU data bank during this reporting quarter. The data bank was prepared for presentation at the Advanced Coal-Based Power and Environmental Systems 98 Conference scheduled for July, 1998. Task 2 work during the past quarter consisted of testing two Dupont PRD-66C candle filters, one McDermott ceramic composite candle filter, one Blasch 4-270 candle filter, and one Specific Surface cordierite candle filter. Tensile and thermal expansion testing is complete and the rest of the testing is in progress. Also, some 20-inch long

  3. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the thirteenth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task I research activities during the past quarter included characterizations of additional ash samples from Pressurized Fluidized-Bed Combustion (PFBC) facilities to the HGCU data base. Task I plans for the next quarter include characterization of samples collected during a site visit on January 20 to the Department of Energy / Southern Company Services Power Systems Development Facility (PSDF). Further work on the HGCU data base is also planned. Task 2 work during the past quarter included creep testing of a Coors P- I OOA- I specimen machined from Candle FC- 007 after 1166 hours in-service at the Karhula Pressurized Circulating Fluid Bed (PCFB) facility. Samples are currently in preparation for microstructural evaluations of Coors P-IOOA-I.Sixteen cordierite rings manufactured by Specific Surfaces were received for testing. Three of the specimens were exposed to the PFBC environment at the PSDF. These specimens are currently being machined for testing.

  4. Particulate Hot Gas Stream Cleanup Technical Issues

    Energy Technology Data Exchange (ETDEWEB)

    Potius, D.; Snyder, T.

    1997-07-01

    The characteristics of entrained particles generated by advanced coal conversion technologies and the harsh flue gas environments from which these particles must be removed challenge current ceramic barrier filtration systems. Measurements have shown that the size distribution, morphology, and chemical composition of particles generated by pressurized fluidized-bed combustion (PFBC) and gasification processes differ significantly from the corresponding characteristics of conventional pulverized-coal ash particles. The entrained particulate matter from these advanced conversion technologies often comprise fine size distributions, irregular particle morphologies, high specific surface areas, and significant proportions of added sorbent material. These characteristics can create high ash cohesivity and high pressure losses through the filter cakes. In addition, the distributions of chemical constituents among the collected particles provide local, highly concentrated chemical species that promote reactions between adjacent particles that ultimately cause strong, nodular deposits to form in the filter vessel. These deposits can lead directly to bridging and filter element failure. This project is designed to address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic filter elements. The activities conducted under Task 1, Assessment of Ash Characteristics, are discussed in this paper. Activities conducted under Task 2, Testing and Failure Analysis of Ceramic Filters, are discussed in a separate paper included in the proceedings of the Advanced Coal-Based Power and Environmental Systems `97 Conference. The specific objectives of Task I include the generation of a data base of the key characteristics of Hot Gas Stream Cleanup (HGCU) ashes collected from operating advanced particle filters (APFS) and the identification of relationships between HGCU ash properties and the operation and

  5. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests

  6. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep

  7. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-05-05

    This is the fourth annual report describing the activities performed under Task 1 of Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97 ® . Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy / Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

  8. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-30

    This is the fourth annual report describing the activities performed under Task 1 of Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97 ® . Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy / Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

  9. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-02-26

    This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes a description of a device developed to harden a filter cake on a filter element so that the element and cake can subsequently be encapsulated in epoxy and studied in detail. This report also reviews the status of the HGCU data base of ash and char characteristics. Task 1 plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF), encapsulation of an intact filter cake from the PSDF, and completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter consisted of hoop tensile and axial compressive stress-strain responses of McDermott ceramic composite and hoop tensile testing of Techniweave candle filters as-manufactured and after exposure to the gasification environment.

  10. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-05

    This is the fourth annual report describing the activities performed under Task 1 of Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This work is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. This report summarizes characterizations of ash and char samples from pressurized fluidized-bed combustion and gasification facilities. Efforts are under way to develop a method for preserving fragile filter cakes formed on ceramic filter elements. The HGCU data base was formatted for Microsoft Access 97{reg_sign}. Plans for the remainder of the project include characterization of additional samples collected during site visits to the Department of Energy/Southern Company Services Power Systems Development Facility and completion and delivery of the HGCU data base.

  11. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the eleventh in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, analyses were completed on samples obtained during a site visit to the Power Systems Development Facility (PSDF). Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. An additional analysis was performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. A manuscript and poster were prepared for presentation at the Advanced Coal-Based Power and Environmental Systems `97 Conference scheduled for July 22 - 24, 1997. A summary of recent project work covering the mechanisms responsible for ash deposit consolidation and ash bridging in APF`s collecting PFB ash was prepared and presented at FETC-MGN in early July. The material presented at that meeting is included in the manuscript prepared for the Contractor`s Conference and also in this report. Task 2 work during the past quarter included mechanical testing and microstructural examination of Schumacher FT20 and Pall 326 as- manufactured, after 540 hr in service at Karhula, and after 1166 hr in service at

  12. Hot-gas filtration for pressurized fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.; Kuby, W.

    1984-03-01

    This topical report discusses the status of the work, conducted under EPRI contract 1336-4, on the evaluation and development of ceramic filter hot gas cleanup technology for pressurized fluidized bed combustion. This topical report represents the status of the work through September 1983. The goal of the effort is to achieve 6000 h of operation on a 13-filter durability test rig. The work includes two parallel tasks. The first is construction of a durability test facility, operation of the facility with an initial candidate filter media installed, and assessment of results. The second task includes a literature survey to identify state-of-the-art ceramic fibers suitable for high-temperature gas filtration applications and filter testing in a single-filter test facility to assess the performance of promising new filter media. The best candidate will be chosen for further evaluation in the durability facility.

  13. Corrosion penetration monitoring of advanced ceramics in hot aqueous fluids

    Directory of Open Access Journals (Sweden)

    Klaus G. Nickel

    2004-03-01

    Full Text Available Advanced ceramics are considered as components in energy related systems, because they are known to be strong, wear and corrosion resistant in many environments, even at temperatures well exceeding 1000 °C. However, the presence of additives or impurities in important ceramics, for example those based on Silicon Nitride (Si3N4 or Al2O3 makes them vulnerable to the corrosion by hot aqueous fluids. The temperatures in this type of corrosion range from several tens of centigrade to hydrothermal conditions above 100 °C. The corrosion processes in such media depend on both pH and temperature and include often partial leaching of the ceramics, which cannot be monitored easily by classical gravimetric or electrochemical methods. Successful corrosion penetration depth monitoring by polarized reflected light optical microscopy (color changes, Micro Raman Spectroscopy (luminescence changes and SEM (porosity changes will be outlined. The corrosion process and its kinetics are monitored best by microanalysis of cross sections, Raman spectroscopy and eluate chemistry changes in addition to mass changes. Direct cross-calibrations between corrosion penetration and mechanical strength is only possible for severe corrosion. The methods outlined should be applicable to any ceramics corrosion process with partial leaching by fluids, melts or slags.

  14. Hot Corrosion in Gas Turbines.

    Science.gov (United States)

    1983-04-27

    in hot corrosion under some circumstances, because its role seems to be principally through reduction of NagSO, or erosion by pyrolytic graphite...same morphology could be produced either by spray -coating with NaxSO, or by diffusing NIS into the cut- edge region under argon at temperature and then

  15. An integrated modular hot gas conditioning technology

    Energy Technology Data Exchange (ETDEWEB)

    Abatzoglou, N.; Bangala, D.; Chornet, E. [Kemestrie Inc., Sherbrooke, Quebec (Canada)

    1999-07-01

    Hot gas conditioning is considered the most scientific and technological challenge on the road towards commercialization of large biomass and waste gasification units. The modular hot gas conditioning system presented in this paper is designed to be integrated into any gasification unit regardless of feedstock type and operation pressure. It comprises a mobile granular bed filtration system and an in-series multi-tubular fixed-bed downdraft steam catalytic reformer. In this work we discuss the concept, the design, the methodology and our results. (author)

  16. Hot Gas Corrosion of Silicon Based Ceramics.

    Science.gov (United States)

    1985-12-13

    results, it must be noted that this is merely because thermodynamic data was unavailable for the beta form. The data generated also indicates that -8% of...N4 will be transformed to SiO 2 (in the form of quartz or cristobalite ) or silicon oxy nitride (Si2 N2 0). While the presence of Si 2 N2 0 has been

  17. Investigation of the beryllia ceramics molding process by the hot casting method

    Science.gov (United States)

    Zhapbasbaev, U. K.; Ramazanova, G. I.; Sattinova, Z. K.

    2013-03-01

    Results of mathematical simulation of the ceramics molding process by the hot casting method are presented. The mathematical model describes the motion of beryllia liquid thermoplastic slurry in a form-building cavity subject to solidification. Velocity and temperature profiles providing homogeneous properties of the beryllia ceramics in the process of molding by the hot casting method are obtained.

  18. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    The aim of this work was to study the catalytic cleaning of gasification gas from tars and ammonia. In addition, factors influencing catalytic activity in industrial applications were studied, as well as the effects of different operation conditions and limits. Also the catalytic reactions of tar and ammonia with gasification gas components were studied. The activities of different catalyst materials were measured with laboratory-scale reactors fed by slip streams taken from updraft and fluid bed gasifiers. Carbonate rocks and nickel catalysts proved to be active tar decomposing catalysts. Ammonia decomposition was in turn facilitated by nickel catalysts and iron materials like iron sinter and iron dolomite. Temperatures over 850 deg C were required at 2000{sup -1} space velocity at ambient pressure to achieve almost complete conversions. During catalytic reactions H{sub 2} and CO were formed and H{sub 2}O was consumed in addition to decomposing hydrocarbons and ammonia. Equilibrium gas composition was almost achieved with nickel catalysts at 900 deg C. No deactivation by H{sub 2}S or carbon took place in these conditions. Catalyst blocking by particulates was avoided by using a monolith type of catalyst. The apparent first order kinetic parameters were determined for the most active materials. The activities of dolomite, nickel catalyst and reference materials were measured in different gas atmospheres using laboratory apparatus. This consisted of nitrogen carrier, toluene as tar model compound, ammonia and one of the components H{sub 2}, H{sub 2}O, CO, CO{sub 2}, CO{sub 2}+H{sub 2}O or CO+CO{sub 2}. Also synthetic gasification gas was used. With the dolomite and nickel catalyst the highest toluene decomposition rates were measured with CO{sub 2} and H{sub 2}O. In gasification gas, however, the rate was retarded due to inhibition by reaction products (CO, H{sub 2}, CO{sub 2}). Tar decomposition over dolomite was modelled by benzene reactions with CO{sub 2}, H

  19. Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Corman; Krishan Luthra

    2005-09-30

    This report covers work performed under the Continuous Fiber Ceramic Composites (CFCC) program by GE Global Research and its partners from 1994 through 2005. The processing of prepreg-derived, melt infiltrated (MI) composite systems based on monofilament and multifilament tow SiC fibers is described. Extensive mechanical and environmental exposure characterizations were performed on these systems, as well as on competing Ceramic Matrix Composite (CMC) systems. Although current monofilament SiC fibers have inherent oxidative stability limitations due to their carbon surface coatings, the MI CMC system based on multifilament tow (Hi-Nicalon ) proved to have excellent mechanical, thermal and time-dependent properties. The materials database generated from the material testing was used to design turbine hot gas path components, namely the shroud and combustor liner, utilizing the CMC materials. The feasibility of using such MI CMC materials in gas turbine engines was demonstrated via combustion rig testing of turbine shrouds and combustor liners, and through field engine tests of shrouds in a 2MW engine for >1000 hours. A unique combustion test facility was also developed that allowed coupons of the CMC materials to be exposed to high-pressure, high-velocity combustion gas environments for times up to {approx}4000 hours.

  20. Advances in hot gas filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.

    The past decade has seen the introduction of new filter media specifically designed for 'hot-gas' filtration. These media are available as woven or knitted fabrics and as non-wovens, i.e. needled felts. Needlefelted fabrics have proven so highly successful in the dedusting of hot gases that they are widely used nowadays in this new and necessary technology. Hot-gas filtration offers advantages in, for example, the saving or recycling of energy, the elimination of the cooling process, and the short-circuiting of process steps. This paper gives a survey of the types of textile fibres available for hot-gas filtration from the more recently developed organic fibres to refractory fibres. It describes, compares and contrasts their salient properties and lists the uses to which they may be put. It concentrates on such fibres which are generally referred to as 'high performance materials', since they are expected to provide satisfactory performance under extreme conditions of temperature, chemical environment and mechanical stress. It touches on filtration theory governing the collection mechanism. 9 refs., 7 figs., 3 tabs.

  1. Research and development of ceramic gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kazuo [National Aerospace Laboratory, Chofu-shi, Tokyo (Japan)

    1993-12-31

    The CO{sub 2} caused by the consumption of hydrocarbon fuel is one of the main gases which affect the global climate. In order to reduce the formation of CO{sub 2}, it is necessary to conserve energy as effectively as possible. Therefore the heat energy provided by the fuel should be utilized in multi-cascades. The energy at the high temperature should be used for the generation of electric power and the energy at low temperature could be used for making the steam and the hot water. The gas turbine is preferable for this purpose. The heat energy of exhaust gas can be reused more easily. The two systems are proposed by using the gas turbine as the high temperature stage. One is the cogeneration system and the other is the combined cycle. The former generates electric power by the gas turbine and make steam or hot water in the exhaust gas. The latter employs the gas turbine as the high temperature cycle and the steam turbine as the low temperature cycle.

  2. Hot Superplastic Powder Forging for Transparent nanocrystalline Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, W. Roger

    2006-05-22

    The program explored a completely new, economical method of manufacturing nanocrystalline ceramics, Hot Superplastic Powder Forging (HSPF). The goal of the work was the development of nanocrystalline/low porosity optically transparent zirconia/alumina. The high optical transparency should result from lack of grain boundary scattering since grains will be smaller than one tenth the wavelength of light and from elimination of porosity. An important technological potential for this process is manufacturing of envelopes for high-pressure sodium vapor lamps. The technique for fabricating monolithic nanocrystalline material does not begin with powder whose particle diameter is <100 nm as is commonly done. Instead it begins with powder whose particle diameter is on the order of 10-100 microns but contains nanocrystalline crystallites <<100 nm. Spherical particles are quenched from a melt and heat treated to achieve the desired microstructure. Under a moderate pressure within a die or a mold at temperatures of 1100C to 1300C densification is by plastic flow of superplastic particles. A nanocrystalline microstructure results, though some features are greater than 100nm. It was found, for instance, that in the fully dense Al2O3-ZrO2 eutectic specimens that a bicontinuous microstructure exists containing <100 nm ZrO2 particles in a matrix of Al2O3 grains extending over 1-2 microns. Crystallization, growth, phase development and creep during hot pressing and forging were studied for several compositions and so provided some details on development of polycrystalline microstructure from heating quenched ceramics.

  3. Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

    Science.gov (United States)

    Tougas, Ian M.; Amani, Matin; Gregory, Otto J.

    2013-01-01

    Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples. PMID:24217356

  4. Metallic and ceramic thin film thermocouples for gas turbine engines.

    Science.gov (United States)

    Tougas, Ian M; Amani, Matin; Gregory, Otto J

    2013-11-08

    Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples.

  5. Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

    Directory of Open Access Journals (Sweden)

    Otto J. Gregory

    2013-11-01

    Full Text Available Temperatures of hot section components in today’s gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today’s engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire thermocouples.

  6. Application of Hot-wire Method for Measuring Thermal Conductivity of Fine Ceramics

    Directory of Open Access Journals (Sweden)

    Shangxi WANG

    2016-11-01

    Full Text Available Ceramic substrate is preferred in high density packaging due to its high electrical resistivity and moderate expansion coefficient. The thermal conductivity is a key parameter for packaging substrates. There are two common methods to measure the thermal conductivity, which are the hot-wire method and the laser-flash method. Usually, the thermal conductivities of porcelain is low and meet the measurement range of hot-wire method, and the measured value by hot-wire method has little difference with that by laser-flash method. In recent years, with the requirement of high-powered LED lighting, some kinds of ceramic substrates with good thermal conductivity have been developed and their thermal conductivity always measured by the means of laser flash method, which needs expensive instrument. In this paper, in order to detect the thermal conductivity of fine ceramic with convenience and low cost, the feasibility of replacing the laser flash method with hot wire method to measure thermal conductivity of ceramic composites was studied. The experiment results showed that the thermal conductivity value of fine ceramics measured by the hot-wire method is severely lower than that by the laser-flash method. However, there is a positive relationship between them. It is possible to measure the thermal conductivity of fine ceramic workpiece instantly by hot-wire method via a correction formula.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12543

  7. METC CFD simulations of hot gas filtration

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, T.J.

    1995-06-01

    Computational Fluid Dynamic (CFD) simulations of the fluid/particle flow in several hot gas filtration vessels will be presented. These simulations have been useful in designing filtration vessels and in diagnosing problems with filter operation. The simulations were performed using the commercial code FLUENT and the METC-developed code MFIX. Simulations of the initial configuration of the Karhula facility indicated that the dirty gas flow over the filter assemblage was very non-uniform. The force of the dirty gas inlet flow was inducing a large circulation pattern that caused flow around the candles to be in opposite directions on opposite sides of the vessel. By introducing a system of baffles, a more uniform flow pattern was developed. This modification may have contributed to the success of the project. Several simulations of configurations proposed by Industrial Filter and Pump were performed, varying the position of the inlet. A detailed resolution of the geometry of the candles allowed determination of the flow between the individual candles. Recent simulations in support of the METC/CeraMem Cooperative Research and Development Agreement have analyzed the flow in the vessel during the cleaning back-pulse. Visualization of experiments at the CeraMem cold-flow facility provided confidence in the use of CFD. Extensive simulations were then performed to assist in the design of the hot test facility being built by Ahlstrom/Pyropower. These tests are intended to demonstrate the CeraMem technology.

  8. [PFBC Hot Gas Cleanup Test Program

    Energy Technology Data Exchange (ETDEWEB)

    1992-10-01

    Four hundred and fifty four clay bonded silicon carbide Schumacher Dia Schumalith candle filters were purchased for installation in the Westinghouse Advanced Particle Filtration (APF) system at the American Electric Power (AEP) plant in Brilliant, Ohio. A surveillance effort has been identified which will monitor candle filter performance and life during hot gas cleaning in AEP's pressurized fluidized-bed combustion system. A description of the candle surveillance program, strategy for candle filter location selection, as well as candle filter post-test characterization is provided in this memo. The period of effort for candle filter surveillance monitoring is planned through March 1994.

  9. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

  10. High temperature, low expansion, corrosion resistant ceramic and gas turbine

    Science.gov (United States)

    Rauch, Sr., Harry W.

    1981-01-01

    The present invention relates to ZrO.sub.2 -MgO-Al.sub.2 O.sub.3 -SiO.sub.2 ceramic materials having improved thermal stability and corrosion resistant properties. The utilization of these ceramic materials as heat exchangers for gas turbine engines is also disclosed.

  11. Gas transport efficiency of ceramic membranes: comparison of different geometries

    NARCIS (Netherlands)

    Radosevic-Zivkovic, T.; Benes, Nieck Edwin; Bouwmeester, Henricus J.M.

    2004-01-01

    The effect of support geometry on the performance of asymmetric ceramic membranes for gas separation is analyzed. Flat plate (FP), tubular (TU) and multichannel (MC) geometries are investigated using the dusty gas model (DGM) to describe transport of a multicomponent gas mixture through the

  12. Experimental and Numerical Investigations on Flue Gas Purification during Hot Gas Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Thulfaut, C.; Renz, U.

    2002-09-19

    The aim of the actual investigations is to integrate the catalytic reduction of carbon monoxide and particularly nitric oxides into the hot gas filtration process with ceramic filter elements of fluidized bed combustors which mainly represent an important N2O-source. According to Klein (Klein 1994) worldwide approx. 260 coal-fired power plants with fluidized bed combustors in the power range > 50 MWel existed in 1994, to which approx. 1% of the global coal dissipation corresponds. These emitted dinitrogen oxide with 70 kt/a, however, 20% of the entire N2O amounts from stationary firing plants. After Kleins calculations an increase of coal-fired fluidized bed combustors only by 10% triples the N2O emission.

  13. Hot gas path component having near wall cooling features

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Carlos Miguel; Kottilingam, Srikanth Chandrudu; Lacy, Benjamin Paul

    2017-11-28

    A method for providing micro-channels in a hot gas path component includes forming a first micro-channel in an exterior surface of a substrate of the hot gas path component. A second micro-channel is formed in the exterior surface of the hot gas path component such that it is separated from the first micro-channel by a surface gap having a first width. The method also includes disposing a braze sheet onto the exterior surface of the hot gas path component such that the braze sheet covers at least of portion of the first and second micro-channels, and heating the braze sheet to bond it to at least a portion of the exterior surface of the hot gas path component.

  14. High-temperature high-pressure gas cleanup with ceramic bag filters. Draft final report

    Energy Technology Data Exchange (ETDEWEB)

    Shackleton, M.; Chang, R.; Sawyer, J.; Kuby, W.; Turner-Tamiyasu, E.

    1982-12-06

    Advanced processes designed for the efficient use of coal in the production of energy will benefit from, or even depend upon, highly efficient, economical, high-temperature removal systems for fine particulates. In the case of pressurized fluidized-bed combustion (PFBC), the hot gas cleanup device must operate at approximately 1600/sup 0/F. Existing commercial filter systems are temperature limited due to the filter material, but ceramic fibers intended for refractory insulation offer the promise of a practical high-temperature filter media if they can be incorporated into a design which combines filter performance with acceptable durability. The current work was initiated to further develop and demonstrate on a larger-scale basis, a ceramic fiber filtration system for application to coal-fired PFBC's. The development effort centered around the need to replace the knit metal wire scrim, used in earlier designs as support for the fine fiber ceramic mat filtration medium, with a corrosion-resistant material. This led to the selection of woven ceramic cloth for support of the mat layer. Because of the substantial difference in strength and other material properties between the metal and ceramic cloth, tests were necessary to optimize the filter; pulse parameters such as pulse duration, pulse pressure, and pulse injection orifice size; woven cloth mesh configuration; the technique for clamping the bag to the support; and similar structural, fluid, and control parameters. The demonstration effort included both tests to prove this concept in a real application and a systems analysis to show commercial feasibility of the ceramic filtration approach for hot gas cleanup in PFBC's. 12 references, 57 figures, 23 tables.

  15. Hot-pressed transparent PLZT ceramics from low cost chemical processing

    Directory of Open Access Journals (Sweden)

    I.A. Santos

    2001-10-01

    Full Text Available Lanthanum-modified lead zirconate titanate (PLZT ceramics were obtained with high transmittance in the visible range by a combination of an inexpensive chemical processing and hot pressing. Optical, microstructural, pyroelectric, ferroelectric and dielectric properties characterized in this study attested the applicability of the employed method in the production of PLZT transparent ferroelectric ceramics. In fact, the corresponding analyzed physical parameters are in very good agreement with those obtained in samples traditionally prepared by other methods. Furthermore, due to high sample quality, a phenomenological analysis of the PLZT 10/65/35 relaxor features was performed in these ceramics.

  16. Sinterable Ceramic Powders from Laser Heated Gas Phase Reactions and Rapidly Solidified Ceramic Materials.

    Science.gov (United States)

    1984-07-01

    Gattuso, T. R., Meunier, M., Adler, D., and Haggerty, J. S., "IR Laser- Induced Deposition of Silicon Thin Films ", to be published in the Proceedings of...and Thin Films by Laser Induced Gas Phase Reactions", presented at the Nineteenth University Conference on Ceramic Science, Emergent Process Methods... Silicon Carbonitrides from Monomeric Organosilicon Precursors". To be presented at the 1983 Annual Meeting of the American Ceramic Society, April 1983

  17. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    D.H. Pontius

    1999-08-30

    This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report reviews the status of the HGCU data bank of ash and char characteristics, including the interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank, and issuance of a comprehensive final report on activities conducted under Task 1. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

  18. PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes summaries of analyses performed on particulate samples from Sierra Pacific Power Company's Pinon Pine Power Project. This report also reviews the status of the HGCU data bank of ash and char characteristics, and plans for enhancing the data bank with interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

  19. Study on the natural gas utilization in the ceramic industry; Estudo sobre a utilizacao do gas natural na industria ceramica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The production, principal applications, characteristics and properties, advantages of the gas natural is showed. A sectorial overview of the ceramic industry and the utilization of the natural gas in the ceramic industry is presented. The expectations are systematized and the impact of the natural gas utilization in the ceramic industry is evaluated. Some conclusions are withdrawn and recommendations suggested.

  20. Ceramic thermal barrier coatings for commercial gas turbine engines

    Science.gov (United States)

    Meier, Susan Manning; Gupta, Dinesh K.; Sheffler, Keith D.

    1991-01-01

    The paper provides an overview of the short history, current status, and future prospects of ceramic thermal barrier coatings for gas turbine engines. Particular attention is given to plasma-sprayed and electron beam-physical vapor deposited yttria-stabilized (7 wt pct Y2O3) zirconia systems. Recent advances include improvements in the spallation life of thermal barrier coatings, improved bond coat composition and spraying techniques, and improved component design. The discussion also covers field experience, life prediction modeling, and future directions in ceramic coatings in relation to gas turbine engine design.

  1. Ceramic stationary gas turbine development. Final report, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    This report summarizes work performed by Solar Turbines Inc. and its subcontractors during the period September 25, 1992 through April 30, 1993. The objective of the work is to improve the performance of stationary gas turbines in cogeneration through implementation of selected ceramic components.

  2. Hot metal gas forming of titanium grade 2 bent tubes

    Science.gov (United States)

    Paul, Alexander; Werner, Markus; Trân, Ricardo; Landgrebe, Dirk

    2017-10-01

    Within the framework of investigations, an exhaust gas component made of Titanium Grade 2 was produced by means of Hot Metal Gas Forming (HMGF) at the Fraunhofer IWU in Chemnitz, Germany. The semi-finished products were two-fold bent, thermal joined, calibrated and pre-formed tubes. So far, a three-stage internal high-pressure forming process at room temperature plus two necessary intermediate heat treatments were used to produce the component. Due to its complexity as well as the limited forming ability of Titanium Grade 2 at room temperature an one step Hot Metal Gas Forming was developed to replace the former procedure.

  3. Hot gas filtration: Investigations to remove gaseous pollutant components out of flue gas during hot gas filtration. Final report; HGR: Untersuchung zur Minimierung von gasfoermigen Schadstoffen aus Rauchgasen bei der Heissgasfiltration. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Christ, A.; Gross, R.; Renz, U.

    1998-07-01

    Power plants with gas and steam turbines in pressurized fluidized bed or pressurized gasification processes enable power generation of coal with high efficiency and little emissions. To run these plants the cleaning of the flue gas is necessary before entering the turbines under the conditions of high temperature and pressure. Ceramic filter elements are the most probable method for hot gas cleaning. A simultaneous reduction of gaseous pollutant components under these conditions could help to make the whole process more efficient. The aim of the project is to integrate the catalytic reduction of carbon monoxide, hydrocarbons and nitric oxides into the hot gas filtration with ceramic filter elements as a one step mecanism. The project is focused on: - the catalytic behaviour of ferruginous ashes of brown coal, - the effectiveness of calcinated aluminates as a catalyst to remove uncombusted hydrocarbons in a hot gas filtration unit, - numerical simulation of the combined removal of particles and gaseous pollutant components out of the flue gas. (orig.) [Deutsch] Gas- und Dampfturbinen-Kraftwerke mit Druckwirbelschicht- oder mit Druckvergasungsverfahren ermoeglichen die Verstromung von Kohle mit hohem Wirkungsgrad und niedrigen Emissionen. Eine Voraussetzung fuer den Betrieb dieser Anlagen ist die Entstaubung der Rauchgase bei hohen Temperaturen und Druecken. Abreinigungsfilter mit keramischen Elementen werden dazu eingesetzt. Eine Reduzierung gasfoermiger Schadstoffe unter den gleichen Bedingungen koennte die Rauchgaswaesche ersetzen. Ziel des Gesamtvorhabens ist es, die Integration von Heissgasfiltration und katalytischem Abbau der Schadstoffe Kohlenmonoxid, Kohlenwasserstoffe und Stickoxide in einem Verfahrensschritt zu untersuchen. Die Arbeitsschwerpunkte dieses Teilvorhabens betreffen - die katalytische Wirkung eisenhaltiger Braunkohlenaschen, - die Wirksamkeit des Calciumaluminats als Katalysator des Abbaus unverbrannter Kohlenwasserstoffe im Heissgasfilter

  4. Influence of gas emission on heat transfer in porous ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Gambaryan-Roisman, T.; Shapiro, M.; Litovsky, E.; Shavit, A. [Laboratory of Transport Processes in Porous Materials, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 32000 (Israel)

    2003-01-01

    It is known that thermal diffusivity, a, of several types of porous ceramic and refractory materials decreases with decreasing gas pressure. However, a of several ceramics (e.g., magnesite refractories with porosity about 25%) measured in vacuum by the monotonous heating exceeds the comparable data registered at atmospheric pressure. A similar effect was found for thermal diffusivity of several insulating materials. However, for some porous ceramics this phenomenon is absent or less prominent. It had been known that several heterogeneous physico-chemical processes take place on pore surfaces of ceramic materials. These processes include heterogeneous chemical reactions accompanied by emission of gaseous products. It had been conjectured that these processes affect thermophysical properties of ceramic materials, especially during fast heating or cooling. In this paper we substantiate this conjecture. Namely, we develop a quantitative model for the apparent thermal diffusivity, as measured by the nonstationary monotonous heating method. It takes into account the emission and adsorption of the gas on the opposite pore sides along the temperature gradient, the diffusive gas motion inside the pores and its removal from the pores due to the material gas permeability. The effect of these processes is shown to produce an additional heat flux inside the pore or crack and, hence, to increase the measured thermal diffusivity. In the presence of the passive gas, the rates of gas emission and its transport within the pore are significantly reduced, which leads to diminution of the effect of gas emission-adsorption on the heat transfer across the pore. Consequently, we show that this leads to a situation (observed in experiment) where thermal diffusivity of a material measured at high temperature in vacuum may exceed the comparable property at atmospheric pressure. When the reaction terminates due to the full conversion of the available solid reactant, the additional heat flow

  5. Review of hot corrosion of thermal barrier coatings of gas turbine

    Directory of Open Access Journals (Sweden)

    LIU Yongbao

    2017-03-01

    Full Text Available The review was done in order to make clear the problem of the hot corrosion of the Thermal Barrier Coatings(TBCsduring gas turbine serving. This paper summarizes the factors resulting from the hot corrosion of TBCs during turbine service and classifies methods for enhancing the corrosive resistance of TBCs. A prospective methodology for improving corrosion resistance is also formulated. The main types of corrosion coating include phase reaction, oxidizing of the bond coating, salt-fog corrosion, CMAS corrosion and fuel impurity corrosion. So far, methods for improving the corrosion resistance of TBCs include developing new coating materials, anticorrosive treatment on the surface of TBCs, modifying the stacking configuration and improving the cleansing functions of the gas turbines. In the future, developing new materials with excellent performance will still be the main direction for boosting the improvement of the hot corrosion resistance of TBCs. Simultaneously, improving the tacking configuration and nanotechnology of TBC coatings are potential approaches for improving corrosion resistance. With the development of a Ceramic Matrix Composite (CMC, the focus of the hot corrosion of TBCs may turn to that of Environmental Barrier Coatings (EBCs.

  6. Hot particulate removal and desulfurization results from the METC integrated gasification and hot gas cleanup facility

    Energy Technology Data Exchange (ETDEWEB)

    Rockey, J.M.

    1995-06-01

    The Morgantown Energy Technology Center (METC) is conducting experimental testing using a 10-inch diameter fluid-bed gasifier (FBG) and modular hot gas cleanup rig (MGCR) to develop advanced methods for removing contaminants in hot coal gasifier gas streams for commercial development of integrated gasification combined-cycle (IGCC) power systems. The program focus is on hot gas particulate removal and desulfurization technologies that match the temperatures and pressures of the gasifier, cleanup system, and power generator. The purpose of this poster is to present the program objectives and results of the work conducted in cooperation with industrial users and vendors to meet the vision for IGCC of reducing the capital cost per kilowatt to $1050 and increasing the plant efficiency to 52% by the year 2010.

  7. Core-in-shell sorbent for hot coal gas desulfurization

    Science.gov (United States)

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  8. Verification of creep performance of a ceramic gas turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.T.; Becher, P.F.; Ferber, M.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Parthasarathy, V. [Solar Turbines Inc., San Diego, CA (United States)

    1998-03-01

    Tensile creep tests were carried out on a Norton NT164 silicon nitride ceramic turbine blade containing 4 wt. % Y{sub 2}O{sub 3} sintering additive at 1,370 C in air under selected stress levels. The objective of this study was to measure the creep properties of test specimens extracted from a complex shaped ceramic gas turbine blade to verify the response of actual components. The creep results indicated that specimens from both the airfoil and dovetail sections exhibited creep rates that were about 4 to 100 times higher than those obtained from both the buttonhead and dogbone creep specimens machined from the developmental billets fabricated with the same composition and processing procedures. Electron microscopy analyses suggested that high creep rates and short lifetimes observed in specimens extracted from the turbine blade resulted from a higher glassy phase(s) content and smaller number density of elongated grain microstructure. Silicon nitride ceramics with an in-situ reinforced elongated microstructure have been the primary candidates for both advanced automotive and land-based gas turbine engine applications.

  9. Hot Molecular Gas in the Circumnuclear Disk

    Science.gov (United States)

    Mills, Elisabeth A. C.; Togi, Aditya; Kaufman, Michael

    2017-12-01

    We present an analysis of archival Infrared Space Observatory observations of H2 for three 14\\prime\\prime × 20\\prime\\prime pointings in the central 3 pc of the Galaxy: toward the southwest region and northeast region of the Galactic center circumnuclear disk (CND), and toward the supermassive black hole Sgr A*. We detect pure rotational lines from 0-0 S(0) to S(13), as well as a number of rovibrationally excited transitions. Using the pure rotational lines, we perform both fits to a discrete temperature distribution (measuring up to three temperature components with T = 500-600 K, T = 1250-1350 K, and T > 2600 K) and fits to a continuous temperature distribution, assuming a power-law distribution of temperatures. We measure power-law indices of n = 3.22 for the northeast region and n = 2.83 for the southwest region. These indices are lower than those measured for other galaxies or other Galactic center clouds, indicating a larger fraction of gas at high temperatures. We also test whether extrapolating this temperature distribution can yield a reasonable estimate of the total molecular mass, as has been recently done for H2 observations in other galaxies. Extrapolating to a cutoff temperature of 50 K in the southwest (northeast) region, we would measure 32% (140%) of the total molecular gas mass inferred from the dust emission, and 26% (125%) of the total molecular gas mass inferred from the CO emission. Ultimately, the inconsistency of the masses inferred in this way suggests that a simple application of this method cannot yield a reliable estimate of the mass of the CND.

  10. Sorbent for use in hot gas desulfurization

    Science.gov (United States)

    Gasper-Galvin, Lee D.; Atimtay, Aysel T.

    1993-01-01

    A multiple metal oxide sorbent supported on a zeolite of substantially silicon oxide is used for the desulfurization of process gas streams, such as from a coal gasifier, at temperatures in the range of about 1200.degree. to about 1600.degree. F. The sorbent is provided by a mixture of copper oxide and manganese oxide and preferably such a mixture with molybdenum oxide. The manganese oxide and the molybdenum are believed to function as promoters for the reaction of hydrogen sulfide with copper oxide. Also, the manganese oxide inhibits the volatilization of the molybdenum oxide at the higher temperatures.

  11. Copper-based sorbents for hot coal gas desulfurization systems

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B.; Zarnegar, M.K. [Inst. of Gas Technology, Des Plaines, IL (United States)] [and others

    1997-07-01

    High-temperature coal gas desulfurization has been recognized as essential in the development of emerging power generation technologies such as the Integrated Gasification Combined Cycle (IGCC), aiming to improve both the efficiency and environmental performance of power generation from coal. Hot gas desulfurization may be accomplished by using regenerable mixed metal oxides sorbents which can reduce the H{sub 2}S content of the coal gas to a few ppmv over many sulfidation/regeneration cycles. The focus of much of the current research on hot gas desulfurization has been on the use of zinc-based sorbents. Although these sorbents have been the subject of extensive pilot-scale and process development work, zinc-based sorbents have been shown to suffer from sulfate formation and zinc volatilization, leading to sorbent degradation over multicycle use, increasing sorbent replacement costs and the overall cost of hot gas desulfurization processes. A novel copper-chromite sorbent has been developed at IGT for hot coal gas desulfurization under the sponsorship of the Illinois Clean Coal Institute (ICCI). Results obtained so far indicate that this sorbent, in granular form (i.e., CuCr-29), has a much higher attrition resistance compared to the commercial granular zinc titanate sorbent, as well as excellent desulfurization efficiency. Furthermore, unlike most zinc titanate sorbents, the reactivity of IGT`s CuCr-29 sorbent gradually and consistently improved during the 20 cycles tested. The sorbent preparation techniques developed at IGT have been applied to produce highly reactive and attrition resistant sorbent pellets for moving-bed applications.

  12. Ceramic thermal barrier coatings for electric utility gas turbine engines

    Science.gov (United States)

    Miller, R. A.

    1986-01-01

    Research and development into thermal barrier coatings for electric utility gas turbine engines is reviewed critically. The type of coating systems developed for aircraft applications are found to be preferred for clear fuel electric utility applications. These coating systems consists of a layer of plasma sprayed zirconia-yttria ceramic over a layer of MCrAly bond coat. They are not recommended for use when molten salts are presented. Efforts to understand coating degradation in dirty environments and to develop corrosion resistant thermal barrier coatings are discussed.

  13. Assessment of coal gasification/hot gas cleanup based advanced gas turbine systems

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The major objectives of the joint SCS/DOE study of air-blown gasification power plants with hot gas cleanup are to: (1) Evaluate various power plant configurations to determine if an air-blown gasification-based power plant with hot gas cleanup can compete against pulverized coal with flue gas desulfurization for baseload expansion at Georgia Power Company's Plant Wansley; (2) determine if air-blown gasification with hot gas cleanup is more cost effective than oxygen-blown IGCC with cold gas cleanup; (3) perform Second-Law/Thermoeconomic Analysis of air-blown IGCC with hot gas cleanup and oxygen-blown IGCC with cold gas cleanup; (4) compare cost, performance, and reliability of IGCC based on industrial gas turbines and ISTIG power island configurations based on aeroderivative gas turbines; (5) compare cost, performance, and reliability of large (400 MW) and small (100 to 200 MW) gasification power plants; and (6) compare cost, performance, and reliability of air-blown gasification power plants using fluidized-bed gasifiers to air-blown IGCC using transport gasification and pressurized combustion.

  14. Ceramic membranes applied in separation of hot gases; Membranas Ceramicas para Separacion de Gases en Caliente

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The aim of this project is to develop and evaluate inorganic membranes of a ceramic type, with nanometric pore size, applied in separation of contaminants and fuel enrichment, gas mixture in coal gasification . etc. Using ceramic materials have the advantage of being highly physical and chemical resistance, which makes these membranes more adequate then metal equivalent for these applications. A support manufacture and the development of natricum membranes technology to estimate the potential fields of applications and industrial viability of ceramic membranes are the intermediate goals so that the project could be considered successful one. The project has been carried out jointly by the following entities: TGI, S. A. (Tecnologia y Gestion de la Innovacion, Spain). CIEMAT (Centro de Investigaciones energeticas, Medioambientales y Tecnologicas, Spain) and CSIC-UAM (Centro mixto Consejo Superior de Investigaciones Cientificas-Universidad Autonoma de Madrid. Instituto de Ciencias de Materiales, Spain). The range of activities proposed in this project is to get the sufficient knowledge of preparation and behaviour of separation membranes to be able to procede to the desing and manufacture of an industrial filter. The project phases include; the ameiloration of ceramic support processing methods, the fluid dynamic evaluation, technology for membrane desing and manufacturing, the mounting (setting up) of an experimental installation for testing and evaluation. As a previous step a state of the art review about the following topics was made: high temperature inorganic membranes, technology separation mechanisms, gasifications process and its previous experience applications of membranes and determination of membranes specifications and characteristics of testing conditions. At the end a new inorganic ceramic membrane, with nanometric pore size and useful in several industrial processes (filtration, separation of contaminants, fuel enrichment, purification of gas mixtures

  15. Large enhancement of the electrocaloric effect in PLZT ceramics prepared by hot-pressing

    Directory of Open Access Journals (Sweden)

    Guangzu Zhang

    2016-06-01

    Full Text Available In this contribution, we demonstrate the optimization of the microstructures of the Pb0.85La0.1(Zr0.65Ti0.35O3 (PLZT relaxor ferroelectric ceramics and subsequent enhancements in their polarization and electrical resistivity by using a hot-pressing process. The resulting superior breakdown strength of hot-pressed PLZT enables the application of high electric field to induce a giant electrocaloric effect, in which the adiabatic change of temperature (ΔT and the isothermal change of entropy (ΔS are around 2 times greater than those of the samples prepared by the conventional sintering approach using muffle furnace. Moreover, the addition of extra PbO to make up the loss of Pb in the high-temperature sintering leads to the further improvements in the phase composition and electrical properties of PLZT, due to inhibition of the pyrochlore phase formation. The relationship among the sintering conditions, the content of excess PbO, and the microstructure as well as the electrical characteristics of PLZT have been investigated in a systematic manner. This work provides a facile approach to enhanced electrocaloric effect in bulk ceramics.

  16. Microstructure and optical properties of hot-pressed Er:CaF{sub 2} transparent ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zuodong [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Mei, Bingchu, E-mail: bcmeilab@163.com [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Song, Jinghong [Center of Materials Research and Analysis, Wuhan University of Technology, Wuhan 430070 (China); Yuan, Dan; Wang, Zhe [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2015-10-15

    CaF{sub 2} nanoparticles doped with different Er concentrations were synthesized by a co-precipitation method. The phase compositions and morphology of the obtained Er:CaF{sub 2} nanoparticles were characterized by X-ray diffraction and transmission electron microscopy analysis. It was found that the size and shape of obtained CaF{sub 2} nanoparticles were modified through Er{sup 3+} doping. High quality Er:CaF{sub 2} transparent ceramics were fabricated by hot-pressed sintering method in a vacuum environment. The influence of Er{sup 3+} doping concentrations and sintering temperatures on optical transmission and microstructure of Er:CaF{sub 2} transparent ceramics were investigated. When doped with 5 mol% Er{sup 3+}, the CaF{sub 2} ceramic sintered at 800 °C showed the best optical transmission, and for the 2 mm thickness sample, the optical transmission reached about 90% in the near-infrared spectral region. - Highlights: • Er:CaF{sub 2} nanoparticles were synthesized by coprecipitation method. • The size and shape of CaF{sub 2} nanoparticles were modified through Er doping. • Influence of Er content on transmissivity and microstructure was investigated. • Influence of temperature on transmissivity and microstructure was investigated.

  17. Ceramic Stationary Gas Turbine Development. Technical progress report, April 1, 1993--October 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    This report summarizes work performed by Solar Technologies Inc. and its subcontractors, during the period April 1, 1993 through October 31, 1994 under Phase II of the DOE Ceramic Stationary Gas Turbine Development program. The objective of the program is to improve the performance of stationary gas turbines in cogeneration through the implementation of selected ceramic components.

  18. X(3872 production and absorption in a hot hadron gas

    Directory of Open Access Journals (Sweden)

    L.M. Abreu

    2016-10-01

    Full Text Available We calculate the time evolution of the X(3872 abundance in the hot hadron gas produced in the late stage of heavy ion collisions. We use effective field Lagrangians to obtain the production and dissociation cross sections of X(3872. In this evaluation we include diagrams involving the anomalous couplings πD⁎D¯⁎ and XD¯⁎D⁎ and also the couplings of the X(3872 with charged D and D⁎ mesons. With these new terms the X(3872 interaction cross sections are much larger than those found in previous works. Using these cross sections as input in rate equations, we conclude that during the expansion and cooling of the hadronic gas, the number of X(3872, originally produced at the end of the mixed QGP/hadron gas phase, is reduced by a factor of 4.

  19. Development of impact design methods for ceramic gas turbine components

    Science.gov (United States)

    Song, J.; Cuccio, J.; Kington, H.

    1990-01-01

    Impact damage prediction methods are being developed to aid in the design of ceramic gas turbine engine components with improved impact resistance. Two impact damage modes were characterized: local, near the impact site, and structural, usually fast fracture away from the impact site. Local damage to Si3N4 impacted by Si3N4 spherical projectiles consists of ring and/or radial cracks around the impact point. In a mechanistic model being developed, impact damage is characterized as microcrack nucleation and propagation. The extent of damage is measured as volume fraction of microcracks. Model capability is demonstrated by simulating late impact tests. Structural failure is caused by tensile stress during impact exceeding material strength. The EPIC3 code was successfully used to predict blade structural failures in different size particle impacts on radial and axial blades.

  20. Particulate hot gas stream cleanup technical issues. Quarterly report, April 1 - June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This is the seventh in a series of quarterly reports describing the activities performed for this project. Our analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, we received and analyzed a hopper ash sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota`s Energy and Environmental Research Center (UNDEERC). We also received six ash samples from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. We selected one of the filter cake ashes from this batch of samples for detailed analyses. We continued our work on the HGCU data base we are constructing in Microsoft Access{reg_sign}. We have been entering a variety of information into the data base, including numerical values, short or long text entries, and photographs. Task 2 efforts during the past quarter focused on hoop tensile testing of Schumacher FT20 and Refractron candle filter elements removed from the Karhula APF after {approximately}540 hours of service.

  1. Electrical anisotropy in the hot-forged CaBi 4Ti 4O 15 ceramics

    Science.gov (United States)

    Rout, S. K.; Hussain, A.; Sinha, E.; Ahn, C. W.; Kim, I. W.

    2009-06-01

    Textured CaBi 4Ti 4O 15 (CBT) ceramics have been fabricated via a hot-forging technique. The effect of grain orientation on the dielectric and electrical properties is studied by impedance ( Z∗) and modulus ( M∗) spectroscopy. The degree of orientation ( F) calculated from X-ray diffraction pattern is found to be 89.4% along the c-axis of the crystal structure. The permittivity was measured along both perpendicular and parallel directions of the forging axis. The ratio of permittivity along perpendicular to parallel direction is found to be ˜3 at the Curie temperature of 797 °C. The non-superimposition of the normalized Z″ and M″ vs. frequency plot revealed the conduction in the material is localized and deviate from ideal Debye behavior. The power law exponent n of the material has been explained on the basis of jump relaxation model and revealed the conduction through grain boundary. Activation energy ( Ea) is obtained from Arrhenius plots of the dc conductivity for both the ceramics and it is found to be 0.89 eV and 0.78 eV for CBT (∥) and CBT (⊥), respectively.

  2. Application of CFCC technology to hot gas filtration applications

    Energy Technology Data Exchange (ETDEWEB)

    Richlen, S.

    1995-06-01

    Discussion will feature high temperature filter development under the DOE`s Office of Industrial Technologies Continuous Fiber Ceramic Composite (CFCC) Program. Within the CFCC Program there are four industry projects and a national laboratory technology support project. Atlantic Research, Babcock & Wilcox, DuPont Lanxide Composites, and Textron are developing processing methods to produce CFCC Components with various types of matrices and composites, along with the manufacturing methods to produce industrial components, including high temperature gas filters. The Oak Ridge National Laboratory is leading a National Laboratory/University effort to increase knowledge of such generic and supportive technology areas as environmental degradation, measurement of mechanical properties, long-term performance, thermal shock and thermal cycling, creep and fatigue, and non-destructive characterization. Tasks include composite design, materials characterization, test methods, and performance-related phenomena, that will support the high temperature filter activities of industry and government.

  3. Ceramic membranes for gas separation in advanced fossil power plants

    Energy Technology Data Exchange (ETDEWEB)

    Meulenberg, W.A.; Baumann, S.; Ivanova, M.; Gestel, T. van; Bram, M.; Stoever, D. [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF)

    2010-07-01

    The reduction or elimination of CO{sub 2} emissions from electricity generation power plants fuelled by coal or gas is a major target in the current socio-economic, environmental and political discussion to reduce green house gas emissions such as CO{sub 2}. This mission can be achieved by introducing gas separation techniques making use of membrane technology, which is, as a rule, associated with significantly lower efficiency losses compared with the conventional separation technologies. Depending on the kind of power plant process different membrane types (ceramic, polymer, metal) can be implemented. The possible technology routes are currently investigated to achieve the emission reduction. They rely on different separation tasks. The CO{sub 2}/N{sub 2} separation is the main target in the post-combustion process. Air separation (O{sub 2}/N{sub 2}) is the focus of the oxyfuel process. In the pre-combustion process an additional H{sub 2}/CO{sub 2} separation is included. Although all separation concepts imply different process requirements they have in common a need in membranes with high permeability, selectivity and stability. In each case CO{sub 2} is obtained in a readily condensable form. CO{sub 2}/N{sub 2} separation membranes like microporous membranes or polymer membranes are applicable in post-combustion stages. In processes with oxyfuel combustion, where the fuel is combusted with pure oxygen, oxygen transport membranes i.e. mixed ionic electronic conducting (MIEC) membranes with mainly perovskite or fluorite structure can be integrated. In the pre-combustion stages of the power plant process, H{sub 2}/CO{sub 2} separation membranes like microporous membranes e.g. doped silica or mixed protonic electronic conductors or metal membranes can be applied. The paper gives an overview about the considered ceramic materials for the different gas separation membranes. The manufacturing of bulk materials as well as supported thin films of these membranes along

  4. Particulate hot gas stream cleanup technical issues. Quarterly report, January 1--March 31, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on January 20 to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF). Comparisons were made between laboratory analyses of these PSDF ashes and field data obtained from facility operation. In addition, selected laboratory techniques were reviewed to assess their reproducibility and the influence of non-ideal effects and differences between laboratory and filter conditions on the quantities measured. Further work on the HGCU data base is planned for the next quarter. Two Dupont PRD-66 candle filters, one McDermott candle filter, one Blasch candle filter, and one Specific Surfaces candle filter were received at SRI for testing. A test plan and cutting plan for these candles was developed. Acquisition of two of the Dupont PRD-66 candle filters will allow candle-to-candle variability to be examined.

  5. Robust, high temperature-ceramic membranes for gas separation

    Science.gov (United States)

    Berchtold, Kathryn A.; Young, Jennifer S.

    2014-07-29

    A method of making ceramic membranes, and the ceramic membranes so formed, comprising combining a ceramic precursor with an organic or inorganic comonomer, forming the combination as a thin film on a substrate, photopolymerizing the thin film, and pyrolyzing the photopolymerized thin film.

  6. Mechanical properties and porosity of dental glass-ceramics hot-pressed at different temperatures

    Directory of Open Access Journals (Sweden)

    Carla Castiglia Gonzaga

    2008-09-01

    Full Text Available The objective of this work was to evaluate biaxial-flexural-strength (σf, Vickers hardness (HV, fracture toughness (K Ic, Young's modulus (E, Poisson's ratio (ν and porosity (P of two commercial glass-ceramics, Empress (E1 and Empress 2 (E2, as a function of the hot-pressing temperature. Ten disks were hot-pressed at 1065, 1070, 1075 and 1080 °C for E1; and at 910, 915, 920 and 925 °C for E2. The porosity was measured by an image analyzer software and s f was determined using the piston-on-three-balls method. K Ic and HV were determined by an indentation method. Elastic constants were determined by the pulse-echo method. For E1 samples treated at different temperatures, there were no statistical differences among the values of all evaluated properties. For E2 samples treated at different temperatures, there were no statistical differences among the values of σf, E, and ν, however HV and K Ic were significantly higher for 910 and 915 °C, respectively. Regarding P, the mean value obtained for E2 for 925 °C was significantly higher compared to other temperatures.

  7. Status of the Ford program to evaluate ceramics for stator applications in automotive gas turbine engines

    Science.gov (United States)

    Trela, W.

    1980-01-01

    The paper reviews the progress of the major technical tasks of the DOE/NASA/Ford program Evaluation of Ceramics for Stator Applications in Automotive Gas Turbine Engines: reliability prediction, stator fabrication, material characterization, and stator evaluation. A fast fracture reliability model was prepared for a one-piece ceramic stator. Periodic inspection results are presented.

  8. Transition duct system with arcuate ceramic liner for delivering hot-temperature gases in a combustion turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, David J.

    2017-11-07

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include an arcuate connecting segment (36). An arcuate ceramic liner (60) may be inwardly disposed onto a metal outer shell (38) along the arcuate connecting segment of the exit piece. Structural arrangements are provided to securely attach the ceramic liner in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liner can be readily removed and replaced as needed.

  9. Integrated hot fuel gas cleaning for advanced gasification combined cycle process

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kangasmaa, K.; Laatikainen, J.; Staahlberg, P.; Kurkela, E. [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1996-12-01

    The fate of halogens in pressurised fluidized-bed gasification and hot gas filtration is determined. Potential halogen removal sorbents, suitable for integrated hot gas cleaning, are screened and some selected sorbents are tested in bench scale. Finally, halogen removal results are verified using the PDU-scale pressurised fluidized-bed gasification and integrated hot gas cleaning facilities of VTT. The project is part of the JOULE II Extension programme of the European Union. (author)

  10. Preparation and characterization of porous Si3 N4 ceramics ...

    Indian Academy of Sciences (India)

    Administrator

    Porous Si3N4 ceramics; preparation; microstructure; mechanical properties; gas permeability. 1. Introduction. Porous ceramics are used ... separation filters have become important to reduce envi- ronmental pollution in various fields. ... (2008) fabricated Si3N4 ceramics with a porosity of 0–30% by using partial hot-pressing.

  11. Pressureless sintering and gas flux properties of porous ceramic membranes for gas applications

    Science.gov (United States)

    Obada, David O.; Dodoo-Arhin, David; Dauda, Muhammad; Anafi, Fatai O.; Ahmed, Abdulkarim S.; Ajayi, Olusegun A.

    The preparation and characterization of kaolin based ceramic membranes using styrofoam (STY) and sawdust (SD) as pore formers have been prepared by mechano-chemical synthesis using pressureless sintering technique with porogen content between (0-20) wt% by die pressing. Pellets were fired at 1150 °C and soaking time of 4 h. The membranes cast as circular disks were subjected to characterization studies to evaluate the effect of the sintering temperature and pore former content on porosity, density, water absorption and mechanical strength. Obtained membranes show effective porosity with maximum at about 43 and 47% respectively for membranes formulated with styrofoam and sawdust porogens but with a slightly low mechanical strength that does not exceed 19 MPa. The resultant ceramic bodies show a fine porous structure which is mainly caused by the volatilization of the porogens. The fabricated membrane exhibited high N2 gas flux, hence, these membranes can be considered as efficient for potential application for gas separation by reason of the results shown in the gas flux tests.

  12. Detection of Hot Gas in Galaxy Groups via the Sunyaev-Zel'dovich Effect

    OpenAIRE

    Moodley, K.; Warne, R.; Goheer, N.; Trac, H.

    2008-01-01

    Motivated by the observed shortfall of baryons in the local universe, we investigate the ability of high resolution cosmic microwave background (CMB) experiments to detect hot gas in the outer regions of nearby group halos. We construct hot gas models with the gas in hydrostatic equilibrium with the dark matter and described by a polytropic equation of state. We also consider models that add entropy to the gas in line with constraints from X-ray observations. We calculate the thermal Sunyaev-...

  13. Mechanical support of a ceramic gas turbine vane ring

    Science.gov (United States)

    Shi, Jun; Green, Kevin E.; Mosher, Daniel A.; Holowczak, John E.; Reinhardt, Gregory E.

    2010-07-27

    An assembly for mounting a ceramic turbine vane ring onto a turbine support casing comprises a first metal clamping ring and a second metal clamping ring. The first metal clamping ring is configured to engage with a first side of a tab member of the ceramic turbine vane ring. The second metal clamping ring is configured to engage with a second side of the tab member such that the tab member is disposed between the first and second metal clamping rings.

  14. 300 kW ceramic gas turbine. Overview (summary for eleven years); 300kW ceramic gas turbine. Zentai gaiyo (11 nenkan no sokatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, A.; Sugiura, T. [Agency of Industrial Science and Technology, Tokyo (Japan)

    1999-09-20

    The ceramic gas turbine (CGT) project had been authorized of its inauguration as a large-scale energy saving technology research and development project, at the inquiry commission for industrial technologies and the energy saving technology development working group held in August 1987. Since a great number of insurmountable barriers had been anticipated ahead in this project, parallel development was performed on multiple number of technologies with an objective of verifying the technological possibility of the CGT. Results of the research and development works revealed that ceramic parts were upscaled successfully, and expansion and deformation of metallic parts due to high temperature operation in small gas turbines can affect more severely than has been thought. Although the bi-axial turbines have succeeded to reach thermal efficiency exceeding 42% and operation of 1000 hours, the mono-axial turbines were not possible of solving such problems as deformation, with the thermal efficiency staying at 34.7%. The fact that ceramics was verified usable as structural members of gas turbines is a very good news for people related with ceramics in the world. (NEDO)

  15. Hot-gas cleanup system model development. Volume II. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ushimaru, K.; Bennett, A.; Bekowies, P.J.

    1982-11-01

    Under Contract to the Department of Energy (DOE) through the Morgantown Energy Technology Center (METC), Flow Industries, Inc., has developed computer models to simulate the physical performance of five hot-gas cleanup devices for pressurized, fluidized-bed combustion (PFBC), combined-cycle power plants. Separate cost models have also been developed to estimate the cost of each device. The work leading to the development of these models is described in Volume I of this report. This volume contains the user's manuals for both the physical and cost models. The manuals for the physical models are given first followed by those for the cost models. Each manual is a complete and separate document. The model names and devices and their respective subroutine names are: (1) Moving Granular Bed Filter by Combustion Power Company, USRCGB, QFCOST; (2) Ceramic Bag Filter by Acurex, USRACB, QDCOST; (3) Electrostatic Granular Bed Filter by General Electric, USRGGB, QACOST; (4) Electrostatic Precipitator by Research Cottrell, USRCEP, QECOST; and (5) Electrocyclone by General Electric, USRGCY, QBCOST.

  16. Particulate hot gas stream cleanup technical issues. Quarterly report, January--March 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-21

    To identify which ash characteristics can lead to problems with filtration, the authors have assembled 235 ash samples from eleven facilities involved in METC`s HGCU program. They have analyzed many of these ashes with a variety of laboratory tests. Physical attributes of the particles that they have examined include size distribution, specific surface area, particle morphology, and bulk ash cohesivity and permeability. They have also performed a range of chemical analyses on these ashes, as well as characterizations of agglomerates of ash removed from filter vessels at Tidd and Karhula. They are in the process of assembling the data obtained in these studies into an interactive data base which will help the manufacturers and operators of high-temperature barrier filters tailor their designs and operations to the specific characteristics of the ashes they are collecting. In order to understand the thermal and mechanical behavior of the various types of ceramic materials used in hot gas filtration, they have been performing hoop and axial tensile tests, thermal expansion, compression, and creep evaluations of these materials at temperatures up to 1,800 F. Nondestructive testing methods they perform on filter specimens include density and ultrasonic velocity. To date they have evaluated various characteristics of Dupont/Lanxide PRD-66, Dupont composite, 3M composite, IF and P Fibrosics, Refractron, Schumacher, and Blasch alumina mullite materials.

  17. Gas turbine ceramic-coated-vane concept with convection-cooled porous metal core

    Science.gov (United States)

    Kascak, A. F.; Liebert, C. H.; Handschuh, R. F.; Ludwig, L. P.

    1981-01-01

    Analysis and flow experiments on a ceramic-coated-porous-metal vane concept indicated the feasibility, from a heat transfer standpoint, of operating in a high-temperature (2500 F) gas turbine cascade facility. The heat transfer and pressure drop calculations provided a basis for selecting the ceramic layer thickness (to 0.08 in.), which was found to be the dominant factor in the overall heat transfer coefficient. Also an approximate analysis of the heat transfer in the vane trailing edge revealed that with trailing-edge ejection the ceramic thickness could be reduced to (0.01 in.) in this portion of the vane.

  18. Kinetic behaviour of iron oxide sorbent in hot gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Y.G. Pan; J.F. Perales; E. Velo; L. Puigjaner [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Chemical Engineering

    2005-06-01

    Although a number of reports on sorbents containing ZnO for H{sub 2}S removal from coal-derived gases can be found in the literature, it is shown in our study that a special sorbent containing Fe{sub 2}O{sub 3}{center_dot}FeO (SFO) with minor promoters (Al{sub 2}O{sub 3}, K{sub 2}O, and CaO) as the main active species is more attractive for both sulfidation and regeneration stages, also under economic considerations. This paper presents the kinetic behaviour of SFO in a hot gas desulfurization process using a thermogravimetric analysis under isothermal condition in the operating range between 500 and 800{sup o}C. The gas stream was N{sub 2} with a 2% wt of H{sub 2}S. Experiences carried out on sorbent sulfidation with SFO (particle sizes in the range of 0.042-0.12 mm) indicate that the sorbent sulfidation capacity sharply increases with temperature in the range of 500-600{sup o}C. It is also shown that the sample weight reaches its maximum absorption capacity, near saturation, at 600{sup o}C so that it makes no sense to increase the sulfidation temperature from this point. To make a comparison between SFO and a zinc titanate based sorbent, a set of sulfidation tests was carried out at 600{sup o}C during 7200 s using the same sieve range for both sorbents between 42 and 90 m. Results show that the sulfidation capacity of SFO is 1.9 times higher than that of zinc titanate. 11 refs., 8 figs., 1 tab.

  19. Gas Sensors Based on Ceramic p-n Heterocontacts

    Energy Technology Data Exchange (ETDEWEB)

    Aygun, Seymen Murat [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    with very high forward currents. Ga doped heterocontacts showed the highest sensitivity observed during current-time measurements as well, even though the sensor response was rather slow. Finally, a possible synergistic effect of doping both p and n-sides was studied by utilizing current-time measurements for 1.5 mol% Ni-CuO/1.5 mol% Ga-ZnO heterocontact. A sensitivity value of ~5.1 was obtained with the fastest response among all the samples. The time needed to reach 90% coverage was lowered by a factor of 4 when compared to the pure heterocontact and the time needed to reach 70% coverage was just over one minute. Heterocontact gas sensors are promising candidates for high temperature sensor applications. Today, Si-based microelectromechanical system (MEMS) technology has shown great promise for developing novel devices such as pressure sensors, chemical sensors, and temperature sensors through complex designs. However, the harsh thermal, vibrational, and corrosive environments common to many aerospace applications impose severe limitations on their use. Sensors based on ceramic p-n heterocontacts are promising alternatives because of their inherent corrosion resistance and environmental stability. The other advantages include their inherent tuning ability to differentiate between different reducing gases and a possible cost efficient production of a wireless sensor. Being a capacitive type sensor, its output can be transformed into a passive wireless device by creating a tuned LC circuit. In this way, the sensor output (the capacitance) can be accessed remotely by measuring the resonant frequency. The relatively simple structure of heterocontacts makes it suitable for thick film fabrication techniques to make sensor packages.

  20. Tunability of laser based on Yb-doped hot-pressed CaF2 ceramics

    Science.gov (United States)

    Sulc, Jan; Doroshenko, Maxim E.; Jelínková, Helena; Basiev, Tasoltan T.; Konyushkin, Vasilii A.; Osiko, Vyacheslav V.

    2012-06-01

    The aim of presented study was an investigation of tunability of diode pumped laser based on hot-pressed Yb:CaF2 ceramics. The tested Yb:CaF2 sample was in the form of 3.5mm thick plane-parallel face-polished plate (without AR coatings). The Yb3+ concentration was 5.5 %. A fiber (core diameter 200 μm, NA= 0.22) coupled laser diode (LIMO, HLU25F200-980) with emission at wavelength 976 nm, was used for longitudinal Yb:CaF2 pumping. The laser diode was operating in the pulsed regime (4 ms pulse length, 20 Hz repetition rate). The duty-cycle 8% ensured a low thermal load even under the maximum diode pumping power amplitude 10W (crystal sample was only air-cooled). This radiation was focused into the crystal (pumping beam waist diameter ~ 170 μm). The 145mm long semi-hemispherical laser resonator consisted of a flat pumping mirror (HR @ 1.01 - 1.09 μm, HT @ 0.97 μm) and curved (r = 150mm) output coupler with a reflectivity of ~ 98% @ 1.01 - 1.09 μm. Tuning of the ytterbium laser was accomplished by using a birefringent filter (single 1.5mm thick quartz plate) placed inside the optical resonator at the Brewster angle between the output coupler and the laser active medium. The extremely broad and smooth tuning was obtained. The laser was continuously tunable over ~ 66nm (from 1015nm to 1081 nm) and the tuning band was mostly limited by free spectral range of used birefringent filter. The tunability FWHM was 40 nm corresponding bandwidth 10 THz results in Fourier limited gaussian pulse width ~ 40 fs (FWHM). The maximum output power amplitude 0.68W was obtained at wavelength 1054nm for absorbed pump power amplitude 6W. The laser slope efficiency was 15%.

  1. FY 1998 annual report. Research and development on ceramic gas turbine (300kW class)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    Research and development have been made on a small ceramic gas turbine which is high in efficiency, low in pollutant emission, capable of corresponding to different fuels, and can be utilized in cogeneration and/or movable electric power generation systems. Fundamental researches in developing and researching heat resistant ceramic parts have been carried out on a method for fabricating turbine nozzles using heat resistant silicon nitride, improvement in accuracy in fabricating combustors using the heat resistant silicon nitride, and casting of turbine blades made from sialon. In developing the devices, researches were made on reliability of bond between a ceramic blade and a metallic disk, air-fuel ratio in a combustor, distribution of fuel concentrations, fuel injection methods, reduction of loss in a diffuser in a compressor, and matching of the diffuser with an impeller. In addition, research and development were performed on a single shaft ceramic gas turbine for cogeneration and a double shaft ceramic gas turbine. Researches were executed on reliability of ceramic materials. (NEDO)

  2. Hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chips using positive temperature coefficient ceramic heater.

    Science.gov (United States)

    Wang, Xia; Zhang, Luyan; Chen, Gang

    2011-11-01

    As a self-regulating heating device, positive temperature coefficient ceramic heater was employed for hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chip because it supplied constant-temperature heating without electrical control circuits. To emboss a channel plate, a piece of poly(methyl methacrylate) plate was sandwiched between a template and a microscopic glass slide on a positive temperature coefficient ceramic heater. All the assembled components were pressed between two elastic press heads of a spring-driven press while a voltage was applied to the heater for 10 min. Subsequently, the embossed poly(methyl methacrylate) plate bearing negative relief of channel networks was bonded with a piece of poly(methyl methacrylate) cover sheet to obtain a complete microchip using a positive temperature coefficient ceramic heater and a spring-driven press. High quality microfluidic chips fabricated by using the novel embossing/bonding device were successfully applied in the electrophoretic separation of three cations. Positive temperature coefficient ceramic heater indicates great promise for the low-cost production of poly(methyl methacrylate) microchips and should find wide applications in the fabrication of other thermoplastic polymer microfluidic devices.

  3. Fiscal 1998 research report on the R and D of ceramic gas turbines; 1998 nendo ceramic gas turbine no kenkyu kaihatsu kenkyu seika

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For development of high-efficiency environment-friendly fuel-unrestricted small- and middle-size engines for cogeneration, this project researches ceramic gas turbines (CGT). Accordingly, the project studies heat-resistant ceramic members and elementary technologies, and verifies the prototype CGT fabricated by integrating the obtained results. Two kinds of CGTs for cogeneration are studied, a single- shaft regenerative turbine and a dual-shaft one, aiming at more than 42% in engine thermal efficiency, 1,350 degreesC in turbine inlet temperature, and 300kW in shaft output. Ceramic parts aim at 400MPa in minimum proof strength and more than 20 in Weibull coefficient at 1,500 degreesC. In fiscal 1998, for the single-shaft system, production technology and elementary technologies for ceramic parts, and design and operation of the prototype CGT were studied. For the dual-shaft system, parts production technology, evaluation technology and elementary technologies were studied. The reliability verification test of ceramic parts was also studied. (NEDO)

  4. Particulate Hot Gas Stream Cleanup Technical Issues: Quarterly report, July 1-September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1996-12-09

    This is the eighth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic barrier filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, additional analyses were performed on ashes from the Ahlstrom 10 MWt Pressurized Fluidized Circulating Fluid Bed (PCFB) facility located at Karhula, Finland. Work continued on the HGCU data base being constructed in Microsoft Access. A variety of information has been entered into the data base, including numerical values, short or long text entries, and photographs. Detailed design of a bench top device for high temperature measurement of ash permeability has also begun. In addition to these activities, a paper was prepared and a poster was presented summarizing recent work performed under this contract at the 1996 DOE/METC Contractor`s Conference. A presentation was also given corresponding to the manuscript entitled Particle Characteristics and High-Temperature Filtration that was prepared for publication in the Proceedings of the Thirteenth Annual International Pittsburgh Coal Conference held this September in Pittsburgh, PA. Arrangements have been made to be present at the DOE/METC Modular Gas Cleanup Rig (MGCR) at the conclusion of the next run of the DOE/METC air blown Fluid Bed Gasifier (FBG). This visit will include on-site sampling to collect and characterize the filter cakes collected during FGB operation. Task 2 efforts during the past quarter focused on

  5. Investigation of a ceramic vane with a metal disk thermal and mechanical contact in a gas turbine impeller

    Directory of Open Access Journals (Sweden)

    Resnick S.V.

    2015-01-01

    Full Text Available Promising directions of a new generation gas turbine engines development include using in gas turbines ceramic materials blades with high strength, thermal and chemical stability. One of the serious problems in developing such motors is insufficient knowledge of contact phenomena occurring in ceramic and metal details connection nodes. This work presents the numerical modeling results of thermal processes on ceramic and metal details rough boundaries. The investigation results are used in conducting experimental researches in conditions reproducing operating.

  6. The origin of the hot metal-poor gas in NGC 1291 - Testing the hypothesis of gas dynamics as the cause of the gas heating

    NARCIS (Netherlands)

    Perez, [No Value; Freeman, K

    In this paper we test the idea that the low-metallicity hot gas in the centre of NGC 1291 is heated via a dynamical process. In this scenario, the gas from the outer gas-rich ring loses energy through bar-driven shocks and falls to the centre. Heating of the gas to X-ray temperatures comes from the

  7. Impact design methods for ceramic components in gas turbine engines

    Science.gov (United States)

    Song, J.; Cuccio, J.; Kington, H.

    1991-01-01

    Methods currently under development to design ceramic turbine components with improved impact resistance are presented. Two different modes of impact damage are identified and characterized, i.e., structural damage and local damage. The entire computation is incorporated into the EPIC computer code. Model capability is demonstrated by simulating instrumented plate impact and particle impact tests.

  8. Numerical Investigation of the Transient Behavior of a Hot Gas Duct under Rapid Depressurization

    Directory of Open Access Journals (Sweden)

    JingBao Liu

    2016-01-01

    Full Text Available A hot gas duct is an indispensable component for the nuclear-process heat applications of the Very-High-Temperature Reactor (VHTR, which has to fulfill three requirements: to withstand high temperature, high pressure, and large pressure transient. In this paper, numerical investigation of pressure transient is performed for a hot gas duct under rapid depressurization. System depressurization imposes an imploding pressure differential on the internal structural elements of a hot gas duct, the structural integrity of which is susceptible to being damaged. Pressure differential and its imposed duration, which are two key factors to evaluate the damage severity of a hot gas duct under depressurization, are examined in regard to depressurization rate and insulation packing tightness. It is revealed that depressurization rate is a decisive parameter for controlling the pressure differential and its duration, whereas insulating-packing tightness has little effect on them.

  9. Combustion Control of a Small HCCI Engine Fuelled with DME using Hot and Cold EGR Gas

    National Research Council Canada - National Science Library

    OHMURA, Tetsuo; KANOTO, Yoshihiko; IIDA, Norimasa

    2009-01-01

    .... The experimental results showed that combustion phasing can be controlled through adjusting the mass-averaged in-cylinder gas temperature at intake valve closure timing by changing the ratio of Hot...

  10. Strength and corrosion behavior of SiC - based ceramics in hot coal combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Breder, K.; Parten, R.J. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    As part of an effort to evaluate the use of advanced ceramics in a new generation of coal-fired power plants, four SiC-based ceramics have been exposed to corrosive coal slag in a laboratory furnace and two pilot scale combustors. Initial results indicate that the laboratory experiments are valuable additions to more expensive pilot plant experiments. The results show increased corrosive attack with increased temperature, and that only slight changes in temperature may significantly alter the degree of strength degradation due to corrosive attack. The present results are part of a larger experimental matrix evaluating the behavior of ceramics in the coal combustion environment.

  11. Factors affecting dustcake drag in a hot-gas filter system collecting coal gasification ash

    Energy Technology Data Exchange (ETDEWEB)

    Dahlin, R.S.; Landham, E.C. [Power Systems Development Facility, Wilsonville, AL (United States)

    2008-01-15

    This paper discusses the use of laboratory drag measurements and filter operating data to analyze factors affecting dustcake flow resistance in a hot-gas filter at the Power Systems Development Facility (PSDF). The hot-gas filter is a Siemens-Westinghouse two-tier candle filter system that is collecting coal gasification ash from a KBR Transport Gasifier. Operating experience with this system has shown that the flow resistance of the dustcake is responsible for most of the pressure drop across the hot-gas filter, and the pressure drop varies substantially with the type of coal being gasified and the operating conditions of the gasifier and filter systems. To analyze factors affecting dustcake drag, samples of gasification ash from various coals and various operating conditions were resuspended in a laboratory test apparatus, and the drag was measured as the dust was collected on a sintered metal filter. The lab-measured drag values were compared to actual values of transient drag determined from the increase in pressure drop, the inlet dust loading, and the face velocity in the hot-gas filter. After correcting the lab drag data to hot-gas filter conditions, good agreement was achieved between the lab measurements and the hot-gas filter transient drag values. Both types of measurements showed that drag was strongly influenced by coal type and carbon content.

  12. Olivine, dolomite and ceramic filters in one vessel to produce clean gas from biomass.

    Science.gov (United States)

    Rapagnà, Sergio; Gallucci, Katia; Foscolo, Pier Ugo

    2018-01-01

    Heavy organic compounds produced during almond shells gasification in a steam and/or air atmosphere, usually called tar, are drastically reduced in the product gas by using simultaneously in one vessel a ceramic filter placed in the freeboard and a mixture of olivine and dolomite particles in the fluidized bed of the gasifier. The content of tar in the product gas during a reference gasification test with air, in presence of fresh olivine particles only, was 8600mg/Nm3 of dry gas. By gasifying biomass with steam at the same temperature level of 820°C in a bed of olivine and dolomite (20% by weight), and in the presence of a catalytic ceramic filter inserted in the freeboard of the fluidized bed gasifier, the level of tar was brought down to 57mg/Nm3 of dry producct gas, with a decrease of more than two orders of magnitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Joe Enneking

    2011-05-01

    Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absoption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

  14. Off-gas characteristics of liquid-fed joule-heated ceramic melters

    Science.gov (United States)

    Goles, R. W.; Sevigny, G. J.

    1982-06-01

    The off gas characteristics of liquid fed joule heated ceramic meters were investigated as a function of melter operational condition and simulated waste feed composition. The identity and behavior patterns of gaseous emissions, the characteristics of melter generated aerosols, the nature and magnitude of melter effluent losses and the factors affecting melter operational performance were established.

  15. ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through December 1999.

  16. Facilitated transport ceramic membranes for high-temperature gas cleanup. Final report, February 1990--April 1994

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, R.; Minford, E.; Damle, A.S.; Gangwal, S.K.; Hart, B.A.

    1994-04-01

    The objective of this program was to demonstrate the feasibility of developing high temperature, high pressure, facilitated transport ceramic membranes to control gaseous contaminants in Integrated Gasification Combined Cycle (IGCC) power generation systems. Meeting this objective requires that the contaminant gas H{sub 2}S be removed from an IGCC gas mixture without a substantial loss of the other gaseous components, specifically H{sub 2} and CH{sub 4}. As described above this requires consideration of other, nonconventional types of membranes. The solution evaluated in this program involved the use of facilitated transport membranes consisting of molten mixtures of alkali and alkaline earth carbonate salts immobilized in a microporous ceramic support. To accomplish this objective, Air Products and Chemicals, Inc., Golden Technologies Company Inc., and Research Triangle Institute worked together to develop and test high temperature facilitated membranes for the removal of H{sub 2}S from IGCC gas mixtures. Three basic experimental activities were pursued: (1) evaluation of the H{sub 2}S chemistry of a variety of alkali and alkaline earth carbonate salt mixtures; (2) development of microporous ceramic materials which were chemically and physically compatible with molten carbonate salt mixtures under IGCC conditions and which could function as a host to support a molten carbonate mixture and; (3) fabrication of molten carbonate/ceramic immobilized liquid membranes and evaluation of these membranes under conditions approximating those found in the intended application. Results of these activities are presented.

  17. Hot gas handling device and motorized vehicle comprising the device

    NARCIS (Netherlands)

    Klein Geltink, J.; Beukers, A.; Van Tooren, M.J.L.; Koussios, S.

    2012-01-01

    The invention relates to a device for handling hot exhaust gasses discharged from an internal combustion engine. The device comprises a housing (2), enclosing a space (3) for transporting the exhaust gasses. The housing (2) is provided with an entrance - opening (4) for the exhaust gasses discharged

  18. Hot Gas Cleanup Test Facility for gasification and pressurized combustion. Quarterly report, October--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility and integrating the particulate control devices (PCDs) into structural and process designs. Substantial progress in underground construction activities was achieved during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. MWK equipment at the grade level and the first tier are being set in the structure.

  19. A solid ceramic electrolyte system for measuring redox conditions in high temperature gas mixing studies

    Science.gov (United States)

    Williams, R. J.

    1972-01-01

    The details of the construction and operation of a gas mixing furnace are presented. A solid ceramic oxygen electrolyte cell is used to monitor the oxygen fugacity in the furnace. The system consists of a standard vertical-quench, gas mixing furnace with heads designed for mounting the electrolyte cell and with facilities for inserting and removing the samples. The system also contains the highinput impedance electronics necessary for measurements and a simplified version of standard gas mixing apparatus. The calibration and maintenance of the system are discussed.

  20. Phase Composition and Microstructure of Hot-Pressing Sintered Ti2AlN Metal-Ceramic Bulk Material

    Directory of Open Access Journals (Sweden)

    LIANG Suying

    2017-06-01

    Full Text Available Ti2AlN metal-ceramic bulk material was fabricated by hot-pressing sintering (HPS using TiN, Ti and Al powder in a stoichiometric ratio of 1:1:1.03 after mechanical mixing. XRD, SEM and TEM were employed to investigate the phase composition and microstructures of the products. The results show that the high purity Ti2AlN can be obtained by HPS at 1300 ℃ for 2.5 h. The sintered Ti2AlN presented a hexagonal system layered structure with an anisotropy. Twins are found in the Ti2AlN. There were a few nano-scale TiN particles in the products.

  1. Hot Gas TVC For Planetary Ascent Vehicle Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Mars ascent vehicle (MAV) uses solid rocket motors to propel soil samples into orbit, but the motors cannot provide steering. Cold gas thrusters are used for...

  2. A new high temperature resistant glass–ceramic coating for gas ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A new high temperature and abrasion resistant glass–ceramic coating system (based on MgO–. Al2O3–TiO2 and ZnO–Al2O3–SiO2 based glass systems) for gas turbine engine components has been developed. Thermal shock resistance, adherence at 90°-bend test and static oxidation resistance at the required ...

  3. The interaction between hot and cold gas in early-type galaxies

    Science.gov (United States)

    Bregman, Joel N.; Hogg, David E.; Roberts, Morton S.

    1995-01-01

    SO and Sa galaxies have approximately equal masses of H I and X-ray emitting gas and are ideal sites for studying the interaction between hot and cold gas. An X-ray observation of the Sa galaxy NGC 1291 with the ROSAT position sensitive proportional counter (PSPC) shows a striking spatial anticorrelation between hot and cold gas where X-ray emitting material fills the large central black hole in the H I disk. This supports a previous suggestion that hot gas is a bulge phenomenon and neutral hydrogen is a disk phenomenon. The X-ray luminosity (1.5 x 10(exp 40) ergs/s) and radial surface brightness distribution (beta = 0.51) is the same as for elliptical galaxies with optical luminosities and velocity dispersions like that of the bulge of NGC 1291. Modeling of the X-ray spectrum requires a component with a temperature of 0.15 keV, similar to that expected from the velocity dispersion of the stars, and with a hotter component where kT = 1.07 keV. This hotter component is not due to emission from stars and its origin remains unclear. PSPC observations are reported for the SO NGC 4203, where a nuclear point source dominates the emission, preventing a study of the radial distribution of the hot gas relative to the H I.

  4. Physical, electrical, and piezoelectric properties of hot-forged Sr2(NbTa)2O7 ceramics

    Science.gov (United States)

    Fuierer, Paul A.; Shrout, Tom R.; Newnham, Robert E.

    Solid solution compositions of Sr2(nb(x)Ta(1-x))2)7 ceramics with T(sub c) ranging from 450 C to 1342 C were fabricated utilizing a hot-forging technique to achieve preferred grain orientation and thus enhance poling. Translucent samples with greater than 99% theoretical density were obtained using this process. Depending on composition, the degree of orientation as determined by x-ray diffraction was found to be 75% to 95%. The thermal expansion, resistivity, and dielectric constant were shown to be very anisotropic. The direction perpendicular to the forging axis proved to be the ferroelctric `easy' direction, exhibiting hysteresis behavior. Piezoactivity in Perovskite layer structure (PLS) polycrystals was measured for the first time. Hot-forged samples were electrically poled and the electromechanical properties determined using the five different modes of vibration. For Sr(Nb(0.5)Ta(0.5))2O7: N(sub 24) = 1504 Hz-m, s(sub 44) = 18.2 x 10(exp -12) sq m/N, k(sub 24) = 3.0%, d(sub 24) = 2.6 pC/n, g(sub 24) = 6.3 x 10(exp -3) Vm/N, and Q(sub m) = 1100. This material was also shown to resist depoling when exposed to temperatures as high as 650 C.

  5. Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

    Science.gov (United States)

    Glass, David E.

    2008-01-01

    Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

  6. Zircon-Based Ceramic Coatings Formed by a New Multi-Chamber Gas-Dynamic Accelerator

    Directory of Open Access Journals (Sweden)

    Marina Kovaleva

    2017-09-01

    Full Text Available In this work, dense zircon-based ceramic coatings were obtained from inexpensive zircon powder on a steel substrate by using a new multi-chamber gas-dynamic accelerator. The microstructure and phase composition of the coating were characterized by scanning electron microscopy, optical microscopy, and X-ray diffraction. The mechanical properties of the coatings were evaluated using microindentation, wear tests and bonding strength tests. The results showed that the obtained zircon-based ceramic coatings were continuous without cracks and bonded well with substrate without a sublayer. The zircon-based ceramic coatings consisted of c-ZrO2 (major phase, m-ZrO2 and SiO2. The zircon-based ceramic coatings had a porosity of 0.1%, hardness of 526 ± 65 HV0.2, and a fracture toughness of 2.5 ± 0.6 (МPа∙m1/2. The coatings showed the low specific wear rate and average erosion rate. The failure mode occurring in the tested coatings was cohesive.

  7. Hot Isostatic Pressed Gd2O2S:Pr, Ce, F Translucent Scintillator Ceramics for X-Ray Computed Tomography Detectors

    Science.gov (United States)

    Ito, Yukio; Yamada, Hiromichi; Yoshida, Minoru; Fujii, Hideji; Toda, Gyozo; Takeuchi, Hiroshi; Tsukuda, Yasuo

    1988-08-01

    Translucent scintillator ceramics of Gd2O2S:Pr, Ce, F were fabricated using a hot isostatic pressing (HIP) technique. The optical transmission is about 60% of the incident light and the X-ray stopping power is also quite high. Owing to the enhancement of these properties by the HIP densification process, the highest light output from a 1 mm thick specimen combined with a silicon photodiode, when excited by 120 kV X-rays, has reached 1.8 times that of CdWO4 single crystals. The present ceramics are very promising candidates for scintillator materials in X-ray computed tomography (CT) detector applications.

  8. Hot corrosion of TD nickel and TD nickel chromium in a high velocity gas stream.

    Science.gov (United States)

    Sanders, W. A.; Probst, H. B.

    1971-01-01

    Results of cyclical tests of TD nickel (2% thoria-dispersed nickel) and TD nickel chromium (2% thoria-dispersed nickel-20% chromium alloy) 1.5 mm (60 mil) sheet specimens for susceptibility to hot corrosion in a Mach 0.5 gas stream of Jet A-1 fuel combustion products containing 2 ppm sea salt. Tests as long as 500 one-hour cycles between room temperature and specimen hot zone temperatures of 899 C (1650 F), 982 C (1800 F), and 1149 C (2100 F) were performed. Evidence of hot corrosion was found for both materials in the 899 C (1650 F) and 982 C (1800 F) tests, but not at 1149 C (2100 F). It was concluded that because of high metal thickness losses neither alloy in sheet form is suitable for long-time engine application in a hot corrosion environment at temperatures of 982 C (1800 F) or above.

  9. Gas purification by use of hot metal getter beds

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, H.

    1992-11-01

    An experimental program is described which was performed in the frame of a tritium technology task for the NET/ITER fusion fuel cycle. The aim was to investigate commercial gas purifiers containing metallic getters for the purification of gas streams such as the plasma exhaust gas. Five purifiers with up to 3000g of getter material were tested in the PEGASUS facility mainly with respect to the removal of methane, which is known to be much more difficult to remove than other impurities like O{sub 2}, N{sub 2}, or CO. A proposal for a fuel cleanup method based on a combination of getter beds and Pd/Ag diffusors is presented as the main conclusion of the test program. The discussion of this method includes the aspects of flow rates, tritium inventory, and consumption of getter material. (orig.) [Deutsch] Im Rahmen einer Tritium Technology Task fuer den NET/ITER Brennstoff-Kreislauf wurde ein experimentelles Vorhaben durchgefuehrt mit dem Ziel, kommerzielle Gasreiniger, die nach dem Prinzip der Rueckhaltung von Verunreinigungen an heissen Metall-Gettern arbeiten, auf ihre Eignung zur Reinigung von inerten Gasstroemen, wie z.B. dem Plasma Exhaust Gas, zu untersuchen. An der zu diesem Zweck gebauten PEGASUS-Anlage wurden fuenf Gasreiniger mit bis zu 3 kg Gettermaterial eingesetzt, um vor allem die Rueckhaltung von Methan zu bestimmen, das sich wesentlich schwerer abtrennen laesst als etwa O{sub 2}, N{sub 2} oder CO. Als Schlussfolgerung aus dem Versuchsprogramm wird ein Brennstoff-Reinigungsverfahren vorgeschlagen, das aus einer Kombination von Getterbetten und Pd/Ag-Permeatoren besteht. In der Diskussion dieses Verfahrens werden u.a. die Aspekte des Gasdurchsatzes, des Tritium Inventares und des Verbrauchs an Gettermaterial angesprochen. (orig.)

  10. Hot gas flow cell for optical measurements on reactive gases

    DEFF Research Database (Denmark)

    Grosch, Helge; Fateev, Alexander; Nielsen, Karsten Lindorff

    2013-01-01

    was validated for high resolution measurements at temperatures of up to 800 K (527 degrees C) in the ultraviolet (UV) and infrared (IR) regions (190-20 000 nm). Verification of the gas temperature in the cell is provided by a thermocouple and emission/transmission measurements in the IR and UV regions. High......-resolution measurements are presented for the absorption cross-section of sulfur dioxide (SO2) in the UV range up to 773 K (500 degrees C)...

  11. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corp. , Columbus, Ohio. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The Solar Energy System located at the Columbia Gas Corporation, Columbus, Ohio, has 2978 ft/sup 2/ of Honeywell single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/h Bryan water-tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton Arkla hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts are included from the site files, specification references, drawings, installation, operation and maintenance instructions.

  12. Injection of Ballistic Hot Electrons and Cool Holes in a Two-Dimensional Electron Gas

    NARCIS (Netherlands)

    Williamson, J.G.; Houten, H. van; Beenakker, C.W.J.; Broekaart, M.E.I.; Spendeler, L.I.A.; Wees, B.J. van; Foxon, C.T.

    1990-01-01

    We have constructed a novel magnetic spectrometer to study the dynamics of hot electrons and cool missing electron states injected by quantum point contacts in the two-dimensional electron gas of a GaAs-AlxGa1-xAs heterostructure. The mean free path of these quasi-particles is found to be longer

  13. A Simple, Hot N2-Gas TL Reader Incorporating a Post-Irradiation Annealing Facility

    DEFF Research Database (Denmark)

    Bøtter-Jensen, Lars

    1978-01-01

    A simple “do-it-yourself” TL reader is outlined. It is based on a hot nitrogen gas heating technique that has been routinely used at Risø for several years and thus intensively investigated. A description is given of the complete TL read-out system including electronic circuit diagrams of the most...

  14. Constraining supernova models using the hot gas in clusters of galaxies

    NARCIS (Netherlands)

    de Plaa, J.; Werner, N.; Bleeker, J.A.M.; Vink, J.; Kaastra, J.S.; Mendes, M.

    2009-01-01

    Context: The hot X-ray emitting gas in clusters of galaxies is a very large repository of metals produced by supernovae. During the evolution of clusters, billions of supernovae eject their material into this Intra-Cluster Medium (ICM). Aims: We aim to accurately measure the abundances in the ICM of

  15. HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Sell, D. A.; Baily, C. E.; Malewitz, T. J.; Medvedev, P. G.; Porter, D. L.; Hilton, B. A.

    2016-09-01

    A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium after the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.

  16. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in

  17. Oxidation Characterization of Hafnium-Based Ceramics Fabricated by Hot Pressing and Electric Field-Assisted Sintering

    Science.gov (United States)

    Gasch, Matt; Johnson, Sylvia; Marschall, Jochen

    2010-01-01

    Ceramic borides, such as hafnium diboride (HfB2) and zirconium diboride (ZrB2), are members of a family of materials with extremely high melting temperatures referred to as Ultra High Temperature Ceramics (UHTCs). UHTCs constitute a class of promising materials for use in high temperature applications, such as sharp leading edges on future-generation hypersonic flight vehicles, because of their high melting points. The controlled development of microstructure has become important to the processing of UHTCs, with the prospect of improving their mechanical and thermal properties. The improved oxidation resistance of HfB2 has also become important if this material is to be successfully used at temperatures above 2000 C. Furthermore, the use of UHTCs on the leading edges of vehicles traveling at hypersonic speeds will mean exposure to a mixed oxidation environment comprised of both molecular and atomic oxygen. The current study has investigated the high-temperature oxidation behavior of HfB2-based materials in a pure O2 environment, as well as in environments containing different levels of dissociated oxygen (O/O2). Materials were processed by two techniques: conventional hot pressing (HP) and electric field-assisted sintering (FAS). Their oxidation behavior was evaluated in both a tube furnace at 1250 C for 3 hours and in a simulated re-entry environment in the Advanced Heating Facility (AHF) arcjet at NASA Ames Research Center, during a 10-minute exposure to a cold wall heat flux of 250W/sq cm and stagnation pressure of 0.1-0.2 atm. The microstructure of the different materials was characterized before and after oxidation using scanning electron microscopy (SEM).

  18. Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, July 1--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/Pressurized Circulating Fluidized Bed Gas Source; hot Gas Cleanup Units to mate to all gas streams; and Combustion Gas Turbine. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF).

  19. Technology of off-gas treatment for liquid-fed ceramic melters

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.A.; Goles, R.W.; Peters, R.D.

    1985-05-01

    The technology for treating off gas from liquid-fed ceramic melters (LFCMs) has been under development at the Pacific Northwest Laboratory since 1977. This report presents the off-gas technology as developed at PNL and by others to establish a benchmark of development and to identify technical issues. Tests conducted on simulated (nonradioactive) wastes have provided data that allow estimation of melter off-gas composition for a given waste. Mechanisms controlling volatilization of radionuclides and noxious gases are postulated, and correlations between melter operation and emissions are presented. This report is directed to those familiar with LFCM operation. Off-gas treatment systems always require primary quench scrubbers, aerosol scrubbers, and final particulate filters. Depending on the composition of the off gas, equipment for removal of ruthenium, iodine, tritium, and noxious gases may also be needed. Nitrogen oxides are the most common noxious gases requiring treatment, and can be controlled by aqueous absorption or catalytic conversion with ammonia. High efficiency particulate air (HEPA) filters should be used for final filtration. The design criteria needed for an off-gas system can be derived from emission regulations and composition of the melter feed. Conservative values for melter off-gas composition can be specified by statistical treatment of reported off-gas data. Statistical evaluation can also be used to predict the frequency and magnitude of normal surge events that occur in the melter. 44 refs., 28 figs., 17 tabs.

  20. Novel Gas Barrier SiOC Coating to PET Bottles through a Hot Wire CVD Method

    Directory of Open Access Journals (Sweden)

    Masaki Nakaya

    2016-01-01

    Full Text Available In an attempt to enhance the gas barrier enhancement of plastic containers such as poly(ethylene terephthalate bottles, a novel method was found using a hot wire CVD technique, where tantalum wire is heated and exposed to a gas flow of vinyl silane. The resultant SiOC thin film was confirmed to characteristically contain Si-Si bonds in its surface and demonstrate a remarkably and highly practical decrease of the permeation of various gas through poly(ethylene terephthalate bottles.

  1. Influence of heat exchange of reservoir with rocks on hot gas injection via a single well

    Science.gov (United States)

    Nikolaev, Vladimir E.; Ivanov, Gavril I.

    2017-11-01

    In the computational experiment the influence of heat exchange through top and bottom of the gas-bearing reservoir on the dynamics of temperature and pressure fields during hot gas injection via a single well is investigated. The experiment was carried out within the framework of modified mathematical model of non-isothermal real gas filtration, obtained from the energy and mass conservation laws and the Darcy law. The physical and caloric equations of state together with the Newton-Riemann law of heat exchange of gas reservoir with surrounding rocks, are used as closing relations. It is shown that the influence of the heat exchange with environment on temperature field of the gas-bearing reservoir is localized in a narrow zone near its top and bottom, though the size of this zone is increased with time.

  2. Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Corman; Krishan Luthra; Jill Jonkowski; Joseph Mavec; Paul Bakke; Debbie Haught; Merrill Smith

    2011-01-07

    This report covers work performed under the Advanced Materials for Advanced Industrial Gas Turbines (AMAIGT) program by GE Global Research and its collaborators from 2000 through 2010. A first stage shroud for a 7FA-class gas turbine engine utilizing HiPerComp{reg_sign}* ceramic matrix composite (CMC) material was developed. The design, fabrication, rig testing and engine testing of this shroud system are described. Through two field engine tests, the latter of which is still in progress at a Jacksonville Electric Authority generating station, the robustness of the CMC material and the shroud system in general were demonstrated, with shrouds having accumulated nearly 7,000 hours of field engine testing at the conclusion of the program. During the latter test the engine performance benefits from utilizing CMC shrouds were verified. Similar development of a CMC combustor liner design for a 7FA-class engine is also described. The feasibility of using the HiPerComp{reg_sign} CMC material for combustor liner applications was demonstrated in a Solar Turbines Ceramic Stationary Gas Turbine (CSGT) engine test where the liner performed without incident for 12,822 hours. The deposition processes for applying environmental barrier coatings to the CMC components were also developed, and the performance of the coatings in the rig and engine tests is described.

  3. Highly sensitive room temperature ammonia gas sensor based on Ir-doped Pt porous ceramic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenlong [College of pharmacy and biological engineering, Chengdu University, Chengdu, 610106 (China); Department of chemical and materials engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan (China); Liu, Yen-Yu [Department of chemical and materials engineering, Tunghai University, Taichung 407, Taiwan (China); Do, Jing-Shan, E-mail: jsdo@ncut.edu.tw [Department of chemical and materials engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan (China); Li, Jing, E-mail: lijing@cdu.edu.cn [College of pharmacy and biological engineering, Chengdu University, Chengdu, 610106 (China)

    2016-12-30

    Highlights: • Water vapors seem to hugely improve the electrochemical activity of the Pt and Pt-Ir porous ceramic electrodes. • The gas sensors based on the Pt and Pt-Ir alloy electrodes possess good sensing performances. • The reaction path of the ammonia on platinum has been discussed. - Abstract: Room temperature NH{sub 3} gas sensors based on Pt and Pt-Ir (Ir doping Pt) porous ceramic electrodes have been fabricated by both electroplating and sputtering methods. The properties of the gaseous ammonia sensors have been examined by polarization and chronoamperometry techniques. The influence of humidity on the features of the resulting sensors in the system has also been discussed, and the working potential was optimized. Water vapors seem to hugely improve the electrochemical activity of the electrode. With increasing the relative humidity, the response of the Pt-Ir(E)/Pt(S)/PCP sensor to NH{sub 3} gas could be enhanced remarkably, and the sensitivity increases from 1.14 to 12.06 μA ppm{sup −1} cm{sup −2} .Then we have also discussed the sensing mechanism of the Pt-Ir sensor and the result has been confirmed by X-ray photoelectron spectroscopy of the electrode surface before and after reaction in the end.

  4. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  5. Characteristics of hot-pressed fiber-reinforced ceramics with SiC matrix

    Science.gov (United States)

    Miyoshi, Tadahiko; Kodama, Hironori; Sakamoto, Hiroshi; Goto, Akihiro; Iijima, Shiroo

    1989-11-01

    Silicon carbide ceramics’ matrix composites with SiC or C filaments were fabricated through hot pressing, and the effects of the filament pullout on their fracture toughness were experimentally investigated. The C-rich coating layers on the SiC filaments were found to have a significant effect on the frictional stress at the filament/matrix interfaces, through assising the filamet pullout from the matrix. Although the coating layers were apt to burn out in the sintering process of SiC matrix compposites, a small addition of carbon to the raw materials was found to be effective for the retention of the layers on the fibers, thus increasing the fracture toughness of the composites. The fracture toughness of the C filament/SiC matrix composite increased with temperature due to the larger interfacial frictional stress at higher temperatures, because of the higher thermal expansion of the filament in the radial direction than that of the matrix.

  6. High temperature alkali corrosion of ceramics in coal gas: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, G.R.; Sun, T.; Brown, J.J. Jr.

    1994-12-31

    There are several ceramic materials which are currently being considered for use as structural elements in coal combustion and coal conversion systems because of their thermal and mechanical properties. These include alumina (refractories, membranes, heat engines); silicon carbide and silicon nitride (turbine engines, internal combustion engines, heat exchangers, particulate filters); zirconia (internal combustion engines, turbine engines, refractories); and mullite and cordierite (particulate filters, refractories, heat exchangers). High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and high efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, and zirconia. The study consists of identification of the alkali reaction products and determination of the kinetics of the alkali reactions as a function of temperature and time. 145 refs., 29 figs., 12 tabs.

  7. Marginal gap, internal fit, and fracture load of leucite-reinforced ceramic inlays fabricated by CEREC inLab and hot-pressed techniques.

    Science.gov (United States)

    Keshvad, Alireza; Hooshmand, Tabassom; Asefzadeh, Farokh; Khalilinejad, Foroogh; Alihemmati, Mohammad; Van Noort, Richard

    2011-10-01

    This in vitro study was designed to evaluate and compare the marginal gap, internal fit, and fracture load of resin-bonded, leucite-reinforced glass ceramic mesio-occlusal-distal (MOD) inlays fabricated by computer-aided design/manufacturing (CAD/CAM) or hot pressing. Fifty caries-free extracted human molars were prepared for standardized MOD inlays. Impressions of each specimen were made and poured using type IV dental stone. Dies were randomly divided into two equal groups. Twenty-five ceramic inlays were fabricated by the hot-pressed technique using IPS Empress leucite-reinforced glass ceramics, and the other 25 ceramic inlays were produced by CAD/CAM technology using ProCAD leucite-reinforced ceramic blocks and CEREC inLab facilities. Inlays were bonded to the teeth using a dual-cured resin cement. The specimens were stored in distilled water at 37°C for 24 hours and then thermocycled for 5000 cycles. The marginal gap measurements were taken with a stereomicroscope. Specimens in each group of inlay systems were randomly divided into two subgroups of 10 and 15 specimens each. Ten specimens in each subgroup were sectioned mesiodistally for evaluation of the internal fit. The fracture load of specimens in the second subgroup (n = 15) of the two inlay systems was determined under compressive load in a universal testing machine. Data were analyzed using Student's t-test at a significance level of p internal gap size in both IPS Empress and ProCAD inlays were less than 100 μm; however, the marginal gap for the IPS Empress restorations was significantly higher than that of ProCAD restorations (p internal fit or the fracture load between the two glass ceramic inlays (p > 0.05). The leucite-reinforced glass ceramic inlay restorations fabricated by CEREC inLab (CAD/CAM) and the hot-pressed technique provided clinically acceptable marginal and internal fit with comparable fracture loads after luting. © 2011 by The American College of Prosthodontists.

  8. Influence of gas pressure on the effective thermal conductivity of ceramic breeder pebble beds

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Weijing [School of Civil Engineering, The University of Sydney, Sydney (Australia); Pupeschi, Simone [Institute for Applied Materials, Karlsruhe Institute of Technology (KIT) (Germany); Hanaor, Dorian [School of Civil Engineering, The University of Sydney, Sydney (Australia); Institute for Materials Science and Technologies, Technical University of Berlin (Germany); Gan, Yixiang, E-mail: yixiang.gan@sydney.edu.au [School of Civil Engineering, The University of Sydney, Sydney (Australia)

    2017-05-15

    Highlights: • This study explicitly demonstrates the influence of the gas pressure on the effective thermal conductivity of pebble beds. • The gas pressure influence is shown to correlated to the pebble size. • The effective thermal conductivity is linked to thermal-mechanical properties of pebbles and packing structure. - Abstract: Lithium ceramics have been considered as tritium breeder materials in many proposed designs of fusion breeding blankets. Heat generated in breeder pebble beds due to nuclear breeding reaction must be removed by means of actively cooled plates while generated tritiums is recovered by purge gas slowly flowing through beds. Therefore, the effective thermal conductivity of pebble beds that is one of the governing parameters determining heat transport phenomenon needs to be addressed with respect to mechanical status of beds and purge gas pressure. In this study, a numerical framework combining finite element simulation and a semi-empirical correlation of gas gap conduction is proposed to predict the effective thermal conductivity. The purge gas pressure is found to vary the effective thermal conductivity, in particular with the presence of various sized gaps in pebble beds. Random packing of pebble beds is taken into account by an approximated correlation considering the packing factor and coordination number of pebble beds. The model prediction is compared with experimental observation from different sources showing a quantitative agreement with the measurement.

  9. Fabrication of ceramic membrane tubes for direct conversion of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Morissette, S.L.; Picciolo, J.J.; Dusek, J.T.; Poeppel, R.B. [Argonne National Lab., IL (United States); Pei, S.; Kleefisch, M.S.; Mieville, R.L.; Kobylinski, T.P.; Udovich, C.A. [Amoco Research Center, Naperville, IL (United States)

    1992-05-01

    Several perovskite-type oxides that contain transition metals on the B-site show mixed (electronic/ionic) conductivity. These mixed conducting oxides are promising materials for oxygen permeating membranes that can operate without the need of electrodes or external electrical circuitry. SrCo{sub 0.8}Fe{sub 0.2}O{sub x} perovskite is known to exhibit very high oxygen permeabilities and one could use this material for producing value added products by direct conversion of methane, the most abundant component of natural gas. This paper deals with the processing and fabrication by plastic extrusion of long lengths ({approx}30 cm) of hollow SrCo{sub 0.8}Fe{sub 0.2}O{sub x} ceramic tubes. These tubes are characterized by scanning electron microscopy, X-ray diffraction (XRD) and their thermodynamic stability is evaluated using room temperature XRD on samples equilibrated at high temperatures in different gas environment.

  10. Thermal cyclic durability testing of ceramic materials for turbine engines

    Science.gov (United States)

    Lindberg, L. J.

    1986-01-01

    The thermal cyclic durability of commercial ceramic materials for turbine engines was under evaluation since 1978. Ceramic materials are exposed to cyclic diesel-fired burner exhaust at either 1204 or 1371 C (2200 or 2500 F) for up to 3500 hours. The test conditions are selected to simulate the environment experienced by the hot flow path components in an automotive gas turbine engine. The silicon nitride and silicon carbide materials tested are the same ceramic materials currently used on the AGT100 and AGT101 ceramic turbine engine program.

  11. Investigating the Potential Dilution of the Metal Content of Hot Gas in Early-Type Galaxies by Accreted Cold Gas

    OpenAIRE

    Su, Yuanyuan; Irwin, Jimmy

    2013-01-01

    The measured emission-weighted metal abundance of the hot gas in early-type galaxies has been known to be lower than theoretical expectations for 20 years. In addition, both X-ray luminosity and metal abundance vary significantly among galaxies of similar optical luminosities. This suggests some missing factors in the galaxy evolution process, especially the metal enrichment process. With {\\it Chandra} and {\\it XMM-Newton}, we studied 32 early-type galaxies (kT $\\lesssim$ 1 keV) covering a sp...

  12. The Thermochemical Degradation of Hot Section Materials for Gas Turbine Engines in Alternative-Fuel Combustion Environments

    Science.gov (United States)

    Montalbano, Timothy

    Gas turbine engines remain an integral part of providing the world's propulsion and power generation needs. The continued use of gas turbines requires increased temperature operation to reach higher efficiencies and the implementation of alternative fuels for a lower net-carbon footprint. This necessitates evaluation of the material coatings used to shield the hot section components of gas turbines in these new extreme environments in order to understand how material degradation mechanisms change. Recently, the US Navy has sought to reduce its use of fossil fuels by implementing a blended hydroprocessed renewable diesel (HRD) derived from algae in its fleet. To evaluate the material degradation in this alternative environment, metal alloys are exposed in a simulated combustion environment using this blended fuel or the traditional diesel-like fuel. Evaluation of the metal alloys showed the development of thick, porous scales with a large depletion of aluminum for the blend fuel test. A mechanism linking an increased solubility of the scale to the blend fuel test environment will be discussed. For power generation applications, Integrated Gasification Combined Cycle (IGCC) power plants can provide electricity with 45% efficiency and full carbon capture by using a synthetic gas (syngas) derived from coal, biomass, or another carbon feedstock. However, the combustion of syngas is known to cause high water vapor content levels in the exhaust stream with unknown material consequences. To evaluate the effect of increased humidity, air-plasma sprayed (APS), yttria-stabilized zirconia (YSZ) is thermally aged in an environment with and without humidity. An enhanced destabilization of the parent phase by humid aging is revealed by x-ray diffraction (XRD) and Raman spectroscopy. Microstructural analysis by transmission electron microscopy (TEM) and scanning-TEM (STEM) indicate an enhanced coarsening of the domain structure of the YSZ in the humid environment. The enhanced

  13. Hot-gas cleanup system model development. Volume I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ushimaru, K.; Bennett, A.; Bekowies, P.J.

    1982-11-01

    This two-volume report summarizes the state of the art in performance modeling of advanced high-temperature, high-pressure (HTHP) gas cleanup devices. Volume I contains the culmination of the research effort carried over the past 12 months and is a summary of research achievements. Volume II is the user's manual for the computer programs developed under the present research project. In this volume, Section 2 presents background information on pressurized, fluidized-bed combustion concepts, a description of the role of the advanced gas cleanup systems, and a list of advanced gas cleanup systems that are currently in development under DOE sponsorship. Section 3 describes the methodology for the software architecture that forms the basis of the well-disciplined and structured computer programs developed under the present project. Section 4 reviews the fundamental theories that are important in analyzing the cleanup performance of HTHP gas filters. Section 5 discusses the effect of alkali agents in HTHP gas cleanup. Section 6 evaluates the advanced HTHP gas cleanup models based on their mathematical integrity, availability of supporting data, and the likelihood of commercialization. As a result of the evaluation procedure detailed in Section 6, five performance models were chosen to be incorporated into the overall system simulation code, ASPEN. These five models (the electrocyclone, ceramic bag filter, moving granular bed filter, electrostatic granular bed filter, and electrostatic precipitator) are described in Section 7. The method of cost projection for these five models is discussed in Section 8. The supporting data and validation of the computer codes are presented in Section 9, and finally the conclusions and recommendations for the HTHP gas cleanup system model development are given in Section 10. 72 references, 19 figures, 25 tables.

  14. Hot surface assisted compression ignition in a direct injection natural gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Aesoey, Vilmar

    1996-12-31

    This study investigates the problem of ignition in a direct injection natural gas engine. Due to poor auto-ignition properties of natural gas compared to regular diesel engine fuels, a special arrangement to assist and secure ignition is required. The objective was to investigate the feasibility of using a hot surface as ignition assistance, primarily for application in medium and large size engines, and further study the main mechanisms involved in the ignition process. A constant volume combustion bomb and a test engine are used for experiments, supported by theoretical analysis and numerical simulations. Variable composition of natural gas depending on the gas source and over time, is a important problem causing significant variation in ignition properties. It is shown that even small quantities of non-methane components, which are normally present in natural gases, strongly influence ignition. Actions to handle the ignition problem caused by variable natural composition, are also discussed. In order to estimate the ignition properties of natural gas, a simple correlation to gas composition is proposed, showing good correlation to the experimental data. Mathematical models for simulation of the processes are developed based on fundamental physical relations and experimental results. They are mainly used in this study to support and analyze the physical experiments, but can also be useful in future design and optimization processes. 71 refs., 80 figs., 6 tabs.

  15. Microstructure, hardness, corrosion resistance and porcelain shear bond strength comparison between cast and hot pressed CoCrMo alloy for metal-ceramic dental restorations.

    Science.gov (United States)

    Henriques, B; Soares, D; Silva, F S

    2012-08-01

    The purpose of this study was to compare the microstructure, hardness, corrosion resistance and metal-porcelain bond strength of a CoCrMo dental alloy obtained by two routes, cast and hot pressing. CoCrMo alloy substrates were obtained by casting and hot pressing. Substrates' microstructure was examined by the means of Optical Microscopy (OM) and by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). Hardness tests were performed in a microhardness indenter. The electrochemical behavior of substrates was investigated through potentiodynamic tests in a saline solution (8g NaCl/L). Substrates were bonded to dental porcelain and metal-porcelain bond strength was assessed by the means of a shear test performed in a universal test machine (crosshead speed: 0.5 mm/min) until fracture. Fractured surfaces as well as undestroyed interface specimens were examined with Stereomicroscopy and SEM-EDS. Data was analyzed with Shapiro-Wilk test to test the assumption of normality. The t-test (pbond strength results. Cast specimens exhibited dendritic microstructures whereas hot pressed specimens exhibited a typical globular microstructure with a second phase spread through the matrix. The hardness registered for hot pressed substrates was greater than that of cast specimens, 438±24HV/1 and 324±8HV/1, respectively. Hot pressed substrates showed better corrosion properties than cast ones, i.e. higher OCP; higher corrosion potential (E(corr)) and lower current densities (i(corr)). No significant difference was found (pbond strength between cast (116.5±6.9 MPa) and hot pressed (114.2±11.9 MPa) substrates. The failure type analysis revealed an adhesive failure for all specimens. Hot pressed products arise as an alternative to cast products in dental prosthetics, as they impart enhanced mechanical and electrochemical properties to prostheses without compromising the metal-ceramic bond strength. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Effect of Additions of Ceramic Nanoparticles and Gas-Dynamic Treatment on Al Casting Alloys

    Directory of Open Access Journals (Sweden)

    Konstantin Borodianskiy

    2015-12-01

    Full Text Available In recent years, improving the mechanical properties of metals has become the main challenge in the modern materials and metallurgical industry. An alloying process is usually used to achieve advanced performance of metals. This paper, however, describes an alternative approach. Modification with ceramic nanoparticles, gas-dynamic treatment (GDT and a combined treatment were investigated on a hypoeutectic Al-Si A356 alloy. Microstructural studies revealed the refinement of coarse α-Al grains and the formation of distributed eutectic Si particles. Subsequent testing of the mechanical properties revealed improvement after applying each of the treatments. The best results were obtained after modification with TiCN nanoparticles followed by GDT; the tensile strength and elongation of the A356 alloys increased by 18% and 19%, respectively.

  17. Non-intrusive measurement of hot gas temperature in a gas turbine engine

    Science.gov (United States)

    DeSilva, Upul P.; Claussen, Heiko; Yan, Michelle Xiaohong; Rosca, Justinian; Ulerich, Nancy H.

    2016-09-27

    A method and apparatus for operating a gas turbine engine including determining a temperature of a working gas at a predetermined axial location within the engine. An acoustic signal is encoded with a distinct signature defined by a set of predetermined frequencies transmitted as a non-broadband signal. Acoustic signals are transmitted from an acoustic transmitter located at a predetermined axial location along the flow path of the gas turbine engine. A received signal is compared to one or more transmitted signals to identify a similarity of the received signal to a transmitted signal to identify a transmission time for the received signal. A time-of-flight is determined for the signal and the time-of-flight for the signal is processed to determine a temperature in a region of the predetermined axial location.

  18. Hot gas path component cooling system having a particle collection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Carlos Miguel; Lacy, Benjamin Paul

    2018-02-20

    A cooling system for a hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface defines at least one interior space. A passage is formed in the substrate between the outer surface and the inner surface. An access passage is formed in the substrate and extends from the outer surface to the inner space. The access passage is formed at a first acute angle to the passage and includes a particle collection chamber. The access passage is configured to channel a cooling fluid to the passage. Furthermore, the passage is configured to channel the cooling fluid therethrough to cool the substrate.

  19. Tree Coring as a Complement to Soil Gas Screening to Locate PCE and TCE Source Zones and Hot Spots

    DEFF Research Database (Denmark)

    Nielsen, Mette Algreen; Trapp, Stefan; Rehne Jensen, Pernille

    2015-01-01

    ) or trichloroethylene (TCE) to evaluate their ability to locate source zones and contaminant hot spots. One test site represented a relatively homogeneous sandy soil and aquifer, and the second a more heterogeneous geology with both sandy and less permeable clay till layers overlying a chalk aquifer. Tree cores from...... different tree species were sampled and analysed, and compared to soil gas measurements and existing soil gas data. Both methods were found useful as screening tools to locate hot spots of PCE and TCE in the shallow subsurface. Tree coring was found to be particularly beneficial as a complement to soil gas...... the feasibility of using tree coring to locate the hot spots. Moreover, a combination of the two methods can help to focus any subsequent investigations like soil or groundwater sampling. The use of tree coring to complement soil gas sampling for pre-screening is expected to result in higher certainty...

  20. Screening of granular sorbents for the removal of gaseous alkali metal compounds from hot flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Swift, W.M.; Johnson, I.

    1979-11-01

    Six commercially available sorbent materials have been tested as granular sorbents to be used in granular-bed filters for the removal of gaseous alkali metal compounds from the hot (800 to 880/sup 0/C) flue gas of pressurized fluidized-bed combustors (PFBC) for proposed combined-cycle power generation. Tests were performed by passing simulated relatively dry flue gas of PFBC through granular-bed filters in either a laboratory-scale, fixed-bed combustor or a high temperature sorption test rig. The experimental results of screening tests are presented. Diatomaceous earth and activated bauxite were found to be the two most promising sorbents. Possible sorption mechanisms and applications of the sorbents are discussed. 3 figures, 7 tables.

  1. DEVELOPMENT OF NOVEL CERAMIC NANOFILM-FIBER INTEGRATED OPTICAL SENSORS FOR RAPID DETECTION OF COAL DERIVED SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Junhang Dong; Hai Xiao; Xiling Tang; Hongmin Jiang; Kurtis Remmel; Amardeep Kaur

    2012-09-30

    The overall goal of this project is to conduct fundamental studies on advanced ceramic materials and fiber optic devices for developing new types of high temperature (>500{degree}C) fiber optic chemical sensors (FOCS) for monitoring fossil (mainly coal) and biomass derived gases in power plants. The primary technical objective is to investigate and demonstrate the nanocrystalline doped-ceramic thin film enabled FOCS that possess desired stability, sensitivity and selectivity for in-situ, rapid gas detection in the syngas streams from gasification and combustion flue gases. This report summarizes research works of two integrated parts: (1) development of metal oxide solid thin films as sensing materials for detection and measurement of important gas components relevant to the coal- and biomass-derived syngas and combustion gas streams at high temperatures; and (2) development of fiber optic devices that are potentially useful for constructing FOCS in combination with the solid oxide thin films identified in this program.

  2. The scatter and evolution of the global hot gas properties of simulated galaxy cluster populations

    Science.gov (United States)

    Le Brun, Amandine M. C.; McCarthy, Ian G.; Schaye, Joop; Ponman, Trevor J.

    2017-04-01

    We use the cosmo-OverWhelmingly Large Simulation (cosmo-OWLS) suite of cosmological hydrodynamical simulations to investigate the scatter and evolution of the global hot gas properties of large simulated populations of galaxy groups and clusters. Our aim is to compare the predictions of different physical models and to explore the extent to which commonly adopted assumptions in observational analyses (e.g. self-similar evolution) are violated. We examine the relations between (true) halo mass and the X-ray temperature, X-ray luminosity, gas mass, Sunyaev-Zel'dovich (SZ) flux, the X-ray analogue of the SZ flux (YX) and the hydrostatic mass. For the most realistic models, which include active galactic nuclei (AGN) feedback, the slopes of the various mass-observable relations deviate substantially from the self-similar ones, particularly at late times and for low-mass clusters. The amplitude of the mass-temperature relation shows negative evolution with respect to the self-similar prediction (i.e. slower than the prediction) for all models, driven by an increase in non-thermal pressure support at higher redshifts. The AGN models predict strong positive evolution of the gas mass fractions at low halo masses. The SZ flux and YX show positive evolution with respect to self-similarity at low mass but negative evolution at high mass. The scatter about the relations is well approximated by log-normal distributions, with widths that depend mildly on halo mass. The scatter decreases significantly with increasing redshift. The exception is the hydrostatic mass-halo mass relation, for which the scatter increases with redshift. Finally, we discuss the relative merits of various hot gas-based mass proxies.

  3. Integrated operation of a pressurized fixed-bed gasifier, hot gas desulfurization system, and turbine simulator

    Energy Technology Data Exchange (ETDEWEB)

    Bevan, S.; Ayala, R.E.; Feitelberg, A.; Furman, A.

    1995-11-01

    The overall objective of the General Electric Hot Gas Cleanup (HGCU) Program is to develop a commercially viable technology to remove sulfur, particulates, and halogens from a high-temperature fuel gas stream using a moving bed, regenerable mixed metal oxide sorbent based process. The HGCU Program is based on the design and demonstration of the HGCU system in a test facility made up of a pilot-scale fixed bed gasifier, a HGCU system, and a turbine simulator in Schenectady, NY, at the General Electric Research and Development Center. The objectives of the turbine simulator testing are (1) to demonstrate the suitability of fuel gas processed by the HGCU system for use in state-of-the-art gas turbines firing at 2,350 F rotor inlet temperature and (2) to quantify the combustion characteristics and emissions on low-Btu fuel gas. The turbine simulator program also includes the development and operation of experimental combustors based on the rich-quench-lean concept (RQL) to minimize the conversion of ammonia and other fuel-bound nitrogen species to NO{sub x} during combustion. The HGCU system and turbine simulator have been designed to process approximately 8,000 lb/hr of low heating value fuel gas produced by the GE fixed bed gasifier. The HGCU system has utilized several mixed metal oxide sorbents, including zinc ferrite, zinc titanate, and Z-Sorb, with the objective of demonstrating good sulfur removal and mechanical attrition resistance as well as economic cost characteristics. Demonstration of halogen removal and the characterization of alkali and trace metal concentrations in the fuel gas are subordinate objectives of the overall program. This report describes the results of several long-duration pilot tests.

  4. Process simulation and experimental validation of Hot Metal Gas Forming with new press hardening steels

    Science.gov (United States)

    Paul, A.; Reuther, F.; Neumann, S.; Albert, A.; Landgrebe, D.

    2017-09-01

    One field in the work of the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz is industry applied research in Hot Metal Gas Forming, combined with press hardening in one process step. In this paper the results of investigations on new press hardening steels from SSAB AB (Docol®1800 Bor and Docol®2000 Bor) are presented. Hot tensile tests recorded by the project partner (University of West Bohemia, Faculty of Mechanical Engineering) were used to create a material model for thermo-mechanical forming simulations. For this purpose the provided raw data were converted into flow curve approximations of the real stress-real strain-curves for both materials and afterwards integrated in a LS-DYNA simulation model of Hot Metal Gas Forming with all relevant boundary conditions and sub-stages. Preliminary experimental tests were carried out using a tool at room temperature to permit evaluation of the forming behaviour of Docol 1800 Bor and Docol 2000 Bor tubes as well as validation of the simulation model. Using this demonstrator geometry (outer diameter 57 mm, tube length 300 mm, wall thickness 1.5 mm), the intention was to perform a series of tests with different furnace temperatures (from 870 °C to 1035 °C), maximum internal pressures (up to 67 MPa) and pressure build-up rates (up to 40 MPa/s) to evaluate the formability of Docol 1800 Bor and Docol 2000 Bor. Selected demonstrator parts produced in that way were subsequently analysed by wall thickness and hardness measurements. The tests were carried out using the completely modernized Dunkes/AP&T HS3-1500 hydroforming press at the Fraunhofer IWU. In summary, creating a consistent simulation model with all relevant sub-stages was successfully established in LS-DYNA. The computation results show a high correlation with the experimental data regarding the thinning behaviour. The Hot Metal Gas Forming of the demonstrator geometry was successfully established as well. Different hardness values

  5. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W.

    1996-06-01

    The objective of the research is to provide databases and design criteria to assist in the selection of optimum alloys for construction of components needed to contain process streams in advanced heat recovery and hot-gas cleanup systems. Typical components include: steam line piping and superheater tubing for low emission boilers (600 to 700{degrees}C), heat exchanger tubing for advanced steam cycles and topping cycle systems (650 to 800{degrees}C), foil materials for recuperators, on advanced turbine systems (700 to 750{degrees}C), and tubesheets for barrier filters, liners for piping, cyclones, and blowback system tubing for hot-gas cleanup systems (850 to 1000{degrees}C). The materials being examined fall into several classes, depending on which of the advanced heat recovery concepts is of concern. These classes include martensitic steels for service to 650{degrees}C, lean stainless steels and modified 25Cr-30Ni steels for service to 700{degrees}C, modified 25Cr-20Ni steels for service to 900{degrees}C, and high Ni-Cr-Fe or Ni-Cr-Co-Fe alloys for service to 1000{degrees}C.

  6. Weldability Characteristics of Sintered Hot-Forged AISI 4135 Steel Produced through P/M Route by Using Pulsed Current Gas Tungsten Arc Welding

    Science.gov (United States)

    Joseph, Joby; Muthukumaran, S.; Pandey, K. S.

    2016-01-01

    Present investigation is an attempt to study the weldability characteristics of sintered hot-forged plates of AISI 4135 steel produced through powder metallurgy (P/M) route using matching filler materials of ER80S B2. Compacts of homogeneously blended elemental powders corresponding to the above steel were prepared on a universal testing machine (UTM) by taking pre-weighed powder blend with a suitable die, punch and bottom insert assembly. Indigenously developed ceramic coating was applied on the entire surface of the compacts in order to protect them from oxidation during sintering. Sintered preforms were hot forged to flat, approximately rectangular plates, welded by pulsed current gas tungsten arc welding (PCGTAW) processes with aforementioned filler materials. Microstructural, tensile and hardness evaluations revealed that PCGTAW process with low heat input could produce weldments of good quality with almost nil defects. It was established that PCGTAW joints possess improved tensile properties compared to the base metal and it was mainly attributed to lower heat input, resulting in finer fusion zone grains and higher fusion zone hardness. Thus, the present investigation opens a new and demanding field in research.

  7. Probing the Hot X-Ray Gas in the Narrow-line Region of Mrk 3

    Science.gov (United States)

    Bogdán, Ákos; Kraft, Ralph P.; Evans, Daniel A.; Andrade-Santos, Felipe; Forman, William R.

    2017-10-01

    We study the prototypical Seyfert 2 galaxy, Markarian 3, based on imaging and high-resolution spectroscopy observations taken by Chandra. We construct a deconvolved X-ray image, which reveals the S-shaped morphology of the hot gas in the narrow-line region (NLR). While this morphology is similar to the radio and [O iii] emission, the distribution of the X-ray gas is broader than that obtained at these other wavelengths. By mapping the density and temperature distribution of the hot gas in the NLR, we demonstrate the presence of shocks toward the west (M={2.5}-0.6+1.0) and east (M={1.5}-0.5+1.0). Moreover, we compute the flux ratios between the [O iii] and 0.5-2 keV band X-ray luminosity and show that it is nonuniform in the NLR, with the western side of the NLR being more highly ionized. In addition, based on the Chandra grating data, we investigate the line ratios of the Si xiii triplet, which are not consistent with pure photoionization. Based on these results, we suggest that in the NLR of Mrk 3 both photoionization and collisional ionization act as excitation mechanisms. We conclude that the canonical picture, in which photoionization is solely responsible for exciting the interstellar medium in the NLR of Seyfert galaxies, may be overly simplistic. Given that weak and small-scale radio jets are commonly detected in Seyfert galaxies, it is possible that shock heating plays a non-negligible role in the NLR of these galaxies.

  8. Natural gas perspectives of diffusion on the brazilian structural ceramics industry; Perspectivas de difusao do gas natural na industria brasileira de ceramica vermelha

    Energy Technology Data Exchange (ETDEWEB)

    Schwob, Marcelo Rousseau Valenca

    2007-03-15

    This study evaluates the perspectives of the natural gas (NG) used by the Brazilian structural ceramics industry (BSCI), according to technological, economic and environmental aspects. It identifies the advantages of using NG, as well as the barriers faced by this energy source. Considering the amount of NG required by the thermal demand of the BSCI processes and the average energy specific use of the furnaces in operation in Brazil, the total consumption of NG will be nearly 12.06 Mm{sup 3/}day. However, the existence of few technical and economical adequate conversion conditions for ceramics furnaces (4% of continuous furnaces) limits the previous potential to only 0.67 Mm{sup 3/}day. In addition, considering the geographic intersection of the ceramics production clusters with the natural gas distribution grid of the Brazilian states, the estimated potential is lowered to 0.28 Mm{sup 3/}day. Yet, the perspective of the NG diffusion in the BSCI in the medium to the long term is more positive, owning to the increasing implementation of large scale production furnaces and cogeneration systems. Also worthwhile to this positive perspective are: the improving demand for certified structural ceramic products, with more quality and value added, and the expanding investment in low income classes dwelling programs. (author)

  9. Gas Engine-Driven Heat Pump Chiller for Air-Conditioning and Hot Water Supply Systems

    Science.gov (United States)

    Fujita, Toshihiko; Mita, Nobuhiro; Moriyama, Tadashi; Hoshino, Norimasa; Kimura, Yoshihisa

    A gas engine-driven heat pump (GHP) uses a natural gas-or LPG-powered engine to drive the compressor in a vapor-compression refrigeration cycle. The GHP has the benefits of being able to use the fuel energy effectively by recovering waste heat from the engine jacket coolant and exhaust gas and also to keep high efficiency even at part-load operation by varying the engine speed with relative ease. Hence, energy-efficient heat source systems for air-conditioning and hot water supply may be constructed with GHP chillers in place of conventional electrical-driven heat pump chillers. GHPs will necessarily contribute to the peak shaving of electrical demand in summer. In this study, the performance characteristics of a 457kW GHP chiller have been investigated by a simulation model analysis, for both cooling and heating modes. From the results of the analysis, it has been found that the part-load characteristics of the GHP chiller are fairly well. The evaluation of the heat source systems using GHP chillers will be described in Part 2.

  10. Hot-Wire Chemical Vapor Deposition Of Polycrystalline Silicon : From Gas Molecule To Solar Cell

    Science.gov (United States)

    van Veenendaal, P. A. T. T.

    2002-10-01

    Although the effort to investigate the use of renewable energy sources, such as wind and solar energy, has increased, their contribution to the total energy consumption remains insignificant. The conversion of solar energy into electricity through solar cells is one of the most promising techniques, but the use of these cells is limited by the high cost of electricity. The major contributions to these costs are the material and manufacturing costs. Over the past decades, the development of silicon based thin film solar cells has received much attention, because the fabrication costs are low. A promising material for use in thin film solar cells is polycrystalline silicon (poly-Si:H). A relatively new technique to deposit poly-Si:H is Hot-Wire Chemical Vapor Deposition (Hot-Wire CVD), in which the reactant gases are catalytically decomposed at the surface of a hot filament, mainly tungsten and tantalum. The main advantages of Hot-Wire CVD over PE-CVD are absence of ion bombardment, high deposition rate, low equipment cost and high gas utilization. This thesis deals with the full spectrum of deposition, characterization and application of poly-Si:H thin films, i.e. from gas molecule to solar cell. Studies on the decomposition of silane on the filament showed that the process is catalytic of nature and that silane is decomposed into Si and 4H. The dominant gas phase reaction is the reaction of Si and H with silane, resulting in SiH3, Si2H6, Si3H6 and H2SiSiH2. The film growth precursors are Si, SiH3 and Si2H4. Also, XPS results on used tantalum and tungsten filaments are discussed. The position dependent measurements show larger silicon contents at the ends of the tungsten filament, as compared to the middle, due to a lower filament temperature. This effect is insignificant for a tantalum filament. Deposition time dependent measurements show an increase in silicon content of the tungsten filament with time, while the silicon content on the tantalum filament saturates

  11. Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, January 1--March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    This quarterly technical progress report summarizes work completed during the Sixth Quarter of the First Budget Period, January 1 through March 31, 1992, under the Department of Energy (DOE) Cooperative Agreement No. DE-FC21-90MC25140 entitled ``Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion.`` The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. The major emphasis during this reporting period was expanding the test facility to address system integration issues of hot particulate removal in advanced power generation systems. The conceptual design of the facility was extended to include additional modules for the expansion of the test facility, which is referred to as the Power Systems Development Facility (PSOF). A letter agreement was negotiated between Southern Company Services (SCS) and Foster Wheeler (FW) for the conceptual design of the Advanced Pressurized Fluid-Bed Combustion (APFBC)/Topping Combustor/Gas Turbine System to be added to the facility. The expanded conceptual design also included modifications to the existing conceptual design for the Hot Gas Cleanup Test Facility (HGCTF), facility layout and balance of plant design for the PSOF. Southern Research Institute (SRI) began investigating the sampling requirements for the expanded facility and assisted SCS in contacting Particulate Control Device (PCD) vendors for additional information. SCS also contacted the Electric Power Research Institute (EPRI) and two molten carbonate fuel cell vendors for input on the fuel cell module for the PSDF.

  12. Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

    DEFF Research Database (Denmark)

    Goutianos, Stergios

    2017-01-01

    are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have......Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts...... to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts....

  13. Integral Hot Gas Pressure Forming of an AA2219 Aluminum Alloy Ellipsoidal Shell

    Science.gov (United States)

    Yuan, S. J.; Zhang, R.; Zhang, W. W.

    2017-04-01

    To overcome the poor plastic deformation performance of AA2219 aluminum alloy sheet and its weld seam at room temperature, an integral hot gas pressure forming (IHGPF) process for a combined welded ellipsoidal shell was proposed. A simulation of the IHGPF process was conducted to analyze the axis length variation and thickness distribution during the forming process of the combined welded ellipsoidal shell at elevated temperature. The results demonstrated that lengths of the short and long axes were 150 mm and 220 mm, respectively, and that maximum wall thinning occurred at the pole. Furthermore, an experiment was conducted using IHGPF, and the forming accuracy was measured by three-dimensional video technology. A sound ellipsoidal shell with final axis length ratio of 1.5 was obtained with a shell diameter accuracy of more than 99.3%. It was experimentally proven that an aluminum alloy ellipsoidal shell can be formed using the proposed IHGPF technology.

  14. Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

    DEFF Research Database (Denmark)

    Goutianos, Stergios

    2017-01-01

    Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts...... to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts....... are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have...

  15. Hot gas stripping of ammonia and carbon dioxide from simulated and actual in situ retort waters

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.L.

    1979-01-01

    This study proved that ammonia and carbon dioxide could be removed from retort water by hot gas stripping and that overall transfer rates were slower than for physical desorption alone. The ammonia in solution complexed with the carbonate species with the result that the CO/sub 2/ transfer rates were linked to the relatively slower desorption of NH/sub 3/ from solution. Ionic reactions in the liquid phase limited the quantity of free NH/sub 3/ and CO/sub 2/, thus decreasing the driving forces for mass transfer. The retort water exhibited foaming tendencies that affected the interfacial area which should be taken into account if a stripping tower is considered on a larger scale. Transfer unit heights were calculated for the process conditions studied and correlated such that scaleup to increased capacities is possible.

  16. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    Alloys for design and construction of structural components needed to contain process streams and provide internal structures in advanced heat recovery and hot gas cleanup systems were examined. Emphasis was placed on high-strength, corrosion-resistant alloys for service at temperatures above 1000 {degrees}F (540{degrees}C). Data were collected that related to fabrication, joining, corrosion protection, and failure criteria. Alloys systems include modified type 310 and 20Cr-25Ni-Nb steels and sulfidation-resistance alloys HR120 and HR160. Types of testing include creep, stress-rupture, creep crack growth, fatigue, and post-exposure short-time tensile. Because of the interest in relatively inexpensive alloys for high temperature service, a modified type 310 stainless steel was developed with a target strength of twice that for standard type 310 stainless steel.

  17. Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

    Science.gov (United States)

    Goutianos, Stergios

    2017-07-01

    Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts.

  18. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  19. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, modified alloy 800, and two sulfidation resistant alloys: HR160 and HR120. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700{degrees}C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925{degrees}C with good weldability and ductility.

  20. Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

    The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

  1. Soft ceramics for high temperature lubrication: graphite-free lubricants for hot and warm forging of steel

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.

    2016-01-01

    The main research focus of this thesis is on the development of the next generation of solid lubricants for high temperature forming of steel. These lubricants are based on ceramic nanoparticles which are more resistant to temperature and oxidation than traditional lubricants. Nowadays, the most

  2. A system using solid ceramic oxygen electrolyte cells to measure oxygen fugacities in gas-mixing systems

    Science.gov (United States)

    Williams, R. J.; Mullins, O.

    1976-01-01

    Details are given for the construction and operation of a 101.3 kN/sq m (1 atmosphere) redox control system. A solid ceramic oxygen electrolyte cell is used to monitor the oxygen fugacity in the furnace. The system consists of a vertical quench, gas mixing furnace with heads designed for mounting the electrolyte cell and with facilities for inserting and removing the samples. The system also contains the high input impedance electronics necessary for measurements, a simplified version of a gas mixing apparatus, and devices for experiments under controlled rates of change relative to temperature and redox state. The calibration and maintenance of the system are discussed.

  3. JSC systems using solid ceramic oxygen electrolyte cells to measure oxygen fugacites in gas-mixing systems

    Science.gov (United States)

    Williams, R. J.; Mullins, O.

    1981-01-01

    Details are given for the construction and operation of a 101.3 KN/sq meter (1 atmosphere) redox control system. A solid ceramic oxygen electrolyte cell is used to monitor the oxygen fugacity in the furnace. The system consists of a vertical quench gas mixing furnace with heads designed for mounting the electrolyte cell and with facilities for inserting and removing the samples, a simplified version of a gas mixing apparatus, and devices for experiments under controlled rates of change of temperature. A thermogravimetric analysis system employing these techniques of redox control and measurement is also described. The calibration and maintenance of the system are discussed.

  4. Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Aubrey L. [WSU Research Corporation, Morgantown, WV (USA)

    2005-07-01

    This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

  5. Hybrid Vehicle Turbine Engine Technology Support (HVTE-TS) ceramic design manual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    This ceramic component design manual was an element of the Advanced Turbine Technology Applications Project (ATTAP). The ATTAP was intended to advance the technological readiness of the ceramic automotive gas turbine engine as a primary power plant. Of the several technologies requiring development before such an engine could become a commercial reality, structural ceramic components represented the greatest technical challenge, and was the prime focus of the program. HVTE-TS, which was created to support the Hybrid Electric Vehicle (HEV) program, continued the efforts begun in ATTAP to develop ceramic components for an automotive gas turbine engine. In HVTE-TS, the program focus was extended to make this technology applicable to the automotive gas turbine engines that form the basis of hybrid automotive propulsion systems consisting of combined batteries, electric drives, and on-board power generators as well as a primary power source. The purpose of the ceramic design manual is to document the process by which ceramic components are designed, analyzed, fabricated, assembled, and tested in a gas turbine engine. Interaction with ceramic component vendors is also emphasized. The main elements of the ceramic design manual are: an overview of design methodology; design process for the AGT-5 ceramic gasifier turbine rotor; and references. Some reference also is made to the design of turbine static structure components to show methods of attaching static hot section ceramic components to supporting metallic structures.

  6. Diatomaceous earth and activated bauxite used as granular sorbents for the removal of sodium chloride vapor from hot flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Swift, W.M.; Johnson, I.

    1980-01-01

    Diatomaceous earth and activated bauxite were tested as granular sorbents for use as filter media in granular-bed filters for the removal of gaseous alkali metal compounds from the hot (800/sup 0/C) flue gas of PFBC. Tests were performed at atmospheric pressure, using NaCl vapor transported in relatively dry simulated flue gas of PFBC. Either a fixed-bed combustor or a high-temperature sorption test rig was used. The effects of sorbent bed temperature, superficial gas velocity, gas hourly space velocity, and NaCl-vapor concentration in flue gas on the sorption behavior of these two sorbents and their ultimate sorption capacities were determined. Both diatomaceous earth and activated bauxite were found to be very effective in removing NaCl vapor from flue gas. Preliminary cost evaluations showed that they are economically attractive as granular sorbents for cleaning alkali vapor from simulated flue gas.

  7. Viewing inside Pyroclastic Flows - Large-scale Experiments on hot pyroclast-gas mixture flows

    Science.gov (United States)

    Breard, E. C.; Lube, G.; Cronin, S. J.; Jones, J.

    2014-12-01

    Pyroclastic density currents are the largest threat from volcanoes. Direct observations of natural flows are persistently prevented because of their violence and remain limited to broad estimates of bulk flow behaviour. The Pyroclastic Flow Generator - a large-scale experimental facility to synthesize hot gas-particle mixture flows scaled to pyroclastic flows and surges - allows investigating the physical processes behind PDC behaviour in safety. The ability to simulate natural eruption conditions and to view and measure inside the hot flows allows deriving validation and calibration data sets for existing numerical models, and to improve the constitutive relationships necessary for their effective use as powerful tools in hazard assessment. We here report on a systematic series of large-scale experiments on up to 30 ms-1 fast, 2-4.5 m thick, 20-35 m long flows of natural pyroclastic material and gas. We will show high-speed movies and non-invasive sensor data that detail the internal structure of the analogue pyroclastic flows. The experimental PDCs are synthesized by the controlled 'eruption column collapse' of variably diluted suspensions into an instrumented channel. Experiments show four flow phases: mixture acceleration and dilution during free fall; impact and lateral blasting; PDC runout; and co-ignimbrite cloud formation. The fully turbulent flows reach Reynolds number up to 107 and depositional facies similar to natural deposits. In the PDC runout phase, the shear flows develop a four-partite structure from top to base: a fully turbulent, strongly density-stratified ash cloud with average particle concentrations <<1vol%; a transient, turbulent dense suspension region with particle concentrations between 1 and 10 vol%; a non-turbulent, aerated and highly mobile dense underflows with particle concentrations between 40 and 50 vol%; and a vertically aggrading bed of static material. We characterise these regions and the exchanges of energy and momentum

  8. Fabrication and properties of (TbxY1-x)3Al5O12 transparent ceramics by hot isostatic pressing

    Science.gov (United States)

    Duan, Pingping; Liu, Peng; Xu, Xiaodong; Wang, Wei; Wan, Zhong; Zhang, Shouyi; Wang, Yinzhen; Zhang, Jian

    2017-10-01

    (TbxY1-x)3Al5O12 (x = 0.2, 0.5, 0.8) transparent ceramics were synthesized by a solid-state reaction and HIP. All the samples were pre-sintered at 1650 °C for 4 h in a muffle and later HIPed at 1650 °C for 3 h. (Tb0.2Y0.8)3Al5O12 transparent ceramics exhibit best microstructure with an average grain size of approximately 5.22 μm and optical transmittance of over 65% in the region of 500-1600 nm. Additionally, average grain sizes of all the samples are less than 10 μm. XRD scanning patterns indicate that only the (Tb0.8Y0.2)3Al5O12 samples have little secondary phases.

  9. Damage Mechanisms and Controlled Crack Propagation in a Hot Pressed Silicon Nitride Ceramic. Ph.D. Thesis - Northwestern Univ., 1993

    Science.gov (United States)

    Calomino, Anthony Martin

    1994-01-01

    The subcritical growth of cracks from pre-existing flaws in ceramics can severely affect the structural reliability of a material. The ability to directly observe subcritical crack growth and rigorously analyze its influence on fracture behavior is important for an accurate assessment of material performance. A Mode I fracture specimen and loading method has been developed which permits the observation of stable, subcritical crack extension in monolithic and toughened ceramics. The test specimen and procedure has demonstrated its ability to generate and stably propagate sharp, through-thickness cracks in brittle high modulus materials. Crack growth for an aluminum oxide ceramic was observed to be continuously stable throughout testing. Conversely, the fracture behavior of a silicon nitride ceramic exhibited crack growth as a series of subcritical extensions which are interrupted by dynamic propagation. Dynamic initiation and arrest fracture resistance measurements for the silicon nitride averaged 67 and 48 J/sq m, respectively. The dynamic initiation event was observed to be sudden and explosive. Increments of subcritical crack growth contributed to a 40 percent increase in fracture resistance before dynamic initiation. Subcritical crack growth visibly marked the fracture surface with an increase in surface roughness. Increments of subcritical crack growth loosen ceramic material near the fracture surface and the fracture debris is easily removed by a replication technique. Fracture debris is viewed as evidence that both crack bridging and subsurface microcracking may be some of the mechanisms contributing to the increase in fracture resistance. A Statistical Fracture Mechanics model specifically developed to address subcritical crack growth and fracture reliability is used together with a damaged zone of material at the crack tip to model experimental results. A Monte Carlo simulation of the actual experiments was used to establish a set of modeling input

  10. Ceramic Nanocomposites from Tailor-Made Preceramic Polymers

    Science.gov (United States)

    Mera, Gabriela; Gallei, Markus; Bernard, Samuel; Ionescu, Emanuel

    2015-01-01

    The present Review addresses current developments related to polymer-derived ceramic nanocomposites (PDC-NCs). Different classes of preceramic polymers are briefly introduced and their conversion into ceramic materials with adjustable phase compositions and microstructures is presented. Emphasis is set on discussing the intimate relationship between the chemistry and structural architecture of the precursor and the structural features and properties of the resulting ceramic nanocomposites. Various structural and functional properties of silicon-containing ceramic nanocomposites as well as different preparative strategies to achieve nano-scaled PDC-NC-based ordered structures are highlighted, based on selected ceramic nanocomposite systems. Furthermore, prospective applications of the PDC-NCs such as high-temperature stable materials for thermal protection systems, membranes for hot gas separation purposes, materials for heterogeneous catalysis, nano-confinement materials for hydrogen storage applications as well as anode materials for secondary ion batteries are introduced and discussed in detail. PMID:28347023

  11. Ceramic Nanocomposites from Tailor-Made Preceramic Polymers

    Directory of Open Access Journals (Sweden)

    Gabriela Mera

    2015-04-01

    Full Text Available The present Review addresses current developments related to polymer-derived ceramic nanocomposites (PDC-NCs. Different classes of preceramic polymers are briefly introduced and their conversion into ceramic materials with adjustable phase compositions and microstructures is presented. Emphasis is set on discussing the intimate relationship between the chemistry and structural architecture of the precursor and the structural features and properties of the resulting ceramic nanocomposites. Various structural and functional properties of silicon-containing ceramic nanocomposites as well as different preparative strategies to achieve nano-scaled PDC-NC-based ordered structures are highlighted, based on selected ceramic nanocomposite systems. Furthermore, prospective applications of the PDC-NCs such as high-temperature stable materials for thermal protection systems, membranes for hot gas separation purposes, materials for heterogeneous catalysis, nano-confinement materials for hydrogen storage applications as well as anode materials for secondary ion batteries are introduced and discussed in detail.

  12. Ceramic tubesheet design analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H.; Swindeman, R.W.

    1996-06-01

    A transport combustor is being commissioned at the Southern Services facility in Wilsonville, Alabama to provide a gaseous product for the assessment of hot-gas filtering systems. One of the barrier filters incorporates a ceramic tubesheet to support candle filters. The ceramic tubesheet, designed and manufactured by Industrial Filter and Pump Manufacturing Company (EF&PM), is unique and offers distinct advantages over metallic systems in terms of density, resistance to corrosion, and resistance to creep at operating temperatures above 815{degrees}C (1500{degrees}F). Nevertheless, the operational requirements of the ceramic tubesheet are severe. The tubesheet is almost 1.5 m in (55 in.) in diameter, has many penetrations, and must support the weight of the ceramic filters, coal ash accumulation, and a pressure drop (one atmosphere). Further, thermal stresses related to steady state and transient conditions will occur. To gain a better understanding of the structural performance limitations, a contract was placed with Mallett Technology, Inc. to perform a thermal and structural analysis of the tubesheet design. The design analysis specification and a preliminary design analysis were completed in the early part of 1995. The analyses indicated that modifications to the design were necessary to reduce thermal stress, and it was necessary to complete the redesign before the final thermal/mechanical analysis could be undertaken. The preliminary analysis identified the need to confirm that the physical and mechanical properties data used in the design were representative of the material in the tubesheet. Subsequently, few exploratory tests were performed at ORNL to evaluate the ceramic structural material.

  13. Volatile emissions and gas geochemistry of Hot Spring Basin, Yellowstone National Park, USA

    Science.gov (United States)

    Werner, C.; Hurwitz, S.; Evans, William C.; Lowenstern, J. B.; Bergfeld, D.; Heasler, H.; Jaworowski, C.; Hunt, A.

    2008-01-01

    We characterize and quantify volatile emissions at Hot Spring Basin (HSB), a large acid-sulfate region that lies just outside the northeastern edge of the 640??ka Yellowstone Caldera. Relative to other thermal areas in Yellowstone, HSB gases are rich in He and H2, and mildly enriched in CH4 and H2S. Gas compositions are consistent with boiling directly off a deep geothermal liquid at depth as it migrates toward the surface. This fluid, and the gases evolved from it, carries geochemical signatures of magmatic volatiles and water-rock reactions with multiple crustal sources, including limestones or quartz-rich sediments with low K/U (or 40*Ar/4*He). Variations in gas chemistry across the region reflect reservoir heterogeneity and variable degrees of boiling. Gas-geothermometer temperatures approach 300????C and suggest that the reservoir feeding HSB is one of the hottest at Yellowstone. Diffuse CO2 flux in the western basin of HSB, as measured by accumulation-chamber methods, is similar in magnitude to other acid-sulfate areas of Yellowstone and is well correlated to shallow soil temperatures. The extrapolation of diffuse CO2 fluxes across all the thermal/altered area suggests that 410 ?? 140??t d- 1 CO2 are emitted at HSB (vent emissions not included). Diffuse fluxes of H2S were measured in Yellowstone for the first time and likely exceed 2.4??t d- 1 at HSB. Comparing estimates of the total estimated diffuse H2S emission to the amount of sulfur as SO42- in streams indicates ~ 50% of the original H2S in the gas emission is lost into shallow groundwater, precipitated as native sulfur, or vented through fumaroles. We estimate the heat output of HSB as ~ 140-370??MW using CO2 as a tracer for steam condensate, but not including the contribution from fumaroles and hydrothermal vents. Overall, the diffuse heat and volatile fluxes of HSB are as great as some active volcanoes, but they are a small fraction (1-3% for CO2, 2-8% for heat) of that estimated for the entire

  14. High temperature corrosion of hot-dip aluminized steel in Ar/1%SO2 gas

    Science.gov (United States)

    Abro, Muhammad Ali; Lee, Dong Bok

    2017-01-01

    Carbon steels were hot-dip aluminized in Al or Al-1at%Si baths, and corroded in Ar/1%SO2 gas at 700-800 °C for up to 50 h. The aluminized layers consisted of not only an outer Al(Fe) topcoat that had interdispersed needle-like Al3Fe particles but also an inner Al-Fe alloy layer that consisted of an outer Al3Fe layer and an inner Al5Fe2 layer. The Si addition in the bath made the Al(Fe) topcoat thin and nonuniform, smoothened the tongue-like interface between the Al-Fe alloy layer and the substrate, and increased the microhardness of the aluminized layer. The aluminized steels exhibited good corrosion resistance by forming thin α-Al2O3 scales, along with a minor amount of iron oxides on the surface. The interdiffusion that occurred during heating made the aluminized layer thick and diffuse, resulting in the formation of Al5Fe2, AlFe and AlFe3 layers. It also smoothened the tongue-like interface, and decreased the microhardness of the aluminized layer. The non-aluminized steel formed thick, nonadherent, nonprotective (Fe3O4, FeS)-mixed scales.

  15. Evolved gas analysis with skimmer interface and ion attachment mass spectrometry for burnout monitoring of organic additives in ceramic processing.

    Science.gov (United States)

    Tsugoshi, Takahisa; Ito, Nanaka; Nagaoka, Takaaki; Watari, Koji

    2006-08-15

    A monitoring of the individual pyrolysis of mixed polymer as a binder for ceramic processing was carried out as an application of evolved gas analysis-mass spectrometry (EGA-MS) with a skimmer interface and ion attachment mass spectrometry (IAMS). It could detect characteristic species evolved by the pyrolysis of the organic additives, according to the instrumental advantages as the transmission of the gaseous species with no transformation by the skimmer interface and complete soft ionization for gaseous species by IAMS technique. Further, the pyrolysis behavior of blended polymers as a binder could be monitored individually as EGA curves of characteristic species evolved by the pyrolyses.

  16. Development of Procedures to Evaluate Hot Section Deterioration for Marine Gas Turbines.

    Science.gov (United States)

    each procedure were discussed. It was demonstrated that reliable comparisons between hot stage component performance of different engiens can best be obtained by utilization of multiple evaluation methods.

  17. Properties of ceramic candle filters

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-06-01

    The mechanical integrity of ceramic filter elements is a key issue for hot gas cleanup systems. To meet the demands of the advanced power systems, the filter components must sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. They must also survive the various mechanical loads associated with handling and assembly, normal operation, and process upsets. For near-term filter systems, these elements must survive at operating temperatures of 1650{degrees}F for three years.

  18. CONSTRAINING THE MILKY WAY'S HOT GAS HALO WITH O VII AND O VIII EMISSION LINES

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Matthew J.; Bregman, Joel N., E-mail: mjmil@umich.edu, E-mail: jbregman@umich.edu [Department of Astronomy, University of Michigan, Ann Arbor, MI 48104 (United States)

    2015-02-10

    The Milky Way hosts a hot (≈2 × 10{sup 6} K), diffuse, gaseous halo based on detections of z = 0 O VII and O VIII absorption lines in quasar spectra and emission lines in blank-sky spectra. Here we improve constraints on the structure of the hot gas halo by fitting a radial model to a much larger sample of O VII and O VIII emission line measurements from XMM-Newton/EPIC-MOS spectra compared to previous studies (≈650 sightlines). We assume a modified β-model for the halo density distribution and a constant-density Local Bubble from which we calculate emission to compare with the observations. We find an acceptable fit to the O VIII emission line observations with χ{sub red}{sup 2} (dof) = 1.08 (644) for best-fit parameters of n{sub o}r{sub c}{sup 3β}=1.35±0.24 cm{sup –3} kpc{sup 3β} and β = 0.50 ± 0.03 for the hot gas halo and negligible Local Bubble contribution. The O VII observations yield an unacceptable χ{sub red}{sup 2} (dof) = 4.69 (645) for similar best-fit parameters, which is likely due to temperature or density variations in the Local Bubble. The O VIII fitting results imply hot gas masses of M(<50 kpc) = 3.8{sub −0.3}{sup +0.3}×10{sup 9} M{sub ⊙} and M(<250 kpc) = 4.3{sub −0.8}{sup +0.9}×10{sup 10} M{sub ⊙}, accounting for ≲50% of the Milky Way's missing baryons. We also explore our results in the context of optical depth effects in the halo gas, the halo gas cooling properties, temperature and entropy gradients in the halo gas, and the gas metallicity distribution. The combination of absorption and emission line analyses implies a sub-solar gas metallicity that decreases with radius, but that also must be ≥0.3 Z {sub ☉} to be consistent with the pulsar dispersion measure toward the Large Magellanic Cloud.

  19. The influence of precursor gas pressure on structure and properties of fluoropolymer coatings by hot wire CVD

    Directory of Open Access Journals (Sweden)

    Safonov Alexey

    2017-01-01

    Full Text Available In this paper we investigated the deposition process of the fluoropolymer coatings by the method of Hot Wire Chemical Vapor Deposition. The dependence of precursor gas pressure on deposition rate, structure and properties of the formed film was investigated. The study has shown that the increasing of precursor gas pressure leads to change of the film structure from porous to continuous with globules and further to solid that have different wettability. Depending on the mode of deposition was obtained the fluoropolymer coating with different structure: the wetting angle changed from 60 to 170°. A mechanism of the formation of fluoropolymer coating was discussed.

  20. The influence of precursor gas pressure on structure and properties of fluoropolymer coatings by hot wire CVD

    Science.gov (United States)

    Safonov, Alexey; Sulyaeva, Veronica; Kubrak, Konstantin; Starinsky, Sergey; Timoshenko, Nikolay

    2017-10-01

    In this paper we investigated the deposition process of the fluoropolymer coatings by the method of Hot Wire Chemical Vapor Deposition. The dependence of precursor gas pressure on deposition rate, structure and properties of the formed film was investigated. The study has shown that the increasing of precursor gas pressure leads to change of the film structure from porous to continuous with globules and further to solid that have different wettability. Depending on the mode of deposition was obtained the fluoropolymer coating with different structure: the wetting angle changed from 60 to 170°. A mechanism of the formation of fluoropolymer coating was discussed.

  1. Abundance and temperature distributions in the hot intra-cluster gas of Abell 4059

    Science.gov (United States)

    Mernier, F.; de Plaa, J.; Lovisari, L.; Pinto, C.; Zhang, Y.-Y.; Kaastra, J. S.; Werner, N.; Simionescu, A.

    2015-03-01

    Using the EPIC and RGS data from a deep (200 ks) XMM-Newton observation, we investigate the temperature structure (kT and σT) and the abundances of nine elements (O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni) of the intra-cluster medium (ICM) in the nearby (z = 0.046) cool-core galaxy cluster Abell 4059. Next to a deep analysis of the cluster core, a careful modelling of the EPIC background allows us to build radial profiles up to 12' (~650 kpc) from the core. Probably because of projection effects, the temperature ICM is not found to be in single phase, even in the outer parts of the cluster. The abundances of Ne, Si, S, Ar, Ca, and Fe, but also O are peaked towards the core. The elements Fe and O are still significantly detected in the outermost annuli, which suggests that the enrichment by both type Ia and core-collapse SNe started in the early stages of the cluster formation. However, the particularly high Ca/Fe ratio that we find in the core is not well reproduced by the standard SNe yield models. Finally, 2D maps of temperature and Fe abundance are presented and confirm the existence of a denser, colder, and Fe-rich ridge south-west of the core, previously observed by Chandra. The origin of this asymmetry in the hot gas of the cluster core is still unclear, but it might be explained by a past intense ram-pressure stripping event near the central cD galaxy. Appendices are available in electronic form at http://www.aanda.org

  2. THE ORIGIN OF THE HOT GAS IN THE GALACTIC HALO: TESTING GALACTIC FOUNTAIN MODELS' X-RAY EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Henley, David B.; Shelton, Robin L. [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Kwak, Kyujin [School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Hill, Alex S. [CSIRO Astronomy and Space Science, Marsfield, NSW (Australia); Mac Low, Mordecai-Mark, E-mail: dbh@physast.uga.edu [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States)

    2015-02-20

    We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a flow of hot gas from the disk to the halo, reproduces the temperature but significantly underpredicts the 0.5-2.0 keV surface brightness of the halo (by two orders of magnitude, if we compare the median predicted and observed values). This is true for versions of the model with and without an interstellar magnetic field. We consider different reasons for the discrepancy between the model predictions and the observations. We find that taking into account overionization in cooled halo plasma, which could in principle boost the predicted X-ray emission, is unlikely in practice to bring the predictions in line with the observations. We also find that including thermal conduction, which would tend to increase the surface brightnesses of interfaces between hot and cold gas, would not overcome the surface brightness shortfall. However, charge exchange emission from such interfaces, not included in the current model, may be significant. The faintness of the model may also be due to the lack of cosmic ray driving, meaning that the model may underestimate the amount of material transported from the disk to the halo. In addition, an extended hot halo of accreted material may be important, by supplying hot electrons that could boost the emission of the material driven out from the disk. Additional model predictions are needed to test the relative importance of these processes in explaining the observed halo emission.

  3. Comparative evaluation of electrical conductivity of hydroxyapatite ceramics densified through ramp and hold, spark plasma and post sinter Hot Isostatic Pressing routes.

    Science.gov (United States)

    Buchi Suresh, M; Biswas, P; Mahender, V; Johnson, Roy

    2017-01-01

    Hydroxyapatite ceramics synthesized through sonochemical route were processed and densified through ramp & hold (R&H) and Spark Plasma Sintering (SPS) routes. The effect of processing route on the relative density and electrical conductivity were studied. Further, the samples were Hot Isostatically Pressed (HIP) under argon pressure at elevated temperature to further densify the sample. All these samples processed under different conditions were characterized by X-ray diffraction, Scanning Electron Microscopy and AC Conductivity. The samples have exhibited hydroxyapatite phase; however, microstructures exhibited distinctly different grain morphologies and grain sizes. AC impedance spectroscopic measurement was carried out on hydroxyapatite samples processed through different routes and the corresponding spectra were analyzed by the analogy to equivalent circuit involving resistors and capacitors. SPS sintered sample after HIPing has exhibited the highest conductivity. This can be attributed to the higher density in combination with finer grain sizes. Activation energy based on Arrhenius equation is calculated and the prominent conduction mechanism is proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing of Ceramic Composites. Part III; Additive Manufacturing and Characterization of Ceramic Composites

    Science.gov (United States)

    Halbig, Michael C.; Grady, Joseph E.; Singh, Mrityunjay; Ramsey, Jack; Patterson, Clark; Santelle, Tom

    2015-01-01

    This publication is the third part of a three part report of the project entitled "A Fully Nonmetallic Gas Turbine Engine Enabled by Additive Manufacturing" funded by NASA Aeronautics Research Institute (NARI). The objective of this project was to conduct additive manufacturing to produce ceramic matrix composite materials and aircraft engine components by the binder jet process. Different SiC powders with median sizes ranging from 9.3 to 53.0 microns were investigated solely and in powder blends in order to maximize powder packing. Various infiltration approaches were investigated to include polycarbosilane (SMP-10), phenolic, and liquid silicon. Single infiltrations of SMP-10 and phenolic only slightly filled in the interior. When the SMP-10 was loaded with sub-micron sized SiC powders, the infiltrant gave a much better result of filling in the interior. Silicon carbide fibers were added to the powder bed to make ceramic matrix composite materials. Microscopy showed that the fibers were well distributed with no preferred orientation on the horizontal plane and fibers in the vertical plane were at angles as much as 45deg. Secondary infiltration steps were necessary to further densify the material. Two to three extra infiltration steps of SMP-10 increased the density by 0.20 to 0.55 g/cc. However, the highest densities achieved were 2.10 to 2.15 g/cc. Mechanical tests consisting of 4 point bend tests were conducted. Samples from the two CMC panels had higher strengths and strains to failure than the samples from the two nonfiber reinforced panels. The highest strengths were from Set N with 65 vol% fiber loading which had an average strength of 66 MPa. Analysis of the fracture surfaces did not reveal pullout of the reinforcing fibers. Blunt fiber failure suggested that there was not composite behavior. The binder jet additive manufacturing method was used to also demonstrate the fabrication of turbine engine vane components of two different designs and sizes. The

  5. Ceramics for the advanced automotive gas turbine engine - A look at a single shaft design

    Science.gov (United States)

    Nosek, S. M.

    1978-01-01

    A single-shaft regenerative design with a single-stage radial turbine is analyzed in terms of achievable fuel economy for the cases of both limited and unlimited turbine tip speed and regenerator inlet temperature. The 100-hp engine for a 3500-lb automobile is designed to use gasoline. Fuel economy data and operating parameters are presented for different values of turbine inlet temperatures, and turbine stress estimates and ceramic design stress estimates are discussed.

  6. Determination of suitability of natural Polish resources for production of ceramic proppants applied in gas exploration from European shale formations

    Science.gov (United States)

    Szymanska, Joanna; Mizera, Jaroslaw

    2017-04-01

    Poland is one of few European countries undertaking innovative research towards effective exploration of hydrocarbons form shale deposits. With regard for strict geological conditions, which occur during hydraulic fracturing, it is required to apply ceramic proppants enhancing extraction of shale gas. Ceramic proppants are granules (16/30 - 70/120 Mesh) classified as propping agents. These granules located in the newly created fissures (due to injected high pressure fluid) in the shale rock, act as a prop, what enables gas flow up the well. It occurs if the proppants can resist high stress of the closing fractures. Commonly applied proppants are quartz sands used only for shallow reservoirs and fissile shales (in the USA). Whereas, the ceramic granules are proper for extraction of gas on the high depths at hard geomechanical conditions (in Europe) to increase output even by 30 - 50%. In comparison to other propping materials, this kind of proppants predominate with mechanical strength, smoother surface, lower solubility in acids and also high stability in water. Such parameters can be available through proper raw materials selection to further proppants production. The Polish ceramic proppants are produced from natural resources as kaolin, bauxite and white clay mixed with water and binders. Afterwards, the slurries are subjected to granulation in a mechanical granulator and sintered at high temperatures (1200 - 1550°C). Taking into consideration presence of geomechanical barriers, that prevent fracture propagation beyond shale formations, it is crucial to determine quality of applied natural deposits. Next step is to optimize the proppants production and select the best kind of granules, what was the aim of this research. Utility of the raw materials was estimated on basis of their particle size distribution, bulk density, specific surface area (BET) and thermal analysis (thermogravimetry). Morphology and shape were determined by Scanning Electron Microscopy (SEM

  7. Panel report on high temperature ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Nolet, T C [ed.

    1979-01-01

    Fundamental research is reported concerning high temperature ceramics for application in turbines, engines, batteries, gasifiers, MHD, fuel cells, heat exchangers, and hot wall combustors. Ceramics microstructure and behavior are included. (FS)

  8. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Interim report, 1994 Summer

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-01-01

    The federal government is the largest single energy consumer in the United States cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This interim report provides the results of a field evaluation that PNL conducted for DOE/FEMP and the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology-a hot water heater conversion system to convert electrically heated hot water tanks to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  9. Advanced hot-gas filter development. Topical report, September 30, 1994--May 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Lane, J.E.; LeCostaouec, J.F.; Painter, C.J.; Sue, W.A.; Radford, K.C.

    1996-12-31

    The application of high-performance, high-temperature particulate control devices is considered to be beneficial to advanced fossil fuel processing technology, to selected high-temperature industrial processes, and to waste incineration concepts. Ceramic rigid filters represent the most attractive technology for these applications due to their capability to withstand high-temperature corrosive environments. However, current generation monolithic filters have demonstrated poor resistance to crack propagation and can experience catastrophic failure during use. To address this problem, ceramic fiber-reinforced ceramic matrix composite (CMC) filter materials are needed for reliable damage tolerant candle filters. This program is focused on the development of an oxide-fiber reinforced oxide material composite filter material that is cost competitive with prototype next generation filters. This goal would be achieved through the development of a low cost sol-gel fabrication process and a three-dimensional fiber architecture optimized for high volume filter manufacturing. The 3D continuous fiber reinforcement provides a damage tolerant structure which is not subject to delamination-type failures. This report documents the Phase 1, Filter Material Development and Evaluation, results. Section 2 provides a program summary. Technical results, including experimental procedures, are presented and discussed in Section 3. Section 4 and 5 provide the Phase 1 conclusions and recommendations, respectively. The remaining sections cover acknowledgements and references.

  10. Methods of Si based ceramic components volatilization control in a gas turbine engine

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John; Dion Ouellet, Noemie

    2016-09-06

    A method of controlling volatilization of silicon based components in a gas turbine engine includes measuring, estimating and/or predicting a variable related to operation of the gas turbine engine; correlating the variable to determine an amount of silicon to control volatilization of the silicon based components in the gas turbine engine; and injecting silicon into the gas turbine engine to control volatilization of the silicon based components. A gas turbine with a compressor, combustion system, turbine section and silicon injection system may be controlled by a controller that implements the control method.

  11. Coupled simulation of CFD-flight-mechanics with a two-species-gas-model for the hot rocket staging

    Science.gov (United States)

    Li, Yi; Reimann, Bodo; Eggers, Thino

    2016-11-01

    The hot rocket staging is to separate the lowest stage by directly ignite the continuing-stage-motor. During the hot staging, the rocket stages move in a harsh dynamic environment. In this work, the hot staging dynamics of a multistage rocket is studied using the coupled simulation of Computational Fluid Dynamics and Flight Mechanics. Plume modeling is crucial for a coupled simulation with high fidelity. A 2-species-gas model is proposed to simulate the flow system of the rocket during the staging: the free-stream is modeled as "cold air" and the exhausted plume from the continuing-stage-motor is modeled with an equivalent calorically-perfect-gas that approximates the properties of the plume at the nozzle exit. This gas model can well comprise between the computation accuracy and efficiency. In the coupled simulations, the Navier-Stokes equations are time-accurately solved in moving system, with which the Flight Mechanics equations can be fully coupled. The Chimera mesh technique is utilized to deal with the relative motions of the separated stages. A few representative staging cases with different initial flight conditions of the rocket are studied with the coupled simulation. The torque led by the plume-induced-flow-separation at the aft-wall of the continuing-stage is captured during the staging, which can assist the design of the controller of the rocket. With the increasing of the initial angle-of-attack of the rocket, the staging quality becomes evidently poorer, but the separated stages are generally stable when the initial angle-of-attack of the rocket is small.

  12. [PFBC Hot Gas Cleanup Test Program]. Third Quarterly technical progress report, July--September 1992, CY 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-10-01

    Four hundred and fifty four clay bonded silicon carbide Schumacher Dia Schumalith candle filters were purchased for installation in the Westinghouse Advanced Particle Filtration (APF) system at the American Electric Power (AEP) plant in Brilliant, Ohio. A surveillance effort has been identified which will monitor candle filter performance and life during hot gas cleaning in AEP`s pressurized fluidized-bed combustion system. A description of the candle surveillance program, strategy for candle filter location selection, as well as candle filter post-test characterization is provided in this memo. The period of effort for candle filter surveillance monitoring is planned through March 1994.

  13. High efficiency tantalum-based ceramic composite structures

    Science.gov (United States)

    Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor); DiFiore, Robert R. (Inventor); Katvala, Victor W. (Inventor)

    2010-01-01

    Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000.degree. F. and above.

  14. Hot Corrosion of Inconel 625 Overlay Weld Cladding in Smelting Off-Gas Environment

    Science.gov (United States)

    Mohammadi Zahrani, E.; Alfantazi, A. M.

    2013-10-01

    Degradation mechanisms and hot corrosion behavior of weld overlay alloy 625 were studied. Phase structure, morphology, thermal behavior, and chemical composition of deposited salt mixture on the weld overlay were characterized utilizing XRD, SEM/EDX, DTA, and ICP/OES, respectively. Dilution level of Fe in the weldment, dendritic structure, and degradation mechanisms of the weld were investigated. A molten phase formed on the weld layer at the operating temperature range of the boiler, which led to the hot corrosion attack in the water wall and the ultimate failure. Open circuit potential and weight-loss measurements and potentiodynamic polarization were carried out to study the hot corrosion behavior of the weld in the simulated molten salt medium at 873 K, 973 K, and 1073 K (600 °C, 700 °C, and 800 °C). Internal oxidation and sulfidation plus pitting corrosion were identified as the main hot corrosion mechanisms in the weld and boiler tubes. The presence of a significant amount of Fe made the dendritic structure of the weld susceptible to preferential corrosion. Preferentially corroded (Mo, Nb)-depleted dendrite cores acted as potential sites for crack initiation from the surface layer. The penetration of the molten phase into the cracks accelerated the cracks' propagation mainly through the dendrite cores and further crack branching/widening.

  15. Infrared observations of hot gas and cold ice toward the low mass protostar Elias 29

    NARCIS (Netherlands)

    Boogert, ACA; Tielens, AGGM; Ceccarelli, C; Boonman, AMS; van Dishoeck, EF; Keane, JV; Whittet, DCB; de Graauw, T

    2000-01-01

    We have obtained the full 1-200 mu m spectrum of the low luminosity (36 L-circle dot) Class I protostar Elias 29 in the rho Ophiuchi molecular cloud. It provides a unique opportunity to study the origin and evolution of interstellar ice and the interrelationship of interstellar ice and hot core

  16. Current Issues with Environmental Barrier Coatings for Ceramics and Ceramic Composites

    Science.gov (United States)

    Lee, Kang N.

    2004-01-01

    The environmental barrier coating (EBC) for SiC/SiC ceramic matrix composites and Si3N4 ceramics is an emerging field as the application of silicon-based ceramics in the gas turbine engine hot section is on the horizon, both for aero and industrial gas turbines. EBC is an enabling technology for silicon-based ceramics because these materials without an EBC cannot be used in combustion environments due to rapid surface recession. Significant progress in EBC development has been made during the last decade through various government-sponsored programs. Current EBCs are based on silicon, mullite (3Al2O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit temperature capability of current EBCs to about 1350 C for long-term applications. There is a need for higher temperature EBCs as the temperature capability of silicon-based ceramics continue to increase. Therefore, research is underway to develop EBCs with improved temperature capability compared to current EBCs. The current status and issues with the advanced EBC development efforts will be discussed.

  17. Ceramics for the advanced automotive gas turbine engine: A look at a single shaft design

    Science.gov (United States)

    Nosek, S. M.

    1977-01-01

    The results of a preliminary analysis of a single shaft regenerative design with a single stage radial turbine are presented to show the fuel economy that can be achieved at high turbine inlet temperatures, with this particular advanced design, if the turbine tip speed and regenerator inlet temperature are not limited. The engine size was 100 hp for application to a 3500 lb auto. The fuel economy was analyzed by coupling the engine to the auto through a continuously variable speed-ratio transmission and operating the system at constant turbine inlet temperature over the Composite Driving Cycle. The fuel was gasoline and the analysis was for a 85 F day. With a turbine inlet temperature of 2500 F the fuel economy was 26.2 mpg, an improvement of 18 percent over that of 22.3 mpg with a turbine inlet temperature of 1900 F. The turbine tip speed needed for best economy with the 2500 F engine was 2530 ft/sec. The regenerator temperature was approximately 2200 F at idle. Disk stresses were estimated for one single stage radial turbine and two two-stage radial-axial turbines and compared with maximum allowable stress curves estimated for a current ceramic material. Results show a need for higher Weibull Modulus, higher strength ceramics.

  18. Achievement report for fiscal 1992. Research and development of ceramic gas turbine (Study on its adaptability with society); 1992 nendo ceramic gas turbine no kenkyu kaihatsu seika hokokusho. Shakai tekigosei kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-05-01

    With an objective to attain a guideline for putting ceramic gas turbine (CGT) into practical application, conceptual discussions on the CGT based industrial cogeneration system (CGS) and the CGT based CGS simulations were performed to discuss quantitatively the effects of the system introduction, and estimate latent markets based on the result of calculating the introduction effects. In addition, investigations were carried out on Germany as the advanced nation with regard to the systems according to utilization patterns, load profiles, operation cost, exhaust gas measures, and the related laws and regulations. The activities may be summarized specifically as follows: 1) putting the back-data for industrial energy demand into order; 2) calculation of CGT introduction effects in industrial areas; 3) discussions on latent demand and social adaptability of CGT in the industrial area; and 4) investigations in overseas countries. Item 2 is composed of the conceptual design of industrial CGT/CGS, and the simulations on the actual status of energy demand in industrial business operation centers and on the effects of the industrial CGT/CGS. (NEDO)

  19. How to get cool in the heat: comparing analytic models of hot, cold, and cooling gas in haloes and galaxies with EAGLE

    Science.gov (United States)

    Stevens, Adam R. H.; Lagos, Claudia del P.; Contreras, Sergio; Croton, Darren J.; Padilla, Nelson D.; Schaller, Matthieu; Schaye, Joop; Theuns, Tom

    2017-05-01

    We use the hydrodynamic, cosmological EAGLE simulations to investigate how the hot gas in haloes condenses to form and grow galaxies. We select haloes from the simulations that are actively cooling and study the temperature, distribution and metallicity of their hot, cold and transitioning 'cooling' gas, placing these in the context of semi-analytic models. Our selection criteria lead us to focus on Milky Way-like haloes. We find that the hot-gas density profiles of the haloes form a progressively stronger core over time, the nature of which can be captured by a β profile that has a simple dependence on redshift. In contrast, the hot gas that will cool over a time-step is broadly consistent with a singular isothermal sphere. We find that cooling gas carries a few times the specific angular momentum of the halo and is offset in spin direction from the rest of the hot gas. The gas loses ˜60 per cent of its specific angular momentum during the cooling process, generally remaining greater than that of the halo, and it precesses to become aligned with the cold gas already in the disc. We find tentative evidence that angular-momentum losses are slightly larger when gas cools on to dispersion-supported galaxies. We show that an exponential surface density profile for gas arriving on a disc remains a reasonable approximation, but a cusp containing ˜20 per cent of the mass is always present, and disc scale radii are larger than predicted by a vanilla Fall & Efstathiou model. These scale radii are still closely correlated with the halo spin parameter, for which we suggest an updated prescription for galaxy formation models.

  20. Advanced turbine design for coal-fueled engines. Phase 1, Erosion of turbine hot gas path blading: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.H.; Johnson, B.V.

    1993-04-01

    The investigators conclude that: (1) Turbine erosion resistance was shown to be improved by a factor of 5 by varying the turbine design. Increasing the number of stages and increasing the mean radius reduces the peak predicted erosion rates for 2-D flows on the blade airfoil from values which are 6 times those of the vane to values of erosion which are comparable to those of the vane airfoils. (2) Turbine erosion was a strong function of airfoil shape depending on particle diameter. Different airfoil shapes for the same turbine operating condition resulted in a factor of 7 change in airfoil erosion for the smallest particles studied (5 micron). (3) Predicted erosion for the various turbines analyzed was a strong function of particle diameter and weaker function of particle density. (4) Three dimensional secondary flows were shown to cause increases in peak and average erosion on the vane and blade airfoils. Additionally, the interblade secondary flows and stationary outer case caused unique erosion patterns which were not obtainable with 2-D analyses. (5) Analysis of the results indicate that hot gas cleanup systems are necessary to achieve acceptable turbine life in direct-fired, coal-fueled systems. In addition, serious consequences arise when hot gas filter systems fail for even short time periods. For a complete failure of the filter system, a 0.030 in. thick corrosion-resistant protective coating on a turbine blade would be eroded at some locations within eight minutes.

  1. Thermal and structural analysis of a filter vessel ceramic tubesheet

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Zievers, J.F. [Industrial Filter & Pump Mfg. Co., Cicero, IL (United States)

    1995-08-01

    A ceramic tubesheet assembly for a hot gas filter vessel is analyzed using the finite element method to determine stresses under differential pressure loading. The stresses include local concentration effects. Selection of the stress measures for evaluation of structural integrity is discussed. Specification of stress limits based upon limited data is considered. Stress results from this ongoing design analysis technology project are shown for one design concept.

  2. Particulate hot gas stream cleanup technical issues. Quarterly technical progress report, July 1995--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-12-15

    This is the fourth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. Task 1 of this contract concerns analyses of HGCU ashes and descriptions of filter performance that are designed to address the problems with filter operation linked to the characteristics of the collected ash. Task 2 of this contract includes characterization of new and used filter elements. Some of the problems observed at the Tidd and Karhula PFBC facilities include excessive filtering pressure drop, the formation of large, tenacious ash deposits within the filter vessel, and bent or broken candle filter elements. These problems have been attributed to ash characteristics, durability of the ceramic filter elements, and specific limitations of the filter design. In addition to these problems related to the characteristics of PFBC ashes, our laboratory characterizations of gasifier and carbonize ashes have shown that these ashes also have characteristics that might negatively affect filtration. Problems with the durability of the filter elements are being addressed by the development and evaluation of elements constructed from alternative ceramic materials.

  3. Particulate hot gas stream cleanup technical issues. Quarterly report, October 1995--December 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This is the fifth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. Task 1 of this contract concerns analyses of HGCU ashes and descriptions of filter performance that are designed to address the problems with filter operation linked to the characteristics of the collected ash. Task 2 of this contract includes characterization of new and used filter elements. Some of the problems observed at the Tidd and Karhula PFBC facilities include excessive filtering pressure drop, the formation of large, tenacious ash deposits within the filter vessel, and bent or broken candle filter elements. These problems have been attributed to ash characteristics, durability of the ceramic filter elements, and specific limitations of the filter design. In addition to these problems related to the characteristics of PFBC ashes, our laboratory characterizations of gasifier and carbonizer ashes have shown that these ashes also have characteristics that might negatively affect filtration. Problems with the durability of the filter elements are being addressed by the development and evaluation of elements constructed from alternative ceramic materials.

  4. Development of ceramic membrane reactors for high temperature gas cleanup. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.L.; Abraham, I.C.; Blum, Y.; Gottschlich, D.E.; Hirschon, A.; Way, J.D.; Collins, J.

    1993-06-01

    The objective of this project was to develop high temperature, high pressure catalytic ceramic membrane reactors and to demonstrate the feasibility of using these membrane reactors to control gaseous contaminants (hydrogen sulfide and ammonia) in integrated gasification combined cycle (IGCC) systems. Our strategy was to first develop catalysts and membranes suitable for the IGCC application and then combine these two components as a complete membrane reactor system. We also developed a computer model of the membrane reactor and used it, along with experimental data, to perform an economic analysis of the IGCC application. Our results have demonstrated the concept of using a membrane reactor to remove trace contaminants from an IGCC process. Experiments showed that NH{sub 3} decomposition efficiencies of 95% can be achieved. Our economic evaluation predicts ammonia decomposition costs of less than 1% of the total cost of electricity; improved membranes would give even higher conversions and lower costs.

  5. XMM-Newton and Chandra Observations of the Galaxy Group NGC 5044. 1; Evidence for Limited Multiphase Hot Gas

    Science.gov (United States)

    Buote, David A.; Lewis, Aaron D.; Brighenti, Fabrizio; Mathews, William G.

    2003-01-01

    Using new XMM and Chandra observations, we present an analysis of the temperature structure of the hot gas within a radius of 100 kpc of the bright nearby galaxy group NGC 5044. A spectral deprojection analysis of data extracted from circular annuli reveals that a two-temperature model (2T) of the hot gas is favored over single-phase or cooling flow (M = 4.5 +/- 0.2 solar mass/yr) models within the central approx.30 kpc. Alternatively, the data can be fitted equally well if the temperature within each spherical shell varies continuously from approx.T(sub h) to T(sub c) approx. T(sub h)/2, but no lower. The high spatial resolution of the Chandra data allows us to determine that the temperature excursion T(sub h) approaches T(sub c) required in each shell exceeds the temperature range between the boundaries of the same shell in the best-fitting single-phase model. This is strong evidence for a multiphase gas having a limited temperature range. We do not find any evidence that azimuthal temperature variations within each annulus on the sky can account for the range in temperatures within each shell. We provide a detailed investigation of the systematic errors on the derived spectral models considering the effects of calibration, plasma codes, bandwidth, variable NH, and background rate. We find that the RGS gratings and the EPIC and ACIS CCDs give fully consistent results when the same models are fitted over the same energy ranges for each instrument. The cooler component of the 2T model has a temperature (T(sub c) approx. 0.7 keV) similar to the kinetic temperature of the stars. The hot phase has a temperature (T(sub h) approx. 1.4 keV) characteristic of the virial temperature of the solar mass halo expected in the NGC 5044 group. However, in view of the morphological disturbances and X-ray holes visible in the Chandra image within R approx. equals 10 kpc, bubbles of gas heated to approx.T(sub h) in this region may be formed by intermittent AGN feedback. Some

  6. Transparent ceramic scintillators for gamma-ray spectroscopy and radiography

    Energy Technology Data Exchange (ETDEWEB)

    Cherepy, Nerine

    2010-01-01

    Transparent ceramics have become available in useful sizes for a variety of applications within the past 15 years thanks to improved understanding of sintering phenomena on the nanoscale.1,2 While traditional ceramics may comprise single or multiple crystalline and amorphous mineral phases and are typically translucent or opaque to light, modern optically transparent ceramics are fully dense monoliths of micron-scale (or smaller) crystallites, in most cases formed from pure-phase cubic crystal structures. Fabrication of transparent ceramics begins with high-purity ceramic nanopowders, which are consolidated into a ‘green body’ by pressing or casting. The green body is sintered to near-full density, and the residual porosity is removed by processing the samples in a pressure vessel with high-pressure argon gas (hot isostatic pressing). A few commercial transparent ceramics are Lumicera lenses (a barium-based oxide made by Murata Mfg.), laser gain media—Nd:YAG (neodymium-doped yttrium aluminum garnet) is available from Konoshima—and transparent armor (aluminum oxynitride and spinel are available from Surmet and other vendors). As the manufacturing processes for transparent ceramics become better understood, industrial optical uses for these transparent materials with excellent mechanical robustness are likely to expand.

  7. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  8. Particulate hot gas stream cleanup technical issues. Annual report, October 1994--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-19

    This is the first annual report describing the activities performed under Contract No. DE-AC21-94MC31160. Task I of this contract is concerned with the analyses of HGCU ashes and descriptions of filter performance and is designed to address the problems with filter operation that are apparently linked to the characteristics of the collected ash. Task 2 of this contract includes characterization of new and used filter elements. Some of the problems observed at the Tidd and Karhula PFBC facilities include excessive filtering pressure drop, the formation of large, tenacious ash deposits within the filter vessel, and bent or broken candle filter elements. In addition to these problems related to the characteristics of PFBC ashes and the ceramic materials used to construct candle filters, our previous laboratory characterizations of gasifier and carbonizer ashes have shown that these ashes also have characteristics that might negatively affect filtration.

  9. Gas tungsten arc welding of ZrB2–SiC based ultra high temperature ceramic composites

    Directory of Open Access Journals (Sweden)

    R.V. Krishnarao

    2015-09-01

    Full Text Available The difficulty in fabricating the large size or complex shape limits the application of ZrB2–SiC composites. Joining them by fusion welding without or with preheating, controlled cooling under protective gas shield leads to thermal shock failure or porosity at the weld interface. In the present work, a filler material of (ZrB2–SiC–B4C–YAG composite with oxidation resistance and thermal shock resistance was produced in the form of welding wire. Using the filler, gas tungsten arc welding (GTAW was performed without employing preheating, post controlled cooling and extraneous protective gas shield to join hot pressed ZrB2–SiC (ZS, and pressureless sintered ZrB2–SiC–B4C–YAG (ZSBY composites to themselves. The fusion welding resulted in cracking and non-uniform joining without any filler material. The weld interfaces of the composites were very clean and coherent. The Vickers micro-hardness across the weld interface was found to increase due to the increase in the volume % of both SiC and B4C in the filler material. The shear strength of the weld was about 50% of the flextural strength of the parent composite.

  10. Breakdown electric fields in dissociated hot gas mixtures of sulfur hexafluoride including teflon: Calculations with experimental validations and utilization in fluid dynamics arc simulations

    Science.gov (United States)

    Yousfi, M.; Merbahi, N.; Reichert, F.; Petchanka, A.

    2017-03-01

    Measurements of breakdown voltage Vb, gas temperature Tg, and density N and the associated critical electric field Ecr/N are performed in hot dissociated SF6 highly diluted in argon and in hot dissociated SF6 mixed with PTFE (Polytetrafluoroethylene or C2F4) also highly diluted in argon. Gases are heated using a microwave source and optical emission spectroscopy is used for measurements of Tg and N while Vb is measured from a specific inter-electrode arrangement placed inside of the cell of the hot gas conditioning. The experimental Ecr/N data in the numerous considered cases of gas temperatures and compositions have been used to evaluate and validate the sets of the collision cross sections of the 11 species involved in hot dissociated SF6 (i.e., SF6, SF5, SF4, S2F2, SF3, SF2, SF, S2, F2, F, and S), the 13 additional species involved either in hot C2F4 or CF4 (C2F6, C2F4, C2F2, CF4, CF3, CF2, CF, F2, F and carbon species as C, C2, C3, C4) and also the 2 further species (CS and CS2) present only in the considered mixtures SF6 + C2F4. The fitted sets of collision cross sections of all these 26 species are then used without argon dilution in hot SF6 and hot SF6 + C2F4 mixtures to calculate and to analyze the Ecr/N data obtained for a wide range of gas temperature (up to 4000 K) and gas pressure (8 bar and more) using a rigorous multi-term solution of the Boltzmann equation for electron energy distribution function and standard calculations of hot gas composition for the species proportions. Such Ecr/N data have been then successfully used to evaluate from a Computational Fluid Dynamics model the switching capacity at terminal fault from a coupled simulation of the electrostatic field and the hot gas flow after current zero.

  11. Tritium Sequestration in Gen IV NGNP Gas Stream via Proton Conducting Ceramic Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fanglin Frank [Univ. of South Carolina, Columbia, SC (United States); Adams, Thad M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reifsnider, Kenneth [Univ. of South Carolina, Columbia, SC (United States)

    2011-09-30

    Several types of high-temperature proton conductors based on SrCeO3 and BaCeO3 have been systematically investigated in this project for tritium separation in NGNP applications. One obstacle for the field application is the chemical stability issues in the presence of steam and CO2 for these proton conductors. Several strategies to overcome such issues have been evaluated, including A site doping and B site co-doping method for perovskite-structured proton conductors. Novel zirconium-free proton conductors have also been developed with improved electrical conductivity and enhanced chemical stability. Novel catalytic materials for the proton-conducting separation membranes have been investigated. A tubular geometry proton-conducting membrane has been developed for the proton separation membranes. Total dose rate estimated from tritium decay (beta emission) under realistic membrane operating conditions, combined with electron irradiation experiments, indicates that proton ceramic materials possess the appropriate radiation stability for this application.

  12. FY16 Annual Accomplishments - Waste Form Development and Performance: Evaluation Of Ceramic Waste Forms - Comparison Of Hot Isostatic Pressed And Melt Processed Fabrication Methods

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dandeneau, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-10-13

    FY16 efforts were focused on direct comparison of multi-phase ceramic waste forms produced via melt processing and HIP methods. Based on promising waste form compositions previously devised at SRNL, simulant material was prepared at SRNL and a portion was sent to the Australian Nuclear Science and Technology Organization (ANSTO) for HIP treatments, while the remainder of the material was melt processed at SRNL. The microstructure, phase formation, elemental speciation, and leach behavior, and radiation stability of the fabricated ceramics was performed. In addition, melt-processed ceramics designed with different fractions of hollandite, zirconolite, perovskite, and pyrochlore phases were investigated. for performance and properties.

  13. A new high temperature resistant glass–ceramic coating for gas ...

    Indian Academy of Sciences (India)

    based on MgO–Al2O3–TiO2 and ZnO–Al2O3–SiO2 based glass systems) for gas turbine engine components has been developed. Thermal shock resistance, adherence at 90°-bend test and static oxidation resistance at the required working ...

  14. Analysis and theory of gas transport in microporous sol-gel derived ceramic membranes

    NARCIS (Netherlands)

    de Lange, R.S.A.; de Lange, Rob; Keizer, Klaas; Burggraaf, Anthonie; Burggraaf, A.J.

    1995-01-01

    Sol-gel modification of mesoporous alumina membranes is a very successful technique to improve gas separation performance. Due to the formed microporous top layer, the membranes show activated transport and molecular sieve-like separation factors. This paper concentrates on the mechanism of

  15. Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schrodt, J.T.

    1981-02-01

    Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

  16. Effect of a condensation utilizer on the operation of steam and hot-water gas-fired boilers

    Science.gov (United States)

    Ionkin, I. L.; Ragutkin, A. V.; Roslyakov, P. V.; Supranov, V. M.; Zaichenko, M. N.; Luning, B.

    2015-05-01

    Various designs for condensation utilizers of the low-grade heat of furnace gases that are constructed based on an open-type heat exchanger are considered. Computational investigations are carried out for the effect of the condensation utilizer with tempering and moistening of air on the operation of steam and hot-water boilers burning natural gas. The investigations are performed based on the predeveloped adequate calculating models of the steam and hot-water boilers in a Boiler Designer program complex. Investigation results for TGM-96B and PTVM-120 boilers are given. The enhancement of the operation efficiency of the condensation utilizer can be attained using a design with tempering and moistening of air supplied to combustion that results in an insignificant increase in the temperature of waste gases. This has no effect on the total operation efficiency of the boiler and the condenser unit, because additional losses with waste gases are compensated owing to the operation of the last. The tempering and moistening of air provide a substantial decrease in the temperature in the zone of active combustion and shortening the nitrogen oxide emission. The computational investigations show that the premoistening of air supplied to combustion makes the technical and economic efficiency of boilers operating with the Condensation Utilizer no worse.

  17. Modelling and experimental validation of the hot-gas defrost process of an air-cooled evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Dopazo, J. Alberto; Fernandez-Seara, Jose; Uhia, Francisco J.; Diz, Ruben [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No 9, 36310 Vigo, Pontevedra (Spain)

    2010-06-15

    A detailed transient simulation model has been developed to predict and evaluate the performance of the hot-gas defrost process of an air-coil evaporator. In the model, the defrost process is subdivided into six stages: preheating, tube frost melting start, fin frost melting start, air presence, tube-fin water film and dry-heating. In each stage, the control volume is subdivided into systems represented by a single node, which has the representative properties of the system. A finite difference approach was used to solve the model equations. The results include the time required to defrost, the distribution of the energy during defrost process, the instantaneous refrigerant properties and the instantaneous fin and tube temperature distribution. The results are compared with experimental data obtained in a local storage facility under actual operating conditions and also using data available in the literature. The model results substantially agree with the experimental data in both cases. (author)

  18. Particulate hot gas stream cleanup technical issues. Quarterly report, April--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This is the third in a series of quarterly reports. Analyses of HGCU ashes and descriptions of filter performance are designed to address aspects of filter operation apparently linked to properties of the collected ash. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters and their components. Task 2 concerns testing and failure analysis of ceramic filters. Mechanical and thermal testing of Dupont/Lanxide PRD-66, Dupont composite, 3M composite, and IF and P Fibrosics is continuing. Thermal expansion values of the PRD-66, 3M composite, and IF and P Fibrosics were measured at 1500{degree}F. Testing of new Refractron and Schumacher candle filter materials is in progress. No creep was detected for the Refractron specimens after {approx}150 hr at 1550{degree}F and creep testing is proceeding at 1600{degree}F. Machined Schumacher creep specimens will be tested following completion of the Refractron tests.

  19. The nearby interstellar medium toward α Leo. UV observations and modeling of a warm cloud within hot gas

    Science.gov (United States)

    Gry, Cecile; Jenkins, Edward B.

    2017-02-01

    Aims: Our aim is to characterize the conditions in the nearest interstellar cloud. Methods: We analyze interstellar absorption features in the full UV spectrum of the nearby (d = 24 pc) B8 IVn star α Leo (Regulus). Observations were obtained with STIS at high resolution and high signal-to-noise ratio by the HST ASTRAL Treasury program. We derive column densities for many key atomic species and interpret their partial ionizations. Results: The gas in front of α Leo exhibits two absorption components. The main one is kinematically identified as the local interstellar cloud (LIC) that surrounds the Sun. The second component is shifted by +5.6 km s-1 relative to the main component, in agreement with results for other lines of sight in this region of the sky, and shares its ionization and physical conditions. The excitation of the C II fine-structure levels and the ratio of Mg I to Mg II reveal a temperature T = 6500 (+750, -600) K and electron density n(e) = 0.11 (+0.025, -0.03) cm-3. Our investigation of the ionization balance yields the ion fractions for 10 different atoms and indicates that about 1/3 of the hydrogen atoms are ionized. Metals are significantly depleted onto grains, with sulfur showing [S/H] -0.27. N(H I) = 1.9 (+0.9, -0.6) × 1018 cm-3, which indicates that this partly neutral gas occupies only 2 to 8 parsecs (about 13%) of the space toward the star, with the remaining volume being filled with a hot gas that emits soft X-rays. We do not detect any absorption features from the highly ionized species that could be produced in an interface between the warm medium and the surrounding hot gas, possibly because of non-equilibrium conditions or a particular magnetic field orientation that reduces thermal conduction. Finally, the radial velocity of the LIC agrees with that of the Local Leo Cold Cloud, indicating that they may be physically related.

  20. The Cosmic History of Hot Gas Cooling and Radio AGN Activity in Massive Early-Type Galaxies

    Science.gov (United States)

    Danielson, A. L. R.; Lehmer, B. D.; Alexander, D. M.; Brandt, W. M.; Luo, B.; Miller, N.; Xue, Y. Q.; Stott, J. P.

    2012-01-01

    We study the X-ray properties of 393 optically selected early-type galaxies (ETGs) over the redshift range of z approx equals 0.0-1.2 in the Chandra Deep Fields. To measure the average X-ray properties of the ETG population, we use X-ray stacking analyses with a subset of 158 passive ETGs (148 of which were individually undetected in X-ray). This ETG subset was constructed to span the redshift ranges of z = 0.1-1.2 in the approx equals 4 Ms CDF-S and approx equals 2 Ms CDF-N and z = 0.1-0.6 in the approx equals 250 ks E-CDF-S where the contribution from individually undetected AGNs is expected to be negligible in our stacking. We find that 55 of the ETGs are detected individually in the X-rays, and 12 of these galaxies have properties consistent with being passive hot-gas dominated systems (i.e., systems not dominated by an X-ray bright Active Galactic Nucleus; AGN). On the basis of our analyses, we find little evolution in the mean 0.5-2 keY to B-band luminosity ratio (L(sub x) /L(sub Beta) varies as [1 +z]) since z approx equals 1.2, implying that some heating mechanism prevents the gas from cooling in these systems. We consider that feedback from radio-mode AGN activity could be responsible for heating the gas. We select radio AGNs in the ETG population using their far-infrared/radio flux ratio. Our radio observations allow us to constrain the duty cycle history of radio AGN activity in our ETG sample. We estimate that if scaling relations between radio and mechanical power hold out to z approx equals 1.2 for the ETG population being studied here, the average mechanical power from AGN activity is a factor of approx equals1.4 -- 2.6 times larger than the average radiative cooling power from hot gas over the redshift range z approx equals 0-1.2. The excess of inferred AGN mechanical power from these ETGs is consistent with that found in the local Universe for similar types of galaxies.

  1. Hot wire chemical vapor deposition chemistry in the gas phase and on the catalyst surface with organosilicon compounds.

    Science.gov (United States)

    Shi, Yujun

    2015-02-17

    CONSPECTUS: Hot wire chemical vapor deposition (HWCVD), also referred to as catalytic CVD (Cat-CVD), has been used to produce Si-containing thin films, nanomaterials, and functional polymer coatings that have found wide applications in microelectronic and photovoltaic devices, in automobiles, and in biotechnology. The success of HWCVD is largely due to its various advantages, including high deposition rate, low substrate temperatures, lack of plasma-induced damage, and large-area uniformity. Film growth in HWCVD is induced by reactive species generated from primary decomposition on the metal wire or from secondary reactions in the gas phase. In order to achieve a rational and efficient optimization of the process, it is essential to identify the reactive species and to understand the chemical kinetics that govern the production of these precursor species for film growth. In this Account, we report recent progress in unraveling the complex gas-phase reaction chemistry in the HWCVD growth of silicon carbide thin films using organosilicon compounds as single-source precursors. We have demonstrated that laser ionization mass spectrometry is a powerful diagnostic tool for studying the gas-phase reaction chemistry when combined with the methods of isotope labeling and chemical trapping. The four methyl-substituted silane molecules, belonging to open-chain alkylsilanes, dissociatively adsorb on W and Ta filaments to produce methyl radical and H2 molecule. Under the typical deposition pressures, with increasing number of methyl substitution, the dominant chemistry occurring in the gas phase switches from silylene/silene reactions to free-radical short chain reactions. This change in dominant reaction intermediates from silylene/silene to methyl radicals explains the observation from thin film deposition that silicon carbide films become more C-rich with a decreasing number of Si-H bonds in the four precursor molecules. In the case of cyclic monosilacyclobutanes, we have

  2. The Low Pressure Gas Effects On The Potency Of An Electron Beam On Ceramic Fabric Materials For Space Welding

    Science.gov (United States)

    Nunes, Arthur C., Jr.; Fragomeni, James M.; Munafo, Paul M. (Technical Monitor)

    2001-01-01

    This investigation was undertaken to evaluate if molten metal or electron beam impingement could damage or burn through the fabric of the astronauts Extravehicular Mobility Unit (EMU) during electron beam welding exercises performed in space. An 8 kilovolt electron beam with a current in the neighborhood of 100 milliamps from the Ukrainian space welding "Universal Hand Tool" burned holes in Nextel AF-62 ceramic cloth designed to withstand temperatures up to 1427 C. The burnthrough time was on the order of 8 seconds at standoff distances between UHT and cloth ranging from 6 to 24 inches. At both closer (2") and farther (48") standoff distances the potency of the beam against the cloth declined and the burnthrough time went up significantly. Prior to the test it had been expected that the beam would lay down a static charge on the cloth and be deflected without damaging the cloth. The burnthrough is thought to be an effect of partial transmission of beam power by a stream of positive ions generated by the high voltage electron beam from contaminant gas in the "vacuum" chamber. A rough quantitative theoretical computation appears to substantiate this possibility.

  3. Dissolver Off-gas Hot Operations Authorization (AFCI CETE Milestone Report)

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, Robert Thomas [ORNL

    2009-06-01

    The head-end processing of the Coupled-End-to-End (CETE) Demonstration includes fuel receipt, fuel disassembly, exposure of fuel (e.g., by segmenting the fuel pins), voloxidation of the fuel to separate tritium, and fuel dissolution. All of these processing steps with the exception of the dissolution step will be accomplished in the Irradiated Fuels Examination Laboratory (IFEL) (Building 3525). The final headend step will be performed in the Radiochemical Engineering Development Center (Building 7920). The primary purpose of the fuel dissolution step is to prepare the solid fuel for subsequent liquid separations steps. This is accomplished by dissolving the fuel solids using nitric acid. During the dissolution process gases are evolved. Oxides of nitrogen are the primary off-gas components generated by the reactions of nitric acid and the fuel oxides however, during the dissolution and sparging of the resulting solution, iodine, C-14 as carbon dioxide, xenon, and krypton gasses are also released to the off-gas stream. The Dissolver Off-gas treatment rack provides a means of trapping these volatile fission products and other gases via various trapping media. Specifically the rack will recover iodine on a solid sorbent bed, scrub NOx in a water/acid column, scrub CO{sub 2} in a caustic scrubber column, remove moisture with solid sorbent drier beds and recover Xe and Kr using solid absorbent beds. The primary purpose of this experimental rack and the off-gas rack associated with the voloxidation equipment located at IFEL is to close the material balances around the volatile gases and to provide an understanding of the impacts of specific processing conditions on the fractions of the volatile components released from the various head-end processing steps.

  4. Potential benefits of a ceramic thermal barrier coating on large power generation gas turbine

    Science.gov (United States)

    Clark, J. S.; Nainiger, J. J.

    1977-01-01

    Thermal barrier coating design option offers benefit in terms of reduced electricity costs when used in utility gas turbines. Options considered include: increased firing temperature, increased component life, reduced cooling air requirements, and increased corrosion resistance (resulting in increased tolerance for dirty fuels). Performance and cost data were obtained. Simple, recuperated and combined cycle applications were considered, and distillate and residual fuels were assumed. The results indicate that thermal barrier coatings could produce large electricity cost savings if these coatings permit turbine operation with residual fuels at distillate-rated firing temperatures. The results also show that increased turbine inlet temperature can result in substantial savings in fuel and capital costs.

  5. WLAN Hot Spot services for the automotive and oil industries :a business analysis Or : "Refuel the car with petrol and information, both ways at the gas station"

    NARCIS (Netherlands)

    L-F. Pau (Louis-François); M.H.P. Oremus

    2003-01-01

    textabstractWhile you refuel for gas ,why not refuel for information or download vehicle data ? This paper analyzes in extensive detail the user segmentation by vehicle usage , service offering , and full business models from WLAN hot spot services delivered to vehicles (private, professional ,

  6. VOF Simulations of Countercurrent Gas-Liquid Flow in a PWR Hot Leg

    Directory of Open Access Journals (Sweden)

    Michio Murase

    2012-12-01

    Full Text Available In order to evaluate flow patterns and CCFL (countercurrent flow limitation characteristics in a PWR hot leg under reflux condensation, numerical simulations have been done using a two-fluid model and a VOF (volume of fluid method implemented in the CFD software, FLUENT6.3.26. The two-fluid model gave good agreement with CCFL data under low pressure conditions but did not give good results under high pressure steam-water conditions. On the other hand, the VOF method gave good agreement with CCFL data for tests with a rectangular channel but did not give good results for calculations in a circular channel. Therefore, in this paper, the computational grid and schemes were improved in the VOF method, numerical simulations were done for steam-water flows at 1.5 MPa under PWR full-scale conditions with the diameter of 0.75 m, and the calculated results were compared with the UPTF data at 1.5 MPa. As a result, the calculated flow pattern was found to be similar to the flow pattern observed in small-scale air-water tests, and the calculated CCFL characteristics agreed well with the UPTF data at 1.5 MPa except in the region of a large steam volumetric flux.

  7. Method of making multilayered titanium ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, George T., II; Hansen; Jeffrey S.; Oden; Laurance L.; Turner; Paul C.; Ochs; Thomas L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  8. Electron beam test of an iron/gas calorimeter based on ceramic parallel plate chambers

    Energy Technology Data Exchange (ETDEWEB)

    Arefiev, A.; Bencze, Gy.L.; Bizzeti, A.; Choumilov, E.; Civinini, C; Dalla Santa, F.; D' Alessandro, R.; Ferrando, A.; Fouz, M.C.; Herve, A.; Iglesias, A.; Ivochkin, V.; Josa, M.I.; Maggi, F.; Malinin, A.; Meschini, M.; Pojidaev, V.; Radermacher, E.; Salicio, J.M.

    1995-07-01

    The baseline option for the very forward calorimetry in the CMS experiment is an iron/gas calorimeter based on parallel plate chambers. A small prototype module of such a calorimeter, has been tested using electrons of 5 to 100 GeV/c momentum with various high voltages and two gases: CO2 (100%) and CF4/CO2 (80/20), at atmospheric pressure. The collected charge has been measured as a function of the high voltage and of the electron energy. The energy resolution has also been measured. Comparisons have been made with Monte-Carlo predictions. Agreement between data an simulation allows to make and estimation of the expected performance of a full size calorimeter. (Author) 23 refs.

  9. Bose-Einstein condensation in an ultra-hot gas of pumped magnons.

    Science.gov (United States)

    Serga, Alexander A; Tiberkevich, Vasil S; Sandweg, Christian W; Vasyuchka, Vitaliy I; Bozhko, Dmytro A; Chumak, Andrii V; Neumann, Timo; Obry, Björn; Melkov, Gennadii A; Slavin, Andrei N; Hillebrands, Burkard

    2014-03-11

    Bose-Einstein condensation of quasi-particles such as excitons, polaritons, magnons and photons is a fascinating quantum mechanical phenomenon. Unlike the Bose-Einstein condensation of real particles (like atoms), these processes do not require low temperatures, since the high densities of low-energy quasi-particles needed for the condensate to form can be produced via external pumping. Here we demonstrate that such a pumping can create remarkably high effective temperatures in a narrow spectral region of the lowest energy states in a magnon gas, resulting in strikingly unexpected transitional dynamics of Bose-Einstein magnon condensate: the density of the condensate increases immediately after the external magnon flow is switched off and initially decreases if it is switched on again. This behaviour finds explanation in a nonlinear 'evaporative supercooling' mechanism that couples the low-energy magnons overheated by pumping with all the other thermal magnons, removing the excess heat, and allowing Bose-Einstein condensate formation.

  10. Advanced hot gas filter development. Topical report, May 1995--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.L.; June, M.R.

    1997-12-31

    Porous iron aluminide was evaluated for use as a particulate filter in pressurized fluid-bed combustion (PFBC) and integrated gasification combined cycles (IGCC) with a short term test. Three alloy compositions were tested: Fe{sub 3}Al 5% chromium (FAL), Fe{sub 3}Al 2% chromium (FAS) and FeAl 0% chromium. The test conditions simulated air blown (Tampa Electric) and oxygen blown (Sierra Pacific) gasifiers with one test gas composition. Four test conditions were used with hydrogen sulfide levels varying from 783 ppm to 78,3000 ppm at 1 atmosphere along with temperatures ranging between 925 F and 1200 F. The iron aluminide was found capable of withstanding the proposed operating conditions and capable of giving years of service. The production method and preferred composition were established as seamless cylinders of Fe{sub 3}Al 2% chromium with a preoxidation of seven hours at 1472 F.

  11. Fiscal 1997 report of the R and D result of industrial science and technology. R and D on synergy ceramics (R and D on an ultrahigh-temperature gas turbine for power generation); 1997 nendo sangyo kagaku gijutsu kenkyu kaihatsu seika hokokusho. Synergy ceramics no kenkyu kaihatsu (hatsuden`yo chokoon gas turbine no kenkyu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For development of high-efficiency power generation gas turbines using petroleum substituting energy, the process technology which can highly harmonize conflicting characteristics and various functions was developed for new ceramic materials. This paper summarizes the result in fiscal 1997. On design technology of the characteristics harmonizing process, the design and synthesis of ceramic precursors were made by using chemical reaction of metal organics. On analysis of fracture behavior by controlling microscopic and macroscopic particle shapes, orientations were observed by convergent ion beam. On control technology of a structure formation process, study was made on continuous pore shape control to form porous material with uni-directionally arranged pores in ceramic matrix, interface control between particles to decrease a plastic deformation temperature and improve a heat insulation, interface control between phases of a rare-earth silicate/silicon-carbide-based composite, boundary control between layers of piezoelectric ceramics, and boundary control of the composite where inorganic-organic hybrids occupy the interface between ceramic particles. 79 refs., 193 figs., 15 tabs.

  12. DEVELOPMENT OF GLASS AND GLASS CERAMIC PROPPANTS FROM GAS SHALE WELL DRILL CUTTINGS

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Fox, K.

    2013-10-02

    The objective of this study was to develop a method of converting drill cuttings from gas shale wells into high strength proppants via flame spheroidization and devitrification processing. Conversion of drill cuttings to spherical particles was only possible for small particle sizes (< 53 {micro}m) using a flame former after a homogenizing melting step. This size limitation is likely to be impractical for application as conventional proppants due to particle packing characteristics. In an attempt to overcome the particle size limitation, sodium and calcium were added to the drill cuttings to act as fluxes during the spheroidization process. However, the flame former remained unable to form spheres from the fluxed material at the relatively large diameters (0.5 - 2 mm) targeted for proppants. For future work, the flame former could be modified to operate at higher temperature or longer residence time in order to produce larger, spherical materials. Post spheroidization heat treatments should be investigated to tailor the final phase assemblage for high strength and sufficient chemical durability.

  13. Effect of electric arc, gas oxygen torch and induction melting techniques on the marginal accuracy of cast base-metal and noble metal-ceramic crowns.

    Science.gov (United States)

    Gómez-Cogolludo, Pablo; Castillo-Oyagüe, Raquel; Lynch, Christopher D; Suárez-García, María-Jesús

    2013-09-01

    The aim of this study was to identify the most appropriate alloy composition and melting technique by evaluating the marginal accuracy of cast metal-ceramic crowns. Seventy standardised stainless-steel abutments were prepared to receive metal-ceramic crowns and were randomly divided into four alloy groups: Group 1: palladium-gold (Pd-Au), Group 2: nickel-chromium-titanium (Ni-Cr-Ti), Group 3: nickel-chromium (Ni-Cr) and Group 4: titanium (Ti). Groups 1, 2 and 3 were in turn subdivided to be melted and cast using: (a) gas oxygen torch and centrifugal casting machine (TC) or (b) induction and centrifugal casting machine (IC). Group 4 was melted and cast using electric arc and vacuum/pressure machine (EV). All of the metal-ceramic crowns were luted with glass-ionomer cement. The marginal fit was measured under an optical microscope before and after cementation using image analysis software. All data was subjected to two-way analysis of variance (ANOVA). Duncan's multiple range test was run for post-hoc comparisons. The Student's t-test was used to investigate the influence of cementation (α=0.05). Uncemented Pd-Au/TC samples achieved the best marginal adaptation, while the worst fit corresponded to the luted Ti/EV crowns. Pd-Au/TC, Ni-Cr and Ti restorations demonstrated significantly increased misfit after cementation. The Ni-Cr-Ti alloy was the most predictable in terms of differences in misfit when either torch or induction was applied before or after cementation. Cemented titanium crowns exceeded the clinically acceptable limit of 120μm. The combination of alloy composition, melting technique, casting method and luting process influences the vertical seal of cast metal-ceramic crowns. An accurate use of the gas oxygen torch may overcome the results attained with the induction system concerning the marginal adaptation of fixed dental prostheses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. A combined SEM, CV and EIS study of multi-layered porous ceramic reactors for flue gas purification

    DEFF Research Database (Denmark)

    He, Zeming; Andersen, Kjeld Bøhm; Nygaard, Frederik Berg

    2013-01-01

    The effect of sintering temperature of 12-layered porous ceramic reactors (comprising 5 cells) was studied using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The difference in microstructures of the reactors was evaluated by SEM...

  15. Monolithic ceramics

    Science.gov (United States)

    Herbell, Thomas P.; Sanders, William A.

    1992-01-01

    A development history and current development status evaluation are presented for SiC and Si3N4 monolithic ceramics. In the absence of widely sought improvements in these materials' toughness, and associated reliability in structural applications, uses will remain restricted to components in noncritical, nonman-rated aerospace applications such as cruise missile and drone gas turbine engine components. In such high temperature engine-section components, projected costs lie below those associated with superalloy-based short-life/expendable engines. Advancements are required in processing technology for the sake of fewer and smaller microstructural flaws.

  16. EVIDENCE FOR THE DIRECT DETECTION OF THE THERMAL SPECTRUM OF THE NON-TRANSITING HOT GAS GIANT HD 88133 b

    KAUST Repository

    Piskorz, Danielle

    2016-11-23

    We target the thermal emission spectrum of the non-transiting gas giant HD 88133 b with high-resolution near-infrared spectroscopy, by treating the planet and its host star as a spectroscopic binary. For sufficiently deep summed flux observations of the star and planet across multiple epochs, it is possible to resolve the signal of the hot gas giant\\'s atmosphere compared to the brighter stellar spectrum, at a level consistent with the aggregate shot noise of the full data set. To do this, we first perform a principal component analysis to remove the contribution of the Earth\\'s atmosphere to the observed spectra. Then, we use a cross-correlation analysis to tease out the spectra of the host star and HD 88133 b to determine its orbit and identify key sources of atmospheric opacity. In total, six epochs of Keck NIRSPEC L-band observations and three epochs of Keck NIRSPEC K-band observations of the HD 88133 system were obtained. Based on an analysis of the maximum likelihood curves calculated from the multi-epoch cross-correlation of the full data set with two atmospheric models, we report the direct detection of the emission spectrum of the non-transiting exoplanet HD 88133 b and measure a radial projection of the Keplerian orbital velocity of 40 +/- 15 km s(-1), a true mass of 1.02(-0.28)(+0.61) M-J, a nearly face-on orbital inclination of 15(-5)(+60), and an atmosphere opacity structure at high dispersion dominated by water vapor. This, combined with 11 years of radial velocity measurements of the system, provides the most up-to-date ephemeris for HD 88133.

  17. High H2O-resistance CaO-MnOx/MSU-H sorbents for hot coal gas desulfurization.

    Science.gov (United States)

    Xia, Hong; Liu, Bingsi

    2017-02-15

    A series of xMnyCa/MSU-H sorbents with various Mn/Ca molar ratio were first designed and synthesized with a sol-gel method. The desulfurization performance of the new sorbent was investigated at 600-800°C in hot coal gas. 90Mn10Ca/MSU-H exhibited better desulfurization performance at 750°C with a breakthrough sulfur capacity (BSC) of 18.69g S/100g sorbent compared to other supported Mn-based sorbents (13.2g S/100g sorbent) in similar desulfurization condition, and strong durability in multiple sulfidation-regeneration cycles using oxidation/reduction regeneration method which resolved the scientific issue of that CaSO4 is hardly decomposed to CaO. The introduction of Ca species effectively promoted the dispersion of active constituents, which improved the desulfurization activity. More importantly, 90Mn10Ca/MSU-H showed excellent H2O-resistance ability due to the fact that CaO enhanced the sorption of H2O. Moreover, the utilization of MSU-H with large pore size and excellent thermal stability effectively assured fast mass-transfer and confined the migration of active particles, which led to long lifetime stability of sorbents. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Ceramic fiber filter technology

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  19. CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS-SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2

    Energy Technology Data Exchange (ETDEWEB)

    Paul K.T. Liu

    2005-07-15

    A high temperature membrane reactor (MR) has been developed to enhance the water-gas-shift (WGS) reaction efficiency with concomitant CO{sub 2} removal for sequestration. This improved WGS-MR with CO{sub 2} recovery capability is ideally suitable for integration into the Integrated Gasification Combined-Cycle (IGCC) power generation system. Two different CO{sub 2}-affinity materials were selected in this study. The Mg-Al-CO{sub 3}-layered double hydroxide (LDH) was investigated as an adsorbent or a membrane for CO{sub 2} separation. The adsorption isotherm and intraparticle diffusivity for the LDH-based adsorbent were experimentally determined, and suitable for low temperature shift (LTS) of WGS. The LDH-based membranes were synthesized using our commercial ceramic membranes as substrate. These experimental membranes were characterized comprehensively in terms of their morphology, and CO{sub 2} permeance and selectivity to demonstrate the technical feasibility. In parallel, an alternative material-base membrane, carbonaceous membrane developed by us, was characterized, which also demonstrated enhanced CO{sub 2} selectivity at the LTS-WGS condition. With optimization on membrane defect reduction, these two types of membrane could be used commercially as CO{sub 2}-affinity membranes for the proposed application. Based upon the unique CO{sub 2} affinity of the LDHs at the LTS/WGS environment, we developed an innovative membrane reactor, Hybrid Adsorption and Membrane Reactor (HAMR), to achieve {approx}100% CO conversion, produce a high purity hydrogen product and deliver a concentrated CO{sub 2} stream for disposal. A mathematical model was developed to simulate this unique one -step process. Finally a benchtop reactor was employed to generate experimental data, which were consistent with the prediction from the HAMR mathematical model. In summary, the project objective, enhancing WGS efficiency for hydrogen production with concomitant CO{sub 2} removal for

  20. Effect of Al Hot-Dipping on High-Temperature Corrosion of Carbon Steel in N2/0.1% H2S Gas

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Abro

    2016-02-01

    Full Text Available High-temperature corrosion of carbon steel in N2/0.1% H2S mixed gas at 600–800 °C for 50–100 h was studied after hot-dipping in the aluminum molten bath. Hot-dipping resulted in the formation of the Al topcoat and the Al-Fe alloy layer firmly adhered on the substrate. The Al-Fe alloy layer consisted primarily of a wide, tongue-like Al5Fe2 layer and narrow Al3Fe layer. When corroded at 800 °C for 100 h, the Al topcoat partially oxidized to the protective but non-adherent α-Al2O3 layer, and the interdiffusion converted the Al-Fe alloy layer to an (Al13Fe4, AlFe3-mixed layer. The interdiffusion also lowered the microhardness of the hot-dipped steel. The α-Al2O3 layer formed on the hot-dipped steel protected the carbon steel against corrosion. Without the Al hot-dipping, the carbon steel failed by forming a thick, fragile, and non-protective FeS scale.

  1. Hot tapping and plugging in gas pipeline - GASCAB-I and GASDUC-I; Furacao em carga e plugueamento em gasodutos - GASCAB-I e GASDUC-I

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Jeziel; Ciuffo, Mauro Cunha; Santa Cruz, Sergio de Freitas [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    It is difficult to accomplish interventions avoiding the shutdown on of the main lines during the operation of process plants or gas pipelines. It involves unit halt as well supply contract interruption, which can result heavy financial penalties with fines or cost due to profit loss. In such case it is necessary to use special techniques as hot tapping or line plugging. This paper aim to present the technical feasibility of applying line-plugging technique in a gas pipeline submitted to high pressure (82 kg f/cm{sup 2}) in non-straight section. It also presents the technical feasibility of repairing the fastening system of the connection plug. (author)

  2. Ceramic Technology Project

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

  3. Porous ceramic membranes

    OpenAIRE

    Biesheuvel, P. M.; Biesheuvel, Pieter Maarten

    2000-01-01

    Synthetic membranes are increasingly used for energy-efficient separation of liquid and gaseous mixtures in household applications, environmental technology and the chemical and energy industry. Besides, membranes are used in component-specific sensors in gas and liquid streams, preferably combined with micro-electronic devices. Ceramic membranes have a large potential over their polymer counterparts for applications at high temperature, pressure and in aggressive environments. Ceramic membra...

  4. Hot Leg Piping Materials Issues

    Energy Technology Data Exchange (ETDEWEB)

    V. Munne

    2006-07-19

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the space nuclear power plant (SNPP) for Project Prometheus (References a and b) the reactor outlet piping was recognized to require a design that utilizes internal insulation (Reference c). The initial pipe design suggested ceramic fiber blanket as the insulation material based on requirements associated with service temperature capability within the expected range, very low thermal conductivity, and low density. Nevertheless, it was not considered to be well suited for internal insulation use because its very high surface area and proclivity for holding adsorbed gases, especially water, would make outgassing a source of contaminant gases in the He-Xe working fluid. Additionally, ceramic fiber blanket insulating materials become very friable after relatively short service periods at working temperatures and small pieces of fiber could be dislodged and contaminate the system. Consequently, alternative insulation materials were sought that would have comparable thermal properties and density but superior structural integrity and greatly reduced outgassing. This letter provides technical information regarding insulation and materials issues for the Hot Leg Piping preconceptual design developed for the Project Prometheus space nuclear power plant (SNPP).

  5. Fabrication of ceramic membrane tubes for direct conversion of natural gas. [SrCo[sub 0. 8]Fe[sub 0. 2]O[sub x] perosvskite

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Morissette, S.L.; Picciolo, J.J.; Dusek, J.T.; Poeppel, R.B. (Argonne National Lab., IL (United States)); Pei, S.; Kleefisch, M.S.; Mieville, R.L.; Kobylinski, T.P.; Udovich, C.A. (Amoco Research Center, Naperville, IL (United States))

    1992-05-01

    Several perovskite-type oxides that contain transition metals on the B-site show mixed (electronic/ionic) conductivity. These mixed conducting oxides are promising materials for oxygen permeating membranes that can operate without the need of electrodes or external electrical circuitry. SrCo[sub 0.8]Fe[sub 0.2]O[sub x] perovskite is known to exhibit very high oxygen permeabilities and one could use this material for producing value added products by direct conversion of methane, the most abundant component of natural gas. This paper deals with the processing and fabrication by plastic extrusion of long lengths ([approx]30 cm) of hollow SrCo[sub 0.8]Fe[sub 0.2]O[sub x] ceramic tubes. These tubes are characterized by scanning electron microscopy, X-ray diffraction (XRD) and their thermodynamic stability is evaluated using room temperature XRD on samples equilibrated at high temperatures in different gas environment.

  6. Combustion gas cleaning in the ceramic tile industry: technical guide; Nettoyage des fumees de combustion dans l'industrie ceramique: guide technique

    Energy Technology Data Exchange (ETDEWEB)

    Lezaun, F.J. [ENAGAS-Grupo Gas Natural (Spain); Mallol, G.; Monfort, E. [instituto de Tecnologia Ceramica, ITC (Spain); Busani, G. [Agenzia Regionale per la Prevenzione e l' Amiente, ARPA (Spain)

    2000-07-01

    This document presents a summary of a technical guide drawn up on combustion gas cleaning systems in ceramic frit and tile production. The guide describes the method to be followed for selecting the best possible solutions for reducing pollutant concentrations in different emission sources, in accordance with current regulatory requirements and the CET recommendation. There are three sources of combustion gas air emissions that need to be cleaned in ceramic tile and frit production and they are usually related to the following process stages: slip spray drying, tile firing and frit melting. The different nature of the emissions means that different substances will need to be cleaned in each emission. Thus, in spray drying and frit melting, the only species to be cleaned are suspended particles, while in tile firing, it is also necessary to reduce the fluorine concentration. The systems analysed in this guide are mainly wet cleaning systems, bag filters and electrostatic precipitators. In the study, the efficiency of these cleaning systems is compared at each emission source from a technical and economic point of view, and concrete solutions are put forward in each case, together with a list of suppliers of the technologies involved. (authors)

  7. The hot gas cleaning with multifunctional sorbent technique at 1-20 bar pressure; Kaasujen kuumapuhdistus multifunktionaalisella sorbenttitekniikalla 1-20 bar:n paineessa

    Energy Technology Data Exchange (ETDEWEB)

    Jaanu, K.; Orjala, M.; Paakkinen, K.; Rantanen, J. [VTT Energy, Espoo (Finland)

    1996-12-01

    The aim of the research was to study the simultaneous hot gas cleanup of alkali metals and selected heavy metals under pressure of 1-20 bar using multifunctional sorbent technology, to investigate effects of it on sulfur and nitrogen emissions and to improve the total efficiency of the hot gas cleanup method by reducing the concentrations of harmful components to the level required by the gas turbines. The research has started in the year 1993. The optimization of the test facility at 900 deg C and 20 bar has been accomplished, as targeted. The main topics have been the alkali metals. The main targets of the year 1994 was to concentrate on the research of sorbent effectiveness to remove the impurities like alkalies etc. from the flue gas. Furthermore researches on kinetics and mechanisms were started. The results showed that the developed multifunctional sorbent are highly effective to remove alkalies from the flue gas. Also a mechanism for alkali and lead sorption was proposed. The main topics for 1995 were scheduled to be the completion of the kinetic and mechanical studies and the modelling and the estimation of the data for the pilot scale unit. The kinetic data for one sorbent has been completed and a model for that has also been developed. The measured and calculated results are indicating that the developed multifunctional sorption process is highly effective to remove alkalies and heavy metals such as lead and cadmium from high-temperature combustion gases. The tests are carried out mainly using the pressurized entrained flow reactor of VTT Energy, located in Jyvaeskylae, and in the university of Arizona, where the tests are conducted under atmospheric pressure. Some comparisons of the results might be made with those of Aabo Akademi during the future modelling. 3. The results are applied to purification of the hot gases in boilers, power and process industry. (Abstract Truncated)

  8. Hot gas path component

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward

    2017-09-12

    Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

  9. Construction of new tie-in in the Bolivia-Brazil Gas Pipeline (GASBOL) using hot tapping techniques; Derivacao do Gasoduto Bolivia-Brasil com a tecnica de hot-tapping

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Frota, Cristiane Souto; Leite Filho, Ismael Casono; Lobao Filho, Jesualdo Pereira; Saavedra, Marcelo Curto [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    To supply 2,4 MM m3/d of natural gas to Tres Lagoas thermo electric plant, it was necessary to install a new delivery point of 12'' in the 32'' trunk line of Bolivia-Brazil gas pipeline. The most efficient method for executing new delivery points and maintenance repairs in pipelines is using the 'hot-tapping' technique, because there is no need to stop flow and blow down lines. This paper shows the project, specifications, planning and a detailed job execution to support this new city-gate, using a T split sleeve welded in the pipeline, explaining all the activities. Complex and innovative aspects related to the welding and inspection processes, executed in a API 5L X70 pipe at 92 kgf/cm{sup 2}, are also reported. (author)

  10. Development of Nano-crystalline Doped-Ceramic Enabled Fiber Sensors for High Temperature In-Situ Monitoring of Fossil Fuel Gases

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hai [Missouri Univ. of Science and Technology, Rolla, MO (United States); Dong, Junhang [Univ. of Cincinnati, OH (United States); Lin, Jerry [Arizona State Univ., Tempe, AZ (United States); Romero, Van [New Mexico Institute of Mining and Technology, Socorro, NM (United States)

    2012-03-01

    This is a final technical report for the first project year from July 1, 2005 to Jan 31, 2012 for DoE/NETL funded project DE-FC26-05NT42439: Development of Nanocrystalline Doped-Ceramic Enabled Fiber Sensors for High Temperature In-Situ Monitoring of Fossil Fuel Gases. This report summarizes the technical progresses and achievements towards the development of novel nanocrystalline doped ceramic material-enabled optical fiber sensors for in situ and real time monitoring the gas composition of flue or hot gas streams involved in fossil-fuel based power generation and hydrogen production.

  11. Hot gas in the cold dark matter scenario: X-ray clusters from a high-resolution numerical simulation

    Science.gov (United States)

    Kang, Hyesung; Cen, Renyue; Ostriker, Jeremiah P.; Ryu, Dongsu

    1994-01-01

    A new, three-dimensional, shock-capturing hydrodynamic code is utilized to determine the distribution of hot gas in a standard cold dark matter (CDM) model of the universe. Periodic boundary conditions are assumed: a box with size 85 h(exp -1) Mpc having cell size 0.31 h(exp -1) Mpc is followed in a simulation with 270(exp 3) = 10(exp 7.3) cells. Adopting standard parameters determined from COBE and light-element nucleosynthesis, sigma(sub 8) = 1.05, omega(sub b) = 0.06, and assuming h = 0.5, we find the X-ray-emitting clusters and compute the luminosity function at several wavelengths, the temperature distribution, and estimated sizes, as well as the evolution of these quantities with redshift. We find that most of the total X-ray emissivity in our box originates in a relatively small number of identifiable clusters which occupy approximately 10(exp -3) of the box volume. This standard CDM model, normalized to COBE, produces approximately 5 times too much emission from clusters having L(sub x) is greater than 10(exp 43) ergs/s, a not-unexpected result. If all other parameters were unchanged, we would expect adequate agreement for sigma(sub 8) = 0.6. This provides a new and independent argument for lower small-scale power than standard CDM at the 8 h(exp -1) Mpc scale. The background radiation field at 1 keV due to clusters in this model is approximately one-third of the observed background, which, after correction for numerical effects, again indicates approximately 5 times too much emission and the appropriateness of sigma(sub 8) = 0.6. If we have used the observed ratio of gas to total mass in clusters, rather than basing the mean density on light-element nucleosynthesis, then the computed luminosity of each cluster would have increased still further, by a factor of approximately 10. The number density of clusters increases to z approximately 1, but the luminosity per typical cluster decreases, with the result that evolution in the number density of bright

  12. Performance of CaO and MgO for the hot gas clean up in gasification of a chlorine-containing (RDF) feedstock.

    Science.gov (United States)

    Corella, José; Toledo, José M; Molina, Gregorio

    2008-11-01

    Calcined limestone (CaO) and calcined dolomite (CaO.MgO) were tested at bench scale to study their usefulness in cleaning hot raw gas from a fluidized bed gasifier of a synthetic or simulated refuse-derived fuel (RDF) with a high (3 wt%) content in chlorine. In the gas cleaning reactor two main reactions occurred simultaneously: the elimination of HCl and the elimination of tar by steam reforming. The elimination of HCl formed CaCl2 and MgCl2 with melting points below the high (above 800 degrees C) temperatures required for the simultaneous tar elimination reaction. So, the CaO-based particles progressively melted and the catalytic gas cleaning reactor became a compact, agglomerated or glued, cake. Therefore, the life and usefulness of the CaO-based solids used was very low. Nevertheless, and to further avoid these problems, some positive guidelines for future research are proposed here.

  13. Strengthening of oxidation resistant materials for gas turbine applications. [treatment of silicon ceramics for increased flexural strength and impact resistance

    Science.gov (United States)

    Kirchner, H. P.

    1974-01-01

    Silicon nitride and silicon carbide ceramics were treated to form compressive surface layers. On the silicon carbide, quenching and thermal exposure treatments were used, and on the silicon nitride, quenching, carburizing, and a combination of quenching and carburizing were used. In some cases substantial improvements in impact resistance and/or flexural strength were observed. The presence of compressive surface stresses was demonstrated by slotted rod tests.

  14. Supported microporous ceramic membranes

    Science.gov (United States)

    Webster, Elizabeth; Anderson, Marc

    1993-01-01

    A method for permformation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms.

  15. Study of adsorption states in ZnO—Ag gas-sensitive ceramics using the ECTV curves method

    Directory of Open Access Journals (Sweden)

    Lyashkov A. Yu.

    2013-12-01

    Full Text Available The ZnO—Ag ceramic system as the material for semiconductor sensors of ethanol vapors was proposed quite a long time ago. The main goal of this work was to study surface electron states of this system and their relation with the electric properties of the material. The quantity of doping with Ag2O was changed in the range of 0,1–2,0% of mass. The increase of the Ag doping leads to a shift of the Fermi level down (closer to the valence zone. The paper presents research results on electrical properties of ZnO-Ag ceramics using the method of thermal vacuum curves of electrical conductivity. Changes in the electrical properties during heating in vacuum in the temperature range of 300—800 K were obtained and discussed. The increase of Tvac leads to removal of oxygen from the surface of samples The oxygen is adsorbed in the form of O2– and O– ions and is the acceptor for ZnO. This results in the lowering of the inter-crystallite potential barriers in the ceramic. The surface electron states (SES above the Fermi level are virtually uncharged. The increase of the conductivity causes desorption of oxygen from the SES settled below the Fermi level of the semiconductor. The model allows evaluating the depth of the Fermi level in the inhomogeneous semiconductor materials.

  16. Tantalum-Based Ceramics for Refractory Composites

    Science.gov (United States)

    Stewart, David A.; Leiser, Daniel; DiFiore, Robert; Kalvala, Victor

    2006-01-01

    A family of tantalum-based ceramics has been invented as ingredients of high-temperature composite insulating tiles. These materials are suitable for coating and/or permeating the outer layers of rigid porous (foam-like or fibrous) ceramic substrates to (1) render the resulting composite ceramic tiles impervious to hot gases and (2) enable the tiles to survive high heat fluxes at temperatures that can exceed 3,000 F ( 1,600 C).

  17. A Transmission Electron Microscope Characterization of Sodium Sulfate Hot Corrosion of Silicon Carbide Fiber-Reinforced Lithium Aluminosilicate Glass-Ceramic Matrix Composite

    Science.gov (United States)

    1994-09-01

    P- spodumene (Li20-Al20 3 -4SiO2 ) and mullite (3A1203- 2SIO2 ) in a high silica glass (88 wt% SiC2 and 12 wt% A1203). The fiber/matrix interface...hot corrosion. The matrix was a very fine mixture of glass and P- spodumene polycrystallites (20 nm in diameter) . The fiber/matrix interface was...binary phase diagram . . . 5 Figure 3. Longitudinal thermal expansion of solid solutions of P- spodumene (Li20-Al203-nSiO2). 6 Figure 4. Volume

  18. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    Science.gov (United States)

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Determination of chlorobenzenes in textiles by pressurized hot water extraction followed by vortex-assisted liquid-liquid microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Lu, Yang; Zhu, Yan

    2013-12-06

    A method for quantitative determination of chlorobenzenes in textiles is developed, using pressurized hot water extraction (PHWE), vortex-assisted liquid-liquid microextraction (VALLME) and gas chromatography-mass spectrometry (GC-MS). VALLME serves as a trapping step after PHWE. The extraction conditions are investigated, as well as the quantitative features such as linearity, limits of detection (LODs), limits of quantification (LOQs), repeatabilities and reproducibilities between days. LOQs of 0.018-0.032mg/kg were achieved. The present method provides good repeatabilities (RSDtextiles. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. The gas phase emitter effect of lanthanum within ceramic metal halide lamps and its dependence on the La vapor pressure and operating frequency

    Science.gov (United States)

    Ruhrmann, C.; Hoebing, T.; Bergner, A.; Groeger, S.; Denissen, C.; Suijker, J.; Awakowicz, P.; Mentel, J.

    2015-08-01

    The gas phase emitter effect increases the lamp lifetime by lowering the work function and, with it, the temperature of the tungsten electrodes of metal halide lamps especially for lamps in ceramic vessels due to their high rare earth pressures. It is generated by a monolayer on the electrode surface of electropositive atoms of certain emitter elements, which are inserted into the lamp bulb by metal iodide salts. They are vaporized, dissociated, ionized, and deposited by an emitter ion current onto the electrode surface within the cathodic phase of lamp operation with a switched-dc or ac-current. The gas phase emitter effect of La and the influence of Na on the emitter effect of La are studied by spatially and phase-resolved pyrometric measurements of the electrode tip temperature, La atom, and ion densities by optical emission spectroscopy as well as optical broadband absorption spectroscopy and arc attachment images by short time photography. An addition of Na to the lamp filling increases the La vapor pressure within the lamp considerably, resulting in an improved gas phase emitter effect of La. Furthermore, the La vapor pressure is raised by a heating of the cold spot. In this way, conditions depending on the La vapor pressure and operating frequency are identified, at which the temperature of the electrodes becomes a minimum.

  1. The gas phase emitter effect of lanthanum within ceramic metal halide lamps and its dependence on the La vapor pressure and operating frequency

    Energy Technology Data Exchange (ETDEWEB)

    Ruhrmann, C.; Hoebing, T.; Bergner, A.; Groeger, S.; Awakowicz, P.; Mentel, J. [Electrical Engineering and Plasma Technology, Ruhr University Bochum, D-44780 Bochum (Germany); Denissen, C.; Suijker, J. [Philips Lighting, Category Professional Lamps, P.O. Box 80020, NL-5600JM Eindhoven (Netherlands)

    2015-08-07

    The gas phase emitter effect increases the lamp lifetime by lowering the work function and, with it, the temperature of the tungsten electrodes of metal halide lamps especially for lamps in ceramic vessels due to their high rare earth pressures. It is generated by a monolayer on the electrode surface of electropositive atoms of certain emitter elements, which are inserted into the lamp bulb by metal iodide salts. They are vaporized, dissociated, ionized, and deposited by an emitter ion current onto the electrode surface within the cathodic phase of lamp operation with a switched-dc or ac-current. The gas phase emitter effect of La and the influence of Na on the emitter effect of La are studied by spatially and phase-resolved pyrometric measurements of the electrode tip temperature, La atom, and ion densities by optical emission spectroscopy as well as optical broadband absorption spectroscopy and arc attachment images by short time photography. An addition of Na to the lamp filling increases the La vapor pressure within the lamp considerably, resulting in an improved gas phase emitter effect of La. Furthermore, the La vapor pressure is raised by a heating of the cold spot. In this way, conditions depending on the La vapor pressure and operating frequency are identified, at which the temperature of the electrodes becomes a minimum.

  2. Sensors for ceramic components in advanced propulsion systems: Summary of literature survey and concept analysis, task 3 report

    Science.gov (United States)

    Bennethum, W. H.; Sherwood, L. T.

    1988-01-01

    The results of a literature survey and concept analysis related to sensing techniques for measuring of surface temperature, strain, and heat flux for (non-specific) ceramic materials exposed to elevated temperatures (to 2200 K) are summarized. Concepts capable of functioning in a gas turbine hot section environment are favored but others are reviewed also. Recommendation are made for sensor development in each of the three areas.

  3. Particulate hot gas stream cleanup technical issues: Task 1.0, Assessment of ash characteristics. Quarterly report, January--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-05-01

    Analyses of Hot Gas Stream Cleanup (HGSC) ashes and descriptions of filter performance were made to address the problems with filter operation that are apparently linked to the collected ash. This task is designed to generate data base of the key properties of ashes collected from operating advanced particle filters and to relate these ash proeprties to the operation and performance of these filters. Activities including initial formatting of the data base and entry, modification of the permeability model, and initial design of a high-temperature test device for measuring uncompacted bulk porosity of ashe aggregates (indicator of relative cohesivity of the ash, filter cake porosity/permeability). Chemical analyses of hopper and filter cake ashes from Tidd showed that the consolidation degree could not be accounted for by condensation/adsorption from the flue gas; the mechanism is likely physical rearrangement of the ash particles.

  4. Fiscal 2000 achievement report on research and development of industrial technologies. Research and development of synergy ceramics (Research and development of ultrahigh temperature gas turbine for power generation); 2000 nendo sangyo kagaku gijutsu kenkyu kaihatsu seika hokokusho. Synergy ceramics no kenkyu kaihatsu (hatsuden'yo chokoon gas turbine no kenkyu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The fruits of fiscal 2000 efforts to develop high temperature energy materials and ultraprecision materials are briefly described. Activities are conducted in the four fields of (1) materials derivation and advanced evaluation/design technologies, (2) application technologies, (3) common base technologies, and (4) multifunction realization process evaluation. Discussed in field (1) are high temperature energy materials, high performance active materials, fundamental technologies for member designing, active materials for dealing with environmental gas, silicon based high resistance energy materials, porous multiple layer ceramic materials, macro-/micro-scale stress analysis technology, and microfracture analysis technology. Discussed in field (2) are heat resistant and damage tolerant materials, heat shielding materials and energy absorbing materials, and nanofilter materials capable of selective separation. In the study of active materials specific for environmental gas, a catalyst is developed, stable at high temperatures and capable of treating NOx selectively. The catalyst is a layered product comprising Ba hexaaluminate layers and stabilized zirconia layers. (NEDO)

  5. What Can Be Learned from X-Ray Spectroscopy Concerning Hot Gas in the Local Bubble and Charge Exchange Processes?

    Science.gov (United States)

    Snowden, S. L.

    2008-01-01

    Both solar wind charge exchange emission and diffuse thermal emission from the Local Bubble are strongly dominated in the soft X-ray band by lines from highly ionized elements. While both processes share many of the same lines, the spectra should differ significantly due to the different production mechanisms, abundances, and ionization states. Despite their distinct spectral signatures, current and past observatories have lacked the spectral resolution to adequately distinguish between the two sources. High-resolution X-ray spectroscopy instrumentation proposed for future missions has the potential to answer fundamental questions such as whether there is any hot plasma in the Local Hot Bubble, and if so, what are the abundances of the emitting plasma and whether the plasma is in equilibrium. Such instrumentation will provide dynamic information about the solar wind including data on ion species which are currently difficult to track. It will also make possible remote sensing of the solar wind.

  6. Layer texture of hot-rolled BCC metals and its significance for stress-corrosion cracking of main gas pipelines

    Science.gov (United States)

    Perlovich, Yu. A.; Isaenkova, M. G.; Krymskaya, O. A.; Morozov, N. S.

    2016-10-01

    Based on data of X-ray texture analysis of hot-rolled BCC materials it was shown that the layerwise texture inhomogeneity of products is formed during their manufacturing. The effect can be explained by saturation with interstitial impurities of the surface layer, resulting in dynamical deformation aging (DDA). DDA prevents the dislocation slip under rolling and leads to an increase of lattice parameters in the external layer. The degree of arising inhomogeneity correlates with the tendency of hot-rolled sheets and obtained therefrom tubes to stress-corrosion cracking under exploitation, since internal layers have a compressive effect on external layers, and prevents opening of corrosion cracks at the tube surface.

  7. High gas velocity oxidation and hot corrosion testing of oxide dispersion-strengthened nickel-base alloys

    Science.gov (United States)

    Deadmore, D. L.; Lowell, C. E.

    1975-01-01

    Several oxide dispersion strengthened (ODS) nickel-base alloys were tested in high velocity gases for cyclic oxidation resistance at temperatures to 1200 C and times to 500 hours and for hot corrosion resistance at 900 C for 200 hours. Nickel-chromium-aluminum ODS alloys were found to have superior resistance to oxidation and hot corrosion when compared to bare and coated nickel-chromium ODS alloys. The best of the alloys tested had compositions of nickel - 15.5 to 16 weight percent chromium with aluminum weight percents between 4.5 and 5.0. All of the nickel-chromium-aluminum ODS materials experienced small weight losses (less than 16 mg/sq cm).

  8. Summary and assessment of METC zinc ferrite hot coal gas desulfurization test program, final report: Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Underkoffler, V.S.

    1986-12-01

    The Morgantown Energy Technology Center (METC) has conducted a test program to develop a zinc ferrite-based high temperature desulfurization process which could be applied to fuel gas entering downstream components such as molten carbonate fuel cells or gas turbines. As a result of prior METC work with iron oxide and zinc oxide sorbents, zinc ferrite evolved as a candidate with the potential for high capacity, low equilibrium levels of H/sub 2/S, and structural stability after multiple regenerations. The program consisted of laboratory-scale testing with a two-inch diameter reactor and simulated fixed-bed gasifier gas; bench-scale testing with a six-inch diameter reactor and actual gas from the METC 42-inch fixed bed gasifier; as well as laboratory-scale testing of zinc ferrite with simulated fluidized bed gasifier gas. Data from sidestream testing are presented. 18 refs.

  9. Effectiveness of sanitizers, dry heat, hot water, and gas catalytic infrared heat treatments to inactivate Salmonella on almonds.

    Science.gov (United States)

    Bari, Md Latiful; Nei, Daisuke; Sotome, Itaru; Nishina, Ikuo; Isobe, Seiichi; Kawamoto, Shinnichi

    2009-10-01

    The majority of almond-related foodborne outbreaks have been associated with Salmonella. Therefore, it is necessary to find an effective method to inactivate these organisms on raw almond prior to market distribution. This study was conducted to assess the effectiveness of sanitizers (strong or mild electrolyzed water, ozonated water, and distilled water), dry heat treatment, and hot water treatments followed by catalytic infrared (IR) heat treatment to inactivate Salmonella populations on raw almond. Raw almonds inoculated with four-strain cocktails of Salmonella were treated either by soaking in different chemical sanitizers or with dry heat and/or hot water for various periods of time followed by catalytic IR heat treatment for 70 seconds. The treated seeds were then assessed for the efficacy of the treatment in reducing populations of the pathogens. After inoculation and air-drying, 5.73 +/- 0.12 log colony-forming units (CFU)/g Salmonella were detected in nonselective medium. Sanitizer treatment alone did not show significant reduction in the Salmonella population, but in combination with IR drying it reduced the population to 3.0 log CFU/g. Dry heating at 60 degrees C for 4 days followed by IR drying for 70 seconds reduced the Salmonella population an additional 1.0 log CFU/g. Hot water treatments at 85 degrees C for 40 seconds followed by IR drying for 70 seconds reduced pathogens to an undetectable level by direct plating, but not by enrichment.

  10. Penetration of natural gas in industrial processes for direct burning: the case of ceramics, cement and glass industries; Penetracao do gas natural em processos industriais de queima direta: caso das industrias ceramica, cimento e vidro

    Energy Technology Data Exchange (ETDEWEB)

    Berni, Mauro Donizeti; Leite, Alvaro A. Furtado [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Dorileo, Ivo Leandro [Universidade Federal do Mato Grosso (NIEPE/UFMT), Cuiaba, MT (Brazil). Nucleo Interdisciplinar de Estudos em Planejamento Energetico; Bajay, Sergio Valdir [Universidade estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Energia], e-mail: bajay@fem.unicamp.com.br

    2008-07-01

    Industrial sector can use the natural gas (NG) as raw material, as fuel and in co-generation. The NG as fuel is used, predominantly, to produce heat in the Brazilian industries. That rate, both main forms of industrial use of the NG are its direct burning in kilns - when the direct contact is had with the product - and the supply of process heat through boilers, for instance. Direct burning is used in the ceramic, cement and glass industries. This work discuss the penetration opportunity of the NG in the direct burning regarding the fuel oil and other energy that it can substitute, the environmental effects and the co-generation possibilities in each one of the analyzed industrial blanches in this work. (author)

  11. Low-pressure-ratio regenerative exhaust-heated gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

    1991-01-01

    A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

  12. Ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E. [Sandia National Lab., Albuquerque, NM (United States)

    1996-04-01

    This paper describes the relation between reactions at ceramic-metal interfaces and the development of strong interfacial bonds in ceramic joining. Studies on a number of systems are described, including silicon nitrides, aluminium nitrides, mullite, and aluminium oxides. Joints can be weakened by stresses such as thermal expansion mismatch. Ceramic joining is used in a variety of applications such as solid oxide fuel cells.

  13. Hot Gas Conditioning: Recent Progress with Larger-Scale Biomass Gasification Systems; Update and Summary of Recent Progress

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D. J.

    2001-09-01

    As a result of environmental and policy considerations, there is increasing interest in using renewable biomass resources as feedstock for power, fuels, and chemicals and hydrogen. Biomass gasification is seen as an important technology component for expanding the use of biomass. Advanced biomass gasification systems provide clean products that can be used as fuel or synthesis gases in a variety of environmentally friendly processes. Advanced end-use technologies such as gas turbines or synthesis gas systems require high quality gases with narrowly defined specifications. Other systems such as boilers may also have fuel quality requirements, but they will be substantially less demanding. The gas product from biomass gasifiers contains quantities of particulates, tars, and other constituents that may exceed these specified limits. As a result, gas cleaning and conditioning will be required in most systems. Over the past decade, significant research and development activities have been conducted on the topic of gas cleanup and conditioning. This report provides an update of efforts related to large-scale biomass gasification systems and summarizes recent progress. Remaining research and development issues are also summarized.

  14. Ceramic membrane development in NGK

    Science.gov (United States)

    Araki, Kiyoshi; Sakai, Hitoshi

    2011-05-01

    NGK Insulators, Ltd. was established in 1919 to manufacture the electric porcelain insulators for power transmission lines. Since then, our business has grown as one of the world-leading ceramics manufacturing companies and currently supply with the various environmentally-benign ceramic products to worldwide. In this paper, ceramic membrane development in NGK is described in detail. We have been selling ceramic microfiltration (MF) membranes and ultra-filtration (UF) membranes for many years to be used for solid/liquid separation in various fields such as pharmaceutical, chemical, food and semiconductor industries. In Corporate R&D, new ceramic membranes with sub-nanometer sized pores, which are fabricated on top of the membrane filters as support, are under development for gas and liquid/liquid separation processes.

  15. Search for Solar Axions by the CERN Axion Solar Telescope with 3 He Buffer Gas: Closing the Hot Dark Matter Gap

    CERN Document Server

    Arik, M.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J.M.; Cetin, S.A.; Collar, J.I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, I.G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P.M.; Laurent, J.M.; Liolios, A.; Ljubičić, A.; Lozza, V.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M.J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P.S.; Solanki, S.K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

    2014-01-01

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  16. Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15

    DEFF Research Database (Denmark)

    Kristensen, Lars Egstrøm; Van Dishoeck, E. F.; Mottram, J. C.

    2017-01-01

    not understood. Aims. We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components within protostellar systems using spectrally resolved Herschel-HIFI data. Methods. Observations are presented of the highly excited CO...... line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs...... excitation components. The warm PACS component (300 K) is associated with the broad HIFI component, and the hot PACS component (700 K) is associated with the offset HIFI component. The former originates in either outflow cavity shocks or the disk wind, and the latter in irradiated shocks. The low water...

  17. The Hot-gas screw-type engine - Simulation as a basis for construction. Pt. 3; Die Heissgasschraubenmaschine - simulationsgestuetzte Auslegung. T. 3

    Energy Technology Data Exchange (ETDEWEB)

    Kauder, K.; Unwerth, T. von [Dortmund Univ. (Germany). FG Fluidenergiemaschinen

    1998-12-31

    In this paper new results of the research regarding the design of the first experimental plant for a hot-gas screw-type machine are reported. Target of the development is the verification of operating behaviour as well as the thermal and mechanical behaviour of the screw-type motor parts. The selection and dimensioning of the plant components is described with a main focus on the construction of the thermally high-loaded hot-gas screw-type engine. Its manufacturing tolerances are based on simulations, with which the mechanical deformations of the rotors and the casing respective the resulting clearance-heights can be calculated. With inclusion of an efficient cooling method for the motor parts, for the, in the article documented, projected nominal working condition with a material-depending limit for the entrance temperature at {theta}{sub E,} {sub M}=600 C, a pressure ratio {pi}=6 and a male rotor peripheral speed u{sub HR}=120 ms{sup -1}, each rotor should be decreased by 0.07 mm. (orig.) [Deutsch] Es wird ueber neue Forschungsergebnisse im Hinblick auf die konstruktive Realisierung der ersten Versuchsanlage einer Heissgasschraubenmaschine berichtet. Ziel der daran durchgefuehrten Untersuchungen ist die Verifikation des Betriebsverhaltens sowie des thermischen und mechanischen Bauteilverhaltens des Heissgasschraubenmotors. Nachzulesen ist die Auswahl und Dimensionierung der Anlagenkomponenten, wobei ein Hauptaugenmerk auf der Auslegung des thermisch hoch belasteten Schraubenmotors liegt. Dessen Dimensionierung liegen Simulationsrechnungen zugrunde, mit deren Hilfe die mechanischen Verformungen der Rotoren und des Gehaeuses respektive der daraus resultierenden Spalthoehen a priori angegeben werden koennen. Fuer den hier dokumentierten, angestrebten Nennbetriebszustand mit einer werkstoffbedingt begrenzten Motoreintrittstemperatur von {theta}{sub E,} {sub M}=600 C, einem Druckverhaeltnis von {pi}=6 und einer Hauptrotorumfangsgeschwindigkeit von u{sub HR}=120 ms

  18. Insulating Structural Ceramics Program, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Mark J.; Tandon, Raj; Ott, Eric; Hind, Abi Akar; Long, Mike; Jensen, Robert; Wheat, Leonard; Cusac, Dave; Lin, H. T.; Wereszczak, Andrew A.; Ferber, Mattison K.; Lee, Sun Kun; Yoon, Hyung K.; Moreti, James; Park, Paul; Rockwood, Jill; Boyer, Carrie; Ragle, Christie; Balmer-Millar, Marilou; Aardahl, Chris; Habeger, Craig; Rappe, Ken; Tran, Diana; Koshkarian, Kent; Readey, Michael

    2005-11-22

    New materials and corresponding manufacturing processes are likely candidates for diesel engine components as society and customers demand lower emission engines without sacrificing power and fuel efficiency. Strategies for improving thermal efficiency directly compete with methodologies for reducing emissions, and so the technical challenge becomes an optimization of controlling parameters to achieve both goals. Approaches being considered to increase overall thermal efficiency are to insulate certain diesel engine components in the combustion chamber, thereby increasing the brake mean effective pressure ratings (BMEP). Achieving higher BMEP rating by insulating the combustion chamber, in turn, requires advances in material technologies for engine components such as pistons, port liners, valves, and cylinder heads. A series of characterization tests were performed to establish the material properties of ceramic powder. Mechanical chacterizations were also obtained from the selected materials as a function of temperature utilizing ASTM standards: fast fracture strength, fatique resistance, corrosion resistance, thermal shock, and fracture toughness. All ceramic materials examined showed excellent wear properties and resistance to the corrosive diesel engine environments. The study concluded that the ceramics examined did not meet all of the cylinder head insert structural design requirements. Therefore we do not recommend at this time their use for this application. The potential for increased stresses and temperatures in the hot section of the diesel engine combined with the highly corrosive combustion products and residues has driven the need for expanded materials capability for hot section engine components. Corrosion and strength requirements necessitate the examination of more advanced high temperture alloys. Alloy developments and the understanding of processing, structure, and properties of supperalloy materials have been driven, in large part, by the gas

  19. [Ceramic posts].

    Science.gov (United States)

    Mainjot, Amélie; Legros, Caroline; Vanheusden, Alain

    2006-01-01

    As a result of ceramics and all-ceram technologies development esthetic inlay core and abutments flooded the market. Their tooth-colored appearance enhances restoration biomimetism principally on the marginal gingiva area. This article reviews indications and types of cores designed for natural teeth and implants.

  20. Environmental Effects on Non-oxide Ceramics

    Science.gov (United States)

    Jacobson, Nathan S.; Opila, Elizabeth J.

    1997-01-01

    Non-oxide ceramics such as silicon carbide (SiC) and silicon nitride (Si3N4) are promising materials for a wide range of high temperature applications. These include such diverse applications as components for heat engines, high temperature electronics, and re-entry shields for space vehicles. Table I lists a number of selected applications. Most of the emphasis here will be on SiC and Si3N4. Where appropriate, other non-oxide materials such as aluminum nitride (AlN) and boron nitride (BN) will be discussed. Proposed materials include both monolithic ceramics and composites. Composites are treated in more detail elsewhere in this volume, however, many of the oxidation/corrosion reactions discussed here can be extended to composites. In application these materials will be exposed to a wide variety of environments. Table I also lists reactive components of these environments.It is well-known that SiC and Si3N4 retain their strength to high temperatures. Thus these materials have been proposed for a variety of hot-gas-path components in combustion applications. These include heat exchanger tubes, combustor liners, and porous filters for coal combustion products. All combustion gases contain CO2, CO, H2, H2O, O2, and N2. The exact gas composition is dependent on the fuel to air ratio or equivalence ratio. (Equivalence ratio (EQ) is a fuel-to-air ratio, with total hydrocarbon content normalized to the amount of O2 and defined by EQ=1 for complete combustion to CO2 and H2O). Figure 1 is a plot of equilibrium gas composition vs. equivalence ratio. Note that as a general rule, all combustion atmospheres are about 10% water vapor and 10% CO2. The amounts of CO, H2, and O2 are highly dependent on equivalence ratio.

  1. AGT (Advanced Gas Turbine) technology project

    Science.gov (United States)

    1988-01-01

    An overall summary documentation is provided for the Advanced Gas Turbine Technology Project conducted by the Allison Gas Turbine Division of General Motors. This advanced, high risk work was initiated in October 1979 under charter from the U.S. Congress to promote an engine for transportation that would provide an alternate to reciprocating spark ignition (SI) engines for the U.S. automotive industry and simultaneously establish the feasibility of advanced ceramic materials for hot section components to be used in an automotive gas turbine. As this program evolved, dictates of available funding, Government charter, and technical developments caused program emphases to focus on the development and demonstration of the ceramic turbine hot section and away from the development of engine and powertrain technologies and subsequent vehicular demonstrations. Program technical performance concluded in June 1987. The AGT 100 program successfully achieved project objectives with significant technology advances. Specific AGT 100 program achievements are: (1) Ceramic component feasibility for use in gas turbine engines has been demonstrated; (2) A new, 100 hp engine was designed, fabricated, and tested for 572 hour at operating temperatures to 2200 F, uncooled; (3) Statistical design methodology has been applied and correlated to experimental data acquired from over 5500 hour of rig and engine testing; (4) Ceramic component processing capability has progressed from a rudimentary level able to fabricate simple parts to a sophisticated level able to provide complex geometries such as rotors and scrolls; (5) Required improvements for monolithic and composite ceramic gas turbine components to meet automotive reliability, performance, and cost goals have been identified; (6) The combustor design demonstrated lower emissions than 1986 Federal Standards on methanol, JP-5, and diesel fuel. Thus, the potential for meeting emission standards and multifuel capability has been initiated

  2. Durability Challenges for Next Generation of Gas Turbine Engine Materials

    Science.gov (United States)

    Misra, Ajay K.

    2012-01-01

    Aggressive fuel burn and carbon dioxide emission reduction goals for future gas turbine engines will require higher overall pressure ratio, and a significant increase in turbine inlet temperature. These goals can be achieved by increasing temperature capability of turbine engine hot section materials and decreasing weight of fan section of the engine. NASA is currently developing several advanced hot section materials for increasing temperature capability of future gas turbine engines. The materials of interest include ceramic matrix composites with 1482 - 1648 C temperature capability, advanced disk alloys with 815 C capability, and low conductivity thermal barrier coatings with erosion resistance. The presentation will provide an overview of durability challenges with emphasis on the environmental factors affecting durability for the next generation of gas turbine engine materials. The environmental factors include gaseous atmosphere in gas turbine engines, molten salt and glass deposits from airborne contaminants, impact from foreign object damage, and erosion from ingestion of small particles.

  3. Photon Doppler Velocimeter to Measure Entrained Additive Manufactured Bulk Metal Powders in Hot Subsonic and Supersonic Oxygen Gas

    Science.gov (United States)

    Tylka, Jonathan

    2016-01-01

    Parts produced by additive manufacturing, particularly selective laser melting (SLM), have been shown to silt metal particulate even after undergoing stringent precision aerospace cleaning processes (Lowrey 2016). As printed parts are used in oxygen systems with increased pressures, temperatures, and gas velocity, the risk of ignition by particle impact, the most common direct ignition source of metals in oxygen, substantially increases. The White Sands Test Facility (WSTF), in collaboration with Marshall Space Flight Center (MSFC), desires to test the ignitability of SLM metals by particle impact in heated oxygen. The existing test systems rely on gas velocity calculations to infer particle velocity in both subsonic and supersonic particle impact systems. Until now, it was not possible to directly measure particle velocity. To increase the fidelity of planned SLM ignition studies, it is necessary to validate that the Photon Doppler Velocimetry(PDV) test system can accurately measure particle velocity.

  4. Liquid hot NAGMA cooled to 0.4 K: benchmark thermochemistry of a gas-phase peptide.

    Science.gov (United States)

    Leavitt, Christopher M; Moore, Kevin B; Raston, Paul L; Agarwal, Jay; Moody, Grant H; Shirley, Caitlyne C; Schaefer, Henry F; Douberly, Gary E

    2014-10-16

    Vibrational spectroscopy and helium nanodroplet isolation are used to determine the gas-phase thermochemistry for isomerization between conformations of the model dipeptide, N-acetylglycine methylamide (NAGMA). A two-stage oven source is implemented to produce a gas-phase equilibrium distribution of NAGMA conformers, which is preserved when individual molecules are captured and cooled to 0.4 K by He nanodroplets. With polarization spectroscopy, the IR spectrum in the NH stretch region is assigned to a mixture of two conformers having intramolecular hydrogen bonds composed of either five- or seven-membered rings, C5 and C7, respectively. The C5 to C7 interconversion enthalpy and entropy, obtained from a van't Hoff analysis, are -4.52 ± 0.12 kJ/mol and -12.4 ± 0.2 J/(mol · K), respectively. The experimental thermochemistry is compared to high-level electronic structure theory computations.

  5. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-12-01

    The Federal government is the largest single energy consumer in the United States with consumption of nearly 1.5 quads/year of energy (10{sup 15} quad = 1015 Btu) and cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP) seeks to evaluate new energy -- saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This report provides the results of a field evaluation that PNL conducted for DOE/FEMP with funding support from the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of 4 candidate energy-saving technology-a water heater conversion system to convert electrically powered water heaters to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  6. Influence of Gas Atmosphere Dew Point on the Selective Oxidation and the Reactive Wetting During Hot Dip Galvanizing of CMnSi TRIP Steel

    Science.gov (United States)

    Cho, Lawrence; Lee, Seok Jae; Kim, Myung Soo; Kim, Young Ha; De Cooman, Bruno C.

    2013-01-01

    The selective oxidation and reactive wetting of intercritically annealed Si-bearing CMnSi transformation-induced plasticity steels were investigated by high-resolution transmission electron microscopy. In a N2 + 10 pct H2 gas atmosphere with a dew point (DP) ranging from 213 K to 278 K (-60 °C to 5 °C), a continuous layer of selective oxides was formed on the surface. Annealing in a higher DP gas atmosphere resulted in a thinner layer of external oxidation and a greater depth of internal oxidation. The hot dipping was carried out in a Zn bath containing 0.22 mass pct Al, and the bath temperature was 733 K (460 °C). Coarse and discontinuous Fe2Al5- x Zn x grains and Fe-Zn intermetallics (ζ and δ) were observed at the steel/coating interface after the hot dip galvanizing (HDG) of panels were annealed in a low DP atmosphere 213 K (-60 °C). The Fe-Zn intermetallics were formed both in areas where the Fe2Al5- x Zn x inhibition layer had not been formed and on top of non-stoichiometric Fe-Al-Zn crystals. Poor wetting was observed on panels annealed in a low DP atmosphere because of the formation of thick film-type oxides on the surface. After annealing in higher DP gas atmospheres, i.e., 263 K and 278 K (-10 °C and 5 °C), a continuous and fine-grained Fe2Al5- x Zn x layer was formed. No Fe-Zn intermetallics were formed. The small grain size of the inhibition layer was attributed to the nucleation of the Fe2Al5- x Zn x grains on small ferrite sub-surface grains and the presence of granular surface oxides. A high DP atmosphere can therefore significantly contribute to the decrease of Zn-coating defects on CMnSi TRIP steels processed in HDG lines.

  7. Influence of Veneering Fabrication Techniques and Gas-Phase Fluorination on Bond Strength between Zirconia and Veneering Ceramics.

    Science.gov (United States)

    Pharr, Stewart W; Teixeira, Erica C; Verrett, Ronald; Piascik, Jeffrey R

    2016-08-01

    Porcelain chipping has been one of the main problems of porcelain-fused-to-zirconia restorations. This study evaluates the bond strengths of layered, pressed, and adhesively bonded porcelain to yttria-stabilized zirconia substrates that have undergone traditional preparation or gas-phase fluorination. A three-point bending test was used to evaluate the bond strength of the porcelain and zirconia interface. Sixty-six specimens were prepared (n = 11) following ISO 9693 and loaded until failure using an Instron testing machine. One-half of the zirconia substrates received gas phase fluorination treatment before veneering application. Three porcelain veneering methods were evaluated: layered, pressed, and adhesively bonded porcelain. Bond strength results were interpreted using a two-way ANOVA and a Bonferroni multiple comparisons test. Statistical significance was set at α = 0.05. ANOVA revealed a statistically significant effect of the veneering fabrication methods. No main effect was observed regarding the surface treatment to the zirconia. There was a significant effect related to the veneering method used to apply porcelain to zirconia. For untreated zirconia, layered porcelain had a significantly higher flexural strength compared to pressed or bonded, while pressed and bonded porcelains were not significantly different from one another. For zirconia specimens receiving fluorination treatment, both layered and pressed porcelains had significantly higher bond strengths than adhesively bonded porcelain. In addition, fluorinated pressed porcelain was not statistically different from the control layered or fluorinated layered porcelain. The choice of veneering fabrication technique was critical when evaluating the zirconia to porcelain interfacial bond strength. Bonded porcelain to zirconia had a lower flexural strength than layered or pressed porcelain, regardless of zirconia surface treatment. In addition, fluorination had an effect on the bond strength of pressed

  8. THE USE OF COATINGS FOR HOT CORROSION AND EROSION PROTECTION IN TURBINE HOT SECTION COMPONENTS

    Directory of Open Access Journals (Sweden)

    Hayrettin AHLATCI

    1999-01-01

    Full Text Available High pressure turbine components are subjected to a wide variety of thermal and mechanical loading during service. In addition, the components are exposed to a highly oxidizing atmosphere which may contain contaminants such as sulphates, chlorides and sulphuorous gases along with erosive media. So the variety of surface coatings and deposition processes available for the protection of blade and vane components in gas turbines are summarised in this study. Coating types range from simple diffusion aluminides to modified aluminides and a CoCrAlY overlayer. The recommendations for corrosion-resistant coatings (for low temperature and high temperature hot corrosion environments are as follows: silicon aluminide and platinumchromium aluminide for different gas turbine section superalloys substrates. Platinum metal additions are used to improve the properties of coatings on turbine components. Inorganic coatings based on ceramic films which contain aluminium or aluminium and silicon are very effective in engines and gas turbines. Diffusion, overlayer and thermal barrier coatings which are deposited on superalloys gas turbine components by pack cementation, plasma spraying processes and a number of chemical vapour deposition, physical vapour deposition processes (such as electron beam, sputtering, ion plating are described. The principles underlying the development of protective coatings serve as a useful guide in the choice of coatings for other high temperature applications.

  9. rhapsody-g simulations - I. The cool cores, hot gas and stellar content of massive galaxy clusters

    Science.gov (United States)

    Hahn, Oliver; Martizzi, Davide; Wu, Hao-Yi; Evrard, August E.; Teyssier, Romain; Wechsler, Risa H.

    2017-09-01

    We present the rhapsody-g suite of cosmological hydrodynamic zoom simulations of 10 massive galaxy clusters at the Mvir ˜ 1015 M⊙ scale. These simulations include cooling and subresolution models for star formation and stellar and supermassive black hole feedback. The sample is selected to capture the whole gamut of assembly histories that produce clusters of similar final mass. We present an overview of the successes and shortcomings of such simulations in reproducing both the stellar properties of galaxies as well as properties of the hot plasma in clusters. In our simulations, a long-lived cool-core/non-cool-core dichotomy arises naturally, and the emergence of non-cool cores is related to low angular momentum major mergers. Nevertheless, the cool-core clusters exhibit a low central entropy compared to observations, which cannot be alleviated by thermal active galactic nuclei feedback. For cluster scaling relations, we find that the simulations match well the M500-Y500 scaling of Planck Sunyaev-Zeldovich clusters but deviate somewhat from the observed X-ray luminosity and temperature scaling relations in the sense of being slightly too bright and too cool at fixed mass, respectively. Stars are produced at an efficiency consistent with abundance-matching constraints and central galaxies have star formation rates consistent with recent observations. While our simulations thus match various key properties remarkably well, we conclude that the shortcomings strongly suggest an important role for non-thermal processes (through feedback or otherwise) or thermal conduction in shaping the intracluster medium.

  10. "Hot spots" of N and C impact nitric oxide, nitrous oxide and nitrogen gas emissions from a UK grassland soil.

    Science.gov (United States)

    Loick, Nadine; Dixon, Elizabeth; Abalos, Diego; Vallejo, Antonio; Matthews, Peter; McGeough, Karen; Watson, Catherine; Baggs, Elizabeth M; Cardenas, Laura M

    2017-11-01

    Agricultural soils are a major source of nitric- (NO) and nitrous oxide (N2O), which are produced and consumed by biotic and abiotic soil processes. The dominant sources of NO and N2O are microbial nitrification and denitrification, and emissions of NO and N2O generally increase after fertiliser application. The present study investigated the impact of N-source distribution on emissions of NO and N2O from soil and the significance of denitrification, rather than nitrification, as a source of NO emissions. To eliminate spatial variability and changing environmental factors which impact processes and results, the experiment was conducted under highly controlled conditions. A laboratory incubation system (DENIS) was used, allowing simultaneous measurement of three N-gases (NO, N2O, N2) emitted from a repacked soil core, which was combined with (15)N-enrichment isotopic techniques to determine the source of N emissions. It was found that the areal distribution of N and C significantly affected the quantity and timing of gaseous emissions and (15)N-analysis showed that N2O emissions resulted almost exclusively from the added amendments. Localised higher concentrations, so-called hot spots, resulted in a delay in N2O and N2 emissions causing a longer residence time of the applied N-source in the soil, therefore minimising NO emissions while at the same time being potentially advantageous for plant-uptake of nutrients. If such effects are also observed for a wider range of soils and conditions, then this will have major implications for fertiliser application protocols to minimise gaseous N emissions while maintaining fertilisation efficiency.

  11. Effect of Mo-rich Fillers in Pulsed Current Gas Tungsten Arc Welding of Inconel 718 for Improved Strength and Hot Corrosion Resistance

    Science.gov (United States)

    Ramkumar, K. Devendranath; Bhalodi, Aman Jayesh; Ashokbhai, Harsh Jivani; Balaji, Abhijit; Aravind, S.; Aravind, K. M.; Varma, Vinayak

    2017-10-01

    The formation of Laves phase in the fusion zone of Inconel 718 welds is considered to be detrimental and requires major attention, as this phase deteriorates the mechanical properties and high-temperature corrosion resistance. This present study addresses the use of current pulsing technique on the gas tungsten arc welding of 5-mm-thick Inconel 718 plates. Nb-free fillers, namely ERNiCrMo-10 and ERNiCrMo-14, are chosen for joining these plates. Microstructure studies revealed the segregation of Mo-rich phases at the inter-dendritic regions of the fusion zone of both the weldments. Further, the occurrence of detrimental Laves phase was minimized while employing Mo-rich fillers. It is inferred from the tensile studies that the fractures occurred in the parent metal for ERNiCrMo-10 filler and at the fusion zone while employing ERNiCrMo-14. Room-temperature Charpy impact studies also affirm that the impact toughness of ERNiCrMo-10 welds is significantly greater than that of ERNiCrMo-14. Hot corrosion studies were performed on the coupons by exposing them to a synthetic molten salt environment comprising Na2SO4 + 60%V2O5 at 800 °C for 50 h. Owing to the presence of higher amounts of Cr2O3 and NiO, both fusion zones exhibited better hot corrosion resistance than the parent metal. The novel outcome of the study reiterates that with the use of current pulsing and Mo-rich fillers, the detrimental phase shall be controlled.

  12. Effect of Mo-rich Fillers in Pulsed Current Gas Tungsten Arc Welding of Inconel 718 for Improved Strength and Hot Corrosion Resistance

    Science.gov (United States)

    Ramkumar, K. Devendranath; Bhalodi, Aman Jayesh; Ashokbhai, Harsh Jivani; Balaji, Abhijit; Aravind, S.; Aravind, K. M.; Varma, Vinayak

    2017-11-01

    The formation of Laves phase in the fusion zone of Inconel 718 welds is considered to be detrimental and requires major attention, as this phase deteriorates the mechanical properties and high-temperature corrosion resistance. This present study addresses the use of current pulsing technique on the gas tungsten arc welding of 5-mm-thick Inconel 718 plates. Nb-free fillers, namely ERNiCrMo-10 and ERNiCrMo-14, are chosen for joining these plates. Microstructure studies revealed the segregation of Mo-rich phases at the inter-dendritic regions of the fusion zone of both the weldments. Further, the occurrence of detrimental Laves phase was minimized while employing Mo-rich fillers. It is inferred from the tensile studies that the fractures occurred in the parent metal for ERNiCrMo-10 filler and at the fusion zone while employing ERNiCrMo-14. Room-temperature Charpy impact studies also affirm that the impact toughness of ERNiCrMo-10 welds is significantly greater than that of ERNiCrMo-14. Hot corrosion studies were performed on the coupons by exposing them to a synthetic molten salt environment comprising Na2SO4 + 60%V2O5 at 800 °C for 50 h. Owing to the presence of higher amounts of Cr2O3 and NiO, both fusion zones exhibited better hot corrosion resistance than the parent metal. The novel outcome of the study reiterates that with the use of current pulsing and Mo-rich fillers, the detrimental phase shall be controlled.

  13. Fatigue lifespan of a mobile blade gas turbine with ceramic coating; Vida util por fatiga de un alabe movil de turbina de gas con recubrimiento ceramico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Illescas, Rafael; Z. Mazur Czerwiec, Zdzislaw; Islas Mungarro, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rgi@iie.org.mx; mazur@iie.org.mx; rick_iie@terra.com.mx

    2010-11-15

    Fatigue analysis of a gas turbine moving blade made of IN738LC was carried out in order to evaluate useful life time. The life estimation was done from a previous 3D linear finite element analysis where thermal and mechanical stress calculation at high temperatures was done during steady and transient state i.e. normal start ups and shutdowns. Several load histories with different stresses and strains in the blade were used for different cooling conditions including a thermal barrier coating in comparison with to simple blade without such coating. The important effect of high temperatures on the blade material and stress calculations is shown. The analysis is focused on two different critical zones in the blade: the leading edge at the middle of the height and a cooling channel surface, where high stresses were found in numerical analysis as well as in reality. Finally, the benefit of the presence of a thermal barrier coating in the blade life is shown. [Spanish] Se realizo el analisis de fatiga de un alabe movil de turbina de gas fabricado de IN738LC a fin de evaluar su vida util. La estimacion de vida fue realizada a partir de simulaciones lineales de esfuerzos termomecanicos por elemento finito en 3D a altas temperaturas y durante el arranque y paro normal. Se utilizaron diversos historiales de carga, esfuerzos y deformaciones del alabe para diferentes configuraciones de enfriamiento incluyendo el recubrimiento ceramico tipo barrera termica en comparacion con los resultados sin incluir dicho recubrimiento. Se presenta el efecto importante de las temperaturas elevadas en las propiedades de fatiga del material del alabe y en sus esfuerzos. El analisis se centra en dos puntos de interes identificados como criticos: borde de entrada y un canal de enfriamiento, en donde esfuerzos elevados fueron encontrados tanto numericamente como en la realidad. Finalmente se muestra el beneficio del recubrimiento tipo barrera termica en la vida del alabe.

  14. Engineering ceramics

    CERN Document Server

    Bengisu, Murat

    2001-01-01

    This is a comprehensive book applying especially to junior and senior engineering students pursuing Materials Science/ Engineering, Ceramic Engineering and Mechanical Engineering degrees. It is also a reference book for other disciplines such as Chemical Engineering, Biomedical Engineering, Nuclear Engineering and Environmental Engineering. Important properties of most engineering ceramics are given in detailed tables. Many current and possible applications of engineering ceramics are described, which can be used as a guide for materials selection and for potential future research. While covering all relevant information regarding raw materials, processing properties, characterization and applications of engineering ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search.

  15. Support Services for Ceramic Fiber-Ceramic Matrix Composites

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, JP

    2001-08-16

    To increase national energy self-sufficiency for the near future, power systems will be required to fire low-grade fuels more efficiently than is currently possible. The typical coal-fired steam cycle used at present is limited to a maximum steam temperature of 540 C and a conversion efficiency of 35%. Higher working-fluid temperatures are required to boost efficiency, exposing subsystems to very damaging conditions. Issues of special concern to materials developers are corrosion and warping of hot-gas particulate filters and corrosion and erosion of high-temperature heat exchangers. The University of North Dakota Energy and Environmental Research Center (EERC) is working with the National Energy Technology Laboratory in conjunction with NCC Engineering, Inc., to provide technical assistance and coal by-products to the Fossil Energy Materials Advanced Research and Technology Development Materials Program investigating materials failure in fossil energy systems. The main activities of the EERC are to assemble coal slag and hot-gas filter ash samples for use by materials researchers, to assist in providing opportunities for realistic tests of advanced materials in pilot-scale fossil energy systems, and to provide analytical support in determining corrosion mechanisms of the exposed materials. In this final report for the project year of September 2000 through August 2001, the facilities at the EERC that can be used by researchers for realistic testing of materials are described. Researchers can include sample coupons in each of these facilities at no cost since they are being operated under separate funding. In addition, two pilot-scale coal combustion tests are described in which material sample coupons were included from researchers involved in the development of fossil energy materials. The results of scanning electron microscopy (SEM) energy dispersive x-ray analyses of the corrosion products and interactions between the surface scales of the coupons and the

  16. Hot Isostatic Pressing of Superconducting Ceramics

    Science.gov (United States)

    1990-10-01

    stain- less steel) tubes . HIPing at 8500 C and 207 MPa for 1 hour in the Pyrex tube resulted in a material that became superconducting at 650 K... Porn -!ty . 12 10 8 6 4 - Type A 2 Type B C] Sintered 0 I 1 1 1 0 50 100 150 200 Processing Pressure (MPa) Figure 6b. Porosity measurements for samples...proposed. All samples were sealed under vacuum in glass tubes . During the initial sequence of the HIP cycle, the samples were heated to the soak temperature

  17. CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2

    Energy Technology Data Exchange (ETDEWEB)

    Paul K. T. Liu

    2004-02-19

    Two process schemes have been investigated by us for the use of hydrotalcites we prepared as CO{sub 2} adsorbents to enhance water gas shift (WGS) reaction: Case I involves the adsorption enhanced WGS packed bed reactor and Case II involves the adsorption enhanced WGS membrane reactor. Both cases will achieve the same objective as the hydrotalcite membrane reactor: i.e., improving the WGS reactor efficiency via the concomitant removal of CO{sub 2} for sequestration. In this report a detailed investigation of the design characteristics and performance of Case II, termed the Hybrid Adsorbent-Membrane Reactor (HAMR), is presented. The HAMR system includes a packed-bed catalytic membrane reactor (hydrogen selective) coupling the WGS reaction (in a porous hydrogen selective membrane) with CO{sub 2} removal with an adsorbent in the permeate side. The reactor characteristics have been investigated for a range of permeance and selectivity relevant to the aforementioned application. The HAMR system shows enhanced CO conversion, hydrogen yield, and product purity, and provides good promise for reducing the hostile operating conditions of conventional WGS reactors, and for meeting the CO{sub 2} sequestration objective. In the next quarterly report we will present the simulation result for Case I as well as the progress on hydrotalcite membrane synthesis.

  18. Ceramic fiber reinforced glass-ceramic matrix composite

    Science.gov (United States)

    Bansal, Narottam P. (Inventor)

    1993-01-01

    A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

  19. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn{sub 2}O{sub 3} sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.F.; Liu, B.S., E-mail: bingsiliu@tju.edu.cn; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-09-15

    Graphical abstract: - Highlights: • Mn{sub 2}O{sub 3}/KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn{sub 2}O{sub 3}/KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn{sub 2}O{sub 3} sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn{sub 2}O{sub 3} sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H{sub 2}S. The fresh and used sorbents were characterized by means of N{sub 2}-adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H{sub 2} temperature- programmed reduction (H{sub 2}-TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn{sub 2}O{sub 3}/diatomite, all mesoporous silica supported Mn{sub 2}O{sub 3} sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn{sub 2}O{sub 3}/MCM-41 and Mn{sub 2}O{sub 3}/HMS sorbent, the Mn{sub 2}O{sub 3}/KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn{sub 2}O{sub 3}/KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn{sub 2}O{sub 3}/KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  20. Fluid geochemistry and soil gas fluxes (CO2-CH4-H2S) at a promissory Hot Dry Rock Geothermal System: The Acoculco caldera, Mexico

    Science.gov (United States)

    Peiffer, L.; Bernard-Romero, R.; Mazot, A.; Taran, Y. A.; Guevara, M.; Santoyo, E.

    2014-09-01

    The Acoculco caldera has been recognized by the Mexican Federal Electricity Company (CFE) as a Hot Dry Rock Geothermal System (HDR) and could be a potential candidate for developing an Enhanced Geothermal System (EGS). Apart from hydrothermally altered rocks, geothermal manifestations within the Acoculco caldera are scarce. Close to ambient temperature bubbling springs and soil degassing are reported inside the caldera while a few springs discharge warm water on the periphery of the caldera. In this study, we infer the origin of fluids and we characterize for the first time the soil degassing dynamic. Chemical and isotopic (δ18O-δD) analyses of spring waters indicate a meteoric origin and the dissolution of CO2 and H2S gases, while gas chemical and isotopic compositions (N2/He, 3He/4He, 13C, 15N) reveal a magmatic contribution with both MORB- and arc-type signatures which could be explained by an extension regime created by local and regional fault systems. Gas geothermometry results are in agreement with temperature measured during well drilling (260 °C-300 °C). Absence of well-developed water reservoir at depth impedes re-equilibration of gases upon surface. A multi-gas flux survey including CO2, CH4 and H2S measurements was performed within the caldera. Using the graphical statistical analysis (GSA) approach, CO2 flux measurements were classified in two populations. Population A, representing 95% of measured fluxes is characterized by low values (mean: 18 g m- 2 day- 1) while the remaining 5% fluxes belonging to Population B are much higher (mean: 5543 g m- 2 day- 1). This low degassing rate probably reflects the low permeability of the system, a consequence of the intense hydrothermal alteration observed in the upper 800 m of volcanic rocks. An attempt to interpret the origin and transport mechanism of these fluxes is proposed by means of flux ratios as well as by numerical modeling. Measurements with CO2/CH4 and CO2/H2S flux ratios similar to mass ratios

  1. Advanced ceramic materials for next-generation nuclear applications

    Science.gov (United States)

    Marra, John

    2011-10-01

    The nuclear industry is at the eye of a 'perfect storm' with fuel oil and natural gas prices near record highs, worldwide energy demands increasing at an alarming rate, and increased concerns about greenhouse gas (GHG) emissions that have caused many to look negatively at long-term use of fossil fuels. This convergence of factors has led to a growing interest in revitalization of the nuclear power industry within the United States and across the globe. Many are surprised to learn that nuclear power provides approximately 20% of the electrical power in the US and approximately 16% of the world-wide electric power. With the above factors in mind, world-wide over 130 new reactor projects are being considered with approximately 25 new permit applications in the US. Materials have long played a very important role in the nuclear industry with applications throughout the entire fuel cycle; from fuel fabrication to waste stabilization. As the international community begins to look at advanced reactor systems and fuel cycles that minimize waste and increase proliferation resistance, materials will play an even larger role. Many of the advanced reactor concepts being evaluated operate at high-temperature requiring the use of durable, heat-resistant materials. Advanced metallic and ceramic fuels are being investigated for a variety of Generation IV reactor concepts. These include the traditional TRISO-coated particles, advanced alloy fuels for 'deep-burn' applications, as well as advanced inert-matrix fuels. In order to minimize wastes and legacy materials, a number of fuel reprocessing operations are being investigated. Advanced materials continue to provide a vital contribution in 'closing the fuel cycle' by stabilization of associated low-level and high-level wastes in highly durable cements, ceramics, and glasses. Beyond this fission energy application, fusion energy will demand advanced materials capable of withstanding the extreme environments of high

  2. Operating safety of a hot-shot wind tunnel with combined test gas heating in stabilization mode

    Science.gov (United States)

    Shumskii, V. V.; Yaroslavtsev, M. I.

    2017-07-01

    In the present paper, we analyze emergency situations typical of short-duration wind tunnels with electric-arc or combined test-gas heating in the presence of stabilization and diaphragm-rupturing systems, which occur in the case of no discharge initiation in the settling chamber, with the capacitor battery having remained charged during the start of wind-tunnel systems. For avoiding such emergency situations, some additional changes based on using feedback elements are introduced into the wind-tunnel design: the piston of the fast-response valve is made hollow for increasing the volume of the shutoff cavity and for making the release of pressure from this cavity unnecessary; the high-pressure channel, which connects the piston and the piston rod with the settling-chamber cavity, is filled with a liquid and is closed from the side of the settling chamber with a piston; the device for controlled diaphragm breakdown is provided with an external electric circuit intended to control the diaphragm-rupturing process. Those modifications allow subsequent functioning of the wind-tunnel systems only in the presence of heat-supply-induced pressure growth in the settling chamber of the wind tunnel.

  3. Low-pressure-ratio regenerative exhaust-heated gas turbine. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

    1991-01-01

    A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

  4. Abrasive wear behaviour of bio-active glass ceramics containing ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. In this study, abrasive wear behaviour of bio-active glass ceramic materials produced with two different processes is studied. Hot pressing process and conventional casting and controlled crystallization process were used to produce bio-active ceramics. Fracture toughness of studied material was calculated by.

  5. Texturing of superconducting Bi-Pb-Sr-Ca-Cu-O ceramics by combining the effect of a magnetic field and hot pressing in one direction; Texturation des ceramiques supraconductrices Bi-Pb-Sr-Ca-Cu-O par combinaison des effets du champ magnetique et de la contrainte uniaxiale a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Noudem, J.G.

    1995-10-27

    Superconducting Bi-(Pb)-Sr-Ca-Cu-O (Bi:2223) ceramics have a weak 77 K transport critical current density (Jc) due to porosity and the presence of misaligned platelets. In order to obtain higher critical current densities in these materials, it is necessary to increase their density and induce a preferential crystallographic orientation. We have developed a texturing process using solidification in a magnetic field combined with hot pressing. The experimental set-up provides a uniaxial pressure of 60 MPa and temperature up to 1100 deg C in a magnetic field of 8 T. Magnetic melt texturing (MMT) proved to be very effective in producing bulk oriented samples of polycrystalline Bi:2223 (crystallite c-axis oriented parallel to the field direction). These samples have Jc values of up to 1450 A/cm{sup 2} and a density of 5.1 g/cm{sup 3}. The texturing by hot pressing (HP) gives homogeneous, dense ({approx} 6 g/cm{sup 3}; 95 % of the theoretical limit) ceramics with a Jc of 2500 A/cm{sup 2}. Tapes of Ag/Bi:2223 provided by Alcatel Alsthom were also successful textured using HP. Finally we have demonstrated that the combination of solidification in a magnetic field with hot pressing (MMHPT) improves both the texture and density of the samples. Moreover the samples are very homogeneous and mechanically resistant. The 77 K transport critical current densities have values up to 3800 A/cm{sup 2} and 1100 A/cm{sup 2} along the (ab) and c-axis respectively. We have demonstrated that these samples are of potential use a current limiters. (author) 146 refs.

  6. The Interstellar Medium in Our Galaxy: a New Interpretation of the Distribution of Hot/cool Gas Boundaries in the Disk, and Models of Supernova Remnants in the Halo.

    Science.gov (United States)

    Shelton, Robin Lynn

    1996-01-01

    O VI in the Interstellar Medium. The Copernicus O^{+5} column densities trace the 10^{5.5} K gas in the interstellar medium. We statistically re-analyze the dataset, including the possibility that local hot gas may contribute a significant O^{+5 } column density to most lines of sight. Our reanalysis includes slight improvements in the statistics and was found to be reliable when tested on simulated data sets. Our conclusions differ considerably from those of the original analysis and strongly influence the understanding of the interstellar medium, in particular the volume occupation of the hot and warm components, and mechanisms responsible for them. The Local Bubble column density compares favorably with the estimated quantity of O^{+5 } within the remnant of an ancient local explosion. Similarly, our mean O^{+5} column density per external feature agrees with models of hot interstellar bubbles from either stellar winds or ancient supernova explosions in a warm diffuse interstellar environment, suggesting that the hot gas in interstellar space may exist primarily within discrete regions of modest volume occupation rather than in a continuous and pervasive phase. Supernova Remnants in the Halo. High latitude observations of C^{+3} N^{+4}, and O ^{+5}, and the shadowing of high latitude x-ray emission by intervening hydrogen clouds indicate the presence of hot (~10 ^4 to 10^6K) gas in the halo of our galaxy. This project explores the contributions made by isolated supernova remnants. Their evolving structures were simulated with a hydrodynamic computer code. The results are intriguing. (1) At late times the remnants collapse faster than the high -stage ions can recombine. (2) The high-stage ions in the ensemble of remnants cover about ~50% of the sky. (3) The ensemble provides average column densities of >3.1 times 10 13 O^ {+5} atoms cm^{-2 }, >2.5 times 1012 N ^{+4} atoms cm^ {-2} and gg9.8 times 1012 C^{+3} atoms cm ^{-2}. The average O ^{+5} column density is

  7. Fibrous-Ceramic/Aerogel Composite Insulating Tiles

    Science.gov (United States)

    White, Susan M.; Rasky, Daniel J.

    2004-01-01

    Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

  8. Additive Manufacturing of Silicon Carbide-Based Ceramic Matrix Composites: Technical Challenges and Opportunities

    Science.gov (United States)

    Singh, Mrityunjay; Halbig, Michael C.; Grady, Joseph E.

    2016-01-01

    Advanced SiC-based ceramic matrix composites offer significant contributions toward reducing fuel burn and emissions by enabling high overall pressure ratio (OPR) of gas turbine engines and reducing or eliminating cooling air in the hot-section components, such as shrouds, combustor liners, vanes, and blades. Additive manufacturing (AM), which allows high value, custom designed parts layer by layer, has been demonstrated for metals and polymer matrix composites. However, there has been limited activity on additive manufacturing of ceramic matrix composites (CMCs). In this presentation, laminated object manufacturing (LOM), binder jet process, and 3-D printing approaches for developing ceramic composite materials are presented. For the laminated object manufacturing (LOM), fiber prepreg laminates were cut into shape with a laser and stacked to form the desired part followed by high temperature heat treatments. For the binder jet, processing optimization was pursued through silicon carbide powder blending, infiltration with and without SiC nano powder loading, and integration of fibers into the powder bed. Scanning electron microscopy was conducted along with XRD, TGA, and mechanical testing. Various technical challenges and opportunities for additive manufacturing of ceramics and CMCs will be presented.

  9. Hot Flashes

    Science.gov (United States)

    ... Risk factors Not all women who go through menopause have hot flashes, and it's not clear why some women do have them. Factors that may increase your risk include: Smoking. Women who smoke are more likely to get hot flashes. Obesity. A high body mass index (BMI) is associated ...

  10. Hot flushes

    African Journals Online (AJOL)

    without thermoregulatory homeostatic mechanisms, such as sweating, being triggered. Small fluctuations in core body. Abstract. Vasomotor symptoms, such as hot flushes and night sweats, are considered to be the cardinal symptoms of menopause, and are experienced by most women. The physiology of hot flushes is not ...

  11. SiC/SiC Leading Edge Turbine Airfoil Tested Under Simulated Gas Turbine Conditions

    Science.gov (United States)

    Robinson, R. Craig; Hatton, Kenneth S.

    1999-01-01

    Silicon-based ceramics have been proposed as component materials for use in gas turbine engine hot-sections. A high pressure burner rig was used to expose both a baseline metal airfoil and ceramic matrix composite leading edge airfoil to typical gas turbine conditions to comparatively evaluate the material response at high temperatures. To eliminate many of the concerns related to an entirely ceramic, rotating airfoil, this study has focused on equipping a stationary metal airfoil with a ceramic leading edge insert to demonstrate the feasibility and benefits of such a configuration. Here, the idea was to allow the SiC/SiC composite to be integrated as the airfoil's leading edge, operating in a "free-floating" or unrestrained manner. and provide temperature relief to the metal blade underneath. The test included cycling the airfoils between simulated idle, lift, and cruise flight conditions. In addition, the airfoils were air-cooled, uniquely instrumented, and exposed to the same internal and external conditions, which included gas temperatures in excess of 1370 C (2500 F). Results show the leading edge insert remained structurally intact after 200 simulated flight cycles with only a slightly oxidized surface. The instrumentation clearly suggested a significant reduction (approximately 600 F) in internal metal temperatures as a result of the ceramic leading edge. The object of this testing was to validate the design and analysis done by Materials Research and Design of Rosemont, PA and to determine the feasibility of this design for the intended application.

  12. Ceramic oxygen transport membrane array reactor and reforming method

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Christie, Gervase Maxwell; Rosen, Lee J.; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-09-27

    A commercially viable modular ceramic oxygen transport membrane reforming reactor for producing a synthesis gas that improves the thermal coupling of reactively-driven oxygen transport membrane tubes and catalyst reforming tubes required to efficiently and effectively produce synthesis gas.

  13. Ceramic Seal.

    Energy Technology Data Exchange (ETDEWEB)

    Smartt, Heidi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Romero, Juan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Custer, Joyce Olsen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hymel, Ross W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Krementz, Dan [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Gobin, Derek [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Harpring, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martinez-Rodriguez, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Varble, Don [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiMaio, Jeff [Tetramer Technologies, Pendleton, SC (United States); Hudson, Stephen [Tetramer Technologies, Pendleton, SC (United States)

    2016-11-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  14. ceramic pigment

    Indian Academy of Sciences (India)

    In contrast, the relatively poor blue colour obtained by dispersing Co2SiO4 into ceramic glazes is mainly attributed to the evolution of Co2+ initially in octahedral coordination of olivine structure to tetrahedral coordination of glassy phase. On the other hand, regarding the growing concern on. Co costs and environmental ...

  15. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  16. IR Hot Wave

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  17. Ceramic technology for Advanced Heat Engines Project

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.

    1991-07-01

    Significant accomplishments in fabricating ceramic components for advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and database and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. This project is managed by ORNL for the Office of Transportation Technologies, Office of Transportation Materials, and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DOD, and industry.

  18. Ceramic Technology For Advanced Heat Engines Project

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. This advanced materials technology is being developed in parallel and close coordination with the ongoing DOE and industry proof of concept engine development programs. To facilitate the rapid transfer of this technology to U.S. industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. Abstracts prepared for appropriate papers.

  19. Experience with hot catchpots

    Energy Technology Data Exchange (ETDEWEB)

    1945-02-02

    The first part of this report was actually a letter regarding the question, ''could the hot circulating pump be omitted when processing pitch at 700 atm.'' It had been stated that the hot circulation pump could be omitted if the quantity of cold letdown was correspondingly increased. The latest experiences with the catchpot at Poelitz showed the following. When running pitch, tar, or petroleum in the liquid-phase stalls, frequent trouble with the hot catchpot was encountered due to the coking. This coking was caused by irregular letdown yield, which could not be avoided due to small temperature fluctuations in the stall. This caused interruption of the uniform flow in the hot catchpot and the deposition of the solids contained in the letdown, largely catalyst solids, due to the asphalt content. Coking of the product was initiated by this concentration of catalyst solids. A perforated double jacket was inserted in the conical part of the catchpot through which about 3000 m/sup 3/ per hour of cold gas was blown in continuously. By this agitation and cooling in the lowest part of the catchpot, catalyst deposits were prevented from forming and the product received a continuous added supply of hydrogen. Another letter was given discussing the same question and an alternate solution. This second letter described Welheim's design for the hot catchpot. It featured introduction of 5000 to 6000 m/sup 3//hr of cold circulating gas into the lower part of the catchpot, and withdrawal of letdown from a point above the gas inlet. The advantages were continued agitation and cooling of the sludge and constant retention of some cold sludge in the catchpot (which evened out throughput and content fluctuations)

  20. Hot conditioning equipment conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  1. Hot Soak

    OpenAIRE

    Goldwater, H.

    2005-01-01

    The DVD is documentation of Hot Soak, as performed at the Queen’s Hotel, Penzance, Cornwall in an en suite bathroom, for Tract: Live Art Festival, 2006, curated by Art Surgery/ Newlyn Art Gallery. Hot Soak was originally made for home, London, 2005. This piece marries an everyday environment (bathroom) with extraordinary materials (ice cubes/ dress bleeding red into water) creating the surreal. Sontag’s understanding of camp as a love of the unnatural, artifice and exaggeration, can be ci...

  2. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  3. Solutions for Hot Situations

    Science.gov (United States)

    2003-01-01

    From the company that brought the world an integral heating and cooling food service system after originally developing it for NASA's Apollo Program, comes yet another orbital offshoot: a product that can be as thin as paper and as strong as steel. Nextel Ceramic Textiles and Composites from 3M Company offer space-age protection and innovative solutions for hot situations, ranging from NASA to NASCAR. With superior thermal protection, Nextel fabrics, tape, and sleevings outperform other high temperature textiles such as aramids, carbon, glass, and quartz, permitting engineers and manufacturers to handle applications up to 2,500 F (1,371 C). The stiffness and strength of Nextel Continuous Ceramic Fibers make them a great match for improving the rigidity of aluminum in metal matrix composites. Moreover, the fibers demonstrate low shrinkage at operating temperatures, which allow for the manufacturing of a dimensionally stable product. These novel fibers also offer excellent chemical resistance, low thermal conductivity, thermal shock resistance, low porosity, and unique electrical properties.

  4. Improving Turbine Performance with Ceramic Matrix Composites

    Science.gov (United States)

    DiCarlo, James A.

    2007-01-01

    Under the new NASA Fundamental Aeronautics Program, efforts are on-going within the Supersonics Project aimed at the implementation of advanced SiC/SiC ceramic composites into hot section components of future gas turbine engines. Due to recent NASA advancements in SiC-based fibers and matrices, these composites are lighter and capable of much higher service temperatures than current metallic superalloys, which in turn will allow the engines to operate at higher efficiencies and reduced emissions. This presentation briefly reviews studies within Task 6.3.3 that are primarily aimed at developing physics-based concepts, tools, and process/property models for micro- and macro-structural design, fabrication, and lifing of SiC/SiC turbine components in general and airfoils in particular. Particular emphasis is currently being placed on understanding and modeling (1) creep effects on residual stress development within the component, (2) fiber architecture effects on key composite properties such as design strength, and (3) preform formation processes so that the optimum architectures can be implemented into complex-shaped components, such as turbine vanes and blades.

  5. Ceramic Integration Technologies for Advanced Energy Systems: Critical Needs, Technical Challenges, and Opportunities

    Science.gov (United States)

    Singh, Mrityunjay

    2010-01-01

    Advanced ceramic integration technologies dramatically impact the energy landscape due to wide scale application of ceramics in all aspects of alternative energy production, storage, distribution, conservation, and efficiency. Examples include fuel cells, thermoelectrics, photovoltaics, gas turbine propulsion systems, distribution and transmission systems based on superconductors, nuclear power generation and waste disposal. Ceramic integration technologies play a key role in fabrication and manufacturing of large and complex shaped parts with multifunctional properties. However, the development of robust and reliable integrated systems with optimum performance requires the understanding of many thermochemical and thermomechanical factors, particularly for high temperature applications. In this presentation, various needs, challenges, and opportunities in design, fabrication, and testing of integrated similar (ceramic ceramic) and dissimilar (ceramic metal) material www.nasa.gov 45 ceramic-ceramic-systems have been discussed. Experimental results for bonding and integration of SiC based Micro-Electro-Mechanical-Systems (MEMS) LDI fuel injector and advanced ceramics and composites for gas turbine applications are presented.

  6. Advanced Ceramic Materials for Future Aerospace Applications

    Science.gov (United States)

    Misra, Ajay

    2015-01-01

    With growing trend toward higher temperature capabilities, lightweight, and multifunctionality, significant advances in ceramic matrix composites (CMCs) will be required for future aerospace applications. The presentation will provide an overview of material requirements for future aerospace missions, and the role of ceramics and CMCs in meeting those requirements. Aerospace applications will include gas turbine engines, aircraft structure, hypersonic and access to space vehicles, space power and propulsion, and space communication.

  7. Hot corrosion of the ceramic composite coating Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO plasma sprayed on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Shirazi, Amir Khodaparast; Kiahosseini, Seyed Rahim [Islamic Azad Univ., Damghan (Iran, Islamic Republic of). Dept. of Engineering

    2017-08-15

    Ni{sub 3}Al-Al{sub 2}O{sub 3}-Al{sub 2}O{sub 3}/MgO three-layered coatings with thicknesses of 50, 100, and 150 μm for Al{sub 2}O{sub 3}/MgO and 100 μm for the other layers were deposited on 316L stainless steel using plasma spraying. X-ray diffraction, atomic force microscopy, furnace hot corrosion testing in the presence of a mixture of Na{sub 2}SO{sub 4} and V{sub 2}O{sub 5} corrosive salts and scanning electron microscopy were used to determine the structural, morphological and hot corrosion resistance of samples. Results revealed that the crystalline grains of MgO and Al{sub 2}O{sub 3} coating were very small. Weight loss due to hot corrosion decreased from approximately 4.267 g for 316L stainless steel without coating to 2.058 g. The samples with 150 μm outer coating showed improved resistance with the increase in outer layer thickness. Scanning electron microscopy of the coated surface revealed that the coating's resistance to hot corrosion is related to the thickness and the grain size of Al{sub 2}O{sub 3}/MgO coatings.

  8. Ceramic Technology Project semiannual progress report, April 1992--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.

    1993-07-01

    This project was developed to meet the ceramic technology requirements of the DOE Office of Transportation Systems` automotive technology programs. Significant progress in fabricating ceramic components for DOE, NASA, and DOE advanced heat engine programs show that operation of ceramic parts in high-temperature engines is feasible; however, addition research is needed in materials and processing, design, and data base and life prediction before industry will have a sufficient technology base for producing reliable cost-effective ceramic engine components commercially. A 5-yr project plan was developed, with focus on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

  9. Hot spots

    National Research Council Canada - National Science Library

    Nia, Amir M; Gassanov, Natig; Er, Fikret

    2014-01-01

    ..., several reddened skin lesions were observed. The obvious ''hot spots'' were located on both sides in the groin and above the bladder, with extension to the genital region, compli- cating the ability to catheterize the patient (Figure 1). The rest of the body surface was not affected, and no infectious source for the skin lesions was evident. After suc...

  10. Mechanics and Durability of Fiber Reinforced Porous Ceramic Composites

    OpenAIRE

    Huang, Xinyu

    2001-01-01

    Porous ceramics and porous ceramic composites are emerging functional materials that have found numerous industrial applications, especially in energy conversion processes. They are characterized by random microstructure and high porosity. Examples are ceramic candle filters used in coal-fired power plants, gas-fired infrared burners, anode and cathode materials of solid oxide fuel cells, etc. In this research, both experimental and theoretical work have been conducted t...

  11. Tribology of selected ceramics at temperatures to 900 C

    Science.gov (United States)

    Sliney, H. E.; Jacobson, T. P.; Deadmore, D.; Miyoshi, K.

    1986-01-01

    Results of fundamental and focused research on the tribological properties of ceramics are discussed. The basic friction and wear characteristics are given for ceramics of interest for use in gas turbine, adiabatic diesel, and Stirling engine applications. The importance of metal oxides in ceramic/metal sliding combinations is illustrated. The formulation and tribological additives are described. Friction and wear data are given for carbide and oxide-based composite coatings for temperatures to at least 900 C.

  12. Correlation of gas sensitivite properties with microstructure of Fe2O3-SnO2 ceramics prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lu, S.W.; Zhou, Y.X.

    1997-01-01

    A remarkable gas sensitivity to ethnaol gas has been observed in nanostructured Fe2O3-SnO2 materials with a composition of 6.4 mol% SnO2 prepared by high energy ball milling. The microstructure of the materials has been examined by x-ray diffraction (XRD) and Mossbauer spectroscopy. It was found ...... that tin in the hematite phase plays an important role in high gas sensitivity....

  13. Ceramic Technology for Advanced Heat Engines Project

    Energy Technology Data Exchange (ETDEWEB)

    1990-08-01

    The Ceramic Technology For Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Advanced Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DOD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic hearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

  14. HOT 2017

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    HOT er en kvalitativ undersøgelse, der hvert år diskuterer og undersøger en lille udvalgt skare af danskkyndige fagpersoners bud på, hvad de er optagede af på literacyområdet her og nu – altså hvilke emner, de vil vurdere som aktuelle at forholde sig til i deres nuværende praksis....

  15. Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15. I. Line profiles, physical conditions, and H2O abundance

    Science.gov (United States)

    Kristensen, L. E.; van Dishoeck, E. F.; Mottram, J. C.; Karska, A.; Yıldız, U. A.; Bergin, E. A.; Bjerkeli, P.; Cabrit, S.; Doty, S.; Evans, N. J.; Gusdorf, A.; Harsono, D.; Herczeg, G. J.; Johnstone, D.; Jørgensen, J. K.; van Kempen, T. A.; Lee, J.-E.; Maret, S.; Tafalla, M.; Visser, R.; Wampfler, S. F.

    2017-09-01

    Context. Through spectrally unresolved observations of high-J CO transitions, Herschel Photodetector Array Camera and Spectrometer (PACS) has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. The excitation and physical origin of this gas is still not understood. Aims: We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components within protostellar systems using spectrally resolved Herschel-HIFI data. Methods: Observations are presented of the highly excited CO line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs. Results: The spectrally resolved line profiles typically show two distinct velocity components: a broad Gaussian component with an average FWHM of 20 km s-1 containing the bulk of the flux, and a narrower Gaussian component with a FWHM of 5 km s-1 that is often offset from the source velocity. Some sources show other velocity components such as extremely-high-velocity features or "bullets". All these velocity components were first detected in H2O line profiles. The average rotational temperature over the entire profile, as measured from comparison between CO J = 16-15 and 10-9 emission, is 300 K. A radiative-transfer analysis shows that the average H2O/CO column-density ratio is 0.02, suggesting a total H2O abundance of 2 × 10-6, independent of velocity. Conclusions: Two distinct velocity profiles observed in the HIFI line profiles suggest that the high-J CO ladder observed with PACS consists of two excitation components. The warm PACS component (300 K) is associated with the broad HIFI component, and the hot PACS component (700 K) is associated with the offset HIFI

  16. Preparation and characterization of porous Si3 N4 ceramics ...

    Indian Academy of Sciences (India)

    Microstructure, mechanical properties and gas permeability of porous Si3N4 ceramics were investigated. The mechanical properties and microstructure of porous Si3N4 ceramics prepared by compression molding were better than those which were prepared by slip casting method, whereas slip casting method is suitable ...

  17. Ceramic Composite Mechanical Fastener System for High-Temperature Structural Assemblies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hot structures fabricated from ceramic composite materials are an attractive design option for components of future high-speed aircraft, re-entry vehicles and...

  18. Influence of granule characteristics on fabrication of translucent alumina ceramics with high strength and reliability

    National Research Council Canada - National Science Library

    TANAKA, Satoshi; GOI, Shota; KATO, Zenji

    2016-01-01

      Translucent alumina ceramics with high strength and reliability were fabricated through dry pressing of industry-grade granules and subsequent vacuum-sintering prior to hot isostatic pressing (HIP...

  19. Promethus Hot Leg Piping Concept

    Energy Technology Data Exchange (ETDEWEB)

    AM Girbik; PA Dilorenzo

    2006-01-24

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  20. Conditions for testing the corrosion rates of ceramics in coal gasification systems

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.P.; Nowok, J.W. [Univ. of North Dakota, Grand Forks, ND (United States)

    1996-08-01

    Coal gasifier operating conditions and gas and ash compositions affect the corrosion rates of ceramics used for construction in three ways: (1) through direct corrosion of the materials, (2) by affecting the concentration and chemical form of the primary corrodents, and (3) by affecting the mass transport rate of the primary corrodents. To perform an accurate corrosion test on a system material, the researcher must include all relevant corrodents and simulate conditions in the gasifier as closely as possible. In this paper, the authors present suggestions for conditions to be used in such corrosion tests. Two main types of corrosion conditions are discussed: those existing in hot-gas cleanup systems where vapor and dry ash may contribute to corrosion and those experienced by high-temperature heat exchangers and refractories where the main corrodent will be coal ash slag. Only the fluidized-bed gasification systems such as the Sierra Pacific Power Company Pinon Pine Power Project system are proposing the use of ceramic filters for particulate cleanup. The gasifier is an air-blown 102-MWe unit employing a Westinghouse{trademark} ceramic particle filter system operating at as high as 1100{degrees}F at 300 psia. Expected gas compositions in the filter will be approximately 25% CO, 15% H{sub 2}, 5% CO{sub 2}, 5% H{sub 2}O, and 50% N{sub 2}. Vapor-phase sodium chloride concentrations are expected to be 10 to 100 times the levels in combustion systems at similar temperatures, but in general the concentrations of the minor primary and secondary corrodents are not well understood. Slag corrosiveness will depend on its composition as well as viscosity. For a laboratory test, the slag must be in a thermodynamically stable form before the beginning of the corrosion test to assure that no inappropriate reactions are allowed to occur. Ideally, the slag would be flowing, and the appropriate atmosphere must be used to assure realistic slag viscosity.

  1. Ceramic corrosion/erosion project description

    Energy Technology Data Exchange (ETDEWEB)

    Nakaishi, C.V.; Carpenter, L.K.

    1981-02-01

    As a part of the United States Department of Energy's High Temperature Turbine Technology Program, the Morgantown Energy Technology Center is participating in a Ceramics Corrosion/Erosion Materials Study. Objective is to create a technology base for ceramic materials which could be used by stationary gas power turbines operating with a high-temperature, coal-derived, low-Btu gas products of combustion environment. Two facilities are designed and installed to burn a varying low-Btu coal-derived gas in a controlled manner. This report contains the objectives and testing philosophy as well as the operating, specimen handling, and emergency procedures for the facilities. The facilities were checked out in August/September 1980. Testing is scheduled to begin in late 1980 with completion of 1000 hours of ceramic materials exposure to be completed by early 1981. Most of the enclosed is an update of two METC Information Releases (IR), i.e., IR 442 (1979) Test Plan for Ceramic Corrosion/Erosion Project, and IR 817 (1980) Ceramic Corrosion/Erosion Project Description.

  2. Verification of ceramic structures

    NARCIS (Netherlands)

    Behar-Lafenetre, S.; Cornillon, L.; Rancurel, M.; Graaf, D. de; Hartmann, P.; Coe, G.; Laine, B.

    2012-01-01

    In the framework of the "Mechanical Design and Verification Methodologies for Ceramic Structures" contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and

  3. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  4. Joining Ceramics By Brazing

    Science.gov (United States)

    Chiaramonte, Francis P.; Sudsina, Michael W.

    1992-01-01

    Certain ceramic materials tightly bond together by brazing with suitable alloys. Enables fabrication of parts of wide variety of shapes from smaller initial pieces of ceramics produced directly in only limited variety of shapes.

  5. Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

    Science.gov (United States)

    Lee, Kang; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

    2017-01-01

    SiC/SiC Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment because of their light weight, higher temperature capability, and oxidation resistance. Limitations of SiC/SiC CMCs include surface recession and component cracking and associated chemical changes in the CMC. The solutions pursued to improve the life of SiC/SiC CMCs include the incorporation of coating systems that provide surface protection, which has become known as an Environmental Barrier Coating (EBC). The development of EBCs for the protection of gas turbine hot section CMC components was a continuation of coating development work for corrosion protection of silicon-based monolithics. Work on EBC development for SiC/SiC CMCs has been ongoing at several national laboratories and the original gas turbine equipment manufacturers. The work includes extensive laboratory, rig and engine testing, including testing of EBC coated SiC/SiC CMCs in actual field applications. Another EBC degradation issue which is especially critical for CMC components used in aircraft engines is the degradation from glassy deposits of calcium-magnesium-aluminosilicate (CMAS) with other minor oxides. This paper addresses the need for and properties of external coatings on SiC/SiC CMCs to extend their useful life in service and the retention of their properties.

  6. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  7. Image-Processing-Based Study of the Interfacial Behavior of the Countercurrent Gas-Liquid Two-Phase Flow in a Hot Leg of a PWR

    Directory of Open Access Journals (Sweden)

    Gustavo A. Montoya

    2012-01-01

    Full Text Available The interfacial behavior during countercurrent two-phase flow of air-water and steam-water in a model of a PWR hot leg was studied quantitatively using digital image processing of a subsequent recorded video images of the experimental series obtained from the TOPFLOW facility, Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR, Dresden, Germany. The developed image processing technique provides the transient data of water level inside the hot leg channel up to flooding condition. In this technique, the filters such as median and Gaussian were used to eliminate the drops and the bubbles from the interface and the wall of the test section. A Statistical treatment (average, standard deviation, and probability distribution function (PDF of the obtained water level data was carried out also to identify the flow behaviors. The obtained data are characterized by a high resolution in space and time, which makes them suitable for the development and validation of CFD-grade closure models, for example, for two-fluid model. This information is essential also for the development of mechanistic modeling on the relating phenomenon. It was clarified that the local water level at the crest of the hydraulic jump is strongly affected by the liquid properties.

  8. Hot and Dry Cleaning of Biomass-Gasified Gas Using Activated Carbons with Simultaneous Removal of Tar, Particles, and Sulfur Compounds

    Directory of Open Access Journals (Sweden)

    Kinya Sakanishi

    2012-05-01

    Full Text Available This study proposes a gas-cleaning process for the simultaneous removal of sulfur compounds, tar, and particles from biomass-gasified gas using Fe-supported activated carbon and a water-gas shift reaction. On a laboratory scale, the simultaneous removal of H2S and COS was performed under a mixture of gases (H2/CO/CO2/CH4/C2H4/N2/H2S/COS/steam. The reactions such as COS + H2 → H2S + CO and COS + H2O → H2S + CO2 and the water-gas shift reaction were promoted on the Fe-supported activated carbon. The adsorption capacity with steam was higher than that without steam. On a bench scale, the removal of impurities from a gas derived from biomass gasification was investigated using two activated filters packed with Fe-supported activated carbon. H2S and COS, three- and four-ring polycyclic aromatic hydrocarbons (PAHs, and particles were removed and a water-gas shift reaction was promoted through the first filter at 320–350 °C. The concentrations of H2S and COS decreased to less than 0.1 ppmv. Particles and the one- and two-ring PAHs, except for benzene, were then removed through the second filter at 60–170 °C. The concentration of tar and particles decreased from 2428 to 102 mg Nm−3 and from 2244 to 181 mg Nm−3, respectively.

  9. Thermoelectric Properties of Texture-Controlled (GeTe) x (AgSbTe2)100-x (x = 75, 80, 85, and 90) Alloys Fabricated by Gas-Atomization and Hot-Extrusion Processes

    Science.gov (United States)

    Kim, Hyo-Seob; Dharmaiah, Peyala; Hong, Soon-Jik

    2017-11-01

    In this study, p-type (GeTe) x (AgSbTe2)100-x : TAGS-x (where x = 75, 80, 85, and 90) thermoelectric materials were fabricated by a combination of gas atomization and a hot-extrusion process, and the effects of chemical composition on microstructure, thermoelectric, and mechanical properties were investigated. The extruded samples exhibited higher relative densities (> 99%), and a significant orientation degree parallel to the extrusion direction with fine and homogeneous microstructure was observed. The hardness of extruded samples was around 200-260 kgf/mm2, which indicates that they have much better mechanical properties than most other TE materials. The power factor of the extruded samples showed excellent values; the maximum power factor achieved was 3.81 × 10-3 W/mK2 for TAGS-90 at 723 K due to an effective combination of the Seebeck coefficient and electrical conductivity.

  10. Creep in ceramics

    CERN Document Server

    Pelleg, Joshua

    2017-01-01

    This textbook is one of its kind, since there are no other books on Creep in Ceramics. The book consist of two parts: A and B. In part A general knowledge of creep in ceramics is considered, while part B specifies creep in technologically important ceramics. Part B covers creep in oxide ceramics, carnides and nitrides. While covering all relevant information regarding raw materials and characterization of creep in ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search.

  11. Thin film ceramic thermocouples

    Science.gov (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  12. Long wavelength infrared radiation thermometry for non-contact temperature measurements in gas turbines

    Science.gov (United States)

    Manara, J.; Zipf, M.; Stark, T.; Arduini, M.; Ebert, H.-P.; Tutschke, A.; Hallam, A.; Hanspal, J.; Langley, M.; Hodge, D.; Hartmann, J.

    2017-01-01

    The objective of the EU project "Sensors Towards Advanced Monitoring and Control of Gas Turbine Engines (acronym STARGATE)" is the development of a suite of advanced sensors, instrumentation and related systems in order to contribute to the developing of the next generation of green and efficient gas turbine engines. One work package of the project deals with the design and development of a long wavelength infrared (LWIR) radiation thermometer for the non-contact measurement of the surface temperature of thermal barrier coatings (TBCs) during the operation of gas turbine engines. For opaque surfaces (e.g. metals or superalloys) radiation thermometers which are sensitive in the near or short wavelength infrared are used as state-of-the-art method for non-contact temperature measurements. But this is not suitable for oxide ceramic based TBCs (e.g. partially yttria stabilized zirconia) as oxide ceramics are semi-transparent in the near and short wavelength infrared spectral region. Fortunately the applied ceramic materials are non-transparent in the long wavelength infrared and additionally exhibit a high emittance in this wavelength region. Therefore, a LWIR pyrometer can be used for non-contact temperature measurements of the surfaces of TBCs as such pyrometers overcome the described limitation of existing techniques. For performing non-contact temperature measurements in gas turbines one has to know the infrared-optical properties of the applied TBCs as well as of the hot combustion gas in order to properly analyse the measurement data. For reaching a low uncertainty on the one hand the emittance of the TBC should be high (>0.9) in order to reduce reflections from the hot surrounding and on the other hand the absorbance of the hot combustion gas should be low (pyrometer and the selection of the optimal wavelength band where the detector should be sensitive. Besides determining the spectral infrared-optical properties (emittance, transmittance and absorbance) of the

  13. Gas doping ratio effects on p-type hydrogenated nanocrystalline silicon thin films grown by hot-wire chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, P.Q. [Solar Energy Institute, Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)], E-mail: robt@sjtu.edu.cn; Zhou, Z.B. [Solar Energy Institute, Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)], E-mail: zbzhou@sjtu.edu.cn; Chan, K.Y. [Thin Film Laboratory, Faculty of Engineering, Multimedia University, Jalan Multimedia, Cyberjaya 63100, Selangor (Malaysia); Tang, D.Y.; Cui, R.Q.; Dou, X.M. [Solar Energy Institute, Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2008-12-30

    Hydrogenated nanocrystalline silicon (nc-Si:H) grown by hot-wire chemical vapor deposition (HWCVD) has recently drawn significant attention in the area of thin-film large area optoelectronics due to possibility of high deposition rate. We report on the effects of diborane (B{sub 2}H{sub 6}) doping ratio on the microstructural and optoelectrical properties of the p-type nc-Si:H thin films grown by HWCVD at low substrate temperature of 200 deg. C and with high hydrogen dilution ratio of 98.8%. An attempt has been made to elucidate the boron doping mechanism of the p-type nc-Si:H thin films deposited by HWCVD and the correlation between the B{sub 2}H{sub 6} doping ratio, crystalline volume fraction, optical band gap and dark conductivity.

  14. Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15

    DEFF Research Database (Denmark)

    Kristensen, Lars Egstrøm; Van Dishoeck, E. F.; Mottram, J. C.

    2017-01-01

    line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs...

  15. Analysis of trace levels of impurities and hydrogen isotopes in helium purge gas using gas chromatography for tritium extraction system of an Indian lead lithium ceramic breeder test blanket module.

    Science.gov (United States)

    Devi, V Gayathri; Sircar, Amit; Yadav, Deepak; Parmar, Jayraj

    2018-01-12

    In the fusion fuel cycle, the accurate analysis and understanding of the chemical composition of any gas mixture is of great importance for the efficient design of a tritium extraction and purification system or any tritium handling system. Methods like laser Raman spectroscopy and gas chromatography with thermal conductivity detector have been considered for hydrogen isotopes analyses in fuel cycles. Gas chromatography with a cryogenic separation column has been used for the analysis of hydrogen isotopes gas mixtures in general due to its high reliability and ease of operation. Hydrogen isotopes gas mixture analysis with cryogenic columns has been reported earlier using different column materials for percentage level composition. In the present work, trace levels of hydrogen isotopes (∼100 ppm of H 2 and D 2 ) have been analyzed with a Zeolite 5A and a modified γ-Al 2 O 3 column. Impurities in He gas (∼10 ppm of H 2 , O 2 , and N 2 ) have been analyzed using a Zeolite 13-X column. Gas chromatography with discharge ionization detection has been utilized for this purpose. The results of these experiments suggest that the columns developed were able to separate ppm levels of the desired components with a small response time (<6 min) and good resolution in both cases. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Film Cooled Recession of SiC/SiC Ceramic Matrix Composites: Test Development, CFD Modeling and Experimental Observations

    Science.gov (United States)

    Zhu, Dongming; Sakowski, Barbara A.; Fisher, Caleb

    2014-01-01

    SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. However, the environmental stability of Si-based ceramics in high pressure, high velocity turbine engine combustion environment is of major concern. The water vapor containing combustion gas leads to accelerated oxidation and corrosion of the SiC based ceramics due to the water vapor reactions with silica (SiO2) scales forming non-protective volatile hydroxide species, resulting in recession of the ceramic components. Although environmental barrier coatings are being developed to help protect the CMC components, there is a need to better understand the fundamental recession behavior of in more realistic cooled engine component environments.In this paper, we describe a comprehensive film cooled high pressure burner rig based testing approach, by using standardized film cooled SiCSiC disc test specimen configurations. The SiCSiC specimens were designed for implementing the burner rig testing in turbine engine relevant combustion environments, obtaining generic film cooled recession rate data under the combustion water vapor conditions, and helping developing the Computational Fluid Dynamics (CFD) film cooled models and performing model validation. Factors affecting the film cooled recession such as temperature, water vapor concentration, combustion gas velocity, and pressure are particularly investigated and modeled, and compared with impingement cooling only recession data in similar combustion flow environments. The experimental and modeling work will help predict the SiCSiC CMC recession behavior, and developing durable CMC systems in complex turbine engine operating conditions.

  17. Development of prototype ovens working with natural gas, applied to ceramics, bread bake industry and incineration of the hospital garbage with the aid of virtual reality; Desenvolvimento de prototipos a gas natural de um incinerador de lixo hospitalar, forno de panificacao e forno para atividade ceramista com auxilio da realidade virtual

    Energy Technology Data Exchange (ETDEWEB)

    Mirapalheta, Felipe; Silva, Djalma R. da; Castro, Italo R. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Fabianski, Michel [RedeGasEnergia (Brazil)

    2004-07-01

    The Universidade Federal do Rio Grande do Norte has been developing prototype ovens, which work with natural gas. All the project of the prototypes, which will be applied to ceramic, bread bake industry and incineration of the hospital garbage, needs to be studied, developed and tested carefully until its conclusion. Then VRML language (Virtual Reality Modelling Language) is used as a tool in the study of the engineering projects and simulation of some tests. The main benefits of the use of this tool are: finding and solving problems in the project of the prototypes faster; optimization in the project since the three-dimensional visualization facilitates the study; and simulation of aspects of functioning of the ovens before its construction. (author)

  18. DRUCKFLAMM - Investigation on combustion and hot gas cleanup in pulverized coal combustion systems. Final report; DRUCKFLAMM - Untersuchungen zur Verbrennung und Heissgasreinigung bei der Druckkohlenstaubfeuerung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Benoehr, A.; Schuermann, H.; Stroehle, J.; Klaiber, C.; Kuhn, R.; Maier, J.; Schnell, U.; Unterberger, S.

    2001-07-01

    The ambitions of making energy supply more efficient and less polluting brought forth the development of coal based combined cycle power plants allowing considerable increases in net efficiencies. One of the regarded firing concepts for a coal based combined cycle power plant is represented by the pressurised pulverised coal combustion process which has the highest efficiency potential compared with the other coal based concepts. The fundamental purpose of the project was to gain firm knowledge concerning firing behaviour of coal in a pressurised pulverised coal combustion system. Detailed investigations were carried out in a pressurised entrained flow reactor taking into account fuel conversion and particle behaviour, pollutant formation and material behaviour under conditions of a pressurised pulverised coal firing. During the project's investigations several different measurement techniques were tested and partially also acquired (e.g. a two-colour-pyrometry system to measure simultaneous particle surface temperature and particle diameter of burning fuel particles). Calculation models under pressurised conditions for pressure vessel simulation and better scale-up were developed synchronously with the experimental investigations. The results gained using the pressurised entrained flow reactor show that many combustion mechanisms are influenced by increased pressure, for instance the fuel conversion is intensified and at the same time pollutant emissions decreased. The material investigations show that the ceramic materials used due to the very high combustion temperatures are very sensitive versus slagging and fast temperature changes, therefore further development requirements are needed to fully realise the high durability of ceramics in the pressurised furnace. Concerning the improvement of existing models for furnace simulation under pressurised conditions, a good resemblance can be observed when considering the actual measurement results from the test

  19. Fabrication of translucent boron nitride dispersed polycrystalline silicon nitride ceramics

    Science.gov (United States)

    Joshi, B.; Fu, Z.; Niihara, K.; Lee, S. W.

    2011-03-01

    Optical transparency was achieved at infrared region and overall translucent silicon nitride was fabricated using hot press sintering (HPS). The increase in h-BN content decreased the optical transparency. Microstructral observations shows that the optical, mechanical and tribological properties of BN dispersed polycrystalline Si3N4 ceramics were affected by the density, α:β-phase ratio and content of h-BN in sintered ceramics. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO and h-BN at 1850°C. The composite contained from 0.25 to 2 mass % BN powder with sintering aids (9% AlN + 3% MgO). Maximum transmittance of 57% was achieved for 0.25 mass % BN doped Si3N4 ceramics. Fracture toughness was increased and wear volume and friction coefficient were decreased with increase in BN content.

  20. Materials Development Program, Ceramic Technology Project addendum to program plan: Cost effective ceramics for heat engines

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    This is a new thrust in the Ceramic Technology project. This effort represents an expansion of the program and an extension through FY 1997. Moderate temperature applications in conventional automobile and truck engines will be included along with high-temp. gas turbine and low heat rejection diesel engines. The reliability goals are expected to be met on schedule by end of FY 1993. Ceramic turbine rotors have been run (in DOE's ATTAP program) for 1000 h at 1370C and full speed. However, the cost of ceramic components is a deterrrent to near-term commercialization. A systematic approach to reducing this cost includes the following elements: economic cost modeling, ceramic machining, powder synthesis, alternative forming and densification processes, yield improvement, system design studies, standards development, and testing and data base development. A draft funding plan is outlined. 6 figs, 1 tab.

  1. Materials Development Program, Ceramic Technology Project addendum to program plan: Cost effective ceramics for heat engines

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    This is a new thrust in the Ceramic Technology project. This effort represents an expansion of the program and an extension through FY 1997. Moderate temperature applications in conventional automobile and truck engines will be included along with high-temp. gas turbine and low heat rejection diesel engines. The reliability goals are expected to be met on schedule by end of FY 1993. Ceramic turbine rotors have been run (in DOE`s ATTAP program) for 1000 h at 1370C and full speed. However, the cost of ceramic components is a deterrrent to near-term commercialization. A systematic approach to reducing this cost includes the following elements: economic cost modeling, ceramic machining, powder synthesis, alternative forming and densification processes, yield improvement, system design studies, standards development, and testing and data base development. A draft funding plan is outlined. 6 figs, 1 tab.

  2. Anisotropy oxidation of textured ZrB2–MoSi2 ceramics

    DEFF Research Database (Denmark)

    Liu, Hai-Tao; Zou, Ji; Ni, De Wei

    2012-01-01

    Oxidation behavior of hot forged textured ZrB2–20vol% MoSi2 ceramics with platelet ZrB2 grains was investigated at 1500°C for exposure time from 0.5 to 12h. Compared to untextured ceramics, the textured ceramics showed obvious anisotropic oxidation behavior and the surface normal to the hot forging...... pressure demonstrated better oxidation resistance. Such improvement in the oxidation resistance is primarily considered as a higher intrinsic ZrB2 atomic density on the orientated {00l} planes in the textured ceramics. It is expectable that the anisotropic textured ZrB2–MoSi2 ceramics can offer better...

  3. Science and Technology of Ceramics

    Indian Academy of Sciences (India)

    Science and Technology of Ceramics. 2. Functional Ceramics. Sheela Ramasesha. In Part 11 we saw that ceramics could be broadly classified as traditional and advanced ceramics. Traditional ceramics are those made from naturally occurring materials like clays and minerals without requiring much refinement. In this part ...

  4. The friction and wear of ceramic/ceramic and ceramic/metal combinations in sliding contact

    Energy Technology Data Exchange (ETDEWEB)

    Sliney, H.E.; Dellacorte, C. (NASA Lewis Research Center, Cleveland, OH (United States))

    1994-07-01

    The tribological characteristics of ceramics sliding on ceramics are compared to those of ceramics sliding on a nickel-based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900 C (in a few cases to 1200 C) were measured for a hemispherically-tipped pin on a flat sliding contact geometry. In general, especially at high temperature, friction and wear were lower for ceramic/metal combinations than for ceramic/ceramic combinations. The better tribological performance for ceramic/metal combinations is attributed primarily to the lubricious nature of the oxidized surface of the metal.

  5. NDE of ceramics and ceramic composites

    Science.gov (United States)

    Vary, Alex A.; Klima, Stanley J.

    Although nondestructive evaluation (NDE) techniques for ceramics are fairly well developed, they are difficult to apply in many cases for high probability detection of the minute flaws that can cause failure in monolithic ceramics. Conventional NDE techniques are available for monolithic and fiber reinforced ceramic matrix composites, but more exact quantitative techniques needed are still being investigated and developed. Needs range from flaw detection to below 100 micron levels in monolithic ceramics to global imaging of fiber architecture and matrix densification anomalies in ceramic composites. NDE techniques that will ultimately be applicable to production and quality control of ceramic structures are still emerging from the lab. Needs are different depending on the processing stage, fabrication method, and nature of the finished product. NDE techniques are being developed in concert with materials processing research where they can provide feedback information to processing development and quality improvement. NDE techniques also serve as research tools for materials characterization and for understanding failure processes, e.g., during thermomechanical testing.

  6. Antibacterial ceramic for sandbox. Sunabayo kokin ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, K. (Ishizuka Glass Co. Ltd. Nagoya (Japan))

    1993-10-01

    Sands in sandboxes in parks have been called into question of being contaminated by colon bacilli and spawns from ascarides. This paper introduces an antibacterial ceramic for sandbox developed as a new material effective to help reduce the contamination. The ceramic uses natural sand as the main raw material, which is added with borax and silver to contain silver ions that have bacteria and fungus resistance and deodorizing effect. The ceramic has an average grain size ranging from 0.5 mm to 0.7 mm, and is so devised as to match specific gravity, grain size and shape of the sand, hence no separation and segregation can occur. The result of weatherability and antibacterial strength tests on sand for a sandbox mixed with the ceramic at 1% suggests that its efficacy lasts for about three years. Its actual use is under observation. Its efficacy has been verified in a test that measures a survival factor of spawns from dog ascardides contacted with aqueous solution containing the ceramic at 1%. Safety and sanitation tests have proved the ceramic a highly safe product that conforms to the food sanitation law. 5 refs., 3 figs., 3 tabs.

  7. Ceramic laser materials

    Science.gov (United States)

    Ikesue, Akio; Aung, Yan Lin

    2008-12-01

    The word 'ceramics' is derived from the Greek keramos, meaning pottery and porcelain. The opaque and translucent cement and clay often used in tableware are not appropriate for optical applications because of the high content of optical scattering sources, that is, defects. Recently, scientists have shown that by eliminating the defects, a new, refined ceramic material - polycrystalline ceramic - can be produced. This advanced ceramic material offers practical laser generation and is anticipated to be a highly attractive alternative to conventional glass and single-crystal laser technologies in the future. Here we review the history of the development of ceramic lasers, the principle of laser generation based on this material, some typical results achieved with ceramic lasers so far, and discuss the potential future outlook for the field.

  8. Analyses of fine paste ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sabloff, J A [ed.

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

  9. Science and Technology of Ceramics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Science and Technology of Ceramics - Advanced Ceramics: Structural Ceramics and Glasses. Sheela K Ramasesha. Series Article Volume 5 Issue 2 February 2000 pp 4-11 ...

  10. Ceramic Technology Project semiannual progress report for October 1991--March 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. Focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. The work is organized into the following elements: materials and processing (monolithics [SiC, SiN], ceramic composites, thermal and wear coatings, joining), materials design methodology, data base and life prediction (structural qualification, time-dependent behavior, environmental effects, fracture mechanics, NDE), and technology transfer. Individual abstracts were prepared for the individual contributions.

  11. Ceramic technology for advanced heat engines project: Semiannual progress report for April through September 1986

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    An assessment of needs was completed, and a five-year project plan was developed with extensive input from private industry. Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines.

  12. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  13. Three-year clinical evaluation of two ceramic crown systems: a preliminary study.

    Science.gov (United States)

    Etman, Maged K; Woolford, M J

    2010-02-01

    The clinical performance and failure mechanisms of recently introduced ceramic crown systems used to restore posterior teeth have not been adequately examined. The purpose of this prospective clinical study was to evaluate and compare the clinical performance of 2 new ceramic crown systems with that of metal ceramic crowns using modified United States Public Health Services (USPHS) criteria. Ninety posterior teeth requiring crown restorations in 48 patients were randomized into 3 equal groups (n=30) for which different crown systems were used: an experimental hot-pressed glass ceramic based on a modified lithium disilicate ceramic (IPS e.max Press), an alumina-coping-based ceramic (Procera AllCeram), and a metal ceramic (Simidur S 2 veneered with IPS Classic Porcelain). The crowns were assessed over 3 years using the modified USPHS criteria. Crowns that developed visible cracks were sectioned and removed, and the surfaces were analyzed using a scanning electron microscope (SEM). The data were analyzed using the Kruskal-Wallis nonparametric statistical test, followed by the Mann-Whitney test with Bonferroni correction (alpha=.05). USPHS evaluation showed that the IPS e.max Press and metal ceramic crowns experienced fewer clinical changes than Procera AllCeram. Visible roughness, wear, and deformity were noticed in occlusal contact areas of Procera AllCeram crowns. SEM images showed well defined wear facets in both ceramic crown systems. Kruskal-Wallis tests showed a significant difference (Pcrown systems. Mann-Whitney tests showed significant differences among groups. IPS e.max Press crowns demonstrated clinical behavior comparable to Procera AllCeram and metal ceramic crowns, but the wear resistance of this crown type was superior to the Procera AllCeram crowns, according to modified USPHS criteria.

  14. Measuring Fracture Times Of Ceramics

    Science.gov (United States)

    Shlichta, Paul J.; Bister, Leo; Bickler, Donald G.

    1989-01-01

    Electrical measurements complement or replace fast cinematography. Electronic system measures microsecond time intervals between impacts of projectiles on ceramic tiles and fracture tiles. Used in research on ceramics and ceramic-based composite materials such as armor. Hardness and low density of ceramics enable them to disintegrate projectiles more efficiently than metals. Projectile approaches ceramic tile specimen. Penetrating foil squares of triggering device activate display and recording instruments. As ceramic and resistive film break oscilloscope plots increase in electrical resistance of film.

  15. In vivo biofilm formation on different dental ceramics.

    Science.gov (United States)

    Bremer, Felicia; Grade, Sebastian; Kohorst, Philipp; Stiesch, Meike

    2011-01-01

    To investigate the formation of oral biofilm on various dental ceramics in vivo. Five different ceramic materials were included: a veneering glass- ceramic, a lithium disilicate glass-ceramic, a yttrium-stabilized zirconia (Y-TZP), a hot isostatically pressed (HIP) Y-TZP ceramic, and an HIP Y-TZP ceramic with 25% alumina. Test specimens were attached to individually designed acrylic appliances; five volunteers wore these appliances for 24 hours in the maxillary arch. After intraoral exposure, the samples were removed from the appliances and the adhering biofilms vitally stained. Then, the two-dimensional surface coating and thickness of the adhering biofilm were determined by confocal laser scanning microscopy. Statistical analysis was performed using one-way ANOVA with the level of significance set at .05. Significant differences (P types of dental ceramics differed significantly; in particular, zirconia exhibited low plaque accumulation. In addition to its high strength, low plaque accumulation makes zirconia a promising material for various indications (including implant abutments and telescopic crowns) that previously were met only with metal-based materials.

  16. Proton conducting ceramic membranes for hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, S [South Jordan, UT; Nair, Balakrishnan G [Sandy, UT; Small, Troy [Midvale, UT; Heck, Brian [Salt Lake City, UT

    2011-09-06

    A multi-phase proton conducting material comprising a proton-conducting ceramic phase and a stabilizing ceramic phase. Under the presence of a partial pressure gradient of hydrogen across the membrane or under the influence of an electrical potential, a membrane fabricated with this material selectively transports hydrogen ions through the proton conducting phase, which results in ultrahigh purity hydrogen permeation through the membrane. The stabilizing ceramic phase may be substantially structurally and chemically identical to at least one product of a reaction between the proton conducting phase and at least one expected gas under operating conditions of a membrane fabricated using the material. In a barium cerate-based proton conducting membrane, one stabilizing phase is ceria.

  17. Method for fabrication of ceramic dielectric films on copper foils

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Beihai; Narayanan, Manoj; Dorris, Stephen E.; Balachandran, Uthamalingam

    2017-06-14

    The present invention provides copper substrate coated with a lead-lanthanum-zirconium-titanium (PLZT) ceramic film, which is prepared by a method comprising applying a layer of a sol-gel composition onto a copper foil. The sol-gel composition comprises a precursor of a ceramic material suspended in 2-methoxyethanol. The layer of sol-gel is then dried at a temperature up to about 250.degree. C. The dried layer is then pyrolyzed at a temperature in the range of about 300 to about 450.degree. C. to form a ceramic film from the ceramic precursor. The ceramic film is then crystallized at a temperature in the range of about 600 to about 750.degree. C. The drying, pyrolyzing and crystallizing are performed under a flowing stream of an inert gas.

  18. Development of high-temperature corrosion-resistant alloys and heat-treatment regimes for components placed in the hot section of stationary gas turbines

    Science.gov (United States)

    Zvezdin, Yu. I.; Kotov, Yu. V.; Kats, E. L.; Lubenets, V. P.; Spiridonov, E. V.; Konter, M. L.

    1991-06-01

    New single-crystal alloys for the blades of gas turbines, highly corrosion-resistant alloys for guide vanes and combustion chambers, and low-cost alloys for the gears of turbine compressors have been developed and implemented. In term sof the set of properties, the new alloys are superior to foreign alloys for stationary turbines. A computer-aided design system for alloys with a given level of properties has been created for the development of a new generation of high-temperature nickel alloys. Special heat-treatment regimes, which make it possible to combine heat treatment with the production cycle involving the application of plasmas protective coatings and to achieve the combination of basic mechanical properties that is optimal for a specific component have been developed as applies to specific operating conditions of turbine components.

  19. Resolution-independent modelling of environmental effects in semi-analytic models of galaxy formation that include ram-pressure stripping of both hot and cold gas

    Science.gov (United States)

    Luo, Yu; Kang, Xi; Kauffmann, Guinevere; Fu, Jian

    2016-05-01

    The quenching of star formation in satellite galaxies is observed over a wide range of dark matter halo masses and galaxy environments. In the recent Guo et al. and Fu et al. semi-analytic + N-body models, the gaseous environment of the satellite galaxy is governed by the properties of the dark matter subhalo in which it resides. This quantity depends of the resolution of the N-body simulation, leading to a divergent fraction of quenched satellites in high- and low-resolution simulations. Here, we incorporate an analytic model to trace the subhaloes below the resolution limit. We demonstrate that we then obtain better converged results between the Millennium I and II simulations, especially for the satellites in the massive haloes (log Mhalo = [14, 15]). We also include a new physical model for the ram-pressure stripping of cold gas in satellite galaxies. However, we find very clear discrepancies with observed trends in quenched satellite galaxy fractions as a function of stellar mass at fixed halo mass. At fixed halo mass, the quenched fraction of satellites does not depend on stellar mass in the models, but increases strongly with mass in the data. In addition to the overprediction of low-mass passive satellites, the models also predict too few quenched central galaxies with low stellar masses, so the problems in reproducing quenched fractions are not purely of environmental origin. Further improvements to the treatment of the gas-physical processes regulating the star formation histories of galaxies are clearly necessary to resolve these problems.

  20. Implementation Challenges for Ceramic Matrix Composites in High Temperature Applications

    Science.gov (United States)

    Singh, Mrityunjay

    2004-01-01

    Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, electronics, nuclear, and transportation industries. In the aeronautics and space exploration systems, these materials are being considered for applications in hot sections of jet engines such as the combustor liner, nozzle components, nose cones, leading edges of reentry vehicles and space propulsion components. Applications in the energy and environmental industries include radiant heater tubes, heat exchangers, heat recuperators, gas and diesel particulate filters (DPFs), and components for land based turbines for power generation. These materials are also being considered for use in the first wall and blanket components of fusion reactors. There are a number of critical issues and challenges related to successful implementation of composite materials. Fabrication of net and complex shape components with high density and tailorable matrix properties is quite expensive, and even then various desirable properties are not achievable. In this presentation, microstructure and thermomechanical properties of composites fabricated by two techniques (chemical vapor infiltration and melt infiltration), will be presented. In addition, critical need for robust joining and assembly technologies in successful implementation of these systems will be discussed. Other implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

  1. 5 case studies : boiler system increases availability of hot water in CAP REIT apartment buildings while saving energy : electric-to-gas retrofit drives down energy costs and improves building performance : Novitherm heat reflector panels saves 28 per cent in heating costs for apartment building : Novitherm heat reflector panel installation with system adjustment saves 33.2 per cent in energy costs : natural gas conversion saves over $315,000 a year for condominium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    These 5 case studies presented the details of new systems and retrofits conducted by Enbridge Gas Distribution and its partners to improve the energy efficiency of various public and residential buildings. System retrofits included the installation of boiler system installed to address tenant demands on the domestic hot water systems of properties purchased purchased by the CAP REIT organization. The comprehensive program used to address the problems included replacement of the systems with high efficiency heating boilers designed to integrate space, hot water, ramp, and pool heat. A centralized controller included setback control, trend-following processors, and the isolation of heating equipment. The second case study described an electric-to-gas conversion of a make-up air unit and boiler system at an all-electric apartment building. The system was designed to address excessive air handling and water heating costs. The gas conversion included new heating and hot water boilers, as well as a number of efficiency upgrades. The third and fourth case study described the installation of Novitherm heat reflector panels at apartment buildings in Toronto. The fifth case study described a natural gas conversion project conducted at a luxury condominium. Energy savings for all 5 projects were presented. 9 figs.

  2. Determining thermal diffusivity and defect attributes in ceramic matrix composites by infrared imaging

    Science.gov (United States)

    Ahuja, Sanjay; Ellingson, William A.; Stuckey, J. B.; Koehl, E. R.

    1996-03-01

    Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber- reinforced-silicon-carbide (SiC(f)/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC(f)/Si3N4), aluminum-oxide-reinforced-alumina (Al2O3(f)/Al2O3, etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly affect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for full-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

  3. A review on waste heat recovery from exhaust in the ceramics industry

    Science.gov (United States)

    Delpech, Bertrand; Axcell, Brian; Jouhara, Hussam

    2017-11-01

    Following the energy crisis in 1980, many saving technologies have been investigated with attempts to implement them into various industries, one of them is the field of ceramic production. In order to comply with energy saving trends and environmental issues, the European ceramic industry sector has developed energy efficient systems which reduced significantly production time and costs and reduced total energy consumption. The last achievement is of great importance as the energy consumption of the ceramic process accounts for a significant percentage of the total production costs. More precisely, the firing stage consumes the highest amount of energy during the whole ceramic production process. The use of roller kilns, fired by natural gas, involves a loss of 50% of the input energy via the flue gas and the cooling gas exhausts. This review paper briefly describes the production process of the different ceramic products, with a focus on the ceramic sector in Europe. Due to the limited on waste heat recovery in the ceramic industry, other high temperature waste heat recovery applications are considered in the paper, such as in concrete and steel production, which could have a potential use in the ceramic industry. The state of the art technologies used in the ceramics industry are reviewed with a special interest in waste heat recovery from the ceramic process exhaust stacks and energy saving technologies.

  4. Ceramic applications in turbine engines. [for automotive application

    Science.gov (United States)

    Byrd, J. A.; Helms, H. E.

    1982-01-01

    In the past the potential of vehicular gas engines could not be realized because component materials served to limit the turbine operating temperature, thereby restricting fuel economy and initial cost. It was, therefore, not possible for the vehicular gas turbine to compete with more conventional engines. The emergence of low-cost, high-temperature ceramic components has the potential to reverse this situation. For example, the Allison GT404 engine, operating with ceramic components at turbine inlet temperatures up to 2350 F to 2500 F, has the potential of a fuel economy which is better than that of current Diesel engines. The Allison AGT100 engine operating with ceramic components offers the possibility of a 30% improvement in fuel economy over 1985 spark ignition engines. The materials considered for an employment in the ceramic components include silicon carbide, silicon nitride, aluminum silicate, and lithium aluminum silicate.

  5. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2001-02-01

    This is the fifth quarterly report on a new study to develop a ceramic membrane/metal joint. Results of wetting experiments on commercially available Nickel based brazing alloys on perovskite surfaces are described. Additionally, experimental and numerical investigations on the strength of concentric ceramic/metal joints are presented.

  6. Ceramic Technology Project. Semiannual progress report, April 1991--September 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS`s Materials Development Program, was developed to meet the ceramic technology requirements of the OTS`s automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

  7. Novel, Ceramic Membrane System For Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, S.

    2012-12-31

    Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

  8. All ceramic structure for molten carbonate fuel cell

    Science.gov (United States)

    Smith, James L.; Kucera, Eugenia H.

    1992-01-01

    An all-ceramic molten carbonate fuel cell having a composition formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The structure includes an anode and cathode separated by an electronically conductive interconnect. The electrodes and interconnect are compositions ceramic materials. Various combinations of ceramic compositions for the anode, cathode and interconnect are disclosed. The fuel cell exhibits stability in the fuel gas and oxidizing environments. It presents reduced sealing and expansion problems in fabrication and has improved long-term corrosion resistance.

  9. Structural design of ceramic internals of HTR-10

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhensheng E-mail: zhenshng@inet.tsinghua.edu.cn; Liu Junjie; He Shuyan; Zhang Zhengming; Yu Suyuan

    2002-10-01

    This article describes the structural design requirements, structural arrangement and structural features of the ceramic and metallic internals of the 10 MW high-temperature gas-cooled reactor-test module (HTR-10). The graphite properties used in the ceramic internals are provided, along with the results of an operating stress analysis of the graphite components and the metallic components. Satisfactory results were obtained for the machining and installation of the ceramic components and the stress analysis of the graphite and metallic components of HTR-10.

  10. Ceramic heat exchanger

    Science.gov (United States)

    LaHaye, P.G.; Rahman, F.H.; Lebeau, T.P.; Severin, B.K.

    1998-06-16

    A tube containment system is disclosed. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture. 6 figs.

  11. Performance of nickel base superalloy components in gas turbines

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter

    2006-01-01

    The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine......The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine...

  12. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  13. Titanium - ceramic restoration: How to improve the binding between titanium and ceramic

    Directory of Open Access Journals (Sweden)

    Harry Laksono

    2011-03-01

    Full Text Available Background: Titanium alloys has been used as an alternative to nickel-chromium alloys for metal-ceramic restorations because of its good biocompatibility and mechanical properties. This indicated that it was possible to design coping according to standards established for metal-ceramics. However, titanium is chemically reacting strongly with gaseous elements which causes problems when ceramics are fused to titanium. Purpose: To provide information about improving the bonding between titanium and ceramic. Review: Titanium has two crystal modifications, the close-packed hexagonal (α structure, up to 880° C, and above this temperature the bodycentered cubic (β structure. The principal problems is the extensive dissolution of oxygen resulting in thick, oxygen-rich titanium layers called α-case that harms the bonding of ceramic to titanium and the great mismatch in the coefficient of thermal expansion of conventional ultra-low fusing ceramic. Methods have been developed for fusing ceramic to titanium like processing methods, the used of ultra-low fusing titanium ceramic, bonding agent, and protocol for ceramic bonding to titanium. Conclusion: Titanium and titanium alloys, based on their physical and chemical properties suitable for titanium-ceramic restorations, but careful selection of processing methods, ceramic materials, laboratory skill and strict protocol for ceramic bonding to titanium are necessary to improve the bonding between titanium and ceramic.Latar Belakang: Logam campur titanium telah dipakai sebagai salah satu bahan alternatif untuk logam nikel-krom pada pembuatan restorasi keramik taut logam karena mempunyai biokompatibilitas dan sifat mekanik yang baik. Hal ini menunjukkan bahwa logam titanium dapat dipakai untuk pembuatan koping logam berdasarkan standar yang dipakai untuk pembuatan restorasi keramik taut logam. Meskipun, secara kimiawi logam titanium bereaksi dengan elemen-elemen gas yang menyebabkan masalah pada perlekatan

  14. Métodos transientes de troca de calor na determinação das propriedades térmicas de materiais cerâmicos: II - o método do fio quente Thermal properties of ceramic materials by the non-steady techniques: II - the hot wire technique

    Directory of Open Access Journals (Sweden)

    W. N. dos Santos

    2005-12-01

    diffusivity is important in non-steady heat transfer calculations. The specific heat is also a decisive property of ceramic materials in high temperature applications, and it is associated with heat consumption during the heating process. Normally these properties are determined separately by individual techniques and apparatus. Nowadays, several different techniques for the determination of the thermal diffusivity and thermal conductivity may be found in the literature. Recently, transient techniques have become the preferable way for measuring thermal properties of materials. In this work it is presented a description as well as a critical analysis of one experimental technique employed worldwide for thermal properties measurements of ceramic materials: the hot wire technique. With this technique it is possible to determine simultaneously from the same temperature transient the three thermal properties. Numerical results are also presented.

  15. Thermal barrier coatings issues in advanced land-based gas turbines

    Science.gov (United States)

    Parks, William P.; Hoffman, Eugene E.; Lee, Woo Y.; Wright, Ian G.

    1995-01-01

    The Department of Energy's Advanced Turbine Systems (ATS) program is aimed at fostering the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS machines will emphasize different criteria in the selection of materials for the critical components. In particular, thermal barrier coatings (TBC's) will be an essential feature of the hot gas path components in these machines. In fact, the goals of the ATS will require significant improvements in TBC technology, since these turbines will be totally reliant on TBC's, which will be required to function on critical components such as the first stage vanes and blades for times considerably in excess of those experienced in current applications. Issues that assume increased importance are the mechanical and chemical stability of the ceramic layer and of the metallic bond coat; the thermal expansion characteristics and compliance of the ceramic layer; and the thermal conductivity across the thickness of the ceramic layer. Obviously, the ATS program provides a very challenging opportunity for TBC's, and involves some significant opportunities to extend this technology. A significant TBC development effort is planned in the ATS program which will address these key issues.

  16. Corrosion of ceramics for slag removal in IGCC-power plants; Korrosion von Keramiken fuer die Fluessigascheabscheidung in IGCC-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, Denny

    2012-06-12

    Coal gasification and the subsequent production of electricity from syngas in combined-cycle powerplants allows plant efficiencies of up to 43% (LHV). Existing technologies allow up to 50% in the short term. Efficiencies beyond 50% however, require concepts and technologies that still need a certain amount of research and development. One such method to raise plant efficiencies would be a high temperature (at temperatures above the melting point of the ash) syngas cleaning. To effectively utilize the heat from the syngas and enable high turbine inlet temperatures, it is necessary to remove slag particles from the hot gas. The feasibility of such a hot syngas cleaning has been successfully demonstrated for the Pressurized Pulverized Coal Combustion (PPCC) by passing the hot gas through a bed of ceramic balls for slag removal. In order to apply this concept to IGCC powerplants the slag resistance of various ceramic materials had to be investigated under gasifying conditions. Therefore, lab-made ceramics and commercially available refractory materials where treated with liquid slag at 1600 C in a number of reducing atmospheres. At first, three synthetic slags with different basicity were used and after evaluating the results, selected materials were treated with a gasifier slag under continuous conditions. It was shown that both slag and ceramic have to be adjusted to ensure a sufficient corrosion resistance of the ceramic bed for slag removal. Furthermore, the impact of the porosity of the utilized ceramic on the corrosion resistance was shown. The composition of the reducing atmosphere (mainly the partial pressure of Oxygen) affected both physical and chemical properties of the slag via slag components that could easily be reduced or oxidized. The materials most suitable for use in slag separation were found to be dense chromium oxide and other ceramics containing a high amount of chromium oxide. [German] Mit Kohlevergasung und der anschliessenden Stromerzeugung in

  17. Continuous Fiber Ceramic Composites (CFCC)

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Wagner

    2002-12-18

    This report summarizes work to develop CFCC's for various applications in the Industries of the Future (IOF) and power generation areas. Performance requirements range from relatively modest for hot gas filters to severe for turbine combustor liners and infrared burners. The McDermott Technology Inc. (MTI) CFCC program focused on oxide/oxide composite systems because they are known to be stable in the application environments of interest. The work is broadly focused on dense and porous composite systems depending on the specific application. Dense composites were targeted at corrosion resistant components, molten aluminum handling components and gas turbine combustor liners. The development work on dense composites led to significant advances in fiber coatings for oxide fibers and matrix densification. Additionally, a one-step fabrication process was developed to produce low cost composite components. The program also supported key developments in advanced oxide fibers that resulted in an improved version of Nextel 610 fiber (commercially available as Nextel 650) and significant progress in the development of a YAG/alumina fiber. Porous composite development focused on the vacuum winding process used to produce hot gas filters and infrared burner components.

  18. Thermal conductivity analysis of SiC ceramics and fully ceramic microencapsulated fuel composites

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeon-Geun, E-mail: hglee@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Kim, Daejong [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Lee, Seung Jae [KEPCO Nuclear Fuel, 242, Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Park, Ji Yeon; Kim, Weon-Ju [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of)

    2017-01-15

    Highlights: • Thermal conductivity of SiC ceramics and FCM pellets was measured and discussed. • Thermal conductivity of FCM pellets was analyzed by the Maxwell-Eucken equation. • Effective thermal conductivity of TRISO particles applied in this study was assumed. - Abstract: The thermal conductivity of SiC ceramics and FCM fuel composites, consisting of a SiC matrix and TRISO coated particles, was measured and analyzed. SiC ceramics and FCM pellets were fabricated by hot press sintering with Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} sintering additives. Several factors that influence thermal conductivity, specifically the content of sintering additives for SiC ceramics and the volume fraction of TRISO particles and the matrix thermal conductivity of FCM pellets, were investigated. The thermal conductivity values of samples were analyzed on the basis of their microstructure and the arrangement of TRISO particles. The thermal conductivity of the FCM pellets was compared to that predicted by the Maxwell-Eucken equation and the thermal conductivity of TRISO coated particles was calculated. The thermal conductivity of FCM pellets in various sintering conditions was in close agreement to that predicted by the Maxwell-Eucken equation with the fitted thermal conductivity value of TRISO particles.

  19. Anionic Conducting Oxide Ceramics

    National Research Council Canada - National Science Library

    Dunn, Bruce

    1998-01-01

    This program has emphasized the interrelationships among synthesis, microstructure and properties for oxygen ion conducting ceramics based on copper-substituted bismuth vanadate (Bi V Cu O ), known as BICUVOX...

  20. Making Ceramic Cameras

    Science.gov (United States)

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  1. Light emitting ceramic device

    Science.gov (United States)

    Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

    2010-05-18

    A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

  2. Conductive ceramic composition and method of preparation

    Science.gov (United States)

    Smith, J.L.; Kucera, E.H.

    1991-04-16

    A ceramic anode composition is formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The anode is prepared as a non-stoichiometric crystalline structure by reaction and conditioning in a hydrogen gas cover containing minor proportions of carbon dioxide and water vapor. The structure exhibits a single phase and substantially enhanced electrical conductivity over that of the corresponding stoichiometric structure. Unexpectedly, such oxides and oxygenates are found to be stable in the reducing anode fuel gas of a molten carbonate fuel cell. 4 figures.

  3. Bonded carbon or ceramic fiber composite filter vent for radioactive waste

    Science.gov (United States)

    Brassell, Gilbert W.; Brugger, Ronald P.

    1985-02-19

    Carbon bonded carbon fiber composites as well as ceramic or carbon bonded ceramic fiber composites are very useful as filters which can separate particulate matter from gas streams entraining the same. These filters have particular application to the filtering of radioactive particles, e.g., they can act as vents for containers of radioactive waste material.

  4. Effects of Starch on Properties of Alumina-based Ceramic Cores

    Directory of Open Access Journals (Sweden)

    LI Fengguang

    2016-12-01

    Full Text Available In order to improve the poor leachability of alumina-based ceramic cores, different amount of starch was added to the specimens as pore former. Alumina-based ceramic cores were prepared by hot injection technology using corundum powder as base material, paraffin wax and beeswax as plasticizer, silica powder and magnesium oxide powder as mineralizing agent, wherein the parameters of the hot injection process were as follows:temperature of the slurry was 90℃, hot injection pressure was 0.5 MPa and holding time was 25 s. The effects of starch content on the properties of alumina-based ceramic cores were studied and discussed. The results indicate that during sintering period, the loss of starch in the specimens makes porosity of the alumina-based ceramic cores increase. When starch content increases, the room-temperature flexural strength of the ceramic cores reduces and the apparent porosity increases; the volatile solvent increases and the bulk density decreases. After being sintered at 1560℃ for 2.5 h, room-temperature flexural strength of the alumina-based ceramic cores with starch content of 8%(mass fraction is 24.8 MPa, apparent porosity is 47.98% when the volatile solvent is 1.92 g/h and bulk density is 1.88 g/cm3, the complex properties are optimal.

  5. Manufacturing of planar ceramic interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, B.L.; Coffey, G.W.; Meinhardt, K.D.; Armstrong, T.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-12-31

    The fabrication of ceramic interconnects for solid oxide fuel cells (SOFC) and separator plates for electrochemical separation devices has been a perennial challenge facing developers. Electrochemical vapor deposition (EVD), plasma spraying, pressing, tape casting and tape calendering are processes that are typically utilized to fabricate separator plates or interconnects for the various SOFC designs and electrochemical separation devices. For sake of brevity and the selection of a planar fuel cell or gas separation device design, pressing will be the only fabrication technique discussed here. This paper reports on the effect of the characteristics of two doped lanthanum manganite powders used in the initial studies as a planar porous separator for a fuel cell cathode and as a dense interconnect for an oxygen generator.

  6. Materials Development Program: Ceramic Technology Project bibliography, 1984--1992

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The Ceramic Technology [for Advanced Heat Engines] Project was begun in 1983 to meet the ceramic materials needs of the companion DOE automotive engine program, the Advanced Gas Turbine (AGT) project, and the Heavy Duty Transport (low-heat-rejection, heavy-duty diesel) project. Goal is to develop an industry technology base for reliable and cost effective ceramics for applications in advanced automotive gas turbine and diesel engines. Research areas were identified following extensive input from industry and academia. Majority of research is done by industry (60%); work is also done at colleges and universities, in-house, and at other national laboratories and government agencies. In the beginning, reliability of ceramic components was the key issue. The reliability issues have largely been met and, at the present time, cost is the driving issue, especially in light of the highly cost-sensitive automotive market. Emphasis of the program has now been shifted toward developing cost-effective ceramic components for high-performance engines in the near-term. This bibliography is a compilation of publications done in conjunction with the Ceramic Technology Project since its beginning. Citations were obtained from reports done by participants in the project. We have tried to limit citations to those published and easily located. The end date of 1992 was selected.

  7. Fiber ceramic structures based on liquid impregnation technique

    Science.gov (United States)

    Krenkel, W.; Schanz, P.

    For future reentry vehicles ceramic matrix composites (CMC) are very favorable materials for hot structures and thermal protection systems. This paper describes the fabrication and evaluation of CMC-components manufactured by the liquid impregnation technique. This process offers the potential for a low-cost CMC production for all components which can be fabricated by resin transfer molding (RTM) or other techniques for reinforcing polymers. The two main fabrication steps, the component shaping and the matrix conversion to ceramics, are described in detail. Experimental data on infiltration parameters as well as mechanical properties and oxidation resistance of the produced fiber ceramics were determined. Emphasis was given on manufacturing real components like panels with integrated stringers to demonstrate the feasibility of the process.

  8. In-situ Formation of Reinforcement Phases in Ultra High Temperature Ceramic Composites

    Science.gov (United States)

    Stackpoole, Margaret M (Inventor); Gasch, Matthew J (Inventor); Olson, Michael W (Inventor); Hamby, Ian W. (Inventor); Johnson, Sylvia M (Inventor)

    2013-01-01

    A tough ultra-high temperature ceramic (UHTC) composite comprises grains of UHTC matrix material, such as HfB.sub.2, ZrB.sub.2 or other metal boride, carbide, nitride, etc., surrounded by a uniform distribution of acicular high aspect ratio reinforcement ceramic rods or whiskers, such as of SiC, is formed from uniformly mixing a powder of the UHTC material and a pre-ceramic polymer selected to form the desired reinforcement species, then thermally consolidating the mixture by hot pressing. The acicular reinforcement rods may make up from 5 to 30 vol % of the resulting microstructure.

  9. Rare Earth Aluminophosphosilicate Glass Precursors for Ceramic-Matrix-Composites (REAPS CMC’s)

    Science.gov (United States)

    2008-07-11

    translucent glasses and glass- ceramic composites via hot pressing at relatively low...sol-gel mixing on mullite microstructure and phase equilibria in the alpha -alumina- silica system. J. Am. Ceram . Soc, 1987. 70(10): p. 704-7. 15...Non- Cryst. Solids, 1988.100(1-3): p. 93-114. 18. Hoffman, D.W., R. Roy, and S. Komarneni, Diphasic xerogels, a new class of materials: phases in the system alumina- silica . J. Am. Ceram . Soc, 1984. 67(7): p. 468-71.

  10. Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

    OpenAIRE

    Taro Shimonosono; Hikari Imada; Hikaru Maeda; Yoshihiro Hirata

    2016-01-01

    The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ), and silicon carbide porous ceramics toward H2, CO2, and H2–CO2 mixtures were investigated at room temperature. The permeation of H2 and CO2 single gases occurred above a critical pressure gradient, which was smaller for H2 gas than for CO2 gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius) of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process. Th...

  11. Salt splitting using ceramic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kurath, D.E. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-10-01

    Many radioactive aqueous wastes in the DOE complex have high concentrations of sodium that can negatively affect waste treatment and disposal operations. Sodium can decrease the durability of waste forms such as glass and is the primary contributor to large disposal volumes. Waste treatment processes such as cesium ion exchange, sludge washing, and calcination are made less efficient and more expensive because of the high sodium concentrations. Pacific Northwest National Laboratory (PNNL) and Ceramatec Inc. (Salt Lake City UT) are developing an electrochemical salt splitting process based on inorganic ceramic sodium (Na), super-ionic conductor (NaSICON) membranes that shows promise for mitigating the impact of sodium. In this process, the waste is added to the anode compartment, and an electrical potential is applied to the cell. This drives sodium ions through the membrane, but the membrane rejects most other cations (e.g., Sr{sup +2}, Cs{sup +}). The charge balance in the anode compartment is maintained by generating H{sup +} from the electrolysis of water. The charge balance in the cathode is maintained by generating OH{sup {minus}}, either from the electrolysis of water or from oxygen and water using an oxygen cathode. The normal gaseous products of the electrolysis of water are oxygen at the anode and hydrogen at the cathode. Potentially flammable gas mixtures can be prevented by providing adequate volumes of a sweep gas, using an alternative reductant or destruction of the hydrogen as it is generated. As H{sup +} is generated in the anode compartment, the pH drops. The process may be operated with either an alkaline (pH>12) or an acidic anolyte (pH <1). The benefits of salt splitting using ceramic membranes are (1) waste volume reduction and reduced chemical procurement costs by recycling of NaOH; and (2) direct reduction of sodium in process streams, which enhances subsequent operations such as cesium ion exchange, calcination, and vitrification.

  12. Hot moons and cool stars

    Directory of Open Access Journals (Sweden)

    Heller René

    2013-04-01

    Full Text Available The exquisite photometric precision of the Kepler space telescope now puts the detection of extrasolar moons at the horizon. Here, we firstly review observational and analytical techniques that have recently been proposed to find exomoons. Secondly, we discuss the prospects of characterizing potentially habitable extrasolar satellites. With moons being much more numerous than planets in the solar system and with most exoplanets found in the stellar habitable zone being gas giants, habitable moons could be as abundant as habitable planets. However, satellites orbiting planets in the habitable zones of cool stars will encounter strong tidal heating and likely appear as hot moons.

  13. The friction and wear of ceramic/ceramic and ceramic/metal combinations in sliding contracts

    Energy Technology Data Exchange (ETDEWEB)

    Sliney, H.E.; Dellacorte, C. [NASA Lewis Research Center, Cleveland, OH (United States)

    1994-07-01

    The tribological characteristics of ceramics sliding on ceramics are compared to those of ceramics sliding on a nickel-based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900{degrees}C (in a few cases to 1200{degrees}C) were measured for a hemispherically-tipped pin on a flat sliding contract geometry. In general, especially at high temperature, friction and wear were lower for ceramic/metal combinations than for ceramic/ceramic combinations. The better tribological performance for ceramic/metal combinations is attributed primarily to the lubricious nature of the oxidized surface of the metal. 12 refs., 6 figs., 1 tab.

  14. Really Hot Stars

    Science.gov (United States)

    2003-04-01

    Spectacular VLT Photos Unveil Mysterious Nebulae Summary Quite a few of the most beautiful objects in the Universe are still shrouded in mystery. Even though most of the nebulae of gas and dust in our vicinity are now rather well understood, there are some which continue to puzzle astronomers. This is the case of a small number of unusual nebulae that appear to be the subject of strong heating - in astronomical terminology, they present an amazingly "high degree of excitation". This is because they contain significant amounts of ions, i.e., atoms that have lost one or more of their electrons. Depending on the atoms involved and the number of electrons lost, this process bears witness to the strength of the radiation or to the impact of energetic particles. But what are the sources of that excitation? Could it be energetic stars or perhaps some kind of exotic objects inside these nebulae? How do these peculiar objects fit into the current picture of universal evolution? New observations of a number of such unusual nebulae have recently been obtained with the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). In a dedicated search for the origin of their individual characteristics, a team of astronomers - mostly from the Institute of Astrophysics & Geophysics in Liège (Belgium) [1] - have secured the first detailed, highly revealing images of four highly ionized nebulae in the Magellanic Clouds, two small satellite galaxies of our home galaxy, the Milky Way, only a few hundred thousand light-years away. In three nebulae, they succeeded in identifying the sources of energetic radiation and to eludicate their exceptional properties: some of the hottest, most massive stars ever seen, some of which are double. With masses of more than 20 times that of the Sun and surface temperatures above 90 000 degrees, these stars are truly extreme. PR Photo 09a/03: Nebula around the hot star AB7 in the SMC. PR Photo 09b/03: Nebula near the hot Wolf-Rayet star BAT99

  15. Hot Jupiter Magnetospheres

    Science.gov (United States)

    Trammell, George B.; Arras, Phil; Li, Zhi-Yun

    2011-02-01

    The upper atmospheres of close-in gas giant exoplanets ("hot Jupiters") are subjected to intense heating and tidal forces from their parent stars. The atomic (H) and ionized (H+) hydrogen layers are sufficiently rarefied that magnetic pressure may dominate gas pressure for expected planetary magnetic field strength. We examine the structure of the magnetosphere using a 3D isothermal magnetohydrodynamic model that includes a static "dead zone" near the magnetic equator containing gas confined by the magnetic field, a "wind zone" outside the magnetic equator in which thermal pressure gradients and the magneto-centrifugal-tidal effect give rise to a transonic outflow, and a region near the poles where sufficiently strong tidal forces may suppress transonic outflow. Using dipole field geometry, we estimate the size of the dead zone to be several to tens of planetary radii for a range of parameters. Tides decrease the size of the dead zone, while allowing the gas density to increase outward where the effective gravity is outward. In the wind zone, the rapid decrease of density beyond the sonic point leads to smaller densities relative to the neighboring dead zone, which is in hydrostatic equilibrium. To understand the appropriate base conditions for the 3D isothermal model, we compute a simple 1D thermal model in which photoelectric heating from the stellar Lyman continuum is balanced by collisionally excited Lyα cooling. This 1D model exhibits a H layer with temperature T ~= 5000-10,000 K down to a pressure P ~ 10-100 nbar. Using the 3D isothermal model, we compute maps of the H column density as well as the Lyα transmission spectra for parameters appropriate for HD 209458b. Line-integrated transit depths sime5%-10% can be achieved for the above base conditions, in agreement with the results of Koskinen et al. A deep, warm H layer results in a higher mass-loss rate relative to that for a more shallow layer, roughly in proportion to the base pressure. Strong magnetic

  16. Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

    Directory of Open Access Journals (Sweden)

    Taro Shimonosono

    2016-11-01

    Full Text Available The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ, and silicon carbide porous ceramics toward H2, CO2, and H2–CO2 mixtures were investigated at room temperature. The permeation of H2 and CO2 single gases occurred above a critical pressure gradient, which was smaller for H2 gas than for CO2 gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process. The H2 fraction for the mixed gas of (20%–80% H2–(80%–20% CO2 through porous Al2O3, YSZ, and SiC approached unity with decreasing pressure gradient. The high fraction of H2 gas was closely related to the difference in the critical pressure gradient values of H2 and CO2 single gas, the inlet mixed gas composition, and the gas flow mechanism of the mixed gas. Moisture in the atmosphere adsorbed easily on the porous ceramics and affected the critical pressure gradient, leading to the increased selectivity of H2 gas.

  17. Separation of Hydrogen from Carbon Dioxide through Porous Ceramics.

    Science.gov (United States)

    Shimonosono, Taro; Imada, Hikari; Maeda, Hikaru; Hirata, Yoshihiro

    2016-11-16

    The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ), and silicon carbide porous ceramics toward H₂, CO₂, and H₂-CO₂ mixtures were investigated at room temperature. The permeation of H₂ and CO₂ single gases occurred above a critical pressure gradient, which was smaller for H₂ gas than for CO₂ gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius) of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process. The H₂ fraction for the mixed gas of (20%-80%) H₂-(80%-20%) CO₂ through porous Al₂O₃, YSZ, and SiC approached unity with decreasing pressure gradient. The high fraction of H₂ gas was closely related to the difference in the critical pressure gradient values of H₂ and CO₂ single gas, the inlet mixed gas composition, and the gas flow mechanism of the mixed gas. Moisture in the atmosphere adsorbed easily on the porous ceramics and affected the critical pressure gradient, leading to the increased selectivity of H₂ gas.

  18. Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

    Science.gov (United States)

    Shimonosono, Taro; Imada, Hikari; Maeda, Hikaru; Hirata, Yoshihiro

    2016-01-01

    The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ), and silicon carbide porous ceramics toward H2, CO2, and H2–CO2 mixtures were investigated at room temperature. The permeation of H2 and CO2 single gases occurred above a critical pressure gradient, which was smaller for H2 gas than for CO2 gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius) of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process. The H2 fraction for the mixed gas of (20%–80%) H2–(80%–20%) CO2 through porous Al2O3, YSZ, and SiC approached unity with decreasing pressure gradient. The high fraction of H2 gas was closely related to the difference in the critical pressure gradient values of H2 and CO2 single gas, the inlet mixed gas composition, and the gas flow mechanism of the mixed gas. Moisture in the atmosphere adsorbed easily on the porous ceramics and affected the critical pressure gradient, leading to the increased selectivity of H2 gas. PMID:28774051

  19. Niobia-silica and silica membranes for gas separation

    NARCIS (Netherlands)

    Boffa, V.

    2008-01-01

    This thesis describes the development of ceramic membranes suitable for hydrogen separation and CO2 recovery from gaseous streams. The research work was focused on the three different parts of which gas selective ceramic membranes are composed, i.e., the microporous gas selective silica layer, the

  20. Preparation of Ceramic-Bonded Carbon Block for Blast Furnace

    Science.gov (United States)

    Li, Yiwei; Li, Yawei; Sang, Shaobai; Chen, Xilai; Zhao, Lei; Li, Yuanbing; Li, Shujing

    2014-01-01

    Traditional carbon blocks for blast furnaces are mainly produced with electrically calcined anthracite owing to its good hot metal corrosion resistance. However, this kind of material shows low thermal conductivity and does not meet the demands for cooling of the hearth and the bottom of blast furnaces. In this article, a new kind of a high-performance carbon block has been prepared via ceramic-bonded carbon (CBC) technology in a coke bed at 1673 K (1400 °C) using artificial graphite aggregate, alumina, metallic aluminum, and silicon powders as starting materials. The results showed that artificial graphite aggregates were strongly bonded by the three-dimensional network of ceramic phases in carbon blocks. In this case, the good resistance of the CBC blocks against erosion/corrosion by the hot metal is provided by the ceramic matrix and the high thermal conductivity by the graphite aggregates. The microstructure of this carbon block resembles that of CBC composites with a mean pore size of less than 0.1 μm, and up to 90 pct of the porosity shows a pore size <1 μm. Its thermal conductivity is higher than 30 W · m-1 · K-1 [293 K (20 °C)]. Meanwhile, its hot metal corrosion resistance is better than that of traditional carbon blocks.

  1. Low-loss binder for hot pressing boron nitride

    Science.gov (United States)

    Maya, Leon

    1991-01-01

    Borazine derivatives used as low-loss binders and precursors for making ceramic boron nitride structures. The derivative forms the same composition as the boron nitride starting material, thereby filling the voids with the same boron nitride material upon forming and hot pressing. The derivatives have a further advantage of being low in carbon thus resulting in less volatile byproduct that can result in bubble formation during pressing.

  2. Catalyzed Ceramic Burner Material

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Amy S., Dr.

    2012-06-29

    period in accomplishing these objectives. Our work in the area of Pd-based, methane oxidation catalysts has led to the development of highly active catalysts with relatively low loadings of Pd metal using proprietary coating methods. The thermal stability of these Pd-based catalysts were characterized using SEM and BET analyses, further demonstrating that certain catalyst supports offer enhanced stability toward both PdO decomposition and/or thermal sintering/growth of Pd particles. When applied to commercially available fiber mesh substrates (both metallic and ceramic) and tested in an open-air burner, these catalyst-support chemistries showed modest improvements in the NOx emissions and radiant output compared to uncatalyzed substrates. More significant, though, was the performance of the catalyst-support chemistries on novel media substrates. These substrates were developed to overcome the limitations that are present with commercially available substrate designs and increase the gas-catalyst contact time. When catalyzed, these substrates demonstrated a 65-75% reduction in NOx emissions across the firing range when tested in an open air burner. In testing in a residential boiler, this translated into NOx emissions of <15 ppm over the 15-150 kBtu/hr firing range.

  3. Testing method for ceramic armour and bare ceramic tiles

    NARCIS (Netherlands)

    Carton, E.P.; Roebroeks, G.H.J.J.

    2016-01-01

    TNO developed an alternative, more configuration independent ceramic test method than the Depth-of-Penetration test method. In this alternative test ceramic tiles and ceramic based armour are evaluated as target without a semi-infinite backing layer. An energy approach is chosen to evaluate and rank

  4. Testing method for ceramic armor and bare ceramic tiles

    NARCIS (Netherlands)

    Carton, E.P.; Roebroeks, G.H.J.J.

    2014-01-01

    TNO has developed an alternative, more configuration independent ceramic test method than the standard Depth-of-Penetration test method. In this test ceramic tiles and ceramic based armor are evaluated as target without a semi-infinite backing layer. An energy approach is chosen to evaluate and rank

  5. Cooled Ceramic Turbine Vane Project

    Data.gov (United States)

    National Aeronautics and Space Administration — N&R Engineering will investigate the feasibility of cooled ceramics, such as ceramic matrix composite (CMC) turbine blade concepts that can decrease specific...

  6. Mechanical properties of ceramics

    CERN Document Server

    Pelleg, Joshua

    2014-01-01

    This book discusses the mechanical properties of ceramics and aims to provide both a solid background for undergraduate students, as well as serving as a text to bring practicing engineers up to date with the latest developments in this topic so they can use and apply these to their actual engineering work.  Generally, ceramics are made by moistening a mixture of clays, casting it into desired shapes and then firing it to a high temperature, a process known as 'vitrification'. The relatively late development of metallurgy was contingent on the availability of ceramics and the know-how to mold them into the appropriate forms. Because of the characteristics of ceramics, they offer great advantages over metals in specific applications in which hardness, wear resistance and chemical stability at high temperatures are essential. Clearly, modern ceramics manufacturing has come a long way from the early clay-processing fabrication method, and the last two decades have seen the development of sophisticated technique...

  7. Diffusion in ceramics

    CERN Document Server

    Pelleg, Joshua

    2016-01-01

    This textbook provides an introduction to changes that occur in solids such as ceramics, mainly at high temperatures, which are diffusion controlled, as well as presenting research data. Such changes are related to the kinetics of various reactions such as precipitation, oxidation and phase transformations, but are also related to some mechanical changes, such as creep. The book is composed of two parts, beginning with a look at the basics of diffusion according to Fick's Laws. Solutions of Fick’s second law for constant D, diffusion in grain boundaries and dislocations are presented along with a look at the atomistic approach for the random motion of atoms. In the second part, the author discusses diffusion in several technologically important ceramics. The ceramics selected are monolithic single phase ones, including: A12O3, SiC, MgO, ZrO2 and Si3N4. Of these, three refer to oxide ceramics (alumina, magnesia and zirconia). Carbide based ceramics are represented by the technologically very important Si-ca...

  8. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  9. Design features of the radioactive Liquid-Fed Ceramic Melter system

    Energy Technology Data Exchange (ETDEWEB)

    Holton, L.K. Jr. (comp.)

    1985-06-01

    During 1983, the Pacific Northwest Laboratory (PNL), at the request of the Department of Energy (DOE), undertook a program with the principal objective of testing the Liquid-Fed Ceramic Melter (LFCM) process in actual radioactive operations. This activity, termed the Radioactive LFCM (RLFCM) Operations is being conducted in existing shielded hot-cell facilities in B-Cell of the 324 Building, 300 Area, located at Hanford, Washington. This report summarizes the design features of the RLFCM system. These features include: a waste preparation and feed system which uses pulse-agitated waste preparation tanks for waste slurry agitation and an air displacement slurry pump for transferring waste slurries to the LFCM; a waste vitrification system (LFCM) - the design features, design approach, and reasoning for the design of the LFCM are described; a canister-handling turntable for positioning canisters underneath the RLFCM discharge port; a gamma source positioning and detection system for monitoring the glass fill level of the product canisters; and a primary off-gas treatment system for removing the majority of the radionuclide contamination from the RLFCM off gas. 8 refs., 48 figs., 6 tabs.

  10. Effects of sintering atmosphere controlled using carbon pellet on translucency of AlN ceramics

    Science.gov (United States)

    Honma, T.; Kamitamari, M.; Kuroki, Y.; Okamoto, T.; Takata, M.

    2011-05-01

    Translucent AlN ceramics were sintered with a carbon pellet in order to control the CO gas surrounding the sample during sintering. The total transmittance of the ceramics increased by sintering with the carbon pellet because of the decrease of light scattering. One of causes of the light scattering was the presence of calcium aluminates at grain boundaries. The light scattering can be controlled by the CO gas using the carbon pellet.

  11. High flow ceramic pot filters

    NARCIS (Netherlands)

    van Halem, D.; van der Laan, H.; Soppe, A. I.A.; Heijman, S.G.J.

    2017-01-01

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more

  12. Glass/Ceramic Composites for Sealing Solid Oxide Fuel Cells

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2007-01-01

    A family of glass/ceramic composite materials has been investigated for use as sealants in planar solid oxide fuel cells. These materials are modified versions of a barium calcium aluminosilicate glass developed previously for the same purpose. The composition of the glass in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass seal was found to be susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/ ceramic composite materials was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking. Each of the composite formulations consists of the glass plus either of two ceramic reinforcements in a proportion between 0 and 30 mole percent. One of the ceramic reinforcements consists of alumina platelets; the other one consists of particles of yttria-stabilized zirconia wherein the yttria content is 3 mole percent (3YSZ). In preparation for experiments, panels of the glass/ceramic composites were hot-pressed and machined into test bars.

  13. Status of plutonium ceramic immobilization processes and immobilization forms

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.B.; Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (United States); Vance, E.R.; Jostsons, A. [Australian Nuclear Science and Technology Organization, Menai (Australia)] [and others

    1996-05-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R&D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi{sub 2}O{sub 7}), the desired actinide host phase, with lesser amounts of hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) and rutile (TiO{sub 2}). Alternative actinide host phases are also being considered. These include pyrochlore (Gd{sub 2}Ti{sub 2}O{sub 7}), zircon (ZrSiO{sub 4}), and monazite (CePO{sub 4}), to name a few of the most promising. R&D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO{sub 2} powder, cold press and sinter fabrication methods, and immobilization form formulation issues.

  14. Verification of Ceramic Structures

    Science.gov (United States)

    Behar-Lafenetre, Stephanie; Cornillon, Laurence; Rancurel, Michael; De Graaf, Dennis; Hartmann, Peter; Coe, Graham; Laine, Benoit

    2012-07-01

    In the framework of the “Mechanical Design and Verification Methodologies for Ceramic Structures” contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and instrument structures. It has been written in order to be applicable to most types of ceramic or glass-ceramic materials - typically Cesic®, HBCesic®, Silicon Nitride, Silicon Carbide and ZERODUR®. The proposed guideline describes the activities to be performed at material level in order to cover all the specific aspects of ceramics (Weibull distribution, brittle behaviour, sub-critical crack growth). Elementary tests and their post-processing methods are described, and recommendations for optimization of the test plan are given in order to have a consistent database. The application of this method is shown on an example in a dedicated article [7]. Then the verification activities to be performed at system level are described. This includes classical verification activities based on relevant standard (ECSS Verification [4]), plus specific analytical, testing and inspection features. The analysis methodology takes into account the specific behaviour of ceramic materials, especially the statistical distribution of failures (Weibull) and the method to transfer it from elementary data to a full-scale structure. The demonstration of the efficiency of this method is described in a dedicated article [8]. The verification is completed by classical full-scale testing activities. Indications about proof testing, case of use and implementation are given and specific inspection and protection measures are described. These additional activities are necessary to ensure the required reliability. The aim of the guideline is to describe how to reach the same reliability level as for structures made of more classical materials (metals, composites).

  15. Effect of binder burnout on the sealing performance of glass ceramics for solid oxide fuel cells

    Science.gov (United States)

    Ertugrul, Tugrul Y.; Celik, Selahattin; Mat, Mahmut D.

    2013-11-01

    The glass ceramics composite sealants are among few materials suitable for the solid oxide fuel cells (SOFC) due to their high operating temperatures (600 °C-850 °C). The glass ceramics chemically bond to both the metallic interconnector and the ceramic electrolyte and provide a gas tight connection. A careful and several stages manufacturing procedure is required to obtain a gas tight sealing. In this study, effects of binder burnout process on the sealing performance are investigated employing commercially available glass ceramic powders. The glass ceramic laminates are produced by mixing glass ceramic powders with the organic binders and employing a tape casting method. The laminates are sandwiched between the metallic interconnectors of an SOFC cell. The burnout and subsequent sealing quality are analyzed by measuring leakage rate and final macrostructure of sealing region. The effects of heating rate, dead weight load, solid loading, carrier gas and their flow rates are investigated. It is found that sealing quality is affected from all investigated parameters. While a slower heating rate is required for a better burnout, the mass flow rate of sweep gas must be adequate for removal of the burned gas. The leakage rate is reduced to 0.1 ml min-1 with 2 °C min-1 + 1 °C min-1 heating rate, 86.25% solid loading, 200 N dead weight load and 500 ml min-1 sweep gas flow rate.

  16. Ceramic backup ring prevents undesirable weld-metal buildup

    Science.gov (United States)

    Leonard, G. E.

    1971-01-01

    Removable ceramic backup material butted against weld zone back prevents weld metal buildup at that site. Method is successful with manual tungsten-inert gas /TIG/ welding of 316 corrosion resistant steel /CRES/ pieces with 0.76 cm throat diameter and 1.57 cm pipe internal diameter.

  17. Ceramic Thermal Barriers For Dirty-Fuel Turbines

    Science.gov (United States)

    Miller, Robert A.

    1988-01-01

    Report discusses performances of ceramic thermal-barrier coating materials for use in electric-utility gas-turbine engines. Variations of standard coating evaluated in search for coating resistant to dirty fuel. Variations included alterations of level of yttria, replacement of yttria by other stabilizers, controlling surface density (by plasma spray processing, infiltration, laser glazing, or sputtering), and interface treatments.

  18. Joining and Assembly of Silicon Carbide-based Advanced Ceramics and Composites for High Temperature Applications

    Science.gov (United States)

    Singh, M.

    2004-01-01

    Silicon carbide based advanced ceramics and fiber reinforced composites are under active consideration for use in wide variety of high temperature applications within the aeronautics, space transportation, energy, and nuclear industries. The engineering designs of ceramic and composite component require fabrication and manufacturing of large and complex shaped parts of various thicknesses. In many instances, it is more economical to build up complex shapes by joining simple geometrical shapes. In addition these components have to be joined or assembled with metallic sub-components. Thus, joining and attachment have been recognized as enabling technologies for successful utilization of ceramic components in various demanding applications. In this presentation, various challenges and opportunities in design, fabrication, and testing o high temperature joints in ceramic matrix composites will be presented. Silicon carbide based advanced ceramics (CVD and hot pressed), and C/SiC and SiC/SiC composites, in different shapes and sizes, have been joined using an affordable, robust ceramic joining technology (ARCJoinT). Microstructure and high temperature mechanical properties of joints in silicon carbide ceramics and CVI and melt infiltrated SiC matrix composites will,be reported. Various joint design philosophies and design issues in joining of ceramics and composites well be discussed.

  19. Grain boundary dynamics in ceramics superplasticity

    Directory of Open Access Journals (Sweden)

    Wakai, E.

    2001-04-01

    Full Text Available Superplasticity refers to an ability of polycrystalline solids to exhibit exceptionally large elongation in tension. The application of superplasticity makes it possible to fabricate ceramic components by superplastic forming (SPF, concurrent with diffusion bonding, and superplastic sinter-forging just like superplastic metals. Furthermore the superplastic deformation plays an important role in stress-assisted densification processes such as hot isostatic pressing (HIP and hot pressing (HP. The ceramics superplasticity has been one of intensive research fields in the last decade. Although most of reports are still limited to those of zirconia[1], new developments have been achieved in superplasticity of Si3N4 and SiC in recent years. It is clearly demonstrated that the superplasticity is one of the common natures of fine-grained ceramics and nanocrystalline ceramics at elevated temperatures.

    La superplaticidad se refiere a la capacidad que posee un sólido policristalino de presentar alargamientos excepcionalmente elevados en tracción. La aplicación de la superplasticidad hace posible la fabricación de componentes cerámicos por conformado superplástico, soldadura por difusión y forja-sinterizado superplástica, igual que en metales superplásticos. Además, la deformación superplástica tiene un rol importante en los procesos de densificación asistidos por tensiones, tales como la compactación isostática en caliente y el prensado en caliente. Las cerámicas superplásticas han sido uno de los campos donde se ha realizado una investigación más intensa en la última década. Aunque, la mayoría de los informes se limitan a la circonia[1] se han alcanzado nuevos desarrollos en superplasticidad de Si3N4 y SiC. Está claramente demostrado que la superplasticidad es una propiedad intrínseca de las cerámicas de pequeño tamaño de grano y de las cer

  20. The separation efficiency of ceramic barrier filters determined at high temperatures by optical particle size and concentration measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hemmer, G.; Umhauer, H.; Kasper, G. [Univ. Karlsruhe, Inst. fuer Mechanische Verfahrenstechnik und Mechanik, Karlsruhe (Germany); Berbner, S. [Freudenberg Nonwovens, Filtration Div., Hopkinsville, KY (United States)

    1999-07-01

    Based on the experiences of earlier investigations a special optical particle counter was developed capable of recording size and quantity (concentration) of the particles directly within a given gas particle stream under the prevailing conditions (true in-situ measurements at high temperatures). In addition to earlier investigations [1], a second type of ceramic filter media with much smaller porosity and a membrane layer on the filtration side was tested. The candles with a length of 1.5 m which are used in industrial applications were mounted in the same hot gas filtration unit already used before. Measurements on the clean gas side at temperatures of up to 1000 C have been conducted using a fraction of quartz particles as test dust. The particle size ranged between 0.3 {mu}m and 10 {mu}m. Filtration velocity (1.5 cm/s) and final pressure drop of dust cake {delta}p (1000 Pa) were kept constant. As a main result the fractional efficiency as function of temperature is discussed and compared with that obtained before for a filter media of type I: The fractional efficiency values of filter type II are at least 100 times higher than that of filter type I. (orig.)

  1. Compact Ceramic Microchannel Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Lewinsohn, Charles [Ceramatec, Inc., Salt Lake City, UT (United States)

    2016-10-31

    The objective of the proposed work was to demonstrate the feasibility of a step change in power plant efficiency at a commercially viable cost, by obtaining performance data for prototype, compact, ceramic microchannel heat exchangers. By performing the tasks described in the initial proposal, all of the milestones were met. The work performed will advance the technology from Technology Readiness Level 3 (TRL 3) to Technology Readiness Level 4 (TRL 4) and validate the potential of using these heat exchangers for enabling high efficiency solid oxide fuel cell (SOFC) or high-temperature turbine-based power plants. The attached report will describe how this objective was met. In collaboration with The Colorado School of Mines (CSM), specifications were developed for a high temperature heat exchanger for three commercial microturbines. Microturbines were selected because they are a more mature commercial technology than SOFC, they are a low-volume and high-value target for market entry of high-temperature heat exchangers, and they are essentially scaled-down versions of turbines used in utility-scale power plants. Using these specifications, microchannel dimensions were selected to meet the performance requirements. Ceramic plates were fabricated with microchannels of these dimensions. The plates were tested at room temperature and elevated temperature. Plates were joined together to make modular, heat exchanger stacks that were tested at a variety of temperatures and flow rates. Although gas flow rates equivalent to those in microturbines could not be achieved in the laboratory environment, the results showed expected efficiencies, robust operation under significant temperature gradients at high temperature, and the ability to cycle the stacks. Details of the methods and results are presented in this final report.

  2. Tick-proof ceramics. Bo dani ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Shimono, F. (Ishizuka Glass Co. Ltd., Nagoya (Japan))

    1993-07-01

    Ishizuka Glass has developed SiO2-B2O3-R2O(RO) based tick-proof ceramics (trade name; Segrocera) in cooperation with Yamato Chemical Industry, insecticide maker. This article is a report on effectiveness of this ceramics. Ticks living indoors are roughly divided into two kinds, namely ticks living in a house itself and ticks which enter the house by parasitizing on animals and plants, and Segrocera has been developed aiming at the former ticks which, irrespective of its kind, need the temperature of 20-30[degree]C and the moisture of 60% or more as its breeding conditions. The tick-proof effect of Segrocera is as excellent as 90-99% and even after keeping its specimen at 75RH for 12 months, it has shown the ratio of inhibiting ticks' breeding of 98-99%. In comparison with that the effect of other tick-proof agent, pyrethroids-based aerosol is limited up to 24 hours, it is the feature of Segrocera that its life is considerably longer. Safety of Segrocera is also very high. 2 refs., 1 fig., 7 tabs.

  3. Transformation Toughening of Ceramics

    Science.gov (United States)

    1992-03-01

    chanical twing of ualaneeting Ceramica at High Temperatures. ILondo, Patigue-crack growth in overaged and partially stabi- U.K., 198.""IS. Itoribe... Ceramica " Chapter 18 In Mechanical Prop- ŗR. M. !AcMeeding and A. 0. Evans, ’Mechanics of Transformation ertles of Engineering Ceramics. Edited by W.W

  4. Microporous alumina ceramic membranes

    Science.gov (United States)

    Anderson, Marc A.; Sheng, Guangyao

    1993-01-01

    Several methods are disclosed for the preparation microporous alumina ceramic membranes. For the first time, porous alumina membranes are made which have mean pore sizes less than 100 Angstroms and substantially no pores larger than that size. The methods are based on improved sol-gel techniques.

  5. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendfra Nagabhushana

    2001-07-01

    The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

  6. Laboratory spectra of hot molecules: Data needs for hot super-Earth exoplanets

    Science.gov (United States)

    Tennyson, Jonathan; Yurchenko, Sergei N.

    2017-09-01

    The majority of stars are now thought to support exoplanets. Many of those exoplanets discovered thus far are categorized as rocky objects with an atmosphere. Most of these objects are however hot due to their short orbital period. Models suggest that water is the dominant species in their atmospheres. The hot temperatures are expected to turn these atmospheres into a (high pressure) steam bath containing remains of melted rock. The spectroscopy of these hot rocky objects will be very different from that of cooler objects or hot gas giants. Molecules suggested to be important for the spectroscopy of these objects are reviewed together with the current status of the corresponding spectroscopic data. Perspectives of building a comprehensive database of linelist/cross sections applicable for atmospheric models of rocky super-Earths as part of the ExoMol project are discussed. The quantum-mechanical approaches used in linelist productions and their challenges are summarized.

  7. The effect of filler on the temperature coefficient of the relative permittivity of PTFE/ceramic composites

    Science.gov (United States)

    Rajesh, S.; Murali, K. P.; Jantunen, H.; Ratheesh, R.

    2011-11-01

    High permittivity and low-loss ceramic fillers have been prepared by means of the solid state ceramic route. Ceramic-filled composites were prepared by the Sigma Mixing, Extrusion, Calendering, which was followed by the Hot pressing (SMECH) process. The microwave dielectric properties of the composites were studied using X-band waveguide cavity perturbation technique. The temperature coefficient of the relative permittivity of the composites was investigated in the 0-100 °C temperature range using a hot and cold chamber coupled with an impedance analyzer. The temperature coefficient of the relative permittivity of the composites showed strong dependence on the temperature coefficient of the relative permittivity of the filler material. In the present study, a high-permittivity polymer/ceramic composite, having τεr ∼63 ppm/K, has been realized. This composite is suitable for outdoor wireless applications.

  8. Ceramic Laser Materials

    Energy Technology Data Exchange (ETDEWEB)

    Soules, T F; Clapsaddle, B J; Landingham, R L; Schaffers, K I

    2005-02-15

    Transparent ceramic materials have several major advantages over single crystals in laser applications, not the least of which is the ability to make large aperture parts in a robust manufacturing process. After more than a decade of working on making transparent YAG:Nd, Japanese workers have recently succeeded in demonstrating samples that performed as laser gain media as well as their single crystal counterparts. Since then several laser materials have been made and evaluated. For these reasons, developing ceramic laser materials is the most exciting and futuristic materials topic in today's major solid-state laser conferences. We have established a good working relationship with Konoshima Ltd., the Japanese producer of the best ceramic laser materials, and have procured and evaluated slabs designed by us for use in our high-powered SSHCL. Our measurements indicate that these materials will work in the SSHCL, and we have nearly completed retrofitting the SSHCL with four of the largest transparent ceramic YAG:Nd slabs in existence. We have also begun our own effort to make this material and have produced samples with various degrees of transparency/translucency. We are in the process of carrying out an extensive design-of-experiments to establish the significant process variables for making transparent YAG. Finally because transparent ceramics afford much greater flexibility in the design of lasers, we have been exploring the potential for much larger apertures, new materials, for example for the Mercury laser, other designs for SSHL, such as, edge pumping designs, slabs with built in ASE suppression, etc. This work has just beginning.

  9. The Role of Ceramics in a Resurgent Nuclear Industry

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J

    2006-02-28

    With fuel oil and natural gas prices near record highs and worldwide energy demands increasing at an alarming rate, there is growing interest in revitalization of the nuclear power industry within the United States and across the globe. Ceramic materials have long played a very important part in the commercial nuclear industry with applications throughout the entire fuel cycle; from fuel fabrication to waste stabilization. As the international community begins to look at advanced fuel cycles that minimize waste and increase proliferation resistance, ceramic materials will play an even larger role. Many of the advanced reactor concepts being evaluated operate at high-temperature requiring the use of durable, heat-resistant materials. Ceramic fuels are being investigated for a variety of Generation IV reactor concepts. These include the traditional TRISO-coated particles as well as advanced inert-matrix fuels. In order to minimize wastes and legacy materials, ceramic processes are also being applied to fuel reprocessing operations. Ceramic materials continue to provide a vital contribution in ''closing the fuel cycle'' by stabilization of associated low-level and high-level wastes in highly durable grout, ceramics, and glass. In the next five years, programs that are currently in the conceptual phase will begin laboratory- and engineering-scale demonstrations. This will require production-scale demonstrations of several ceramic technologies from fuel form development to advanced stabilization methods. Within the next five to ten years, these demonstrations will move to even larger scales and will also include radioactive demonstrations of these advanced technologies. These radioactive demonstrations are critical to program success and will require advances in ceramic materials associated with nuclear energy applications.

  10. Perancangan Cowper Guna Pemanfaatan Gas Buang Peleburan Logam

    OpenAIRE

    Octaviano, Yoska; Mujalis, Yusep; Siantury, Benny; Sukarnoto, Tono; Sulamet, Rianti Dewi

    2014-01-01

    A prototype of homemade furnace was built and the highest temperature it can reach during the trial process is approximately 400OC. Beside liquid metal, the furnace also produced exhaust gas as a side product. The exhaust gas is still hot. Hot gas can be used to improve the furnace's temperature based on blast furnace method. To apply this method, the furnace should be companied with cowper. In designing cowper, several parameters should be notice. The parameters are hot gas temperature, air ...

  11. Hot interstellar matter in elliptical galaxies

    CERN Document Server

    Kim, Dong-Woo

    2012-01-01

    Based on a number of new discoveries resulting from 10 years of Chandra and XMM-Newton observations and corresponding theoretical works, this is the first book to address significant progress in the research of the Hot Interstellar Matter in Elliptical Galaxies. A fundamental understanding of the physical properties of the hot ISM in elliptical galaxies is critical, because they are directly related to the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and the growth of super-massive black holes. Thanks to the outstanding spatial resolution of Chandra and the large collecting area of XMM-Newton, various fine structures of the hot gas have been imaged in detail and key physical quantities have been accurately measured, allowing theoretical interpretations/predictions to be compared and tested against observational results. This book will bring all readers up-to-date on this essential field of research.

  12. Hot-pressed geopolymer

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mohammad; Maheri, Mahmoud R.

    2017-01-01

    /FA, duration of hot-pressing and sodium concentration are studied. Together with detailed experimental studies, our results reveal that the most dominant factor is the induced pressure. The main results indicated that the highest compressive strength of the geopolymer (134 MPa) could be obtained by employing...... the hot pressing, temperature and duration of 41.4 MPa, 350 °C and 20 min, respectively. The microstructure of the hot-pressed specimens showed more developed geopolymer matrix compared with conventional ones leading to higher compressive strength in much shortest time. The improved mechanical properties...

  13. Ceramic-on-ceramic total hip arthroplasty early dislocation rate.

    Science.gov (United States)

    Colwell, Clifford W; Hozack, William J; Mesko, J Wesley; D'Antonio, James A; Bierbaum, Benjamin E; Capello, William N; Jaffe, William L; Mai, Kenny T

    2007-12-01

    Wear debris from metal-on-polyethylene articulation in conventional total hip arthroplasty can limit the implant's longevity. Modern ceramic material with high wear resistance and low fracture risk has the potential to extend the lifetime of total hip arthroplasty, which makes the procedure potentially more suitable for young, active patients. Concerns with brittle ceramic material include fracture risk, the "squeak" phenomenon, and potentially a higher dislocation rate secondary to limited neck lengths and liner options. We therefore determined the early dislocation rate in modern ceramic-on-ceramic total hip arthroplasty. In 1635 total hip arthroplasties performed over the 9-year period (1996-2005), we observed three anterior and 15 posterior dislocations (1.1%). All were treated successfully, one with a revision and 17 with closed reduction under general anesthesia. Ceramic-on-ceramic total hip arthroplasty can be a good alternative bearing surface with a low dislocation rate.

  14. Preparation of biomorphic silicon carbide–mullite ceramics using molten salt synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wwchem@126.com [Department of Chemical Engineering, College of Environment Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang’an University, 126# Yanta Road, Xi' an 710054, Shaanxi (China); Hou, Guangya [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014 (China); Wang, Boya; Deng, Shunxi [Department of Chemical Engineering, College of Environment Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang’an University, 126# Yanta Road, Xi' an 710054, Shaanxi (China)

    2014-09-15

    Biomorphic silicon carbide–mullite ceramics were prepared from beech wood using liquid Si infiltration and molten salts synthesis. The resulting mullite whiskers coating, as well as the growth mechanism in molten Al{sub 2}(SO{sub 4}){sub 3}–Na{sub 2}SO{sub 4} environment, have been investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques. The biomorphic SiC ceramics derived from the beech wood template have coarse pore walls consisting of β-SiC grains with diameters ranging from 5 μm to 20 μm. After the molten salts reactions between biomorphic SiC substrate and mixture molten salts (Al{sub 2}(SO{sub 4}){sub 3}–Na{sub 2}SO{sub 4}), porous Silicon carbide–mullite ceramics with cilia-like microstructure were obtained. This unique structure has potential application in hot gases filters. An oxidation–dissolution cycle was proposed to explain the mullite whiskers growth in molten salts environment. - Graphical abstract: Biomorphic silicon carbide–mullite ceramics with cilia-like microstructure prepared from beech wood using liquid Si infiltration (LSI) and molten salts reactions (MSR) processes. Mullite whiskers with nanometer-sized diameters and micrometer-sized lengths grow on the surface of SiC substrate, and the biomorphic silicon carbide–mullite ceramics inherit the porous microstructure originated from biomorphic SiC ceramics and beech wood. The mullite whiskers grow on the pores' surface of biomorphic SiC to form cilia-like surface, and this special structure can be used for hot gases filter. - Highlights: • Biomorphic silicon carbide–mullite ceramics were prepared. • An oxidation–dissolution mechanism was proposed to explain the coating formation. • The unique structure has potential application in hot gases filter.

  15. Grain boundaries in ceramics and ceramic-metal interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, D.R.; Wolf, D.

    1986-01-01

    Three interfaces exist: the crystal-crystal grain boundary in very pure single-phase ceramics, the crystal-glass-crystal grain boundary in most single-phase and polyphase ceramics, and the ceramic-metal interface. It is needed to correlate their structure and adhesion/failure. Methods for studying the bonding, interfacial structure, and fracture and adhesion are discussed, and recommendations are given. 42 refs. (DLC)

  16. China's 'Hot Money' Problems

    National Research Council Canada - National Science Library

    Martin, Michael F; Morrison, Wayne M

    2008-01-01

    .... The recent large inflow of financial capital into China, commonly referred to as "hot money," has led some economists to warn that such flows may have a destabilizing effect on China's economy...

  17. Hot Weather Tips

    Science.gov (United States)

    ... hot, heavy meals and don’t use the oven. Monitor medications: Find out if the person’s medications ... nia.nih.gov Photo: By High Contrast (Own work) [CC BY 3.0 de ( http://creativecommons.org/ ...

  18. NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    Roger H.L. Chen, Ph.D.; Alejandro Kiriakidis

    1999-09-01

    Nondestructive evaluation (NDE) techniques have been used to reduce the potential mechanical failures and to improve the reliability of a structure. Failure of a structure is usually initiated at some type of flaw in the material. NDE techniques have been developed to determine the presence of flaws larger than an acceptable size and to estimate the remaining stiffness of a damaged structure (Chen, et. al, 1995). Ceramic candle filters have been tested for use in coal-fueled gas turbine systems. They protect gas turbine components from damage due to erosion. A total of one hundred and one candle filters were nondestructively evaluated in this study. Ninety-eight ceramic candle filters and three ceramic composite filters have been nondestructively inspected using dynamic characterization technique. These ceramic filters include twelve unused Coors alumina/mullite, twenty-four unused and fifteen used Schumacher-Dia-Schumalith TF-20, twenty-five unused and nine used Refractron 326, eight unused and three used Refractron 442T, one new Schumacher-T 10-20, and one used Schumacher-Dia-Schumalith F-40. All filters were subjected to a small excitation and the dynamic response was picked up by a piezoelectric accelerometer. The evaluation of experimental results was processed using digital signal analysis technique including various forms of data transformation. The modal parameters for damage assessment for the unexposed (unused) vs. exposed (used) specimen were based on two vibration parameters: natural frequencies and mode shapes. Finite Element models were built for each specimen type to understand its dynamic response. Linear elastic modal analysis was performed using eight nodes, three-dimensional isotropic solid elements. Conclusions based on our study indicate that dynamic characterization is a feasible NDE technique in studying structural properties of ceramic candle filters. It has been shown that the degradation of the filters due to long working hours (or

  19. Silanated Surface Treatment: Effects on the Bond Strength to Lithium Disilicate Glass-Ceramic.

    Science.gov (United States)

    Baratto, Samantha Schaffer Pugsley; Spina, Denis Roberto Falcão; Gonzaga, Carla Castiglia; Cunha, Leonardo Fernandes da; Furuse, Adilson Yoshio; Baratto Filho, Flares; Correr, Gisele Maria

    2015-10-01

    The aim of this study was to evaluate the effect of silanization protocols on the bond strength of two resin cements to a lithium disilicate glass-ceramic. Thirty-two ceramic discs were assigned to 2 groups (n=16): G1 - dual-cured resin cement and G2 - light-cured resin cement. Four subgroups were evaluated according to the used silanization protocol. The glass-ceramic was etched with 10% hydrofluoric acid for 20 s and silane was applied for 1 min, as follows: CTL - according to the manufacturer's instructions; HA - dried with hot air; NWA - washed and dried with water and air at room temperature; HWA - washed and dried with hot water and hot air. Thereafter, adhesive was applied and light-cured for 20 s. Silicon molds were used to prepare resin cement cylinders (1x1 mm) on the ceramic surface. The specimens were stored in deionized water at 37 °C for 48 h and subjected to a micro-shear test. The data were submitted to statistical analysis (?#61537;=0.05). Group G1 showed higher bond strengths than G2, except for the CTL and NWA subgroups. Differences as function of the silanization protocol were only observed in G1: HWA (25.13±6.83)≥HA (22.95±7.78)≥CTL(17.44±7.24) ≥NWA(14.63±8.76). For G2 there was no difference among the subgroups. In conclusion, the silanization protocol affected the resin cement/ceramic bond strengths, depending on the material. Washing/drying with hot water and/or hot air increased only the bond strength of the dual-cured resin cement.

  20. Synthesis of highly sinterable Yb: SrF2 nanopowders for transparent ceramics

    Science.gov (United States)

    Li, Weiwei; Huang, Haijun; Mei, Bingchu; Song, Jinghong

    2018-01-01

    In this paper, ytterbium doped strontium fluoride (Yb: SrF2) nanoparticles were synthesized by direct precipitation method. High-speed centrifugation was used to separate high sintering activity of nanopowders from powders with hard aggregated and large size. Using powders at different parts of the centrifugal tube as starting powders, Yb: SrF2 transparent ceramics was fabricated by hot pressed (HP) method for the first time. Effects of morphology and particle size on the sinterability of Yb: SrF2 nanopowders were investigated. The transmittance reached 77% at the wavelength of 1200 nm and pores stilled remained in the ceramics. The spectroscopic and thermal properties of Yb: SrF2 transparent ceramics were also investigated. This paper provides an effective way to obtain well dispersed and high sinterability nanoparticles for SrF2 ceramics sintering.

  1. Enhancing Piezoelectric Performance of CaBi2Nb2O9 Ceramics Through Microstructure Control

    Science.gov (United States)

    Chen, Huanbei; Zhai, Jiwei

    2012-08-01

    Calcium bismuth niobate (CaBi2Nb2O9, CBN) is a high-Curie-temperature ( T C) piezoelectric material with relatively poor piezoelectric performance. Attempts were made to enhance the piezoelectric and direct-current (DC) resistive properties of CBN ceramics by increasing their density and controlling their microstructural texture, which were achieved by combining the templated grain growth and hot pressing methods. The modified CBN ceramics with 97.5% relative density and 90.5% Lotgering factor had much higher piezoelectric constant ( d 33 = 20 pC/N) than those prepared by the normal sintering process ( d 33 = 6 pC/N). High-temperature alternating-current (AC) impedance spectroscopy of the CBN ceramics was measured by using an impedance/gain-phase analyzer. Their electrical resistivity was approximately 6.5 × 104 Ω cm at 600°C. Therefore, CBN ceramics can be used for high-temperature piezoelectric applications.

  2. Fabrication of translucent boron nitride dispersed polycrystalline silicon nitride ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, B [Department of Metallurgy and Material Engineering, Sunmoon University (Korea, Republic of); Fu, Z [State Key Lab of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology (China); Niihara, K [Nagaoka University of Technology, Nagaoka (Japan); Lee, S W, E-mail: joshibhupen@gmail.com [Department of Environment Engineering, Sunmoon University, Asan (Korea, Republic of)

    2011-03-15

    Optical transparency was achieved at infrared region and overall translucent silicon nitride was fabricated using hot press sintering (HPS). The increase in h-BN content decreased the optical transparency. Microstructral observations shows that the optical, mechanical and tribological properties of BN dispersed polycrystalline Si{sub 3}N{sub 4} ceramics were affected by the density, {alpha}:{beta}-phase ratio and content of h-BN in sintered ceramics. The hot pressed samples were prepared from the mixture of {alpha}-Si{sub 3}N{sub 4}, AlN, MgO and h-BN at 1850 deg. C. The composite contained from 0.25 to 2 mass % BN powder with sintering aids (9% AlN + 3% MgO). Maximum transmittance of 57% was achieved for 0.25 mass % BN doped Si{sub 3}N{sub 4} ceramics. Fracture toughness was increased and wear volume and friction coefficient were decreased with increase in BN content.

  3. Integration Science and Technology of Advanced Ceramics for Energy and Environmental Applications

    Science.gov (United States)

    Singh, M.

    2012-01-01

    The discovery of new and innovative materials has been known to culminate in major turning points in human history. The transformative impact and functional manifestation of new materials have been demonstrated in every historical era by their integration into new products, systems, assemblies, and devices. In modern times, the integration of new materials into usable products has a special relevance for the technological development and economic competitiveness of industrial societies. Advanced ceramic technologies dramatically impact the energy and environmental landscape due to potential wide scale applications in all aspects of energy production, storage, distribution, conservation, and efficiency. Examples include gas turbine propulsion systems, fuel cells, thermoelectrics, photovoltaics, distribution and transmission systems based on superconductors, nuclear power generation, and waste disposal. Robust ceramic integration technologies enable hierarchical design and manufacturing of intricate ceramic components starting with geometrically simpler units that are subsequently joined to themselves and/or to metals to create components with progressively higher levels of complexity and functionality. However, for the development of robust and reliable integrated systems with optimum performance under different operating conditions, the detailed understanding of various thermochemical and thermomechanical factors is critical. Different approaches are required for the integration of ceramic-metal and ceramic-ceramic systems across length scales (macro to nano). In this presentation, a few examples of integration of ceramic to metals and ceramic to ceramic systems will be presented. Various challenges and opportunities in design, fabrication, and testing of integrated similar (ceramic-ceramic) and dissimilar (ceramic-metal) material systems will be discussed. Potential opportunities and need for the development of innovative design philosophies, approaches, and

  4. Seal between metal and ceramic conduits

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Richard Paul; Tentarelli, Stephen Clyde

    2015-02-03

    A seal between a ceramic conduit and a metal conduit of an ion transport membrane device consisting of a sealing surface of ceramic conduit, a sealing surface of ceramic conduit, a single gasket body, and a single compliant interlayer.

  5. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  6. Development of Sesquioxide Ceramic for High Energy Lasers

    Science.gov (United States)

    2015-05-25

    Ceramic Matrix Composites , Ceramics ...important. 15. SUBJECT TERMS Laser Materials Processing, Ceramic Matrix Composites , Ceramics 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF... ceramic processing, optimizing the processing requires time and resources. Once the fabrication process is established, composition adjustment

  7. Thermal Effect of Ceramic Substrate on Heat Distribution in Thermoelectric Generators

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse

    2012-01-01

    in the heat sink, a parallel microchannel heat sink is applied to a real TEG. The focus of this study is a discussion of the temperature difference variation between the cold/hot sides of the TEG legs versus the variation of the thermal conductivity of the ceramic substrate and the thickness of the substrate...... on the hot side. While the imposed heat flux on the TEG is homogeneously constant, different pressure drops are applied along the microchannel heat sink. The three-dimensional governing equations for the fluid flow and heat transfer are solved using the finite-volume method. The results show...... that the temperature difference is affected remarkably by the pressure drops in the heat sink, the thermal conductivity of the ceramic substrate, and the thickness of the substrate on the hot side....

  8. Tailored Ceramics for Laser Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, Joel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2007-12-10

    Transparent ceramics match or exceed the performance of single-crystal materials in laser applications, with a more-robust fabrication process. Controlling the distribution of optical dopants in transparent ceramics would allow qualitative improvements in amplifier slab design by allowing gain and loss to be varied within the material. My work aims to achieve a controlled pattern or gradient of dopant prior to sintering, in order to produce tailored ceramics.

  9. Fabrication and measurement of optical and spectral properties of the transparent Yb:MgAl2O4 ceramics

    Science.gov (United States)

    Balabanov, S. S.; Belyaev, A. V.; Gavrishchuk, E. M.; Mukhin, I. B.; Novikova, A. V.; Palashov, O. V.; Permin, D. A.; Snetkov, I. L.

    2017-09-01

    In this paper results concerning the fabrication of transparent (with 0.1% mol Yb3+), translucent (with 0.5% mol Yb3+) and opaque (up to 5% mol Yb3+) Yb3+: MgAl2O4 ceramics by hot pressing are presented. The alkoxotechnology of starting magnesium aluminate spinel nanopowder synthesis with homogeneous distribution of Yb ions is proposed. The structural properties of the prepared powders and ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET method. The optical transmittance, absorption and emission cross sections, and the upper level lifetime of the Yb3+:MgAl2O4 ceramics were measured.

  10. Laser Micromachining of Ceramics

    OpenAIRE

    SCITI, Diletta; Bellosi, Alida

    2011-01-01

    Laser surface processing of ceramics is an area of considerable technological importance for several structural, tribological, optical and electronic applications. The laser beam behaves as a heat source that induces a temperature rise on the surface and within the bulk of the material. Depending on laser parameters and material characteristics, lasers can be used for fabricating microholes at designated locations, for cutting, scribing, for surface modifications In this work different types ...

  11. Statistic><Ceramics

    DEFF Research Database (Denmark)

    Hansen, Flemming Tvede

    2008-01-01

    Co-organizer for and participant at the exhibition: Statistic><Ceramics The Röhsska Museum of Design and Decorative Arts; Gothenborg 5/2-16/3 2008 Museum fur Kunst und Gewerbe, Hamburg 3/4-27/4 2008......Co-organizer for and participant at the exhibition: Statistic>2-16/3 2008 Museum fur Kunst und Gewerbe, Hamburg 3/4-27/4 2008...

  12. Dental ceramics: a current review.

    Science.gov (United States)

    Lawson, Nathaniel C; Burgess, John O

    2014-03-01

    Ceramics are used for many dental applications and are characterized in various ways, including by their hardness, brittleness, thermal and electrical insulation, and biocompatibility. The ceramics most commonly used in dentistry are oxides, particularly silicon dioxide (SiO2), or silica; aluminum oxide (Al2O3), or alumina; and zirconium dioxide (ZrO2), or zirconia. This article reviews the microstructure of current dental ceramic materials and how it relates to their mechanical properties, clinical techniques, and optical properties. Typical ceramics currently in use are described, and their clinically relevant properties such as strength, fracture, polishability, and wear are compared. Cementation methods are also discussed.

  13. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Adcock, K.D.; Fain, D.E.; James, D.L.; Powell, L.E.; Raj, T.; Roettger, G.E.; Sutton, T.G. [East Tennessee Technology Park, Oak Ridge, TN (United States)

    1997-12-01

    The separative performance of the authors` ceramic membranes has been determined in the past using a permeance test system that measured flows of pure gases through a membrane at temperatures up to 275 C. From these data, the separation factor was determined for a particular gas pair from the ratio of the pure gas specific flows. An important project goal this year has been to build a Mixed Gas Separation System (MGSS) for measuring the separation efficiencies of membranes at higher temperatures and using mixed gases. The MGSS test system has been built, and initial operation has been achieved. The MGSS is capable of measuring the separation efficiency of membranes at temperatures up to 600 C and pressures up to 100 psi using a binary gas mixture such as hydrogen/methane. The mixed gas is fed into a tubular membrane at pressures up to 100 psi, and the membrane separates the feed gas mixture into a permeate stream and a raffinate stream. The test membrane is sealed in a stainless steel holder that is mounted in a split tube furnace to permit membrane separations to be evaluated at temperatures up to 600 C. The compositions of the three gas streams are measured by a gas chromatograph equipped with thermal conductivity detectors. The test system also measures the temperatures and pressures of all three gas streams as well as the flow rate of the feed stream. These data taken over a range of flows and pressures permit the separation efficiency to be determined as a function of the operating conditions. A mathematical model of the separation has been developed that permits the data to be reduced and the separation factor for the membrane to be determined.

  14. Evaluation of the thermal comfort of ceramic floor tiles

    Directory of Open Access Journals (Sweden)

    Carmeane Effting

    2007-09-01

    Full Text Available In places where people are bare feet, the thermal sensation of cold or hot depends on the environmental conditions and material properties including its microstructure and crustiness surface. The uncomforting can be characterized by heated floor surfaces in external environments which are exposed to sun radiation (swimming polls areas or by cold floor surfaces in internal environments (bed rooms, path rooms. The property named thermal effusivity which defines the interface temperature when two semi-infinite solids are putted in perfect contact. The introduction of the crustiness surface on the ceramic tiles interferes in the contact temperature and also it can be a strategy to obtain ceramic tiles more comfortable. Materials with low conductivities and densities can be obtained by porous inclusion are due particularly to the processing conditions usually employed. However, the presence of pores generally involves low mechanical strength. This work has the objective to evaluate the thermal comfort of ceramics floor obtained by incorporation of refractory raw materials (residue of the polishing of the porcelanato in industrial atomized ceramic powder, through the thermal and mechanical properties. The theoretical and experimental results show that the porosity and crustiness surface increases; there is sensitive improvement in the comfort by contact.

  15. Ceramic technology for advanced heat engines project. Semiannual progress report, April-September 1985

    Energy Technology Data Exchange (ETDEWEB)

    1986-05-01

    An assessment of needs was completed, and a five-year project plan was developed with input from private industry. Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. Focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. The work described in this report is organized according to the following WBS project elements: management and coordination; materials and processing (monolithics, ceramic composites, thermal and wear coatings, joining); materials design methodology (contact interfaces, new concepts); data base and life prediction (time-dependent behavior, environmental effects, fracture mechanics, NDE development); and technology transfer. This report includes contributions from all currently active project participants.

  16. Fracture strength of three all-ceramic systems: Top-Ceram compared with IPS-Empress and In-Ceram.

    Science.gov (United States)

    Quran, Firas Al; Haj-Ali, Reem

    2012-03-01

    The purpose of this study was to investigate the fracture loads and mode of failure of all-ceramic crowns fabricated using Top-Ceram and compare it with all-ceramic crowns fabricated from well-established systems: IPS-Empress II, In-Ceram. Thirty all-ceramic crowns were fabricated; 10 IPS-Empress II, 10 In-Ceram alumina and 10 Top-Ceram. Instron testing machine was used to measure the loads required to introduce fracture of each crown. Mean fracture load for In-Ceram alumina [941.8 (± 221.66) N] was significantly (p > 0.05) higher than those of Top-Ceram and IPS-Empress II. There was no statistically significant difference between Top-Ceram and IPS-Empress II mean fracture loads; 696.20 (+222.20) and 534 (+110.84) N respectively. Core fracture pattern was highest seen in Top- Ceram specimens.

  17. Thermal Conductivity and Water Vapor Stability of Ceramic HfO2-Based Coating Materials

    Science.gov (United States)

    Zhu, Dong-Ming; Fox, Dennis S.; Bansal, Narottam P.; Miller, Robert A.

    2004-01-01

    HfO2-Y2O3 and La2Zr2O7 are candidate thermal/environmental barrier coating materials for gas turbine ceramic matrix composite (CMC) combustor liner applications because of their relatively low thermal conductivity and high temperature capability. In this paper, thermal conductivity and high temperature phase stability of plasma-sprayed coatings and/or hot-pressed HfO2-5mol%Y2O3, HfO2-15mol%Y2O3 and La2Zr2O7 were evaluated at temperatures up to 1700 C using a steady-state laser heat-flux technique. Sintering behavior of the plasma-sprayed coatings was determined by monitoring the thermal conductivity increases during a 20-hour test period at various temperatures. Durability and failure mechanisms of the HfO2-Y2O3 and La2Zr2O7 coatings on mullite/SiC Hexoloy or CMC substrates were investigated at 1650 C under thermal gradient cyclic conditions. Coating design and testing issues for the 1650 C thermal/environmental barrier coating applications will also be discussed.

  18. Characterization of CVI densification of ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Starr, T.L.; Stock, S.R.; Lee, S. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-05-01

    Ceramic matrix composites promise higher operating temperature and better thermodynamic efficiency in many enregy conversion systems. In particular, composites fabricated by the chemical vapor infiltration (CVI) process have excellent mechanical properties and, using the forced flow-thermal gradient variation, good processing economics in small scale demonstrations. Scale-up to larger, more complex shapes requires understanding of gas flow through the fiber preform and of the relationship between fiber architecture and densification behavior. This understanding is needed for design of preforms for optimum infiltration. The objective of this research is to observe the deposition of matrix material in the pores of a ceramic fiber preform at various stages of the CVI process. These observations allow us to relate local deposition rates in various regions of the composite to the connectivity of the surrounding network of porosity and to better model the relationship between gas transport and fiber architecture in CVI preforms. Our observation of the CVI process utilizes high resolution X-ray tomographic microscopy (XTM) in collaboration with Dr. John Kinney at Lawrence Livermore National Laboratory with repeated imaging of a small preform specimens after various processing times. We use these images to determine geometry and dimensions of channels between and through layers in cloth lay-up preform during CVI densification and relate these to a transport model.

  19. The behavior of multilayer ceramic protections at quick thermal shock

    Directory of Open Access Journals (Sweden)

    Alexandru MIHAILESCU

    2013-06-01

    Full Text Available Protective layers of “hot parts” of the turbo engines as well as co-generative systems of energy industry are exposed to a combination of wear factors which may act together at high values.The main goal of the paper is the behavior of some advanced layers, duplex and triplex, multifunctional, ceramics in relation to the most complex wear factor and disturbing as well, the quick thermal shock.The quick thermal shock test installation designed and constructed by the INCAS covers the domain of some high gradients of heating/cooling and is currently integrated in a network of European infrastructure that evaluates the properties of functional layers for turbo engines.Micro-structure inter- and intra- facial changes gradually induced in ceramic structures are highlighted and on this basis their ranking and selection for application on physical parts are established.

  20. Thermal shock behavior of rare earth modified alumina ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junlong; Liu, Changxia [Ludong Univ., Yantai (China). School of Transportation

    2017-05-15

    Alumina matrix ceramic composites toughened by AlTiC master alloys, diopside and rare earths were fabricated by hot-pressing and their thermal shock behavior was investigated and compared with that of monolithic alumina. Results showed that the critical thermal shock temperature (ΔT) of monolithic alumina was 400 C. However, it decreased to 300 C for alumina incorporating only AlTiC master alloys, and increased with further addition of diopside and rare earths. Improvement of thermal shock resistance was obtained for alumina ceramic composites containing 9.5 wt.% AlTiC master alloys and 0.5 wt.% rare earth additions, which was mainly attributed to the formation of elongated grains in the composites.