Begell House Inc.
High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes
HTM
1093-3611
7
4
2003
THERMAL PLASMA DESTRUCTION OF OZONE-DEPLETING SUBSTANCES: TECHNOLOGIES AND CHEMICAL EQUILIBRIUM, CHEMICAL KINETIC AND FLUID DYNAMIC MODELLING
415-433
10.1615/HighTempMatProc.v7.i4.10
Anthony B.
Murphy
CSIRO Manufacturing Flagship, Sydney, Australia
Plasma technologies for the destruction of ozone-depleting substances are reviewed. Particular attention is paid to the PLASCON process, based on an argon plasma produced by a dc plasma torch, which is used to destroy halons and chlorofluorocarbons in Australia and the UK. Three different approaches to modelling the destruction of ozone-depleting substances in a thermal plasma are presented: chemical equilibrium, chemical kinetic and fluid dynamic. Chemical equilibrium modelling does not accurately predict the products of the destruction process; however, the equilibrium mixing temperature is shown to be well correlated with the destruction and removal efficiency. The ratio of the feed rate to the plasma power also predicts the destruction and removal efficiency for a given oxidising gas. Chemical kinetic calculations are shown to give a good prediction of the products of the destruction process, while fluid dynamic modelling, which takes into account turbulent mixing and recirculating flow phenomena, is required to calculate concentrations of the different species within the reaction zone. The importance of interconversion of different ozone-depleting substances during the destruction process is demonstrated, and it is shown that the use of steam rather than oxygen as the oxidising gas in the process greatly reduces interconversion and improves destruction performance. Keywords: plasma waste destruction, thermal plasma, CFC, chlorofluorocarbon, halon, Montreal Protocol.
ENERGY RECOVERY FROM WASTE AND PLASMA CONVERSION
435-454
10.1615/HighTempMatProc.v7.i4.20
D.
Bendix
Department of Engineering Sciences, Martin - Luther - University Halle - Wittenberg, Merseburg, Germany
D.
Hebecker
Department of Engineering Sciences, Martin - Luther - University Halle - Wittenberg, Merseburg, Germany
Present technologies for energy recovery from waste are reviewed. It is shown by examples that the conversion of mixed waste without pre-treatment in “high-technology” plants leads generally to lower energy recovery rates than the conversion of refuse materials with a low fraction of harmful substances due to pre-treatment. Plasma waste conversion offers favorable conditions for the conversion of the fraction of the waste materials charged with harmful substances in the pre-treatment. The development of a plasma technology for waste conversion from laboratory scale to a pilot plant is presented. Results of experiments showing effects of mixing and of dynamic phenomena are shown in detail. The potential for an increase of the average energy recovery from waste is derived from the presented results of the pilot plant operation.
HALOGENATED HYDROCARBON DECOMPOSITION BY STEAM THERMAL PLASMAS
455-474
10.1615/HighTempMatProc.v7.i4.30
Takayuki
Watanabe
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
Shigehiro
Shimbara
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
Applications for the destruction of hazardous and waste materials such as halogenated hydrocarbons by reactive thermal plasmas are reviewed. For halogenated hydrocarbon decomposition, key technologies are the stable generation of DC steam plasmas and the off-gas treatment after the decomposition of halogenated hydrocarbon. Therefore, DC 100%-steam plasma characteristics were investigated for the application of halogenated hydrocarbon decomposition. The described steam plasma system is a portable light-weight plasma generation system that does not require any gas supply. The system has high energy-efficiency since cooling water is not needed. In addition, a dry process was developed for halogenated hydrocarbon decomposition and simultaneously adsorbing fluorine and bromine with solid alkaline reactants.
APPLICATION OF REACTIVE PLASMA TO NUCLEAR WASTE TREATMENT - POSSIBILITY OF SEPARATION PROCESS OF ZR-NB ALLOY BY REACTIVE THERMAL PLASMA TREATMENT
475-485
10.1615/HighTempMatProc.v7.i4.40
Masaaki
Suzuki
Department of Chemical Engineering, Tokyo Institute of Technology 2-12-1 0-okayama, Meguro-ku, Tokyo 152-8552, Japan
Takeshi
Ichihashi
Department of Chemical Engineering, Tokyo Institute of Technology 2-12-1 0-okayama, Meguro-ku, Tokyo 152-8552, Japan
Arata
Jote
Department of Chemical Engineering, Tokyo Institute of Technology 2-12-1 0-okayama, Meguro-ku, Tokyo 152-8552, Japan
Shigeru
Nishio
The Wakasa Wan Energy Research Center 64-52-1, Hase, Tsuruga-shi, Hukui 914-0192, Japan
Shinji
Kawagoe
Fugen Nuclear Power Station, Japan Nuclear Cycle Development Institute 3 Myojin-cho, Tsuruga-shi, Hukui 914-8510, Japan
Applications of thermal plasmas in the nuclear engineering field are reviewed, and as an application example of a reactive thermal plasma treatment, the possibility of separation of zirconium-niobium alloy is reported. Some experiments, which use a thermal fluorine plasma have been carried out and the following results have been obtained. When the process takes place above the melting point of this alloy, Zr is extracted successfully in the evaporated fine particles and Nb is enriched in the bulk alloy. This phenomenon can be explained well by using Gibbs free energy of fluorine reactions. For a better separation, a higher temperature of the sample and a more effective mass transfer of Nb in the melting alloy is required. The results confirm the possibility of this separation method.
THE PLASMA DESTRUKTION OF ODOROUS MOLECULES: ORGANOSULPHUR COMPOUNDS
487-499
10.1615/HighTempMatProc.v7.i4.50
Imtiaz K.
Ahmad
Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
Anna E.
Wallis
Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
J. Christopher
Whitehead
Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
The plasma destruction of methyl mercaptan and dimethyl sulphide has been studied in both nitrogen and air gas streams with a non-thermal, atmospheric pressure discharge using a packed bed of BaTiO3 beads. Destructions in excess of 85% can be achieved for pollutant concentrations of 30 to 100 ppm with energy costs in the order of 75 to 200 kWh/kg. The detected end-products of the processing are H2S, HCN, NH3 in a N2 stream and SO2, CH2O, CO and CO2 in air. The implications for odour control are discussed.
A METHOD OF MODELLING HEAT TRANSFER AND GASODYNAMIC PROCESSES IN ARC PLASMA GENERATORS
501-524
10.1615/HighTempMatProc.v7.i4.60
A. M.
Krouchinin
Faculty of Electrical Engineering, Technical University of Czestochowa, 42-200 Czestochowa - Poland
A.
Sawicki
Faculty of Electrical Engineering, Technical University of Czestochowa, 42-200 Czestochowa - Poland
The paper investigates the processes of heat and gas mass transfer under the generalized physico-mathematical model of both plasma jet generators and plasma torches (also referred to as transferred- and non-transferred arc plasmatrons). A method is presented of solving the system of equations of the monoliquid arc model by introducing simplifying assumptions which make it equivalent to the two-layer arc model. The boundary condition on the surface of the cylindrical part of the column is given. The phenomena and thermophysical characteristics of plasma in both the cylindrical and the conical part of the column are described. A new method is offered for formulating an additional internal boundary condition of heat transfer in the plasma-gas system. The cases considered include the arc stabilized by metal walls, by laminar or turbulent gas flow in the discharge channel of a plasma jet generator, as well as the arc stabilized by gas flow in plasma torches used for melting metal pieces.
MEASURED AND CALCULATED STARK PARAMETERS FOR SEVERAL AR I SPECTRAL LINES
525-534
10.1615/HighTempMatProc.v7.i4.70
Vladimir
Milosavljevic
Plasma Research Group, College of Science and Health, Dublin Insitute of Technology, Dublin 1, Ireland
Milan S.
Dimitrijevic
Astronomical Observatory, Volgina 7, 11160 Belgrade, Serbia and Montenegro
Stevan
Djenize
Faculty of Physics, University of Belgrade, P.O.B. 368, Belgrade, Serbia
On the basis of the precisely recorded five neutral argon (Ar I) line shapes (in the 4s-5p transition) we have obtained the separate electron (We) Stark width. Moreover, we have determined as well and ion (Wi) contributions to the total Stark width, not measured previously for these lines. Also, we have calculated Stark parameters for these five neutral argon lines within the semiclassical- perturbation formalism.
We have tested also recently published line deconvolution procedure which enables to determine beside line broadening parameters, electron temperature (T) and electron density (N). An excellent agreement has been found among plasma parameters, obtained parameters by well established techniques and the examined method, which recommends proposed deconvolution procedure for diagnostic purposes.
OPTICAL SPECTROSCOPIC DIAGNOSTIC OF AN Ar+H2 RF THERMAL PLASMA USED TO THE SILICON POWDER PURIFICATION. EFFECT OF THE EVAPORATION PHENOMENA
535-546
10.1615/HighTempMatProc.v7.i4.80
M.
Benmansour
Laboratoire de Génie des Procédés Plasmas et Traitement de Surface − Université Pierre et Marie Curie − Paris 6 - ENSCP, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 05
M.
Nikravech
Laboratoire de Genie des Precedes Plasmas et Traitement de Surfaces, Universite P. et M. Curie, Ecole Nationale Superieure de Chimie de Paris, 11 rue Pierre et Marie Curie 75005 Paris, France
S.
Darwiche
Laboratoire de Genie des Procedes Plasmas et Traitement de Surface - Université Pierre et Mane Curie- ENSCP 11-13, rue Pierre et Marie Curie 75231 Paris Cedex 05 France
J.
Chapelle
LASEP, Centre Universitaire de Bourges, Rue Gaston Berger, BP 4043, 18028 Bourges Cedex, France
Daniel
Morvan
Laboratoire de Genie des Precedes Plasmas Universite P. et M. Curie, ENSCP 11 rue P. et M. Curie 75005 Paris France
Jacques
Amouroux
Laboratoire de Genie des Precedes Plasmas Universite P. et M. Curie, ENSCP 11 rue P. et M. Curie 75005 Paris France
Ar+H2 RF thermal plasma spraying is used to melt, purify and hydrogenate metallurgical silicon particles in order to elaborate a thin layer for photovoltaics applications. Hydrogenation and purification phenomena have been analysed by a spectroscopic diagnostic. Transitions of excited argon, hydrogen and silicon detected have been used to calculate the electronic density, electronic temperature and silicon vapor content in the plasma flow.
THERMAL MODELLING OF COMPOSITE IRON/ALUMINA PARTICLES SPRAYED UNDER PLASMA CONDITIONS PART I: PURE CONDUCTION
547-558
10.1615/HighTempMatProc.v7.i4.90
M.
Bouneder
SPCTS UMR 6638 CNRS, Faculte des Sciences et Techniques. 123 Albert Thomas, 87060 Limoges Cedex, France; and Institut d'Aeronautique, Universite Saad Dahleb. Route de Soumaa B.P 270, Blida, Algerie
Bernard
Pateyron
Laboratoire SPCTS UMR CNRS 7315, ENSCI, Centre Europeen de la Ceramique, Limoges, France
Pierre
Fauchais
Laboratoire Sciences des Procedes Ceramiques et de Traitements de Surface UMR CNRS 6638 University of Limoges 123 avenue Albert Thomas, 87060 LIMOGES - France
A model predicting the temperature profiles of composite sprayed particles during their flight in the plasma jet is developed. Lumped thermal capacitance method is compared to full simulation taking into account the dependency of physical parameters on temperature. Coated particles composed of two materials (iron core/alumina shell) are considered for spray applications showing the influence of the possible thermal contact resistance between both materials.
COLLISIONAL-RADIATIVE TYPE MODELLING AND APPLICATION IN PLASMA DIAGNOSTICS
559-568
10.1615/HighTempMatProc.v7.i4.100
K.
Katsonis
Laboratoire de Physique des Gaz et des Plasmas (LPGP), UMR 8578, Universite Paris-sud, 91405 Orsay cedex, FRANCE
Stephane
Pellerin
GREMI, CNRS-Universite d'Orleans, BP 6759, 45067 Orleans Cedex 2, France LASEP, Universite d'Orleans - Antenne de Bourges, BP4043, 18028 Bourges, France
K.
Dzierzega
Marian Smoluchowski Inst. of Physics, Jagellonian University, ul. Reymonta 4,30-459 Krakow, Poland
Detailed modeling of rare gases plasmas, taking into consideration their atomic structure specificity is relevant to laboratory studies and industrial applications and also essential for astrophysical research. We are here describing the general trends of their Collisional-Radiative type modeling including some examples. It is shown how the atomic data to be used in such modelings are determining the global plasma properties description and therefore data evaluation is indispensable for obtaining a satisfactory optical diagnostics.
CALIBRATION AND APPLICATION OF CR-39 TYPE NUCLEAR TRACK DETECTORS IN PLASMA FOCUS AND OTHER PLASMA EXPERIMENTS
569-578
10.1615/HighTempMatProc.v7.i4.110
A.
Szydlowski
The Andrzej Soltan Institute for Nuclear Studies (SINS), 05-400 Otwock-Swierk, Poland
A.
Banaszak
The Andrzej Soltan Institute for Nuclear Studies (IPS), 05-400 Swierk-Otwock, Poland
Marek
Sadowski
Department of Plasma Physics and Technology (P-V) The Andrzej Soltan Institute for Nuclear Studies (IPJ) 05-400 Otwock-Swierk by Warsaw, Poland
M.
Scholz
Institute of Plasma Physics and Laser Microfusion (IPFLM), 23 Hery, 00-908 Warsaw 49, Poland
To use these detectors in the optimal way and to determine their detection characteristics, detailed calibration studies of the selected plastic detectors, and especially CR-39 and PM-355 types have been performed at IPJ for several years. The paper presents detection characteristics, i.e. track diameters as a function of ion energy, atomic number and etching time. There are also presented in the paper different applications of the detectors in question, particulary in the Plasma Focus experiments.