Plasma Jet Reactor Research Articles

Synthesis of ?-WC1?x in an atmospheric-pressure, thermal plasma jet reactor

Studies of the chemical reactions between α-WC and CH4 as well as between WO3 and CH4 in an atmospheric argon plasma jet reactor reveal that the high-temperature tungsten carbide (β-WC1−x) may be formed by injecting either α-WC or WO3 with methane as carrier gas into an argon plasma jet. The maximum conversion of α—WC into β-WC1−x reaches 52%, whereas conversion ratios in excess of 98% are observed when WO3 is used as the primary reactant. X-ray diffraction studies indicate a new FCC phase with a lattice parameter smaller than that of β-WC1−x which is typically produced in some of the reactions. This new phase shows a sharp lattice parameter change between 700 and 800°C upon annealing in argon. The temperature of transition of β-WC1−x to the other two more common carbide phases occurs around 470°C. The β-WC1−x is more stable than β-W2C to acid attack and its resistance is approximately the same as that of α-WC.

Design and use of an Efficient Plasma Jet Reactor for High Temperature Gas/Solid Reactions

ABSTRACTA unique and efficient plasma jet reactor has been developed and used to study the high temperature production of carbon monoxide from a reaction between powdered carbon and a pure carbon dioxide plasma. The plasma jet reactor was designed to allow the injection of powdered carbon above the arc discharge region rather than into the plasma flame below the arc discharge region. High yields of carbon monoxide, produced at relatively high efficiencies, were a direct result of this technique. The plasma jet was also designed to enable rapid changing and testing of various anode insertsAverage yields of carbon monoxide in the product gases were as high as 80–87% in selected experimental trials. Carbon monoxide was produced at rates exceeding 15,000 1/hr (at STP) with a power expenditure of 52 Kw.

気相反応法による炭化けい素超微粉体の合成へのプラズマジェットの利用

Highly crystalline and ultrafine SiC powders with particle sizes of -0.02 μ were obtained with a high yield by the vapor phase reaction of CH3SiCl3-H2 system in a simple plasma jet reactor. The formation of SiC powders from CH3SiCl3-N2 system was difficult by the same method.

Plasma Engineering in Metallurgy and Inorganic Materials Tcchnology

An account is presented of the work done in the USSR on the generation of thermal plasma, plasma melting, and plasma jet processes. The various methods of plasma generation are reviewed, such as arc plasma generators and high frequency (HF) plasma generators including HF-induction plasmatrons, HF-capacity plasmatrons and HF-flame plasmatrons. Plasma melting techniques covered include plasma-arc remelting and reduction melting. Plasma jet reactors, multi-jet reactors, and processes such as product extraction, dispersed material behaviour in plasma jets, production of disperse materials, reduction of metals, synthesis of metal compounds, and production of composite materials are briefly described.

Modeling of heterogeneous systems in a plasma jet reactor

AbstractA theoretical model of the behavior of a plasma jet reactor (5 000 K to 12 000 K) considering a three‐dimensional, nonisothermal, turbulent, compressible, swirling, confined flow is developed. Single particle trajectories are predicted by solving the equations of motion for the axial, radial, and tangential directions. Calculations are carried out for both argon and nitrogen gases. The model is then extended to a multiparticle system on the basis of a feed particle size distribution, concentration distribution, and loading ratio.The calculations are applied to a study of the decomposition of molybdenum disulfide particles into molybdenum metal and elemental sulfur. Results are presented in terms of the effects on the particle history (trajectory, temperature, and conversion) of the following variables: particle size, nozzle exit temperature and velocity, injection velocity, location and angle of injection, swirl velocity, and ambient temperature conditions.

Treatment of ilmenite ore in a plasma jet reactor

Ground ilmenite ore was injected with hydrogen or ammonia into the arc- heated argon issuing from a plasma torch. Product collected either as consolidated or powder material on the walls of watercooled quench tubes and consisted of titanium-iron oxides of variable composition and metallic iron. Separation of titanium and Fe was most effective in the consolidated product where Ti contents ranged up to 49.5% (82.5% TiO2) and iron contents down to 12.1% (15.6% FeO). Unconsolidated material showed very little reaction of ilmenite but hematite contained in test samples was reduced. Résumé Du minerai broyé d'ilménite a été injecté avec de l'hydrogéne ou de l'ammoniaque dans un arc produit par une torche á plasma á l'argon. Les produits recueillis, solides ou pulvérulents, sur les parois refroidies á l'eau d'un tube de trempe étaient constitués d'oxydes de fer et de titane de diverses compositions et de fer métallique. La séparation du fer et du titane était plus efficace dans Ie produit solide pour lequel la teneur en titane s'élevait á 49.5% (82.5% TiO2) et la teneur en fer aussi faible que 12.1% (15.6% FeO). Le produit pulvérulent ne présentait que trés peu de réaction de l'ilménite mais l'hématite contenu dans les échantillons analysés était réduite.

Treatment of ilmenite ore in a plasma jet reactor

Ground ilmenite ore was injected with hydrogen or ammonia into the arc- heated argon issuing from a plasma torch. Product collected either as consolidated or powder material on the walls of watercooled quench tubes and consisted of titanium-iron oxides of variable composition and metallic iron. Separation of titanium and Fe was most effective in the consolidated product where Ti contents ranged up to 49.5% (82.5% TiO2) and iron contents down to 12.1% (15.6% FeO). Unconsolidated material showed very little reaction of ilmenite but hematite contained in test samples was reduced. Résumé Du minerai broyé d'ilménite a été injecté avec de l'hydrogéne ou de l'ammoniaque dans un arc produit par une torche á plasma á l'argon. Les produits recueillis, solides ou pulvérulents, sur les parois refroidies á l'eau d'un tube de trempe étaient constitués d'oxydes de fer et de titane de diverses compositions et de fer métallique. La séparation du fer et du titane était plus efficace dans Ie produit solide pour lequel la teneur en titane s'élevait á 49.5% (82.5% TiO2) et la teneur en fer aussi faible que 12.1% (15.6% FeO). Le produit pulvérulent ne présentait que trés peu de réaction de l'ilménite mais l'hématite contenu dans les échantillons analysés était réduite.

Production of Acetylene from Methane Using Plasma Jet (IV)

In the acetylene formation methane using an argon plasma jet reactor, effects of argon, methane flow rates and plasma power on acetyelene yield have been investigated.The results obtained were as follows:(1) Optimum condition was found to be indicated as(Q0, m/FM) 1.53= (100/43.2) (FA/FM+1)where Q0, m is plasma power, FA and Fm flow rate of argon and methane respectively.(2) Maximum acetylene yield obtained was 80-90%.

Production of Acetylene from Methane Using a Plasma Jet (I)

An argon plasma jet reactor has been designed and built to produce acetylene from methane. In order to obtain the characteristics of the reactor, several tests have been carried out.The effects of both the diameter of the anode nozzle and the methane feeding holes on the methane conversion have been confirmed to be little. The position and direction of methane feeding within the distance, ca. 50mm, from the nozzle have been little effect on the conversion. It has been found that the flow rate of quenching water must be kept below ca. 2.5l/min in order to prevent some unfavorable reactions of water with the reacting gas mixture. From these results we have arrived at the conclusion that the reactor is quite useful in further research of the acetylene formation by plasma jet.

DIVISION OF ENGINEERING: CHEMICAL REACTIONS IN THE PLASMA JET*

Chemistry at extremely high temperatures, especially of ionized gases, or plasma, is discussed. As an example, the properties of nitrogen at atmospheric pressure at temperatures from about 3000 deg to 25000 deg K are described. Methods for generating a plasma at 15000 deg K at atmospheric pressure are outlined and illustrated by use of an open electric arc for which the temperature ordinarily varies from 6000 to 8000 deg K. The production and characteristics of the plasma jet are explained, with reference to a small commercial plasma jet of 40-kw capacity. Applications of the plasma jet principle, particularly for the production of acetylene, are discussed. In a survey of possible plasma jet applications where the price of heat is that of electricity, molecules with atoms of high atomic weight will be most promising. The use of extremely fast cooling rates in a plasma to make very finely divided nickel powder by the thermal decomposition of nickel carbonyl are described. The so-called intermediate section plasma jet reactor is described and discussed in detail. Preliminary results of experiments in a nitrogen plasma that take advantage of the rapid temperature drop experienced by the effluent plasma to freeze and determine the equilibrium populationmore » of atomic species are reported. When methane is fed to the nitrogen jet, it is rapidly converted to C/sub 2/ and precursors at the high temperatures involved. When these collide with nitrogen atoms or ions, CN radicals should form, which in the cooler portions of the jet combine with hydrogen to form HCN. (BBB)« less