Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Current distribution of an electric arc at the surface of plasma torch electrodes (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 1263-1268 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Current distributions of the arc foot on the surface of the electrodes in a geometry simulating a plasma torch are reported. Most of the experiments were to determine the arc current distribution at the cathode. The results were obtained using a novel technique and represent experiments using different plasma gases (Ar, He, Ar+0.3% CO, He+0.4% CO, He+0.4% N2, N2, CO) and operating conditions (magnetic field and arc velocity). It is shown that all three, the surface composition due to contamination, the transverse magnetic field used to move the arc, and the arc velocity have a strong influence on the current distribution. Higher erosion rates were found for higher current densities of the arc foot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Method to measure current distribution of an electric arc at tubular plasma torch electrodes (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 1259-1262 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A novel technique was developed to measure the current distribution of an electric arc foot on the electrodes of a plasma torch. The method is based on the induced voltage generated by the passage of the arc over the measuring probe. The technique is suitable for long operation times in plasma torches. Examples of measurements are given for arcs in pure Ar and in Ar+0.3% CO, moving at 9 m/s at 100 and 140 A, respectively. The peaks in the linear current density were 7.6 and 4.2×104 A/m for Ar and Ar+0.3% CO, respectively. The current density was estimated to be around 104 A/cm2 for Ar and 2×103 A/cm2 for Ar+0.3% CO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141222
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nonintrusive fast response concentration measurement device for chemical reactors (1996)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 847-848 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A device is proposed by which the residence time distribution in a tubular chemical reactor can be measured with a response time on the order of hundreds of microseconds. This device works on the principle of infrared laser absorption spectroscopy. Because the light beam passes directly through the reactor cross section, there is no measurement cell thus making the technique nonintrusive. The device has been successfully tested with a tubular reactor with a gaseous flow at average residence times ranging from 0.04 to 0.7 s. The level of micromixing in the reactor can also be estimated due to the very fast response of the instrument. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146822
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Spectroscopic study of a magnetically rotating arc between opper electrodes in contaminated argon (1992)
    Springer
    Plasma chemistry and plasma processing 12 (1992), S. 1-16 
    Details
    ISSN: 1572-8986
    Keywords: Thermal plasmas ; electrode erosion ; plasma spectroscopy ; metal vapor plasma ; electrode contamination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The effects of N2 and CO contaminants in atmospheric-pressure argon on an arc rotating between two concentric copper electrodes has been studied using optical spectroscopy of copper lines. The axial temperature of the magnetically driven arc in Ar + %N2 was determined to be around 10,000 K for arc currents of SO to 200 A. The diffusion process of the copper vapor from the cathode was also studied. A copper density maximum 1 mm from the cathode along the arc column was found in Ar + %N2. Removal of the contaminated cathode surface layers by the arc when contaminant injection in the plasma gas was stopped was found to be a slow process with a time scale depending on the type of the gas contaminant. The presence of gas contaminant in the electrode material controls the cathode erosion mechanism and the overall arc behavior in the transition between a contaminated to a pure argon arc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01447941
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The effect of low concentrations of a polyatomic gas in argon on erosion on copper cathodes in a magnetically rotated arc (1987)
    Springer
    Plasma chemistry and plasma processing 7 (1987), S. 349-364 
    Details
    ISSN: 1572-8986
    Keywords: Electrode erosion ; plasma torches ; magnetic rotation ; effect of gas composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Experimental results are presented for electrode erosion on copper cathodes in magnetically rotated arcs in argon, dry air, nitrogen, ammonia, and carbon monoxide as well mixtures of the above with argon. Water-saturated argon was also used. Erosion rates were determined by weight loss after chemical cleaning, and the runs were sufficiently long (between 5 to 60 min) to represent steady-state operation. Arc currents of 100 A and gas pressures of 1.1 atm. were used. Pure argon gave the highest erosion rates and the lowest arc velocities. Small concentrations of any of the diatomic gases in argon greatly increased the arc velocity and decreased the erosion rates. The results suggest that erosion is primarily a thermal phenomenon but that the surface chemistry can greatly influence erosion rates by modifying arc behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01016522
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Cathode erosion in inert gases: The importance of electrode contamination (1989)
    Springer
    Plasma chemistry and plasma processing 9 (1989), S. 121-132 
    Details
    ISSN: 1572-8986
    Keywords: Electrode erosion ; plasma torches ; magnetic rotation ; contamination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Experimental results are presented for electrode erosion on copper electrodes in magnetically rotated arcs in argon and helium. Measurements were also made of the arc voltage and velocity. The effects due to the contamination of the electrode surface by either a native contaminant layer (copper oxide and carbon traces) or the continuous injection of very small amounts of various diatomic gases (nitrogen, oxygen, chlorine, and carbon monoxide) into the inert plasma gases were determined. The erosion rates for pure argon were significantly higher than those for pure helium (13.5 μg/C for argon and 1 μg/C for helium) and with both gases, very high arc velocities were measured initially (〉60 m/s for argon and 〉160 m/s for helium) when a natural contaminant layer was still present on the cathode. The removal of this layer resulted in lower velocities (2m/s for argon and 20m/s for helium) and higher erosion rates. The removal of the layer was much faster with argon, due possibly to higher electrode surface current densities for argon arcs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01015830
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Characteristics and electrode erosion rates of a D.C. plasma torch operating with TiCl4 plasma gas (1994)
    Springer
    Plasma chemistry and plasma processing 14 (1994), S. 73-85 
    Details
    ISSN: 1572-8986
    Keywords: Electrode erosion ; titanium tetrachloride ; composite electrodes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A stable TiCl4 plasma was produced using a simplified d.c. torch. The arc was struck between two concentric ring electrodes, d mm apart, and rotated using a magnetic coil. The electrode material was a new TaC composite. The arc was operated at 100 A for up to I h using plasma gas containing 0–30% TiCl4. The voltage was 24–60 V, depending on the TiCl4 concentration. The electrode erosion rate was of the order of 20μg/C. It is shown that the erosion rate is a function of the aerodynamic drag of the are column.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01448738
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Synthesis gas production from peat using a steam plasma (1984)
    Springer
    Plasma chemistry and plasma processing 4 (1984), S. 297-313 
    Details
    ISSN: 1572-8986
    Keywords: Nontransferred arc ; peat gasification ; plasma reaction model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A steam plasma was used to convert peat into a synthesis gas, suitable for methanol production, in a cocurrent transport reactor. A cylindrical stainless-steel reactor 20 cm in diameter and 120 cm long was used. The effects of temperature and the carbon/ steam molar ratio on the product gas composition and carbon conversion were investigated. Finely ground peat (mean particle size, 63 µm; moisture content, 15.5%) was fed continuously through the reactor top and exposed to mean reaction temperatures ranging from 1250 to 1420 K. The plasma inlet temperature was calculated to be of the order of 3500 K and total powers as high as 62 kW were used. A carbon conversion of 89% and a hydrogen-to-carbon monoxide ratio of 1.8 in the product gas were obtained. A simple model of the reacting system suggested that a conversion of 90% (needed for an industrial process) and a hydrogen-to-carbon monoxide ratio of two could be obtained with equipment modifications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00568983
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Cathode erosion on copper electrodes in steam, hydrogen, and oxygen plasmas (1992)
    Springer
    Plasma chemistry and plasma processing 12 (1992), S. 203-218 
    Details
    ISSN: 1572-8986
    Keywords: Electrode erosion ; plasma torches ; steam ; hydrogen ; oxygen ; magnetic rotation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Experimental data are presented for cathode erosion rates on copper cathodes (or magnetically rotated arcs in steam, and mixtures of steam, hydrogen, and oxygen with argon. Measurements were also made of the arc voltage and velocity. The erosion rates for steam and oxygen plasmas were significantly lower than those .16r argon and hydrogen. Pure steam and 10% oxygen in argon gave erosion rates of 2.3 and 6.1 μg/ C respectively while pure argon and 70% hydrogen in argon gave rates of 14.8 and 13.0 μg/C respectively. Erosion rates decreased with increasing are velocities. The variation of arc velocity with operating conditions is described in terms of both aerodynamic and “surface drag” on the arc and arc root respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01447447
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Electrode erosion in plasma torches (1992)
    Springer
    Plasma chemistry and plasma processing 12 (1992), S. 327-343 
    Details
    ISSN: 1572-8986
    Keywords: Plasma torches ; cold cathode erosion ; experimental
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Cathode erosion rates are reported (or copper electrodes in a simulated plasma torch operating at atmospheric pressure. The are current was 100A (or most experiments; the magnetic field used to move the arc varied between 0.001 and 0.15 T. Different plasma gases were used (Ar, He, air, N2, CO, and mixtures of the noble gases with O2, N2, CO, CH4, Cl2, and H2S) at flow rates varying between 0.2 and 20 liters/min. Different criteria (arc velocity, arc attachment residence time, arc current density) were used to analyze the erosion results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01447029
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...