Combustion, Explosion and Shock Waves

, Volume 23, Issue 2, pp 239–245 | Cite as

Detonation limits of clouds of coal dust in mixtures of oxygen and nitrogen

  • D. H. Edwards
  • P. J. Fearnley
  • M. A. Nettleton


Ignition and the subsequent acceleration of flame in clouds of coal dust dispersed in mixtures of oxygen and nitrogen have been studied. Two coal sizes, 24 and 54 μm, in concentrations ranging from 0.05 to 0.22 kg/m3 were employed. Flame acceleration and the approach to transition to a stable detonation were monitored by a combination of microwave interferometry and pressure measurements. Flame and shock velocities up to 1.85 km/sec were observed. Ignition distances were found to be independent of the concentrations of dust and oxygen and particle size.


Oxygen Nitrogen Particle Size Dust Microwave 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. 1.
    M. A. Nettleton and R. Stirling “Detonations in suspensions of coal dust in oxygen’, Combust. Flame,21, 307 (1973).Google Scholar
  2. 2.
    S. Wojcicki and M. Zalesinski, “The mechanisms of transition from combustion to detonation in a mixture of coal dust and gaseous oxidizer”, in: Recent Developments in Shock Tube Research, Proc. 9th Int. Shock Tube Symp., (D. Bershader, and W. Griffith, editors), Stanford University Press (1973), p. 821.Google Scholar
  3. 3.
    M. Zalesinski, A. Kusmierz, A. Teodorczyk, and S. Wojcicki, 1st Specialists Meeting (Int.) Combustion Institute, French Section Combust. Institute (1981), p. 503Google Scholar
  4. 4.
    M. Zalesinski and S. Wojcicki, “Generation of detonations by two-stage burning, “in: Gasdynamics of Detonations and Explosions, J. R. Bowen, N. Manson, A. K. Oppenheim, and R. E. Soloukhin, editors), Progress in Astronautics and Aeronautics 75 (1981), p. 439.Google Scholar
  5. 5.
    E. A. Ural, “Shock Wave Ignition of Pulverized Coal,” PhD Thesis, University of Michigan (1981).Google Scholar
  6. 6.
    A. M. Goodridge, S. Badzioch, and P. G. W. Hawksley, “A particle size classifier for preparing graded subsieved fractions”, J. Sci. Instrum., 39, 611 (1962).Google Scholar
  7. 7.
    D. H. Edwards, E. M. Job, and T. R. Lawrence, “Observations on gaseous detonation waves using a microwave interferometer, Nature,195, 372 (1962).Google Scholar
  8. 8.
    D. H. Edwards, G. Hooper, and R. J. Meddins, Microwave velocity measurements of marginal detonations”, J. Phys. D.,3, 1130 (1970).Google Scholar
  9. 9.
    M. A. Netvleton, “Shock waves in dust/droplet suspensions with particular reference to the initiation of a detonation”, Arch. Term. Span.,6, 457 (1975).Google Scholar
  10. 10.
    V. P. Korobeinikov, “On simple theoretical models of two-phase flows associated with combustion”, Acta Astron.6, 931 (1979).Google Scholar
  11. 11.
    M. A. Nettleton and R. Stirling “The ignition of clouds of coal particles in shockheated oxygen”, Proc. R. Soc. London,A300, 62 (1967).Google Scholar
  12. 12.
    P. J. Fearnley, “The effects of confinement and chemical composition on explosions,” PhD Thesis, University College, Aberystwyth (1983).Google Scholar
  13. 13.
    M. A. Nettleton and R. Stirling, “The combustion of clouds of coal particles in shockheated mixtures of oxygen and nitrogen, “Proc. R. Soc. London,322, 207.Google Scholar
  14. 14.
    M. D. Gray and G. M. Kimber, Rapid devolatilization of small coal particles”. Combust. Flame,11, 360 (1967).Google Scholar
  15. 15.
    I. I. Glass and J. G. Hall, Handbook of Supersonic Aerodynamics: 18 Shock Tubes, Navord Report 1488, Vol,6, US Govt. Printing Office, Washington, D. C. (1959).Google Scholar

Copyright information

© Plenum Publishing Corporation 1987

Authors and Affiliations

  • D. H. Edwards
    • 1
  • P. J. Fearnley
    • 2
  • M. A. Nettleton
    • 3
  1. 1.Department of PhysicsUniversity College of WalesPenglaisUK
  2. 2.BP Research CentreSunbury on ThamesEngland
  3. 3.CERLLeatherheadEngland

Personalised recommendations