Combustion of Boron Particles at Elevated Pressures

Abstract

Combustion of single boron particles, about 75 microns in diameter, from a crystalline powder sample has been studied. Particles were ignited by being dropped through a focused laser beam in several oxidizing gases over a range of pressures. In pure oxygen, in air, and in O2/Ar(20/80), particles were merely preheated to a temperature about 2000K; ignition took place spontaneously after a measurable induction period. Quantitative values of both the induction period and the subsequent self-sustained combustion period are listed. It was shown that the classical theory of ignition and combustion can account for all three observed burning modes: metastable surface reaction during the preignition period, rapid self-sustained diffusion-combustion, and decaying combustion. Previously reported reaction-rate and ignition-limit data were used for quantitative estimates of parameters pertaining to the three regimes.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1970
Accession Number
AD0710747

Entities

People

  • Andrej Macek
  • J. M. Semple

Organizations

  • Purdue University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Arrhenius Equation
  • Autoignition
  • Barometric Pressure
  • Burning Rate
  • Carbon Dioxide
  • Chemical Reaction Properties
  • Combustion
  • Diffusion
  • Equations
  • Heat Energy
  • High Pressure
  • Ignition
  • Laser Beams
  • Mechanical Engineering
  • Partial Pressure
  • Steady State
  • Surface Reactions

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Combustion science or combustion engineering.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers