VAPOR-PHASE COMBUSTION OF BERYLLIUM AND ALUMINUM.
Abstract
Experimental studies of the vapor-phase combustion of beryllium and aluminum were conducted using electrically vaporized wire as a source of high-temperature, high-pressure metal vapor. The effect of oxidizing atmospheres such as oxygen, water, and carbon dioxide in various mixtures and with inert diluents was investigated as well as the effect of total pressure from subatmospheric to 15 atm. Under all conditions, the beryllium oxide particles were produced in the form of regular hexagonal prisms, rather than spheres as in the case of aluminum oxide. The intensity of continuum and band radiation from aluminum and beryllium flames was investigated spectroscopically. The results showed that scattering of radiation by metal oxide particles had a strong effect on the spectral distribution of continuum radiation. A set of equations describing the condensation of beryllium or aluminum oxide droplets from an atmosphere containing metal vapor and oxygen was formulated and programmed for solution on a high-speed digital computer. Starting with a given mass fraction of metal vapor, condensation takes place both by nucleation of new particles and growth of all the particles in the system, until the partial pressure of metal vapor decreases to the equilibrium value. The time required for condensation and the resulting particle size distribution were calculated for different initial metal vapor concentrations and temperatures. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0670529
Entities
People
- Robert W. Hermsen