Abstract

A two-wavelength transmissometer employing a He-Cd laser (λ₁ = 0.325 μm) and a He-Ne laser (λ₂ = 3.39 μm) has been developed for measuring the Sauter mean diameter of mineral ash droplets in high-temperature high-velocity coal-fired combustion flows. From transmission measurements at the two wavelengths, it is shown that mean diameters in the 0.3–3.5-μm range may be inferred with a weak sensitivity to particle refractive index and size distribution shape. The volume concentration or loading of the aerosol may then be determined from the measured transmission at either wavelength. The instrument has been used to measure the mean size and loading of ash droplets in a pulverized coal-fire channel flow at temperatures to ~2900 K and velocities of up to 400 m-sec⁻¹ for combustion MHD power generation applications.

© 1980 Optical Society of America

Multiplex CARS temperature measurements in a coal-fired MHD environment

Edward J. Beiting
Appl. Opt. 25(10) 1684-1692 (1986)

Some chemical, physical, and optical properties of fly ash particles

Philip J. Wyatt
Appl. Opt. 19(6) 975-983 (1980)

Diode laser measurements of trace concentrations of ammonia in an entrained-flow coal reactor

Joel A. Silver, David S. Bomse, and Alan C. Stanton
Appl. Opt. 30(12) 1505-1511 (1991)

Analysis of particle sizes, concentration, and refractive index in measurement of light transmittance in the forward-scattering-angle range

Anatoli P. Nefedov, Oleg F. Petrov, and Olga S. Vaulina
Appl. Opt. 36(6) 1357-1366 (1997)

Method for measuring the size and velocity of spheres by dual-beam light-scatter interferometry

William D. Bachalo
Appl. Opt. 19(3) 363-370 (1980)