Some peculiarities of formation of smoke aerosol dispersion structure at thermal decomposition of needle wood. 3. Afterburning of non-decomposed residuals.
The microstructure of smoke formed at afterburning (at temperatures <i>Т</i> ~ 700 ÷ 800 °С) of charcoal is analyzed. It is shown, that the size spectrum of smoke particles at afterburning of charcoal noticeably differs from smokes formed by thermal decomposition of resinous wood samples. The results of data inversion have shown, that, in spite of high temperature of decomposition and free oxygen access to the chamber of thermal decomposition, the optical properties of the formed smoke are mostly determined by particles with <i>r</i> ≈ 0.03 ÷ 0.35 μm and complex parameter of refraction <i>m</i> ≈ 1.590 - 0.011<i>i</i>. Obtained estimations of complex parameter of refraction show low concentration of absorbing components (soot particles) as against usual smokes of burning. The volumetric concentration of medium-size particles in the range (0.35 < <i>r </i>< 0.7 μm) is negligibly small. The specificity of optical and microphysical aerosol characteristics in this case is connected with the low contents of complex organic compounds and resinous components in structure of burnt samples (charcoal).