Comments on “Influence of temperature and hydroxyl concentration on incipient soot formation in premixed flames,” by M. M. Harris, G. B. King, and N. M. Laurendeau

✍ Scribed by F. Takahashi; I. Glassman

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 165 KB
• Volume: 67
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(87)90103-9

✦ Synopsis

In a recent article [1], Harris et al. have closely followed both the experiments and analysis on the sooting tendency in premixed flames previously conducted at Princeton . As the authors of the principal reference paper in this article [1], we appreciate their efforts to clarify further the effects of the flame temperature and OH concentration on the soot formation process. Unfortunately, however, there appear to be some misleading statements and inappropriate criticisms in this paper probably stemming in part from overgeneralization of their results.

First, the authors have concluded that the measured flame temperature, rather than the adiabatic flame temperature, must be reported along with the critical equivalence ratio at sooting. This criticism is true for flat flames, which they used, for which the heat loss to the burner surface (and the radical loss by wall destruction) results in a considerable deviation (typically a few hundred degrees K) of actual flame temperature from its adiabatic value. As a result, the actual flame temperature (and the burning velocity) depend on the gas mixture flow velocity, which determines the position of the flame zone and, in turn, the degree of the heat loss to the burner . By contrast, nonluminous cone-shaped flames (formed on a Bunsen-type burner) with a hot combustion-gas shroud at sufficiently high flow velocities, which we used, have long been known to have maximum temperatures with relatively small deviations (< 10OK) from the theoretical values. Even if there are such deviations, they may not vary significantly with varying experimental