Influence of additives on the velocity of laminar flames

Molecular basis of flame inhibition

“…It also follows from the definition of cPv that the degree of inhibition should be proportional to the amount of inhibitor added to the flame. Experimental observations (e.g., see Lask et al [43]), show that this is approximately valid for a variety of homogeneous inhibitors.…”

“…For example, why do PCb and PBr3 have the same effectiveness in n-hexane-air mixtures when Br2 and HBr are substantially superior to ·Ck or HCI? Why is the inhibiting action of halogens more pronounced for fuels with low hydrogen content (e.g., CsHs) than for Hz or CH4 [43]? Why is Fe(CO)s much less effective in Hz-fueled flames?…”

“…Why is Fe(CO)s much less effective in Hz-fueled flames? Similarly, why is Fe(CO)5 less effective in an OZ-CH4 flame than an air-CH4 stoichiometric flame [43]?…”

“…Values of cPv for a selected variety of inhibitor types have been calculated from the data of Lask et al [43], and unpublished data of Wagner cited by Morrison and Scheller [44] for n-hexane fueled flames, and D. Miller et al [45], for H2 fueled flames . The values listed in the table 15 are given in approximate order of increasing effectiveness as flame inhibitors and we shall refer to this table later when discussing specific inhibitor types.…”

Chemical Transformations in Inhibited Flames over Range of Stoichiometry

“…Lask and Wagner (Lask & Wagner, 1962) were the first to measure the effect of iron pentacarbonyl Fe(CO) 5 on the speed of H 2 /air flame and to show that it was 2 orders of magnitude greater than that of CF 3 Br. Miller et al (Miller et al, 1963) studied the effect of certain inhibitors, including Fe(CO) 5 , on the speed of H 2 /air flames for various stoichiometry and the inhibitor concentration of 0.5% by volume.…”