Second and third limits higher pressures

To test the application of the theory of branching chains to the third limit, Willboum and Hinshelwood [27] assumed a reaction mechanism consisting of an initiating step of rate fi producing either H or OH, and followed by reactions (i), (ii), (iii), (iv), (vb) and (xia). This leads, by the usual methods, to the following expression for the rate of formation of water in the steady state, viz. 

Since diffusion coefficients are required relative to hydrogen only, we may now use Dm = ho, -Hj / hoi -m (and similarly for O2), giving, on substitution of (21) into (19), the explosion condition 

The influence of hydrogen—oxygen ratio and of additions of 100 mm of nitrogen and carbon dioxide, respectively, on the third limit at 586 °C in a KCl coated vessel of 5.5 cm diameter are shown as the broken lines in Fig. 10. The solid lines show limits calculated from eqn. (23) with K24 = 144, C = 1100 and the values of m and given in Table 12 (results for 

Warren s results [25] are also consistent with those of Willboum and Hinshelwood [27] and Cullis and Hinshelwood [38] regarding the values of the vessel constant C. 

With regard to the second limit, the regeneration term [H2] [H2] +I)o2[02] +Dm[M]  

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