Page 328 - Dust Explosions in the Process Industries

Propagation of Flames in Dust Clouds 297

Sorbic acid 5.50 345 0.66
Stearic acid 6.00 290 0.46
~~~~
Sulfur, 700% 44 ,urn 3.85 213 0.75
Titanium 6.20 760 1.15

4.2.5.2
Three-Zone Model by Bradley and Mitcheson

Bradley and Mitcheson (1976) carried the theoretical analysis further by first giving
further support to the useful relation

(4.58)

suggested by Lewis and von Elbe (1961). Equation (4.58) simply says that the fractional
pressure rise equals the fractional mass burned and rests on a number of assumptions of
chemj-caland physical nature. Simplified analytical solutions of pressure versus time
obtained by using this equation agreed fairly well with comprehensive computer solu-
tions. Equation (4.58) replaces assumptions concerning the density and specificheat ratio