Gas phase ignition

Fig. 5. Gas-phase ignition of propellant samples in shock tube (P8).

Miyajima, H. et al., Combust. Sci. Technol., 1973, 8, 199-200 Combinations with hydrazine, methylhydrazine, 1,1-dimethylhydrazine or mixtures thereof are hypergolic and used in rocketry [1]. The hypergohc gas-phase ignition of hydrazine at 70-160°C/53-120 mbar has been studied [2],... 

Surl iiec Icmpcraturc K Figure 26.1 The mole fraction of H2 just above the surface as a function of the surface temperature for 1 (a), 3 (6), and 4 atm (c), respectively. Gas-phase ignitions and extinctions are represented by arrows. The HB and VH points are indicated with circles and triangles, respectively. Stable and unstable branches are represented by solid and dashed curves, respectively. The mixture is 10% H2-air and the strain rate is 200 s ... 

From a safety point of view, one is also interested in grain elevator and coal dust explosions. Such explosions are not analyzed in this text, and the reader is referred to the 1 iterature [17]. However, many of the thermal concepts discussed for homogeneous gas-phase ignition will be fruitful in understanding the phenomena that control dust ignition and explosions. 

Tign for PMMA and unsaturated polyester is 310 and 390 °C, respectively. From these results it follows that PMMA and similar products are more easy to ignite and to burn than unsaturated polyesters, under a given external heat flux qe. It is interesting to note that q0 ign values, obtained from flame spread experiments in this manner, are consistent with the q0 ign values determined from direct ignitability tests. This is an evidence of the validity of the treatment of flame spread on a surface as a continuous gas-phase ignition of polymer decomposition products. 

Alexander JM. (1990) Gas phase ignition in liquid phase oxidation processes a recipe for disaster. Trans Inst. Chem. Eng. (UK), B68 17-23. 

A comparison between ceramic foams and metallic microstructured monoliths of Fecralloy was performed for the OSR and CPO of propane under similar conditions of total catalyst amount, catalyst composition and modified catalyst residence time [40], A major difference in this investigation was, however, that uncoated foam was located before and after the catalytically coated foam to prevent gas-phase ignition. Irrespective of this difference, two main conclusions can be drawn first, the catalyst supported on the microchaimel structure did not deactivate like the foam catalyst under OSR conditions. This could be due to the fact that peak temperature... 

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