Explosion characteristics of flammable organic vapors in nitrous oxide atmosphere

Abstract

Despite unexpected explosion accidents caused by nitrous oxide have occurred, few systematic studies have been reported on explosion characteristics of flammable gases in nitrous oxide atmosphere compared to those in air or oxygen. The objective of this paper is to characterize explosion properties of mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with nitrous oxide and nitrogen using three parameters: explosion limit, peak explosion pressure, and time to the peak explosion pressure. Then, similar mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with oxygen and nitrogen were prepared to compare their explosion characteristics with the mixtures containing nitrous oxide. The explosion experiments were performed in a cylindrical vessel at atmospheric pressure and room temperature. The measurements showed that explosion ranges of the mixtures containing nitrous oxide were narrow compared to those of the mixtures containing oxygen. On the other hand, the maximum explosion pressures of the mixtures containing nitrous oxide were higher than those of the mixtures containing oxygen. Moreover, our experiments revealed that these mixtures differed in equivalence ratios at which the maximum explosion pressures were observed: the pressures of the mixtures containing nitrous oxide were observed at stoichiometry; in contrast, those of the mixtures containing oxygen were found at fuel-rich area. Chemical equilibrium calculations confirmed these behaviors.

Explosion behavior of n-alkane/nitrous oxide mixtures

“…These results imply that the mixtures with N 2 O exhibited lower mixture activities and explosion severity compared with the corresponding mixtures with O 2 . In addition, the mixtures containing N 2 O had higher calculated adiabatic flame temperatures than the corresponding mixtures containing O 2 , which is in good agreement with the findings of earlier studies (Koshiba et al, 2010).…”

“…1 and following previously described procedures (Koshiba et al, 2010). The closed cylindrical explosion vessel had a diameter of 100 mm and a height of 120 mm; it included tungsten electrodes for ignition, a fan, and two pressure transducers.…”

“…For instance, Vandebroek et al (2005) demonstrated that the LEL values of toluene/N 2 O mixtures are less than those of toluene/air mixtures at an initial temperature of 70 • C and 1 bar. Koshiba et al (2010) reported that fuel/N 2 O mixtures have narrower flammability ranges and higher explosion pressures compared with those of corresponding fuel/oxygen mixtures. The present study describes the results of an investigation of the explosion characteristics of alkane/N 2 O mixtures at ambient temperature and pressure using three primary parameters: the explosion limit, the explosion pressure, and the rate of the explosion rise.…”

Flammability limits: A review with emphasis on ethanol for aeronautical applications and description of the experimental procedure

“…Koshiba et al [20] characterized the explosion properties of mixtures of n-pentane, diethyl ether, diethylamine, or n-butyraldehyde with nitrous oxide and nitrogen using three parameters: explosion limit, peak explosion pressure, and time to peak explosion pressure. The explosion experiments were performed in a cylindrical vessel at atmospheric pressure and room temperature.…”

Numerical and experimental study of the explosion pressures and flammability limits of lower alkenes in nitrous oxide atmosphere

“…The flammability limits were measured using the experimental apparatus illustrated in Fig. 2, which is the same as that used in an earlier study (Koshiba et al, 2010). The closed cylindrical chamber (100 mm in diameter and 120-mm high, i.e., 0.94 L) includes tungsten electrodes (1.0 mm in diameter) for ignition, a stirrer (1000 rpm), and two pressure transducers.…”