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Hazard evaluation of ignition sensitivity and explosion severity for three typical MH_(2) (M=Mg,Ti,Zr)of energetic materials

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Defence Technology（防务技术） 2021年第4期17卷 1262-1268页

作者： Xing-liang Wu Sen Xu Ai-min Pang Wei-guo Cao Da-bin Liu Xin-yu Zhu Fei-yang Xu Xu Wang School of Chemical Engineering Nanjing University of Science and TechnologyNanjingJiangsu210094PR China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyXiangyang441003PR China School of Environmental and Safety Engineering North University of ChinaTaiyuan030051ShanxiPR China

MgH_(2),TiH_(2),and ZrH_(2) are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent *** evaluate ignition sensitivity and explosion severity,the Hartmann device and spherical pressure vessel were used to test ignition energy and explosion pressure,*** results showed that the ignition sensitivity of ZrH_(2),TiH_(2) and MgH_(2) gradually *** the concentration of MgH_(2) is 83.0 g/m^(3) in Hartmann device,the ignition energy attained a minimum of 10.0 *** explosion pressure of MgH_(2) were 1.44 times and 1.76 times that of TiH_(2) and ZrH_(2),respectively,and the explosion pressure rising rate were 3.97 times and 9.96 times that of TiH_(2) and ZrH_(2),respectively,through the spherical pressure *** indicated that the reaction reactivity and reaction rate of MgH_(2) were higher than that of TiH_(2) and ZrH_(2).In addition,to conduct in edepth theoretical analysis of ignition sensitivity and explosion severity,gas production and combustion heat per unit mass of ZrH_(2),TiH_(2) and MgH_(2) were tested by mercury manometer and oxygen bomb *** experimental results revealed that MgH_(2) had a relatively high gas production per unit mass(5.15 mL/g),while TiH_(2) and ZrH_(2) both had a gas production of less than 2.0 mL/*** thermal stability gradually increased,leading to a gradual increase in ignition ***,compared with theoretical combustion heat,the combustion ratio of MgH_(2),TiH_(2) and ZrH_(2) was more than 96.0%,with combustion heat value of 29.96,20.94 and 12.22 MJ/kg,respectively,which was consistent with the explosion pressure and explosion severity test results.

关键词： Ignition energy explosion pressure Reaction activity Combustion heat

Experimental investigation of flame propagation characteristics in the in-line crimped-ribbon flame arrester

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Science China(Technological Sciences) 2017年第5期60卷 678-691页

作者： SUN ShaoChen DING ChunHui HU XiYu LIU Gang YE Chen BI MingShu School of Chemical Machinery Dalian University of Technology Dalian 116024 China Shenyang Institute of Special Equipment Inspection and Research Shenyang 110179 China

An experimental system that consisted of gas mixing equipment, a sensor detection system, a data acquisition device, and an electric spark ignition device was set up to investigate fuel/air deflagration flame propagation and quenching processes through a crimped-ribbon flame arrester in an enclosed horizontal pipe. Deflagration suppression experiments showed that when the concentration of flammable gas was close to the stoichiometric ratio, the evolution processes of explosion pressure for the propane-air and ethylene-air premixed gases in the pipe diameter （DN32-DN400） were similar and could be divided into four stages： isobaric combustion, slow pressure rise, quick pressure rise, and pressure oscillation. However, the explosion duration of the hydrogen-air premixed gas was relatively short, and the peak explosion pressure was high. The pressure rose quickly after the isobaric combustion stage. Therefore, the process can be divided into three stages in the pipe diameter （DN15-DN150）. Deflagration speed results indicated that the propane-air flame speed initially increased and eventually decreased along with increases in the pipe diameter （DN32-DN400）; however, the ethylene-air flame speed gradually increased with the increase of the pipe diameter （DNS0-DN400）. No notable pattern of change in the hydrogen-air flame speed was observed in the pipe diameter （DN15-DN150）. The maximum propane-air flame speed occurred at 5% concentration. The maximum flame speed for ethylene-air and hydrogen-air happened when the mixture was close to stoichiometric ratio. Under the conditions of the same size of experimental tube configuration and the same ignition distance but different pipe lengths, or the same pipe length but different ignition distances, experimental results showed that the flame arrester successfully stopped the flames at high flame speed and low explosion pressure, but failed at low flame speed and high explosion pressure.

关键词： deflagration flame crimped-ribbon flame arrester explosion pressure flame speed flammable gas concentration

Inhibiting effect of Al(OH)_3 and Mg(OH)_2 dust on the explosions of methane-air mixtures in closed vessel

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Science China(Technological Sciences) 2012年第5期55卷 1371-1375页

作者： WANG QiuHong WEN Hu WANG QingSong SUN JinHua State Key Laboratory of Fire Seience University of Science and Technology of ChinaHeJei 230026China School of Energy Engineering Xi'an University of Science and TechnologyXi'an 710054China

The inhibiting effect of AI（OH）3 and Mg（OH）2 dust on explosion of methane-air mixtures was investigated by means of explosion parameter tests in a 20-liter closed vessel. The influences of varying methane concentration and dust concentration on explosion parameters were characterized based on the experimental data to determine the maximum explosion pressure, maximum rate of pressure rise, lower explosion limits and upper explosion limits. The inhibiting mechanisms of these kinds of dust were analyzed as well. The investigations indicate that AI（OH）3 and Mg（OH）2 dust can be used as inhibitors to prevent meth- ane explosion, however, their inhibiting effects are less than those of inert gas such as N2 and CO2 in that their dust can weaken the methane explosion but cannot totally eliminate it. The tests show that all of the explosion parameters with dust additives are strongly dependent on methane/air ratio and dust concentration, and AI（OH）3 dust has better performance than Mg（OH）2 dust in inhibiting methane explosion. The average percentage decreases of maximum explosion pressure and maximum rate of pressure rise with AI（OH）3 dust are 11.08% and 66.15%, respectively. Experiments also showed that there is a special phe- nomenon when methane explosion is inhibited by AI（OH）3 and Mg（OH）2 dust, in which is that during the process of explosion the maximum explosion pressure value first decreases then increases as dust concentration increases. The best dust concentrations to inhibit the explosion are 250 g/m3 with methane/air ratio at 9.5%, and 200 g/m3 with methane/air ratio at 7%. It is suggested that water vapor produced by the thermal decomposition of metal hydroxides makes the particles of descending dust combine, resulting in a decrease of the real dust concentration in the vessel. Water vapor also is the major cause of another phenomenon that the LEL curve and the UEL curve never meet with the increase of gas concentration.

关键词： explosion inhibition explosion pressure explosion limits dust metal hydroxides

Suppression effect of solid inertants on coal dust explosion

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Journal of Measurement Science and Instrumentation 2018年第4期9卷 335-338页

作者： TAN Ying-xin CAO Wei-guo ZHANG Yun CHANG Hao School of Environment and Safety Engineering North University of China Taiyuan 030051 China PLA Unit 63961 Beijing 100012 China

The effect of solid inertants like rock dust on explosion suppression was experimentally *** adding solid inertants with different concentrations into three kinds of coal dust,the maximum explosion pressure P max and the rate of explosion pressure rise(d p/d t)max were *** on this,the suppression effect of rock dust on coal dust explosion was *** experimental and analytical results show that there are two major factors that play an important role in explosion suppression:composition of solid inertant and particle size of solid *** higher the concentration of solid inertant and the smaller the particle size of solid inertant,the better the suppression *** addition,the smaller the particle size of coal dust,the larger the amount of rock dust.

关键词： coal dust explosion explosion pressure solid inertants rock dust