摘要
为揭示粒径分布对聚甲基丙烯酸甲酯(polymethyl methacrylate,PMMA)粉尘云火焰温度的影响,本文分别采用热电偶和高速比色测温法测量了开敞空间不同粒径PMMA粉尘云的火焰温度特性。结果表明:相比30μm粉尘粒子,100 nm粉尘粒子热解/挥发速率较快,燃烧更加充分,粉尘云火焰的最高温度可达1551℃,而30μm粉尘云火焰最高温度仅为1 108℃;在微米尺度,随着PMMA粉尘粒径的增大,火焰最高温度和高温火焰区面积先增大后减小; 20μm粉尘粒子由于其分散性较好,裂解气化特征时间尺度与燃烧反应特征时间尺度较接近,燃烧反应充分,火焰最高温度和高温火焰区面积均最大。
In the present study,to find out about the effects of particle size distributions on the flame temperatures of polymethyl methacrylate( PMMA) dust clouds,we measured the flame temperatures of PMMA dust clouds with different particle size distributions using the thermocouple and high-speed colorimetric method. The results show that,due to the faster pyrolysis/volatilization rate of 100 nm dust particle,the temperature was able to reach 1 551 ℃ while the maximum temperature of 30 μm dust cloud was only 1 108 ℃. The maximum flame temperature and high temperature flame area increased and then decreased with the increase of PMMA dust particle size for micron-scale. The pyrolysis/volatilization time scale of 20 μm dust particles was close to the combustion reaction time scale because of their good dispersibility. As a result,the maximum temperature and high temperature flame area were the largest among the particles with different particle size distributions.
引文
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