硝酸铵气溶胶挥发动力学

Kinetics of Ammonium Nitrate Aerosols Evaporation

研究了单分散ＮＨ４ＮＯ３干气溶胶在流动反应器内的挥发动力学．结果表明，挥发反应符合零级反应，凝聚反应符合二级反应．ＮＨ４ＮＯ３气溶胶计算粒径为０．６５μｍ，计算数浓度为８０—１２０个／ｃｍ３时，挥发和凝聚反应的表观活化能分别为２８１．７９ｋＪ／ｍｏｌ和９７．５４ｋＪ／ｍｏｌ，表观速率常数的指数前因子分别为６．８１×１０４７μｌ·ｍ－３·ｍｉｎ－１（ｐｐｂｖ·ｍｉｎ－１）和１．１３×１０１４μｌ－１·ｍ３·ｍｉｎ－１（ｐｐｂｖ－１·ｍｉｎ－１）．说明ＮＨ４ＮＯ３气溶胶的挥发受化学反应控制．

The kinetics of evaporation of monodisperse dry NH 4NO 3 aerosols generated by aerosol generator was studied in a flow reactor.The results showed that the evaporation obeys zero order reaction and the condensation second order reaction.For NH 4NO 3 aerosols with calculated particle radius 0.65μm and calculated number concentration ranging from 80 to 120cm -3 ,the apparent activation energies of these reactions are 281.79kJ/mol and 97.54kJ/mol respectively and the exponential factors of apparent velocity constants are 6.81×10 47 ppbv·min -1 (μl·m -3 ·min -1 ) and 1.13×10 14 ppbv -1 ·min -1 (μl -1 ·m 3·min -1 )respectively.Therefore,the evaporation of NH 4NO 3 aerosols is controlled by chemical reaction.