摘要
采用绝热加速量热仪(Accelerating Rate Calorimeter,ARC)对正常和潮湿条件下的过硫酸铵进行对比热容分析试验,得到了不同条件下过硫酸铵样品的热分解温度和压力随时间的变化曲线及压力和温升速率随温度的变化曲线。分析了过硫酸铵的热分解过程,用速率常数法计算了表观活化能E_a和指前因子A,得到了样品在最危险状态即绝热状态下的初始放热温度、初始温升速率、最大温升速率、自反应放热最高温度、绝热温升等反映其热稳定性的参数。结果表明,在绝热环境中,潮湿条件下的过硫酸铵比正常条件下更具有热危险性,更易发生自反应放热分解,且过程更加剧烈。过硫酸铵在储存过程中若不慎与水或潮湿空气接触,应尽量进行通风冷却和干燥处理,防止发生自分解放热进而引发火灾。
The paper is engaged in the investigation of the thermal stability of ammonium persulfate for two sample systems by using an adiabatic calorimeter called AC （Accelerating Calorimeter）. The main components of the two sample systems are by nature the same except that the water content of No.2 sample has 9.16% for the purpose of comparison. Whereas the specific heat of No. 1 sample is 2.450 kJ/（kg· ℃ ）, No.2 is 2.610 kJ/（kg· ℃ ） . Since the samples are chemically purified, the weight of No. 1 was 1. 875 8 g whereas No.2 was 1. 424 2 g, both of which were loaded in the titanium bombs. The bombs each weigh 14.615 8 g in a volume of 8.75 mL with specific heat of 0.523 kJ/（ kg· ℃）. The initial temperature of No. 1 sample is set up at 60 ℃ but No. 2 is set up at 40 ℃, with the sensitivity being set up at 0.02 ℃/min. When the sample reaction system, the sample and the bonth included, reaches 60 ℃or 40 ℃, the procedure of 5 ℃ steps of heating （10 minutes waiting and searching） would automatically turn up with the help of processor controller until a self-heating rate is detected greater than 0.02 ℃/min. The reaction system would then be heated by the reaction heat under adiabatic conditions. At this moment, the thermal decomposition temperature and the pressure vs the time would increase to the point as is shown in the curve. The experimental measuring resuits indicate that the normal sample of ammonium persulfate has better thermal stability than the man-made samples. When the sample temperature and pressure rise up to a certain value, the temperature and the pressure would ramp up to high levels too. Actually, no no- ticeable transient could be found existing between the slow process and the ramp.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2011年第3期191-195,共5页
Journal of Safety and Environment
关键词
安全学
过硫酸铵
绝热加速量热仪
热稳定性
初始放热温度
动力学参数
safety science
ammonium persulfate
accelerating ratecalorimeter
thermal stability
initial self-heating temperature
kinetics parameter
