一种在线监测快速过程质谱仪的设计与测试

Design and Test for On-Line Rapid Process Mass Spectrometer

工业生产过程中,如何实现准确、连续、可靠地检测目标组分是产物及排放物在线监测的重点。本工作研制了一种在线监测快速过程质谱仪,采用高增益的复合跨导线性放大技术代替传统的过程质谱仪所采用的对数放大技术,该技术可实现质谱仪在高增益条件下仍然具有超高速的特点,结合16位高速AD转换器,可以实现更快的扫描速度和更高的数据输出频率,能够更准确地捕捉快速反应(如热解)过程的气体生成物随时间的变化信息,进而实现反应特性的精准分析和量化,为反应动力学研究提供无失真的在线分析数据。本实验对该仪器的质量分辨率、灵敏度、质量轴稳定性、长时稳定性等关键技术指标进行了测试,同时结合煤热解反应过程监控需求进行了实际应用测试。结果表明,该仪器各项指标已基本达到市场主流过程质谱仪器的水平。

The on-line monitoring technology of the processing products and emissions in the process industry is focused on the accurate and continuous detection of the target components.In this paper,the on-line rapid process mass spectrometer was applied to the real-time monitoring and the tracking of the reaction components based on the analysis of its characteristics.It could provide the on-line analysis data with distortion-free for the study of reaction kinetics.Compared with the traditional process mass spectrometer with logarithmic amplification technology,the on-line rapid process mass spectrometer had the characteristics of high speed even under high gain conditions due to thehigh-gain composite transconductance linear amplification technology.In addition,combined with the 16-bit high-speed AD converter,this instrument could achieve faster scanning speed and higher data output frequency,which could accurately capture the rapid reaction product information（such as pyrolysis）including the in-progress gas changing with time,and then reached the precise analysis and quantization of reaction characteristic.The key technical indicators,such as mass resolution,sensitivity,mass stability and long-term stability of the instrument were tested in detail.The practical application of the monitoring and control of coal pyrolysis reaction process were also carried out.The results showed that the instrument reached the basic indicators of the market mainstream mass spectrometer.However,it was found that the detection response of hydrogen was low in the high-speed scan mode.At the same time,the linear amplification technology also brought the problem of narrower dynamic range.These problems will be the authors＇ next research direction.