水蒸气等离子体发生器工作特性实验研究

Experimental Study on the Working Characteristics of Steam Plasma Torch

水蒸气等离子体射流具有较高的安全性、富含羟基组分、良好的环保特性、工作介质廉价等优点,在危废处理和化学合成等领域具有显著应用前景。但由于水蒸气在输运过程中易冷凝,严重影响水蒸气等离子体发生器的稳定性及电极使用寿命,制约着水蒸气等离子体发生器的工业化应用。本文针对水蒸气易冷凝的特点,提出了一系列防止水蒸气冷凝的措施,并设计了专用的水蒸气等离子体发生器,采用数据采集卡与光谱分析仪等对水蒸气等离子体发生器的工作特性进行了实验研究。实验结果表明:与常规的水蒸气等离子体发生器相比,经本文防冷凝优化后的水蒸气等离子体发生器电弧电压稳定性明显较好,同时等离子体发生器的电弧电压随电弧电流或水蒸气流量的增大而增大。羟基作为水蒸气等离子体射流中特有的还原性物质,其相对含量随电弧电流的增大而增大,但增大水蒸气流量,羟基自由基相对含量反而减少。

Steam plasma jet has the advantages of higher security,plenty of hydroxyl component,good environmental protection and cheap working medium,etc.It is a promising tool in the hazardous waste treatment and chemical synthesis.However,as steam is easy to condense during the transportation process,it will seriously affect the stability of plasma torch as well as its service life,limiting its wide application in industries.In this paper,a series of techniques were proposed to prevent the condensation of the steam.A special steam plasma torch was designed.A data acquisition system and optical emission spectrometer were used in experiments to reveal the working characteristics of this steam plasma torch.The experimental results show that the stability of the as-designed steam plasma generator is better than that of the conventional one.In addition,the arc voltage increases with the increases of the arc current or steam flow rate.As the special substance in steam plasma,the hydroxyl′s relative content increases with the increase of arc current,but decreases with the increase of the steam flow rate.