低温活性炭降氡技术研究

Study on Radon Adsorption of Activated Carbon in Low Temperature Condition

地下低本底实验室在创造低放射性本底实验环境方面有着很大的降氡需求,为此本文研发了一种原理性活性炭降氡装置,以筛选出的KC-6型活性炭为研究对象,使用连续进气法,在-50~25℃温度范围内测量了活性炭对氡的动力学吸附系数。实验结果表明,在该温度范围内,活性炭的动力学吸附系数与绝对温度呈指数关系,降低活性炭的温度能显著提高活性炭对氡的吸附性能,在-48℃的温度条件下,活性炭的动力学吸附系数达171.4L/g,较室温条件下增加了20倍以上。依据本实验获得的实验数据,计算出KC-6型活性炭的吸附热Q=(20.5±1.7)kJ/mol。

Underground low-background laboratories have great demand in radon reduction in creating a low.radioactive background environment. A kind of principle radon reduction device was developed. KC-6 activated carbon was selected as the object of study. The dynamic adsorption coefficient of activated carbon to radon was measured at -50 ℃ to 25 ℃ using continuous air inlet method. The experimental results show that the dynamic adsorption coefficient of activated carbon has an exponential relationship with the absolute temperature in this temperature range. I he aecrease oi temperature can significantly improve the radon adsorption ability of activated carbon. Under the temperature of -48 ℃, the activated carbon has a dynamic adsorption coefficient of 171.4 L/g, which is 20 times higher than that in room temperature condition. In addition, the adsorption heat of KC-6 activated carbon is calculated to be （20. 5±1.7） kJ/mol.