空气干燥基煤的等温吸附平衡模式分析

Analysis on equilibrium model of air-drying coal isothermal adsorption

针对国标要求的等温吸附测试需时较长,探讨压力随时间变化率平衡模式下所需时间及测试结果的可靠性,为提高实验效率奠定基础.利用Terratek公司IS-300型等温吸附仪,用空气干燥基煤样分别按照每个压力点平衡12 h和压力随时间变化率2种平衡模式进行实验.实验结果表明压力随时间变化率设置为10-8,所测兰氏体积与国标测试结果误差在10%以内,精度可以满足工程的需要,但花费时间缩短50%以上.因此按照斜率模式进行干燥煤样的等温吸附实验,所测结果在工程应用中是可信的且实验效率大幅提高.

According to the national standard, isothermal adsorption test needs longer time. This paper discussed the time rate and the reliability of the test results with pressure balance mode to improve the efficiency of experiment. By using IS -300 type isotherm apparatus produced by Terratek company and two equilibrium models of the each pressure point balancing for 12 h and the rate changing of pressure with time, the isothermal adsorption experiment is done with dry coal samples. The results indicate the measured Langmuir volume and Langmuir pressure are very close to the measured results of the national standard when the rate changing of pressure with time less than 10^-8, which basically meets the needs of engineering precision, but the testing time significantly is reduced by 50%. Therefore, the measured results obtained from the adsorption isotherm experiment in accordance with the slope mode of drying coal sample, is credible in engineering applications to improve the efficiency increases.