采用位移传感器测量煤的溶胀行为研究

SWELLING BEHAVIOR OF COAL IN SOLVENT BY A LINEAR VARIABLE DIFFERENTIAL TRANSFORMER DEFORMATION TRANSDUCER

根据溶胀测量原理,采用位移传感器,可以对煤的溶胀过程进行在线监测.测量获得了L1褐煤和B3烟煤在9种溶剂(4种非极性溶剂、4种极性溶剂和蒸馏水)中的溶胀等温线,溶胀等温线对时间求导得到溶胀速率曲线.同时考察了另外4种煤样(2种褐煤和2种烟煤)在N-甲基吡咯烷酮(NMP)中的溶胀曲线.结果表明,采用位移传感器可以在线监测煤样的溶胀过程.L1褐煤在4种非极性溶剂中没有显著溶胀,在4种极性溶剂中溶胀显著,尤其在NMP中溶胀比最大,在蒸馏水中也有显著溶胀.B3烟煤在4种非极性溶剂中除正己烷外均有显著溶胀,在极性溶剂NMP中溶胀比最大,在蒸馏水中也有显著溶胀.由溶胀速率曲线可知,在溶胀初始时刻,L1褐煤和B3烟煤在乙腈和乙醇中溶胀速率最快,两种煤样在二硫化碳中溶胀速率较快.在NMP中,3种烟煤均呈现较大溶胀比,3种褐煤的溶胀行为差异较大,其中1种褐煤的溶胀比显著高于另外2种褐煤的溶胀比,与烟煤的溶胀比相近.

ABSTRACT According to the swelling measurement principle, combined with a linear varia- ble differential transformer （LVDT） deformation transducer, an apparatus for measuring coal swelling in solvent was made. The swelling isothermals of L1 and B3 in nine solvents （four non- polar solvents, four polar solvents and distilled water） were obtained by the linear variable differ- ential transformer （LVDT） deformation transducer. The swelling rate curves were obtained by derivative swelling isotherms. Furthermore, the swelling behaviors of other four coal samples （two lignites and two bitumites） in N-methyl-2-pyrrolidone （NMP） were investigated. There is no significant swelling for L1 in four non-polar solvents; but swelling in the four polar solvents significantly, especially in NMP having the maximum swelling ratio~ and swelling in distilled wa- ter significantly. The swelling of B3 in four non-polar solvents except for n-hexane were signifi- cant, even the swelling ratio in toluene greater than in polar solvent acetonitrile. The swelling ra- tio in the polar solvent NMP was the maximum, showing a significant swelling in distilled water. At the initial time, the maximum swelling rate for two coals in non-polar solvents was shown in carbon disulfide. In all experimental solvents, the swelling in acetonitrile showed the maximum swelling rate. In NMP, three bitumite showed large swelling ratio and the swelling behaviors of three lignites were quite different. The swelling ratio of a lignite was significantly higher than that of the other two lignites and was equal to the bitumite. KEY WORDS swelling, LVDT, swelling rate