压力及粒度对煤热解结焦过程膨胀收缩特性影响

Influence of pressure and particle size on the expansion and contraction characteristics of coal pyrolysis

对单种煤样进行了粒度组成分析,发现煤样粒度均以1~3 mm为主,在4个粒度范围内,所有单种煤样粒度<0.1 mm的含量均最少,这有利于炼焦煤样的装炉操作,减少粉尘的产生,有利于炼焦装炉环境治理。采用自主开发的煤热解结焦过程可视化测试仪研究了现场典型粉压煤不同压力、不同颗粒大小样品在均匀加热温度条件下的膨胀收缩行为,结果表明:粉压煤随着块煤堆密度的增加,煤的膨胀收缩率减小;4种煤样均经历一个先少量收缩然后再膨胀的过程,煤样在700℃以后仍然会收缩;随着粉压煤粒度的增加,所有煤样膨胀收缩率均增加,1~3 mm粒度煤样的最大膨胀率最大,而粒度<0.1 mm煤样的最大膨胀率最小。同一种煤,不论其颗粒大小,煤热解过程随着温度变化的曲线规律均类似。

The particle size composition of some typical single coals is analyzed,and the results show that the particle size of coal samples is mainly 1~3 mm.Within the four particle size ranges,the content of all single coal samples less than 0.1 mm is the least.This is conducive to the charging operation of coking coal samples and reduces the generation of dust,therefore it is in favor of the treatment of the coking charging environment.Depending on the self-developed visual testing instrument for the coal pyrolysis coking process,the pressure and particle size on the expansion and contraction behavior of some typical coals is investigated under the uniform heating temperature.The results indicate that with the increase of bulk density of pulverized coal,the expansion and contraction rate of coal decrease.All four coal samples undergo a process of a small amount of shrinkage and then expansion.The coal sample will still shrink after 700℃.With the increase of particle size of pulverized coal,the expansion and contraction rates of all coal samples improve.The maximum expansion rate of 1~3 mm particle size coal samples is the biggest,but the maximum expansion rate of<0.1 mm particle size coal samples is the smallest.For the same coal,regardless of particle size,the curve change law with temperature is similar during coal pyrolysis.