蒙东褐煤固定床热解破碎粉化特性研究

Study on pulverization characteristics of east Inner Mongolia lignite during pyrolysis in a fixed bed

为了研究褐煤在热解条件下的粉化特性,利用微型固定床热解反应器对粒径0.5~6.0 mm的内蒙古锡林浩特和宝日希勒2种褐煤的热解破碎粉化进行试验研究,考察了粒径、加热终温、加热速率及固体停留时间对褐煤热解粉化程度的影响。试验结果表明:随着2种褐煤入料粒级降低,对应半焦的原粒级及低一级粒级的总质量分数分别由89.62%增加至99.49%,由77.11%增加至99.53%,2种褐煤的粉化程度随着粒径的增大、加热终温的升高、加热速率的增大及停留时间的延长而加剧。通过灰色关联分析得出升温速率和粒径是影响褐煤粉化的主要因素,而停留时间对其影响较小。建立了粉化前后颗粒群平均粒径的关联模型,经验证能够较好地对颗粒粉化的粒度变化进行预测。

In order to study the pulverization characteristics of lignite under pyrolysis conditions,the pyrolysis of two lignites from Xilinhaote and Baorixile with sizes of 0.5 - 6.0 mm were studied in a mini-fixed bed reactor. The test influential parameters included particle sizes,final temperature,heating rate and residence time of particles were conducted. The following results showed： with the decrease of the grain size of the two kinds of lignites,the total mass fraction of the primary particle and the lower particle of the semi coke increased from 89.62% to 99.49% and 77.11% to 99.53% respectively; the pulverization degree of two lignites increased with increases in the particle sizes,final temperature,heating rate and residence time of particles. The gray relational analysis showed that the heating rate and particle sizes were the major influencing factors,but the influence of residence time was not significant on the pulverization of lignite during pyrolysis. The correlation model of average particle size before and after pulverization was established,and it was proved that the change of particle size could be predicted well.