不同制粉粒度对混煤热解和燃烧性的影响

Effects of different milling particle size on the pyrolysis and combustion characteristic of mixed coal

为了研究磨煤时间对混煤热解和燃烧性的影响,采用原始粒度组成相同的原煤,按照挥发分质量分数进行混煤,将混煤分别磨制2、4、6和8min,利用热重分析法分析混煤在氮气条件下的热解和空气条件下的燃烧。结果表明,混煤在低温段的热解主要是神华烟煤的热解过程,不受磨煤时间的限制,在高温段,混煤的损失质量均随着磨煤时间的增加而增加;混煤的着火温度随着磨煤时间的增加而增加,燃尽温度随着磨煤时间的增加而降低,失重速率曲线随着磨煤时间的增加向低温区移动,最大失重速率峰随着磨煤时间的增加出现小幅上升,最大失重速率峰对应的温度逐渐下降。

In order to study the effects of different grinding time on mixed coal pyrolysis and combustion characteristic a,three types of raw coal with the identical size distribution were mixed according to the content of volatiles,which were grinded 2minutes,4minutes,6minutes and 8min respectively.The pyrolysis at nitrogen atmosphere and combustion at air atmosphere of mixed coal were conducted by thermo-gravimetric analysis experiments.Experimental results showed that,the pyrolysis process of Shenhua bituminous coal was the major at low temperature in the mixed coal without the limit of grinding time,while the weightlessness of mixed coal rose as the grinding time increased at high temperature.The ignition temperature of mixed coal increased with the increase of grinding time but the burnout temperature decreased,the derivative thermogravimetry curves of the mixed coal were moved to the low temperature section,and the maximum weight-loss rate increased slightly,whose corresponding temperature decreased.