Fragmentation during pulverized coal particles conversion shifts the particle size distribution of the fuel towards smaller particle sizes, affecting both conversion rates and heat release. After pyrolysis of a high volatiles Colombian coal in CO₂ atmosphere in a drop tube reactor at 1573 K, solid carbonaceous particles of different size, from 100 µm of the particle feed down to the nanometric size, have been observed. A fragmentation model has been used to predict the fate of Colombian coal particles under the experimental conditions of the drop tube experiment and predict the particle size distribution (PSD). Model and experimental results are in very good agreement and indicate that in the DTR experiment the coal underwent almost complete pyrolysis and that fragmentation generated a 36 wt% population of particles with size close to 30 µm. The close match between the PSDs obtained from experiments and from the fragmentation model is an important novelty. It demonstrates that fragmentation occurs not only under fluidized bed conditions but also under the conditions of pulverized coal combustion. Experimentalists are warned against the fact that the fine particulate sampled at the outlet of laminar flow reactors and boilers is not always composed of soot only. Char fragments can be misidentified as soot. The implementation of fragmentation submodels in pulverized fuel combustion and gasification codes is highly recommended.

煤粉转化过程中的碎裂会使燃料的粒度分布向更小的粒度转移，从而影响转化率和放热。高挥发分的哥伦比亚煤在CO _2中热解后在下降管反应器中在1573 K的大气中，已观察到大小不同的固体碳质颗粒，从进料的100 µm颗粒到纳米尺寸。碎片模型已用于预测在滴管实验的实验条件下哥伦比亚煤颗粒的命运，并预测颗粒大小分布（PSD）。模型和实验结果非常吻合，表明在DTR实验中，煤几乎完成了热解，碎裂产生了36 wt％的颗粒，其粒径接近30 µm。从实验和碎片模型获得的PSD之间的紧密匹配是一个重要的新颖性。它表明碎裂不仅在流化床条件下发生，而且在粉煤燃烧的条件下也发生。警告实验人员注意以下事实：在层流反应器和锅炉出口处采样的细小颗粒并不总是仅由烟灰组成。焦炭碎片可能会误认为烟灰。强烈建议在粉状燃料燃烧和气化程序中实施分段子模型。