细粒褐煤干燥的影响因素研究

Study on Influencing Factors of Fine Lignite Drying

利用红外水分仪对3mm以下细粒褐煤进行干燥实验,主要研究了粒径、温度、灰分和重介质对干燥效果的影响,并使用有效水分扩散系数对干燥效果进行动力学分析,结果表明:温度和粒径对细粒褐煤干燥效果有重要影响,随着粒径的减小,干燥速率增大,有效水分扩散系数减小;随着温度的升高,干燥速率增大,有效水分扩散系数增大;灰分含量的提高,使干燥速率降低,有效水分扩散系数减小;添加重介质(磁铁矿粉和磁珠)后,干燥性能会变强,其中加磁珠时干燥效果最好,在磁珠含量占50%时可以达到最佳的干燥效果。

Influence of particle size, temperature, ash content and dense medium on the dehydration effect of fine lignite （below 3. 0mm） were investigated, applying infrared moisture meter. The dynamic analysis of the drying results was carried out using effective moisture diffusivity. The results indicate that particle size and temperature have great influence on dehydration efficiency, the decrease of particle size causes increase of the drying rate and decrease effective moisture diffusivity. The drying rate and the effective moisture diffusivity show increasing trend with the increase of temperature. The lignite drying rate decreases with the decrease of ash content. The drying performance is enhanced with the addition of dense medium, and the magnetic balls work best, achieving the best drying performance when the mass fraction of magnetic balls is 50%.