磁铁矿球团干燥过程动力学

STUDY ON DRYING KINETICS OF MAGNETITE GREEN PELLET

采用热重分析实验技术,在氮气流下,100～300℃温度区间,不同的气流速度范围,研究了磁铁矿生球团干燥过程动力学。实验表明,干燥过程可分为增速、恒速、减速(一)和减速(二)四个阶段,生球中绝大部分水份是在前三个阶段中脱除的。在热量和质量传递过程同时进行的理论分析基础上,对前三个阶段建立了统一的干燥过程动力学模型。由实验数据求得了模型中参数或表达式。应用此模型对球团干燥过程进行模拟计算的结果与实验测定结果很吻合,证明了本动力学模型的适用性。

The drying kinetics of magnetite green pellet has been investigated through thermogravimetric analyses in nitrogen atmosphere with various flow rate at the temperature of 100～300℃. The result obtained shows that the drying process might divided into four periods: increasing rate, constant rate, first falling rate and second falling rate periods,The moisture in green ball was removed mostly during the first three periods. The comprehensive drying kinetic model for the first three periods was developed based on the theoretical pre-supposition that the heat and mass transfer proceeded simultaneously. The model rarameters or their representations were derived from experimental data. The calculated results from the model well agreed with the experimental data.