陶瓷料浆喷雾干燥三维DPM数值模拟

Three-Dimensional Numerical Simulation on Ceramic Slurry Spray Drying by DPM

针对现有陶瓷料浆喷雾干燥二维数学模型简化了干燥过程中干燥塔内复杂气固两相运动,造成计算结果与实际存在较大偏差等问题,基于CFD方法,采用DPM模型描述干燥塔中陶瓷料浆颗粒相运动轨迹,进行陶瓷料浆喷雾干燥过程三维数学模型构建及数值求解。在数学模型经实验验证有效的基础上,模拟了不同料浆流量、入口热空气温度的陶瓷料浆喷雾干燥过程,对比分析了干燥塔中颗粒粒径分布、空气湿度场、颗粒温度变化情况,获得了陶瓷料浆喷雾干燥的最佳操作参数。对于此小型喷雾干燥装置,当陶瓷料浆初始湿含量为60%、入口热空气速度为0.3 m·s-1时,最佳的陶瓷料浆流量和入口热空气温度参数值分别为0.01 kg·s-1和413 K。

As to the existing two-dimensional mathematical model of the ceramic slurry spray drying,the movement of gas-solid two phases in the drying chamber are assumed and simplified. There are obvious differences between the calculation results and the actual experimental values of the ceramic slurry spray drying process. Using DPM model to describe the trajectory of ceramic slurry particles, a threedimensional mathematical model of the ceramic slurry drying process was established by CFD approach.The three-dimensional model was verified effectively by the comparison between experimental results and calculation results. Subsequently,the ceramic slurry spray drying processes were simulated respectively under different imported slurry flow rates and imported air temperatures. The hot air humidity filed,the ceramic particles diameter distribution and temperature in the spray drying tower were analyzed comparatively. The optimum operating parameter values of ceramic slurry spray drying were obtained for the spray drying device. When the initial moisture content of ceramic slurry is 60% and the inlet flow rate of air is 0. 3 ·s- 1,the optimum values of ceramic slurry flow rate and inlet hot air temperature are0. 01 kg·s- 1and 413 K,respectively.