柿果浆低温喷雾干燥数值模拟与试验

利用计算机流体力学及算法建立喷雾干燥机结构模型及气体连续相、液滴离散相等数值计算模型,得到柿果浆低温喷雾干燥过程中气相流场、温度场、压力场和颗粒运动轨迹等信息,分析了进风温度和进料速率对喷雾干燥柿粉的水分含量、集粉率和喷雾干燥机出风温度的影响,并将模拟结果与实验结果进行对比。结果表明,水分含量和出风温度的模拟值与实验值接近,且变化规律相同。结合数值模拟和正交实验结果,确定柿果浆最佳低温喷雾干燥工艺参数组合为进风温度388 K、入口进风量0.05 m3/s、进料速率为4.5×10-3L/s,实验集粉率为78.14%。 

Numberical simulation and experiment verification study on low temperature spray-drying of persimmon pulp

The physical model and the numerical model were built to acquire some information on gas flow field, temperature field, pressure field and particle trajectory by the computational fluid dynamics ( CFD) model and algorithm.The effects of inlet temperature and feed rate on the water content of spray drying persimmon, powder recovery and outlet temperature were analyzed. The results showed that the values obtained from numberical simulation were very close to that of the orthogonal experiment. The optimal technical parameters of spray drying persimmon powders were established to be inlet temperature of 388 K, air feed volume of 0.05 m3/ s and feed rate of 4.5 × 10- 3L / s by combination of CFD and orthogonal experiment. Under the optimal conditions, the powder recovery was 78.14%. The results suggested that CFD could be used to simulate the process of spray drying persimmon powder effectively.