内热式振动流化床喷雾造粒试验研究

Experimental Study of Spray Granulation by Inner Heat Vibrating Fluidized Bed

为了开发内热式振动流化床造粒技术的潜在应用价值,对流化床喷雾造粒装置进行改进,同时引入了机械振动和内置加热管群,并以1.6mm磷酸铵颗粒为晶种,磷酸铵溶液为浆料,在不同操作条件下进行喷雾造粒特性试验。试验结果表明:①在同样的进气温度下提高流化气速会加快颗粒生长,过大则导致粉尘生成率增加;②内加热功率的增大有利于提高颗粒的生长速度;③振动频率和振幅对颗粒成长的影响相似,适度的振动有利于颗粒成长,过大则使粉尘生成率提高。根据试验数据拟合了颗粒生长的经验公式,计算值与试验数据的误差在15%以内。

The fluidized bed spray granulation unit is revamped to develop the potential application value of the inner heat vibrating fluidized bed granulation technology.Mechanical vibration and built-in heating tube bundle are introduced,and the experiment is done for spraying granulation characteristics at different operating conditions by using the 1.6 mm ammonium phosphate particle as the crystal seed and ammonium phosphate solution as the slurry.The experiment results show:① at the same gas inlet temperature,the particle growth can be sped up by increasing the fluidizing gas speed,and if it is too big,it will cause increased dust generation rate;② the increase of inner heat power will help increase the growth rate of the particle;③ vibration frequency and amplitude has similar effect on the particle growth,appropriate vibration will help the particle growth,while excessive vibration will cause increased dust generation rate.The empirical formula for particle growth is formulated based on the experimental data,and the error between the calculated value and experimental data is within 15%.