【作者】 蓝锐； 刘永辉； 王亭杰； 阚成友； 金涌；

【Author】 LAN Rui,LIU Yong-hui,WANG Ting-jie,KAN Cheng-you,JIN Yong (Department of Chemical Engineering,Tsinghua University,Beijing 100084,China)

【机构】 清华大学化学工程系；

【摘要】 聚合物乳液喷雾包膜制备缓控释包膜化肥,不使用有机溶剂,是绿色工艺。流化床喷雾包膜过程的特点是多次间歇随机喷雾成膜,并伴随群体颗粒的碰撞,过程复杂。本文建立转筒喷雾成膜实验模拟装置,模拟乳液喷雾包膜过程,简化喷雾成膜过程中的随机性包覆、群量颗粒和颗粒碰撞等复杂因素,考察乳液喷雾成膜过程的关键影响因素和影响规律。通过周期性控制喷雾包膜,获得模拟喷雾包覆膜层,测定气相和液相渗透系数。考察了环境温度、喷雾速率、乳液固含、雾化气量对喷雾成膜过程的影响,确定成膜过程中水分传质是喷雾成膜过程的关键因素。更多还原

【Abstract】 Using polymer latex as coating material to product controlled release urea is environment friendly,which can radically eliminate the pollution and recovery problems of the toxic organic solvent.The spray coating process in fluidized bed with collision of urea particles is random,intermittent and repeatable,which is difficult to investigate the film formation process.In this work,a rotary drum to form a film intermittently was used to simulate the film formation process on urea particles in the fluidized bed,which can idealize the complex process and avoid the influence of particles Randomness and collision.Mean while,a large area film was obtained so that the film pervasion and mechanism properties can be measured.The spray coating process was analyzed and the influences of latex spray rate,latex solid content,atomization gas quantity and coating temperature on film structure and film permeability coefficient were investigated.It was concluded that the water transfer of film formation process is the key factor affecting film formation.更多还原