超声波技术测量气固流化床的料位高度  

Measurement of bed level in gas-solid fluidized bed by ultrasonic technique

作　　者：徐清[1] 曹翌佳[2] 蒋斌波[2] 王靖岱[2] 阳永荣[2] 

机构地区：[1]浙江大学医院,浙江杭州310027 [2]浙江大学化学工程与生物工程学系,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2007年第8期1361-1365,共5页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金重大资助项目(20490205)

摘　　要：利用颗粒运动碰撞壁面产生声波的机理以及声波信号随流化床高的规律性变化,根据料位处的声信号能量及声信号均方差均达到最大的状态,提出了声信号测定料位高度的判据,即声信号的均方差比达到最大时的床高即为料位高度.通过Φ150 mm冷模流化床和Φ3 500 mm工业热态流化床的声信号轴向测量实验,发现基于声信号测定的料位判据适用于气固流化床中聚乙烯生产的冷、热态料位高度的在线检测,具有较好的精度,能替代现有对人体具有致命伤害的γ射线,实现料位高度的在线检测.A criterion of the fluidized bed level was presented based on the relationship between acoustic emission（AE） signals emitted from the collision between moving particles and inside wall and the height of the investigating location in fluidized bed.The criterion is that the location with according to the maximal mean square deviation of the AE signals is the height level of fluidized bed.Experiments carried out in gas-solid fluidized beds with an inside diameter of 150 mm in cold mold and 350 mm in industrial mold showed that this criterion is suitable to the online measurement of fluidized bed level for polyethylene production.The criteria can meet the requirements of the online measurement of fluidized bed and replace the γ-ray.

关 键 词：声发射 气固流化床 料位高度 均方差 聚乙烯 

分 类 号：TQ051.1[化学工程]