静电引发剂对气固流化床内静电分布的影响  

Electrostatic potential in gas-solids fluidized beds influenced by injection of charge inducing agents

作　　者：徐怡[1] 王靖岱[1] 阳永荣[1] 

机构地区：[1]化学工程联合国家重点实验室浙江大学化学工程与生物工程学系,浙江杭州310027

出　　处：《化工学报》2009年第7期1629-1637,共9页CIESC Journal

基　　金：国家自然科学基金重大项目(20490205;20736011);国家高技术研究发展计划项目(2007AA04Z182)~~

摘　　要：气固流化床内静电荷的积累会导致颗粒团聚、静电放电、结片甚至爆炸等严重后果,在工业流化床反应器内控制静电的水平具有重要的现实意义。针对LLDPE-N2体系,对静电引发剂的加入提出了电势-电负性(δU-χi)假设,即金属离子的电负性χi很大程度上决定了金属氧化物与聚乙烯颗粒接触分离后的电性,χi与静电引发剂添加前后静电电势的变化呈负相关。将静电引发剂分成负静电引发剂、正静电引发剂和非活泼液体静电引发剂3类,推测了3类静电引发剂加入后对于床内静电势分布的影响,并设计了相应的在气固流化床内添加静电引发剂的实验。实验结果显示负静电剂的加入,使得整床的静电水平显著升高;正静电引发剂的少量加入,流化床内的静电水平有明显降低;非活泼液体静电引发剂的注入,流化床内的静电水平显著下降。实验结果与利用δU-χi假设预测的结果相吻合,可为生产过程中静电引发剂的添加提供指导。Accumulation of electrostatic charges in gas-solids fluidized beds can lead to particle adhesions, electrostatic discharges, wall sheeting and even explosion, so it is of vital importance to reduce the electrostatic level in industrial fluidized beds. δU-Xi theory was proposed for the LLDPE-N2 system. The electronegativity Xi of the metal ion was assumed to play an important role in determining the polarity of the LLDPE particles, and the change of the electrostatic potential was in negative correlation to the electronegativity of the metal ion after contact and separation of the particles and LLDPE. The charge inducing agent included the positive charge inducing agent, negative charge inducing agent and the inactive liquid charge inducing agent. The experiments in gas-solids fluidized bed with the introduction of three kinds of charge inducing agent were designed and carried out. It was found that the addition of negative charge inducing agent increased the electrostatic level obviously, the addition of a small amount of positive charge inducing agent decreased visibly the electrostatic level, and the addition of inactive liquid charge inducing agent reduced the electrostatic level significantly in the fluidized bed. The results agreed well with the prediction according to the theory proposed, which would be helpful to choosing charge inducing agent in industrial application.

关 键 词：静电引发剂 静电电势 电负性 静电电荷 气固流化床 

分 类 号：TQ021.8[化学工程]