搅拌力场辅助的粘附性粗颗粒流态化研究

Gas-solid fluidization system with rotary components can achieve steady fluidization for coarse particles with high adhesion surface, but its operating mechanism and the positive/negative effects of external stirring force field are not clear. The olefin solventfree gas phase polymerization process is proposed to be the research background, and the coarse particles (Geldart, B, and D) with high adhesion surface are the research object. On the basis of the applicant preliminary study, the gas-solid fluidization with a stirring force field is investigated. Based on experimental and computational fluid dynamics simulation method, the particles agglomerate, the flow field, and fluidization in the fluidized bed are studied. The laws of agglomerate bond of cohesive coarse particles, regulation of particle agglomerates by rotary components, the synergistic effect on fluidization of the rotary components and gas turbulence are obtained. Finally, the ways to strengthen the stirring force field fluidization are explored. This project will promote the gas-solid fluidization theory and methods, and improve the efficient design of fluidized bed reactor.

气固流态化系统引入旋转运动内构件可实现高粘附性粗颗粒的流态化,其运行机理和外加搅拌力场的正负效应尚不明确。拟以烯烃无溶剂气相聚合过程为研究背景，具有高粘附性的粗颗粒（Geldart B和D类）为对象，在申请人前期研究基础上，对搅拌力场气固流态化进行系统研究。基于实验和计算流体力学数值模拟方法，研究搅拌流化床内颗粒聚团、流场、流态化特性。获取粘性粗颗粒的流态化聚团粘结规律；明确旋转运动内构件调控颗粒聚团的规律；揭示旋转运动内构件与气体湍动诱导流态化的协同效应；探索强化搅拌力场流态化的途径。本项目将对气固流态化理论与方法的完善和高效流化床反应器设计起促进作用。

本研究将复杂旋转运动内构件引入传统气固流态化系统，实现了高粘附性粗颗粒的流态化。以烯烃和乙丙橡胶无溶剂气相聚合过程为应用研究背景，具有高粘附性的粗颗粒为对象，对搅拌力场存在下气固流态化进行系统研究,考察了气流湍动和外加搅拌力场的耦合作用规律。基于实验和计算流体力学数值模拟方法，研究了搅拌流化床内流场、流态化和压力脉动特性，得到了Geldart B和D 类颗粒特殊的散式流态化操作相图。由实验和离散元数值模拟方法，获取了粘性粗颗粒的静态聚团和流态化动态聚团粘结规律。机械剪切作用可以破坏聚团，通过采用复杂自清洁运动内构件强化搅拌力场，扩展了高粘附性粗颗粒稳定流态化的操作范围。揭示了旋转运动内构件与气体湍动诱导流态化的协同效应，得到了高粘附性的粗颗粒在搅拌流化床中的操作相图；本研究促进了流态化工程理论和新型高效流化床反应器技术的发展，并为实现乙丙橡胶、顺丁橡胶和高乙烯含量的烯烃弹性体的无溶剂气相聚合奠定了工程基础。