气固顺流下行流化床反应器入口结构的实验研究

EXPERIMENTAL INVESTIGATION OF THE ENTRANCE STRUCTURE FOR THE REACTOR WITH G/S CO-CURRENT DOWNFLOW

本文针对气固顺流下行流化床流动中在进口段存在不稳定加速区,影响气固反应中两相均匀接触的问题,设计了三种不同的气固进口结构,实验结果证明,使用侧吹式分布器与文氏管串联的结构设计,可以减小或消除进口端操作不稳定的影响,此结构可提供有关使用部门作为设计依据.

It has been reported that an acceleration region existed in the entry region of a cocurrent downflow system where the solids particles are accelerated to a terminal velocity and the unstable flow patterns generally result in uneven contact between gas and solids. In this work, the unstable region is found to be about (70-100)d, depending upon the gas velocity, solid flux, the properties of gas and solid and the diameter of apparatus etc. Better design of suitable entrance is required to improve the reactor performance structure. The effects of entrance structure on the acceleration region in G/S co-current downflow systems was experimentally investigated using 3 types of entrance structures for G/S feed in two sets of experimental apparatus of φ32mm × 5m and φ65mm × 7m respectively. The Multi-pipe and side-blow type structures have no effect on reducing the unstable phenomena. The Venturi type structure provides stable operation only in a narrow range of Ug. The sideblow plus Venturi type structure can diminish or eliminate the unstable phenomena.