气液外环流反应器中气泡行为的实验研究

Experimental Study on the Bubble Behavior in Gas-Liquid External Loop Reactors

详细考察了气液外环流反应器中上升管、下降管的气泡行为随轴向、径向的变化规律.由于外环流反应器的结构特点,发现在上升管底部存在偏流,并对分布板区气泡行为随角向的变化规律进行了研究.分析实验结果得出,气含率和气泡速度均随表观气速的升高而升高;在上升管内,气含率和气泡速度自中心向边壁逐渐降低,而沿轴向变化很小;在分布板区,由于受分布器及下降管的影响,使气含率和气泡速度在不同角向存在不同的径向分布.在下降管中,气含率自中心向边壁逐渐降低,而气泡速度则基本不变;且下降管中的气体循环率随表观气速的升高而升高.

This work dealed with the variation of bubble behavior in axial and radial directions. It was shown that the bubble behavior at the distributor region was axially unsymmetrical. The gas holdup and bubble velocity increased with increasing superficial gas velocity. The gas holdup in both the riser and downcomer and the bubble velocity in the riser decreased gradually from the center to the wall while the bubble velocity in the downcomer was almost uniform in the radial direction. The gas circulating rate increases with increasing superficial gas velocity and the trend of this increase became slower with the increase of superficial gas velocity.