射流鼓泡反应器内气液分散状态检测

射流鼓泡反应器内随着射流速度的增大，先后经历气泛、载气和完全分散三种气液分散状态。本文在射流鼓泡反应器实验装置中，利用Pavlov管测量气体分布器上方壁面附近的液速波动信号，发现液速标准差和时均液速随射流速度的增大均依次出现第一平稳段、上升段、下降段和第二平稳段，其中，第一平稳段对应气泛状态，上升和下降段对应载气状态，第二平稳段对应完全分散状态。据此提出了临界射流速度的判断准则：第一平稳段与快速上升段的交点对应的射流速度为泛点射流速度u _jf，下降段与第二平稳段的交点对应的射流速度为完全分散射流速度u _jcd。与目测法相比，液速标准差分析得到的u _jf的平均相对偏差为5.82%，u _jcd的平均相对偏差为18.2%；时均液速分析得到的u _jf的平均相对偏差为5.86%，u _jcd的平均相对偏差为12.1%。研究还发现泛点射流速度随表观气速的增大而增大。

Detection of gas-liquid dispersion in jet bubbling reactor

In the jet bubbling reactor, as the liquid jet velocity increases, the gas-liquid dispersion shows three states including the flooding, loading, and complete dispersion. In this work, the liquid velocity near the wall above the gas distributor of the jet bubbling reactor was measured by the Pavlov tube to identify the aforementioned three dispersion states. It was found that the standard deviation of liquid velocity and the average liquid velocity both appeared four stages with the increase of jet velocity, which included the first plateau, the ascending stage, descending stage and second plateau. Wherein, the first plateau corresponded to the flooding state, the ascending and descending stages corresponded to the loading state, and the second plateau corresponded to the complete dispersion state. Therefore, the criterion for the critical jet velocity was proposed. The jet velocity at the intersection of the first plateau and the ascending stage was the flooding velocity u _jf, and the jet velocity at the intersection of the descending stage and the second plateau was the complete dispersion velocity u _jcd. Compared with the visual observation method, the average relative deviation of u _jf obtained by liquid velocity standard deviation analysis was 5.82%, the average relative deviation of u _jcd was 18.2%; the average relative deviation of u _jf obtained by time-averaged liquid velocity analysis was 5.86%, and the average relative deviation of u _jcd was 12.1%. The study also found that the blunt jet velocity increases as the superficial gas velocity increases.