Abstract:

In order to study liquid flow structure of scrubbing cooling chamber, two-head conductance probe was used to measure the gas holdup distributions, the Pitot tube-differential pressure transmitter speed measuring system was used to measure the axial and tangential liquid velocity distributions in a scrubbing cooling chamber cold model apparatus. The results showed that the axial velocity flowed downward near the outer wall of the descending tube, while the inner wall of the liquid pool flowed upward at the outlet of the descending tube and the bottom of the bubble breaking plate. The turning points of the liquid phase are r/R=0.7 and r/R=0.6 respectively. The existence of the bubble breaker makes the axial liquid velocity distribution be parabolic. The average tangential velocity is smaller than the axial velocity and fluctuates within the range of -0.15—0.1 m/s. The velocity distribution of liquid phase under different apparent gas velocities is similar, and the velocity of liquid phase increases with the increase of apparent gas velocities. By normalizing the velocity distribution of liquid phase at h =523 mm, the U_z/U_c model correlation equation was obtained. After the inspection, the change of the center velocity of the annulus with the tower diameter and the apparent gas velocity can be approximately described by the Nottenkaemper correlation.

Key words: scrubbing cooling chamber, bubble column, Pitot tube, gas-liquid flow, liquid velocity, gas holdup

摘要：

在与工业气化炉几何相似的洗涤冷却冷态模拟装置内，借助双头电导探针和皮托管-差压变送器，测量了环隙空间的气含率及内轴向和切向的液相速度分布，对洗涤冷却室内的液相流动结构进行研究。结果表明：下降管出口及破泡板下方轴向液速呈现近下降管外壁向下流动，液池内壁向上流动的结构，液相转折点分别为 r/R=0.7和r/R=0.6；破泡器的存在使轴向液速呈抛物线分布；切向速度相比轴向速度较小，在-0.15~0.1 m/s范围内波动；不同表观气速下的液相速度分布具有相似性，随着表观气速的增加，液相速度增大；通过对h=523 mm处液相速度分布的归一化处理，得到U_z/U_c模型关联式；经检验，环隙中心速度随塔径和表观气速的变化可近似用Nottenkaemper关联式描述。

关键词: 洗涤冷却室, 鼓泡塔, Pitot管, 气液两相流, 液相速度, 气含率