The effect of impeller geometry on bubble breakage in a stirred tank was investigated for a range of impeller Reynolds number (Re) using a high speed imaging method. The bubble dynamic behavior and breakage mechanism were investigated for four different impeller geometries namely, two-flat blades impeller, four-flat blades impeller, four-twisted blades impeller, and two-pinned blades impeller. The performance of each geometry was investigated by determining the breakage probability and number of fragments (daughter bubbles) produced. The contributions of dominant breakage mechanisms for each geometry were specified and discussed by identifying the breakage locations relative to the impeller. Three main breakage mechanisms were observed, namely: bubble collision with the blade, bubble breakage by blade shear, and breakage by turbulent fluctuation away from the blade. The number of fragments by each breakage mechanism was specified for the entire range of Re. The four-flat blades impeller exhibited the highest breakage probability and produced the highest number of fragments. The Pinned blades gave a high performance compared to the smooth blades, especially at higher Re. This is considered to be due to the high turbulence level provided by this type of impeller. The twisted blades impeller showed low bubble breakage probability compared with the other geometries. Breakages by collision with the blades and by shearing effect resulted in a higher number of fragments compared to the breakages caused by turbulent fluctuations. The number of fragments produced by ‘collision with blade’ exhibited a higher dependence on Re than by ‘blade shear’ or by ‘turbulent fluctuations’.

在一定范围内的叶轮雷诺数（Re）下研究了叶轮几何形状对搅拌釜中气泡破裂的影响。）使用高速成像方法。研究了两种不同叶轮几何形状的气泡动力学行为和破损机理，即两个平叶片叶轮，四个平叶片叶轮，四捻叶片叶轮和两销叶片叶轮。通过确定断裂几率和产生的碎片（女儿气泡）数量来研究每种几何形状的性能。通过确定相对于叶轮的破损位置，确定并讨论了每种几何形状的主要破损机理的贡献。观察到三个主要的破裂机理，即：与叶片的气泡碰撞，由于叶片剪切引起的气泡破裂以及由于远离叶片的湍流波动而导致的破裂。每种破损机制的碎片数量在再。四平叶片叶轮表现出最高的破损机率，产生的碎片数量最高。与光滑刀片相比，固定刀片具有更高的性能，尤其是在Re较高的情况下。认为这是由于这种叶轮提供的高湍流度造成的。与其他几何形状相比，螺旋叶片式叶轮显示出较低的破泡率。与湍流波动造成的破损相比，与叶片碰撞和剪切作用造成的破损导致碎片数量更高。与“叶片剪切”或“湍流波动”相比，“与叶片碰撞”产生的碎片数量对Re的依赖性更高。