固液搅拌槽内近壁区液相速度研究

在直径476mm的固液搅拌槽内，采用自行研制的双电导电极探头对搅拌槽内距壁0.4mm的近壁区液相速度进行了测定。平均固相体积分数φ_v从10%至54%。实验结果表明：固体颗粒离底悬浮最小液相速度与固液的物理性质有关，而与实验的操作条件无关；液相速度和搅拌转速在近壁上流区成正比关系，而在槽底区不成正比关系；临界均匀悬浮时，近壁上流区液相速度不随固相体积分数变化；悬浮高度处液相速度和操作条件无关等。

Determination of liquid velocity near wall region in a solid-liquid stirred tank

Experiment was carried out in a cylindrical plexiglass tank of 476mm diameter with a solid liquid system. A new type of bi-electrode probe was used to measure the liquid-velocity near the wall region of the tank with solid volumetric concentration(φ_v) from 10% to 54%.The result show that the minimum liquid velocity in the just suspension region was influenced by the properties of the solid and liquid, such as the density of the solid and liquid, the diameter of the solid, and not by the operation conditions. The relations between the impeller speed and the liquid velocity are different in the bottom region and the up flow wall region. The liquid velocity in the up flow wall region is not influenced by the solid concentration for just uniform suspension and the liquid velocity in just pure liquid layer are not influenced by the operational condition,etc.