Abstract
The rate and position of particle-impeller impact for a six-bladed 45°-pitched turbine in the vessels of different scales were measured by the crayon method developed by the authors previously. The impact rate of the pitched turbine pumping upward is higher than that of the pitched turbine pumping downward, but both of them are about 1/6 and 1/17 time, respectively, that of a Rushton turbine. A mathematical model was developed to explain the high dependency of impact rate on impeller speed and impeller diameter. The impact mostly occurs in the outer and upper corners of the blades for the pitched turbine pumping downward, which is consistent with that of the abrasion point of blades of marine impellers used in the chemical industry.
