Influences of vertically staggered blades arrangement and draft-tubes spacing field on the flow shear stress in the vertical impinging stream reactor

Flow turbulence intensity is one of the most important indexes in measuring the shear performance of vertical impinging stream reactor (VCISR). The staggered forms of the upper and lower blades and the distances among draft-tube are the significant factors affecting the turbulence intensity in the reactor. In order to explore the law that the structure parameters impact the internal flow field, a series of the numerical simulations are employed to investigate the flow field under different conditions, including various vertically staggered arrangement and diverse draft-tubes spacing in the VCISR. The inclination angle of the blades is set as 45° and the rotate speed is adjusted as 900rpm. The staggered angles β of two paddles are set as 15°, 30°, 45°, 60°, respectively. Two draft-tubes spacing L are set as 8, 10, 12, 14 cm, severally. The computation results show that the turbulence intensity on the characteristics impact surface is the maximum under the condition of β=30°, L=12 cm, at the same time the shear stress is also maximal. In this paper, power consumption and rotating moment of blades are discussed in the reactor. When β=15° and L=8 cm, consuming energy of the reactor and the energy consumption under unit average intensity are minimum; the moment of the rotated blades is minimum at β=30°, L=12 cm. All the results provide the references for selection of the reactor motor and the materials of rotation axes as well as energy consumption.