关键词: 快速流化床, 颗粒速度, 筛分分布, 实验研究

Abstract: The flow characteristics of FCC particles were studied in a fast fluidized bed reactor with 300 mm diameter. Flow behaviors of gas and solids in the system were measured by pressure cyclic detecting and optical fiber measuring instruments, respectively. The effects of operating conditions on catalyst concentration, particles velocity, screening distribution along the bed axle and radial direction were examined. The experimental results show that when the superficial gas velocity is enhanced in 2.0~2.6 m/s, the catalyst flux is increased to 60~160 kg/(m2×s) and the axial distribution of catalyst concentration can be maintained in 50~650 kg/m3. The radial distribution of catalyst concentration is lower in the central region and higher near the wall. In the axial direction, the radial local catalyst concentration gradually decreases in the particle accelerating region and tends to smooth in the fully developed region. The radial local catalyst concentration decreases with superficial gas velocity increasing or catalyst flux decreasing, radial homogenization is improved. And catalyst concentration appears to be close at the non-dimensional radial position r/R<0.7. The radial distribution of particle velocity is the parabola structure with higher particle velocity in the central region and lower near the wall. The radial local particle velocity increases with superficial gas velocity increasing or catalyst flux decreasing.

Key words: fast fluidized bed, particles velocity, screening distribution, experimental study