关键词: 高速数字摄影, 循环流化床, 气固两相流, 颗粒旋转

Abstract: By using an advanced measurement system composed of a high-speed digital video camera and a high-power laser sheet, an experimental research was carried out on the particle rotation characteristics in a cold Circulating Fluidized Bed (CFB) riser with square cross-sectional area of 200 mm×200 mm and height of 4 m.Particle movement images were analyzed with Matlab, PhotoShop and ACDSee software, captured at 13 measurement points in a quarter of a cross-section in the upper dilute phase area of the CFB riser.Particle rotation speed was observed and checked by the dual-frequency method. The results showed that the particle rotated when moving along the riser in gas-solid two-phase flow of the CFB riser, and the average particle rotational speed in the wall area was higher than that in the center area in the testing cross-section. Those particles, with either relatively smaller diameter or higher radial component of velocity,were inclined to have a higher rotational speed. The average rotational velocity of irregular particles was obviously higher than that of regular ones.Average particle rotational velocity in the CFB riser was 300 r•s^-1 and maximum rotational velocity was 2000r•s^-1 at superficial gas velocity V_g=5 m•s^-1,recycling solids mass flux G_s=1.5 kg•m^-2•s^-1 and particle average diameter d_p=0.5 mm.

Key words: 高速数字摄影, 循环流化床, 气固两相流, 颗粒旋转