Liquid Radial Dispersion in Liquid-solid Circulating Fluidized Beds with Viscous Liquid Medium |
| |
Authors: | Y J Cho P S Song C G Lee Y Kang S D Kim L T Fan |
| |
Affiliation: |
a School of Chemical Engineering, Chungnam National University, Daejeon, Korea
b Department of Biomolecular and Chemical Engineering, KAIST, Daejeon, Korea
c Department of Chemical Engineering, Kansas State University, Manhattan, Kansas |
| |
Abstract: | Liquid dispersion in the radial direction was investigated in the riser of a viscous liquid-solid fluidized bed 0.102 m in diameter and 3.5 m in height. Pressure fluctuations in the riser were also measured and analyzed to examine the behavior of fluidized particles. Effects of liquid velocity (0.15-0.45 m/s), solid circulation rate (2-8 kg/m2s), particle size (1-3 mm), and liquid viscosity (0.96-38 mPas) on pressure fluctuations and the liquid radial dispersion coefficient were determined. The infinite space model was employed to obtain the radial dispersion coefficient from the radial concentration profiles of the tracer. The pressure fluctuations were analyzed by means of autocorrelation coefficient as well as power spectral density function. The dominant frequency obtained from the autocorrelation coefficient or power spectral density function of pressure fluctuations decreases with increasing liquid viscosity or liquid velocity, but it increases with increasing particle size. The liquid radial dispersion coefficient decreases with increasing liquid velocity or viscosity, but it increases as the solid circulation rate or particle size increases. The liquid radial dispersion coefficient is related closely to the resultant behavior of fluidized particles. The radial dispersion coefficient has been well correlated with operating variables in terms of dimensionless groups. |
| |
Keywords: | Liquid-solid Circulating fluidized bed Radial dispersion coefficient Viscous liquid medium Pressure fluctuations |
本文献已被 InformaWorld 等数据库收录! |
|