화학공학소재연구정보센터
Chemical Engineering Science, Vol.52, No.5, 829-841, 1997
Investigation on Bubble Characteristics in a Gas-Fluidized Bed
To characterize the bubble behavior in a fluidized-bed reactor experiments were carried out with a capacitance probe. The probe consisted of two measuring tips with a distance of 10 mm. Cross correlation of the two time-averaged signals could not be used to determine the bubble rising velocity because of the log-normal bubble Size distribution. Therefore, a statistical method was developed to analyze and fit the experimentally determined time-averaged signals. Quartz sand powders with mean sieve particle sizes of 106, 165, 230 and 587 mu m were used as fluidizing powders. The theoretical equivalent bubble diameter calculated with the equation of Darton et al. (1977) was found to be about 2.7 times the determined radial averaged mean pierced bubble length. A stable bubble height h* of about 60 cm was determined for the powder with an average particle size of 106 mu m. Combined with other data it is argued that h* increases with increasing particle size.