Weiguo Yang

Bubble behavior in gas–liquid–solid three-phase circulating fluidized beds

Abstract A novel fiber optic probe system has been developed for studying the bubble behavior in gas–liquid–solid three-phase circulating fluidized beds (TPCFBs). Mathematical method to analyze data by probe technique has also been discussed in this paper. The bubble size and its distribution, bubble Sauter diameter, gas–liquid interfacial area and bubble rise velocity, have been experimentally studied using the fiber optic probe. The experimental results show that the bubble size distribution in TPCFBs follows lognormal function. The bubble Sauter diameter has the radial profile with smaller value in the central region than in the near-wall region, different from the conventional three-phase fluidized beds (CTPFBs) without outer particle circulation. The distribution of bubble rise velocity, gas–liquid interfacial area and effect of the operation conditions have been experimentally studied.

Mass Transfer Characteristics of Syngas Components in Slurry System at Industrial Conditions

The gas-liquid mass transfer behavior of syngas components, H 2 and CO, has been studied in a three-phase bubble column reactor at industrial conditions. The influences of the main operating conditions, such as temperature, pressure, superficial gas velocity and solid concentration, have been studied systematically. The volumetric liquid-side mass transfer coefficient k L a is obtained by measuring the dissolution rate of H 2 and CO. The gas holdup and the bubble size distribution in the reactor are measured by an optical fiber technique, the specific gas-liquid interfacial area a and the liquid-side mass transfer coefficient k L are calculated based on the experimental measurements. Empirical correlations are proposed to predict k L and a values for H 2 and CO in liquid paraffin/solid particles slurry bubble column reactors.

Gas–liquid mass transfer behavior in three-phase CFB reactors

The gas-to-liquid volumetric mass transfer behavior has been studied using the oxygen dissolution method in a three-phase circulating fluidized-bed (CFB) reactor 140 mm in inner diameter and 3.0 m in height. The volumetric mass transfer coefficient kLa is obtained from the measured bulk concentrations of the liquid phase by means of the axial dispersion model. The influences of the main operation conditions, such as superficial gas velocity and superficial liquid velocity and solid circulating rate, on the volumetric mass transfer coefficient are studied systematically.

EXPERIMENTAL STUDY ON GAS-HOLDUP AND GAS-LIQUID INTERFACIAL AREA IN TPCFBs∗

Abstract A new fiber optic probe system has been developed for measuring the gas-holdup εg and bubble size distribution Ps(db) in multiphase reactors. Experiments have been carried out in a gas-liquid-solid three-phase circulating fluidized bed (TPCFB) with 140mm inner diameter and 3 m height, in which air, tap water and 0.4 mm glass beads are used as the gas, liquid and solid phase, respectively. Based on the measured data, the gas-liquid interracial area a, one or the most important parameters concerning the mass transfer, has been derived. The radial profile of the gas holdup and the gas-liquid interracial area, and the influence or main operating conditions have been studied experimentally in TPCFBs.