CFD Analysis of a Water Vaporization Process in a Three-Dimensional Spouted Bed for Flue Gas Desulfurization

Abstract

In this work, the gas−solid flow and water vaporization process are simulated by the method of Euler−Eulerian two-fluid model in a three-dimensional spouted bed, which have a significant influence on the desulfurization efficiency. The results of simulation indicate that the change trends of the particle volume fraction are similar under superficial gas velocities of 0.7 and 0.8 m/s. The degree of particle pulsation is the highest at the bottom of the spout area, and the degree of gas pulsation is the highest at the junction of the annulus area and spout area. The temperatures of gas, liquid, and particles are also analyzed. The results demonstrate that in the spout area, the gas temperature is much higher than that of the liquid and particles, but the three phases are uniformly mixed and have similar temperatures in other areas. Moreover, water vaporization mainly occurs at the junction of the annulus area and the spout area, a small amount of liquid is vaporized at the center of the spout area, and basically no vaporization reaction occurs in the outer radius of the annulus area. With the increase in gas velocity, gas temperature, and liquid temperature and the decrease in gas humidity, water vaporization reaction is promoted.

Numerical Investigations for the Two-Phase Flow Structures and Chemical Reactions within a Tray Flue Gas Desulfurization Tower by Porous Media Model

“…The ideal mathematical model that simplifies the flow conditions with uniform velocity [1,[6][7][8] could hardly capture these complex geometric effects within a facility, and hence, the Computational Fluid Dynamics (CFD) technique can provide more insightful information and benefit to optimal design. CFD has already been applied widely to solve the multiphase flow dynamics within the FGD tower [4,5,[9][10][11][12][13][14][15][16] and other facilities or processes with relevant fields, such as scrubbers of CO 2 emissions [11] and fine particle dust concentrators [17]. Depending on its approach to the interactions between liquid-solid and gas phase, the multiphase flow model can be categorized as an Eulerian-Lagrangian model [9,[11][12][13][14] and an Eulerian-Eulerian model [5,10].…”