Experimental And Numerical Study On Fine Particle Influence On Gas-liquid Mass Transfer

Wet limestone scrubbing is the most common flue gas desulfurizationprocess for control of sulfur dioxide emissions from the combustion of fossilfuels, and forced oxidation is a key part of the reaction. Actually, during theprocess of the combustion of coal, especially the combustion of powderedcoal, gas contains lots of particles, besides, as the oxidation rate isn’t far fromenough, the reaction forms calcium sulfite and calcium sulfate’s crystal.These result lots of particles exists in the liquid. These particles have hugeinfluences on gas-liquid reaction.This work is to find how temperature、solid loading、particle’s size andstirring speed influence the reaction. The apparatus used in this work is stirredvessel. The concentration of sulfite is about0.5mol/L, fine particles used areactivated carbon and glass bead. The experiment results indicate that kLbecomes large with the increase of solid loading, but exists a critical valuewhich is about0.6g/L; The relationship between kLand particle’s size isinverse proportion. When particle’s size is larger than10μm, kLdoesn’tchange too much with the change of particle’s size. The experiment resultsindicate that glass bead has a bigger influence on mass transfer than activatecarbon because the change of gas-liquid layer’s character made by fineparticles is bigger than shuttle mechanism. In the end, this work develop aone-dimensional mass transfer model to explain solid loading experimentresults. Model’s results are very close to the experiment results.