Studies Of Slurry Jet Flue Gas Desulfurization

There are many control technologies of pollutant SO2 discharged by coal-fired boiler at the present time, including of wet lime/limestone-gypsum flue gas desulfurization(FGD), which is the most effective FGD technology and used in many fields. Slurry jet FGD is one of the advanced FGD technologies, charactered by strong gas-liquid turbulence mass transfer, credible operation and high-degree desulfurization. The target of this research is to study the overall performance of the slurry jet FGD technology and various influencing factors in pilot plant and other two application plants, with the aim to supply the complete FGD set with own knowledge property right.Performance engineering tests in Shenyang fertilizer plant indicated that the slurry jet FGD technology operated stably and credibly, and can be applied to various FGD projects with difference flue gas flux and inlet SO2 concentration. The main influencing factors include: pH of recycled slurry, inlet SO2 concentration, inlet flue gas flux and recycled slurry flux. The desulfurization capability of per unit recycled slurry can be described by , which is confirmed by the application of slurry jet FGD technology to Nanning and Hangzhou FGD projects. So it can direct the optimization for the future projects.Calculation and engineering tests in Shenyang, Nanning and Hangzhou FGD projects indicates that it is the O2 mass transport process which controls the oxidation rate of desulfurization product in consecutive operation of desulfurization tower. Other tests include: the presence of F- and Cl- ions in Hangzhou projects can reduce the desulfurization efficiency by about 10%. The gypsum crystallization kinetics process can be described by the gypsum crystallization model based on â–³L law. The slurry sedimentation tests indicates that the sedimentaton velocity of slurry is fast, so the attention must be applied to avoid silt and blockade in design of slurry ducts.With the aim of more information of the chemical reactions and mass transport processes, the further investigations of a detailed model for slurry jet FGD pilot plant are developed. The calculate results accord with test results in pilot plant, which indicates that the model can well describe the desulfurizaiton processes in FGD tower. And the numerical simulation of gas-liquid two-phase flow field in FGD tower in pilot plant indicates that the two phases in tower are uniform distributing and well intermixed, which assures the high desulfurization efficiency in the FGD tower.