Research On Limestone Activity & Flow Field And Desulphurization Characteristics Of Liquid Column Impinging Tower

In the slurry scrubbers for wet flue gas desulphurization, limestone is widely used as absorbent. The activity of limestone strongly influences the SO₂ removal efficiency and the operation cost of the WFGD system. Combining experiment and academic mathematical model, this paper studies the limestone dissolution dependence factors, such as the slurry pH and temperature, PSD of limestone, fly ash, Al³⁺, F^- and so on.As can be seen from the results, the slurry pH observably affects the limestone dissolution rate and low pH is favorable. Increasing the slurry temperature slightly accelerates limestone dissolution. And the limestone with smaller particle size distribution has the higher dissolution rate. A small quantity of CaSO₄ restrains limestone dissolution appreciably. The results also indicate that, 0.06 wt% fly ash is disadvantageous for limestone dissolution, but it is not remarkable. Al³⁺ and F^- added synchronously, even if volume is little, hinder the dissolution extremely. The apparent dissolution rate of limestone from experimentation reflects its activity in a certain extent. The limestone dissolution model based on double film theory is logical relative to experimental data.In a wet flue gas desulphurization scrubber of liquid column impinging tower, the atomizing effect of liquid column has crucial influence on its desulphurization efficiency. Employing particle image velocity (PIV) techniques, the liquid column atomized gas-liquid two-phase flow field inside an experimental platform is measured. The results indicate that, type of baffle, inlet liquid flux, flue gas velocity and space between nozzle and baffle determine the atomizing properties of liquid column. Besides, the particle size distribution corresponds with the Rosin-Rammler distribution model perfectly. The experimental conclusions between flow field research with PIV and study of desulphurization characteristic on liquid column impinging tower have a little difference. Based on this study, the operation conditions of liquid column impinging tower can be optimized.