关键词: 水力喷射-空气旋流器, 湿法脱硫, 气-液传质, 有效相界面积

Abstract: Wet desulfurization of flue gas was investigated with Ca(OH)₂ slurry as absorbent in a water-sparged aerocyclone(WSA),new and high efficiency gas-liquid mass transfer equipment.The results show that the removal efficiency of SO₂ increases with the inlet gas velocity,first increases linearly with liquid jet velocity u_L,and then remains almost constant when u_L is equal to or greater than 0.29 m·s^-1.The removal efficiency of SO₂ decreases as SO₂ concentration in the flue gas increases,and presents a maximum value with the increase of liquid reflux ratio and Ca(OH)₂ concentration in the absorbent slurry.The removal efficiency of SO₂ can reach 88.9%-97.7% under the following conditions:flue gas flow rate of 24-72 m³·h^-1,absorbent recirculation flow rate of 0.4-0.8 m³·h^-1,Ca(OH)₂ concentration in absorbent of 7500 g·m^-3,and SO₂ concentration in flue gas of 1891-6373 mg·m^-3.No fouling and blocking were found in the WSA because of the self-cleaning ability of the cyclone gas and liquid jet.The mass transfer mechanism in the WSA was also investigated.The results show that the overall volumetric mass transfer coefficient K_Ga and the interfacial area a increase with the increase of inlet gas velocity u_G,the overall mass transfer coefficient K_G increases with u_G slowly.K_Ga and K_G increase quickly with liquid jet velocity u_L when u_L≤0.26 m·s^-1 and then increase slowly,and a increases almost linearly with the increase of u_L.As Ca(OH)₂ concentration c_L increases,K_Ga and K_G increase first and then decrease.The empirical formulae fit the experimental data well and could be used to predict the mass transfer characteristics for wet desulfurization in WSA.Under the experimental conditions,the mass transfer in wet desulfurization in the WSA is controlled by both gas film and liquid film,mainly by liquid film.

Key words: water-sparged aerocyclone, wet desulfurization, gas-liquid mass transfer, interfacial area