荷电石灰浆雾滴吸收SO2的传质特性分析

在石灰浆荷电雾化脱硫理论分析和试验研究的基础上,建立石灰浆雾滴吸收SO2的传质模型,计算荷电前后不同气液流量,不同n(Ca)/n(S)时的气相传质系数、液相传质系数、总传质系数和增强因子,并进行SO2吸收特性分析.结果表明:n(Ca)/n(S)一定时,随着入口SO2体积分数的增加,脱硫效率增大,SO2吸收速率逐渐增大,增强因子逐渐减小;相同入口SO2体积分数时,加大液气比可以增大脱硫效率,同时使脱硫吸收速率增加,但是增加到一定量后,吸收速率开始下降.无论何种工况,荷电后的吸收速率和增强因子都比非荷电时大,说明荷电对SO2传质和化学反应具有明显促进作用.

Mass transfer mechanism of charged lime droplets and SO2

Experimental system for desulphurization was applied to test the SO2 concentration variation after the lime droplets were charged.The mass transfer rate,gas phase transfer coefficient,liquid phase mass transfer coefficient,gas phase overall mass transfer coefficient and enhancement factor were calculated respectively in different lime charged conditions.The results show that in the case of fixed n(Ca)/n(S),the SO2 removal efficiency and the Absorbing rate increase whereas the enhancement factor decreases with higher inlet concentration of SO2.When the concentration is fixed,increasing the lime-gas ratio below critical point can improve both the removal efficiency and Absorbing rate;above that,the former increases but the latter decreases.It is concluded that both the Absorbing rate and enhancement factor are improved when the droplets are charged.