石灰石湿法脱硫过程中SO2吸收数学模型

为揭示石灰石湿法脱硫体系中喷淋塔内SO2的浓度和脱硫效率的变化情况,针对喷淋塔内石灰石在气膜控制、气液膜控制和固体溶解控制的3个不同阶段,以双膜理论为基础,以单个石灰石颗粒为研究对象,通过石灰石在不同阶段的转化率和粒径变化,得到SO2在不同阶段脱硫效率随时间的变化规律,建立SO2吸收的数学模型.模型计算结果表明,在烟气行程上,脱硫效率受SO2气膜传质阻力和石灰石溶解速率限制.在吸收塔底部和上端SO2吸收速率较低,在SO2和石灰石摩尔比在适宜条件下,有效吸收段高度为2 m左右.理论模型揭示的规律对喷淋塔的设计和运行参数选取有一定借鉴意义.

Mathematic model of absorption of sulfur dioxide in wet flue gas desulfurization

In order to disclose the concentration of sulfur dioxide in spray tower and dynamic alteration of desulfurization efficiency in the system of wet limestone desulfurization, dynamic mathematic model for flue gas desulfurization (FGD) in spray tower was established on the basis of double-membrane and mass transfer theory. The research focused on single limestone grain. The model analyzed how the desulfurization rate changed with the variety of influencing factors. The reaction process can be divided into three stages. They are respectively controlled by gas phase resistance, both gas and liquid phases resistance and liquid phase resistance. The results revealed that the desulfurization efficiency increased with the increasing height of spray tower. But the influence of the tower height weakened when the height reached to a certain altitude.