烟气直接接触蒸发浓缩脱硫废水研究

Study on Evaporation and Concentration of Desulfurization Wastewater by Direct Contact with Flue Gas

模拟烟道气和脱硫废水直接接触传质传热过程,进行了热空气和氯化钠溶液相关实验,研究了气液传质系数和系统蒸发量随操作条件的变化规律。结果表明,气液传质系数和系统蒸发量随空气流量、空气温度、溶液温度的提高变大,随溶液盐度的增加而变小。其中空气温度的影响最为明显,当空气温度从65℃增加到110℃时,气液传质系数由10 g/(m^2·s)增加到21 g/(m^2·s),系统蒸发量由0.13 kg/h增加至0.51 kg/h。烟道气与脱硫废水进行逆向流动直接接触方法对实际脱硫废水的现场实验表明,脱硫废水浓缩倍率达到10以上。可为利用电厂烟道气处理脱硫废水提供依据。

The heat and mass transfer process of flue gas contacted with desulfurization wastewater directly was simulated,the related experiment of hot air and sodium chloride solution was carried out,the change rule of gas-liquid mass transfer coefficient and system evaporation capacity with operation conditions was studied.The results showed that,with the increasing of air flow,air temperature and solution temperature,the evaporation capacity and mass transfer coefficients increased significantly,but they were decreased with the increase of solution salinity.The effect of air temperature was the most obvious,with the increase of air temperature from 65℃to 110℃,the mass transfer coefficients increased from 10 g/(m^2·s)to 21 g/(m^2·s)and the evaporation capacity increased from 0.13 kg/h to 0.51 kg/h.The field experiment of flue gas contacted with actual desulfurization wastewater directly in a countercurrent flow showed that,the concentration ratio of desulfurization wastewater was above 10,which provided basis for desulfurization wastewater treatment by flue gas in power plant.