氢氧化钙浆液脱硫反应及其干燥特性

Desulfurization and Drying Characteristic of Ca(OH)_2 Slurry

采用热天平研究了低温(80°C)条件下Ca(OH)2浆液在一定水钙质量比、SO2浓度范围内的脱硫特性及干燥特性.结果表明,不同水钙比及SO2浓度下浆液干燥特性明显不同;Ca(OH)2浆液在SO2气氛下在浆液表面反应生成的CaSO3·0.5H2O晶体比在N2气氛下由于干燥而析出的晶体多,硫分以CaSO3·0.5H2O固定在浆液中,其干燥速率要低些;不同干燥条件下的浆液临界湿含量不同,反应及蒸发过程在浆滴表面产生的晶体越多,临界湿含量越大;在低SO2浓度时,Ca(OH)2转化率随SO2浓度的升高迅速增加,当入口SO2浓度增大到一定值后,Ca(OH)2转化率增加趋缓.

Thermobalance was employed to study the drying characteristic and desulfurization of Ca（OH）2 slurry at low temperature （80℃）. The experimental results show that the drying characteristic is different under the different mass ratio of H2O/Ca（OH）2 and SO2 concentration. When the Ca（OH）2 slurry is dried in the atmosphere of SO2, drying rate would be slower because of more crystals of CaSO3 ·0. 5H2O precipitating on the surface of the slurry. The critical moisture content is different under the different drying conditions. It could be found from experimental results that the more the crystals precipitating on the surface of the slurry, the larger the critical moisture content. The Ca（OH）2 conversion increases with the increasing of SO2 concentration when SO2 concentration is low. The Ca（OH）2 conversion increases slowly with the increasing SO2 concentration when SO2 concentration is high.