环境工程学报2011，Vol.5Issue(4)：726-730,5.
高含盐废水降膜蒸发过程中液膜破裂的抑制
Suppression of liquid film rupture during falling film evaporation for high salinity wastewater
摘要
Abstract
To avoid the appearance of dry region and scaling caused by liquid film rupture during the falling film evaporation for high salinity wastewater, an experimental investigation was performed on the liquid film flow after heated falling film breaking by using a sensitive infrared camera technique. The results indicate that the thermal Marangoni effect and solutal Marangoni effect co-exit in transverse direction on the broken falling film surface. The thermal Marangoni effect induced the falling film shrinking from the lateral brim to the center bulk,generating stable dry region. And the solutal Marangoni effect caused the fouling along the lateral brim. Adding 50 mg/L surfactant of 2-ethyl-l-hexanol (ETH) into the salinity wastewater, the tendency of falling film breaking was effectively suppressed. The presence of ETH on the film surface varied the sign of change rate of surface tension σ with respect to temperature. Thus the thermal Marangoni effect generated in transverse direction caused the film spreading from the bulk to the lateral. Meanwhile, the solutal Marangoni effect, induced by the surfactant evaporating on the film surface, further promoted the film extending towards the lateral, preventing the occurrence of the dry region and scaling.关键词
盐/废水/降膜蒸发/Marangoni效应/表面活性剂Key words
salinity/ wastewater/ falling film evaporation/ Marangoni effect/ surfactant分类
资源环境引用本文复制引用
赵贤广,李武,张志炳,徐炎华..高含盐废水降膜蒸发过程中液膜破裂的抑制[J].环境工程学报,2011,5(4):726-730,5.基金项目
国家"985工程"资助 （）
国家自然科学基金项目(20576050) （20576050）
