【摘要】 自然循环自动清洗式蒸发器的综合效益相当高。其中的结晶垢自动清洗研究比较充分,技术也比较成熟,产生足够的自然循环推动力成为关键,并且与蒸发压力密切相关。为此研究它的蒸发压力适应性问题。得到的结果是,常压蒸发和加压蒸发中影响自然循环推动力大小的主要因素是汽化深度,分别在20℃、25℃以上的传热温差下,都可以达到带动长管加热室、光滑扭带自动清洗需要的11kPa以上,并且加压蒸发更有优势;真空蒸发中汽化深度和出口动能损失两者的影响都大,因此难以形成大的自然循环推动力,则需要采用旋流冲推齿形扭带自动清洗的短管加热室结构。该技术适用于国内普遍采用的0.6MPa加热蒸汽源的三效蒸发工艺。更多还原

【Abstract】 Comprehensive efficiency of self-cleaning evaporator with natural circulation is rather high,in which the study on self-cleaning of crystal incrustation is comparatively sufficient and technology is mature. The key to this technology is to produce sufficient driving force with natural circulation which is also closely related to evaporation pressure.For this purpose,the adaptability of its evaporation pressure is studied.The result is that degree of vaporization is the main factor affecting the driving force with natural circulation under normal and positive pressure.The pressure can reach 11kPa that is needed to drive long-tube evaporator and automatically wash smooth twisting belt under temperature difference of heat transfer above 20 ℃ and 25℃ respectively.Positive pressure evaporation is more advantageous.Degree of vaporization and outlet dynamic loss in vacuum evaporation are greatly affected,so it′s difficult to create large driving force with natural circulation. Short-tube heater structure with spiral flow flushing toothed twisting belt is applied,which is suitable for triple-effect evaporation process with 0.6Mpa heating steam commonly used in China.更多还原