ANYANG INSTITUTE OF TECHNOLOGY本 科 毕 业 论 文年产 20 万吨水溶液全循环法尿素蒸发系统工艺设计与优化The process design and optimization of evaporation system in aqueous solution total recycle which yearly produces two hundred thousand ton urea年产 20 万吨水溶液全循环法尿素蒸发系统工艺设计与优化摘要水溶液全循环法生产尿素工艺装置，主要包括六个方面：原料的压缩和净化，尿素的合成，中低压解吸收，解吸，蒸发造粒。原料 CO2由合成车间净化工段送来，液氨由氨库送来，两种反应物经加压加热送入合成塔反应生成尿素。合成塔出来的合成液中含有尿素、氨基甲酸铵、过剩的氨和水。再经过循环回收进入合成塔，整个过程靠水作为循环介质。由闪蒸槽流出的尿液进入一段蒸发器的加热段加热至 130℃，在 0.033Mpa 压力下，尿素浓度达到 96％（W）,进入二段蒸发加热器，加热至 140℃，继续减压至 0.0033Mpa（绝），尿液浓度提高至 99.7％（W），尿液进入熔融泵送往造粒塔，由旋转喷头喷洒造粒。本设计主要通过参考工厂数据进行蒸发阶段的物料与热量衡算，得出蒸发阶段各部分的出入物料与热量，然后进行设备选型与对整个工段进行优化。关键词：水溶液全循环法 一段蒸发器 物料衡算 热量衡算 The process design and optimization of evaporation system in aqueous solution total recycle which yearly produces two hundred thousand ton ureaAbstractTotal recycleureasolutionproductionprocess equipment, including sixareas:raw materials,compression andpurification,ureasynthesissolutionin thelowabsorption,desorption, evaporation and granulation.CO2from thepurification ofraw materials,syntheticplantSectionsent,liquid ammoniafrom theammonialibrarybroughtthe tworeactantsintothereactorby thepressure and heatthe reaction ofurea.Reactorout ofthesynthesis solutioncontainingurea,ammonium carbamate, excessammoniaand water.Then afterrecyclinginto thereactor,the wholeprocessby thewater asthe circulating medium. Outflowof urinefrom theflash tank into a heating section of the evaporator heated to 130 ℃, the pressure in the 0.033Mpa urea concentration 96%...
