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1、ANYANGINSTITUTEOFTECHNOLOGY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Theprocessdesignandoptimizationofevaporationsysteminaqueoussolutiontotalrecyclewhichyearlyproducestwohundredthousandtonurea年产20万吨水溶液全循环法尿素蒸发系统工艺设计及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
2、,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及
3、热量衡算,得出蒸发阶段各部分的出入物料及热量,然后进行设备选型及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TheprocessdesignandoptimizationofevaporationsysteminaqueoussolutiontotalrecyclewhichyearlyproducestwohundredthousandtonureaAbstractTotalrecycleureasolutionproductionprocessequipment,includingsi
4、xareas:rawmaterials,compressionandpurification,ureasynthesissolutioninthelowabsorption,desorption,evaporationandgranulation.CO2fromthepurificationofrawmaterials,syntheticplantSectionsent,liquidammoniafromtheammonialibrarybroughtthetworeactantsintothereactorby
5、thepressureandheatthereactionofurea.Reactoroutofthesynthesissolutioncontainingurea,ammoniumcarbamate,excessammoniaandwater.Thenafterrecyclingintothereactor,thewholeprocessbythewaterasthecirculatingmedium.Outflowofurinefromtheflashtankintoaheatingsectionofthee
6、vaporatorheatedto130℃,thepressureinthe0.033Mpaureaconcentration96%(W),intothesecondaryevaporatorheater,heatedto140℃,todecompressionTo0.0033Mpa(absolute),urineconcentrationsincreasedto99.7%(W),theurineintothemeltpumpsenttothegranulationtower,fromtherotatingnoz
7、zlespraygranulation.Thereferenceplantdesigndata,primarilythroughtheevaporationstageofmaterialsandheatbalance,obtainedaccesstoallpartsofevaporationstageofmaterialsandenergy,thentheentiresectioninequipmentselectionandoptimization.KeywordsAqueoussolutiontotalrec
8、ycle;Evaporatorsection;Materialbalance;Heatbalance目录第一章水溶液全循环法概述引言尿素别名碳酰二胺、碳酰胺、脲,由碳、氮、氧和氢三种元素组成,是第一种以人工合成无机物质而得到的有机化合物,分子式:CO(NH2)2,分子量60.06,外观为无色或白色针状结晶体或粉末,工业或农业品为白色略带微红色固体颗粒,无臭无味,密度1.3