【作者】 李伟；

【导师】 金君素； 付晶；

【作者基本信息】 北京化工大学 ， 化学工程（专业学位）， 2017， 硕士

【摘要】 本文依托山东华鲁恒升化工股份有限公司2013年新建投产的吸附法16 wt/年浓硝酸装置,论述了装置运行中稀硝酸、硝酸镁、蒸汽和循环水消耗偏高,酸性废水和废气处理困难,浓硝酸管线结晶堵结,部分耐酸管道和设备出现明显腐蚀,浓缩塔运行效果不佳等问题,并对这些问题逐一分析研究、优化改造。文中重点分析了浓硝酸生产核心设备硝酸浓缩塔运行效果差、硝酸镁加热器易腐蚀泄漏的原因,通过比对现有精馏塔装置改造经验,结合塔外分布实验,分析得出本装置浓缩塔运行主要受浓缩塔塔顶液体分布器分布效果差、规整填料装填不合理,以及填料与塔壁间存在缝隙,引起塔内流体发生壁流、沟流等不合理流动状态所影响。经过实施相应改造,硝酸浓缩塔运行效果有了明显改善,成品酸产量、质量指标也有较大提高,运行周期由两个月延长至四个月,平均蒸汽消耗取得显著降低,取得了良好的改造效果。本文采用喷射泵对酸气进行吸收,再将酸水输送至稀硝酸合成装置作为吸收液,经过改造后酸气和酸水得到了有效回收。本文对比了装置改造前和改造后运行情况,结果表明:装置经改造后63.5%稀硝酸消耗由1.60 t/t硝酸(折纯)降低为1.57 t/t,硝酸镁消耗由1.12kg/t硝酸(折纯)降低为0.96kg/t,蒸汽消耗由2.09t/t硝酸(折纯)降低为1.87 t/t,冷却水消耗由208 m3/t浓硝酸降低为202 m3/t;通过改造硝酸镁管路系统,减少盲端并增加回流,调整伴热管数量,在最长运行周期四个月内浓硝酸镁管线和硝酸镁蒸发器未出现堵结现象,耐酸管道和硝酸镁加热器等设备腐蚀泄漏状况明显好转。更多还原

【Abstract】 This paper relies on the 16Wt per year concentrated nitric acid plant using magnesium nitrate method which went into operation in 2013.And the paper discusses the high consumption of dilute nitric acid,magnesium nitrate,steam and circulating water,the treatment of acidic waste water and waste gas,the condensation of concentrated nitric acid pipeline,the obvious corrosion of some acid-resistant pipes and equipment,the poor running effect of concentrating tower,and one by one analyzes these issues combining with the experiment results,then makes the appropriate transformation measures.This paper focuses on the core equipment of concentrated nitric acid nitric acid enrichment tower operating poor results,easy to corrode magnesium nitrate leak leakage through the existing rectification tower retrofit experience,combined with the tower outside the experiment,analysis of the device was concentrated The tower operation is mainly affected by poor distribution of liquid distributor in the top of the condensing tower,unreasonable filling of the structured packing,and gaps between the packing and the tower wall,causing the wall flow and channeling in the tower to be affected by unreasonable flow conditions.After the implementation of the corresponding transformation,the operating efficiency of the nitric acid enrichment tower has been significantly improved.The acid output and the quality index of the finished products have also been greatly improved.The operation period has been extended from two months to four months.The average steam consumption has been significantly reduced and a good transformation has been achieved effect.In this paper,the acid gas is absorbed by the jet pump,and then the acid water is delivered to the dilute nitric acid synthesis unit as the absorption liquid.After being reformed,the acid gas and the acid water are effectively recovered.In this paper,the operation conditions of the device before and after the transformation are compared.The results show that the device after modification of 63.5%dilute nitric acid consumption by 1.60 t/t nitrate(pure)reduced to 1.57 t/t,1.12 kg/t nitrate consumed by nitrate(pure)reduced to 0.96 kg/t,the steam consumption by 2.09 t/t nitrate(pure)reduced to 1.87t/t,cooling water consumption reduced from 208 m3/t concentrated nitric acid to 202 m3/t.Operation time of the device is extended from one month to more than four months.In the period,concentrated magnesium nitrate pipeline and magnesium nitrate evaporator do not appear blocking phenomenon,acid resistant pipeline and magnesium nitrate heater and other equipment do not appear a new leak.更多还原