合成氨系统停车后氧含量升高的原因分析

Analysis of Causes for Increase in Oxygen Content after Shut-down of Ammonia System

介绍了合成氨系统短期(在8 h以内)停车检修后再开车时煤气系统存在的氧含量高的问题,并从循环洗涤水中的解吸氧、气化炉开车时下吹煤气管道内的填充空气、清理洗气箱过程带入的空气、煤气总管温度降低后易形成负压而吸入的空气4个方面进行原因分析、计算和论证。提出了解决合成氨系统停车及开车时氧含量高的措施,并在实际生产中得到了充分的证明和体现,解决了合成氨系统停车检修后开停车过程因氧含量升高的问题。

A description is given of the high oxygen content in the gas system on restart-up after a short period （less than 8 h） of shut-down for maintenance of the ammonia plant. An analysis of the causes from four sources is carried out： the desorbed oxygen from the circulating washings, the filler air in the down-blow gas pipe during gasifier start-up, the air brought in during cleaning the gas- washing box, and the air sucked in by the negative pressure formed easily after a decrease in the temperature of the gas main pipe, and they are calcucated and demonstrated. Measures are proposed for lowering the high oxygen content in the ammonia plant during shut-down and start-up, and they have been proved and reflected fully in actual production, thereby solving the problem of an increase in oxygen content in start-up and shut-down after a shut-down for maintenance of the ammonia plant.