Zhongyuan Dahua Ammonia Synthesis Plant replaces molecular sieves and desiccants

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Zhongyuan Dahua Ammonia Synthesis Plant Replaces Molecular Sieves and Desiccants Author/Source: Zhongyuan Dahua Date: 2022-03-19 Clicks: 15 The dryer in Unit 11 of the Ammonia Synthesis Plant, which is part of the fertilizer production facility, relies on molecular sieves and aluminum oxide to remove ammonia and water from the process gases. To prevent these substances from entering subsequent systems, where they could condense into solids and block the piping equipment inside the cold box, thereby increasing the pressure difference in that box and affecting the safe operation of the equipment as well as the overall performance of the facility, it was decided during this maintenance period to replace the molecular sieves and desiccants. To ensure the successful completion of the replacement of the molecular sieve desiccant, after the system was shut down, process engineers and instrumentation technicians verified on-site the opening and closing status of each valve, and arranged for nitrogen to be used to purge the dryer. Open the top cover in advance to ensure everything is in order. The main work involved in this replacement was carried out by the synthesis team. Before starting the unloading process, the branch factory provided detailed safety training and instructions to the workers and supervisors, requiring everyone to wear safety helmets, gloves, and dust masks to prevent accidents. The supervisors ensured oversight of the entire molecular sieve replacement process. Since the porcelain balls on the top layer can be reused depending on the circumstances. To process the ceramic balls, personnel need to enter the dryer tank, use an iron sieve to remove the small amount of molecular sieve mixed in them, and then put the ceramic balls into woven bags for recycling. The headspace is narrow, so technicians who are slim and agile are chosen to enter the dryer. They crouched over the porcelain balls, picking them up with their hands and putting them into bags, with clouds of dust rising around them from time to time. Once the cleaning of the ceramic balls is essentially complete, the next step is to remove the molecular sieve and aluminum oxide. After being pumped out with a vacuum pump, they are placed in bags. Technicians are responsible for controlling the pumping speed of the vacuum pump above the dryers, while other staff handle bagging. By 6:11 p.m., both tanks in Dryer Unit 11 had been emptied. After a full day of continuous work, the loading was finally completed around 9:30 p.m., successfully finishing the task of replacing the molecular sieve and desiccant.