【Haichuan’s Best Practices】Large-grain urea granulation: exhaust dust recovery upgrade saves 470,000 yuan

Thread Content

Urea exhaust gas recovery upgrade yields 470,000 yuan in additional benefits. Recently, the Linyi branch of Lu’an Fengxi Group completed a project to recover dust from the exhaust gas generated during the granulation of large-particle urea, addressing the bottleneck issues that hindered the simultaneous production of urea and melamine. This upgrade is expected to generate an additional 470,000 yuan in benefits each year. 　　Throughout the years, the dust generated during the production of large-grain urea by this company has been sent to a water washing and dust removal device via an exhaust fan; the urea solution produced as a result of this washing process is then sent to the urea production facility for reuse in urea manufacturing. To increase the hardness and strength of large-particle urea, an appropriate amount of 37% formalin solution is added to the outlet pipeline of the molten urea pump during the production process, so that the washing liquid also contains formalin. After the washing liquid returns to the urea system, it causes formaldehyde to be present in the urea. When melamine is produced from molten urea containing formaldehyde, the polymerization between formaldehyde and melamine generates melamine-formaldehyde resin, which affects the product quality. 　　To address the above issues, the company’s R&D team organized professional technicians to conduct research in similar enterprises and research institutions in order to gain valuable insights. After numerous experiments and validations, it was ultimately decided to use bag filters instead of water-based dust collectors. During operation, the device draws in the dust generated by large urea particles into the newly installed bag filter. At the bottom of the bag filter, there is an electromagnetic valve-based automatic unloading system; urea dust is discharged through this system and then packaged for sale. The small amount of exhaust gas remaining after dust removal is further filtered and then discharged harmlessly through an exhaust fan, completely eliminating the problem caused by formaldehyde. 　　After its commissioning, this project resolved the problem of being unable to operate the large-particle urea plant and the melamine plant simultaneously. It helps to save 5,214 tons of steam annually and generates an additional benefit of 470,000 yuan.