Corrosion Detection, Theory And Protection Analysis Of Cdu&Vdu Unit

Petroleum and petrochemical industries are both playing the most important roles in the industrial production and people’s life. With the trend of large equipment, many small problems have become some big problems which are affecting the whole production line. Because of these faults, the production line may be forced to shut down for maintenance of the equipment, repair costs, meanwhile, during shutdown period it would spend a lot of manpower and material resources. Along with higher concern and attention of national and enterprise for petrochemical equipment safety issues, in order to ensure smooth production, the task of corrosion and protection for petrochemical plant is becoming more and more important, and the demand of preservation of strategy research and the scientific mechanism of corrosion is very urgent.This paper was mainly on the corrosion study and mechanism analysis using ultrasonic thickness measurement technology in petrochemical plant, and a set of strategies for the preservation was made out. The atmospheric and vacuum distillation units in Daqing Petrochemical Company was as a case for the study, including the observation of external morphology, thickness measurement in different parts of the equipment, and scraping the samples of the corrosion products on the surface of metal equipment. Elements analysis, physical and chemical characterization methods were used for analyzing the samples. According to the comparison of analysis results, confirmed the degree and reasons of the corrosion of equipment, and extracted corresponding corrosion mechanism. In the aspect of corrosion protection technology, raw materials, water, preservative agent and corrosion medium were all need to study in detail, and made out solutions for the protection scheme. As for the corrosion loop, oil phase, water corrosion, high temperature, medium temperature, low temperature corrosion were all studied in detail, too. And then we selected the most serious corrosion place as representation to make preservation strategy. Eventually, the overall strategy system was applied in the actual production process, and achieved good results.