The extensive analysis and study of metallurgy, performance, operating conditions, corrosion forms, corrosion products of the failed tubes of vacuum furnace in atmospheric-vacuum distillation unit have located the corrosion media and corrosion causes of large scale corrosion of tube wall.

The main conditions and measures of deep-cut technology were discussed including the pressure of top vacuum tower,total pressure drop,outlet temperature of vaccum furnace et al in crude oil unit.

Through the effective control of converter profile and charge material design,optimization of oxygen nozzles parameters and analysis and summarization of converter operation, the problem of splashing has been basically resolved.