Research On Erosion For Catalysing-Cracking Oil System

For the cracking failure and leaking caused by erosion destruction, the typical petrochemical pipe was regarded as the main investigated object in the paper . The leaking cause and mechanism analysis was given based on the two-phase flow for the pipe brushing-erosion, and the computational simulation was focused on main pipe piece.The cause of leaking, brushing-erosion mechanism of idiografic pipe piece, forecast dangerous point and regulations between petrochemical pipes'erosion destruction and working or structure condition were studied in the paper as the emphases.First, the disabled case elbow and piping tee were studied.The thickness of pipe was measured and metallography structure was analysis by metallography test, further, eroding comeout was checked out by electrical scaning. It was found that leaking cause included stress erosion,chemical erosion and liquid dynamics factors.Thereinto, liquid dynamics factors were emphases of the paper.Therefor,two-phase model building and computational simulation were based on the dangerous pipe piece which was always to cause leaking in the Third Catalysing-cracking System, and model building and computational simulation method were given in the paper. While, the computational simulation for elbow,piping tee and valve puted in practice in different condition, for example,work condition,parameter and structure,then sum up the regulation of brushing-invalidation for each pipe.The computational simulation showed that velocity, inside diameter ratio,valve open rate and valve inside diameter were the main factors of brushing-invalidation,please consider them for effect adequately when they change,and avoid the guard point appearing for work condition in practice.Last, it was summed up that two-side wall of elbow was dangerous point caused by brushing-invalidation.The paper tried to bring forward improved project that blind piping tee was used instead of elbow to weaken brushing-invalidation, and the elbow and blind piping tee were compared in main factors through computational simulation to analyse feasibility . The computational simulation result showed that the effect of inproved project was distinct to protect unsubstantial point of elbow.The above research production is in accordance with the phenomena of disabled case and can explain the erosion mechanism and effect of factor reasonably. This indicate that the method with CFD simulation can effectively reveal the mechanism of the erosion destruction which occurred in the petrochemical pipe under the condition of two-phase flow.The conclusion is able to direct the actual fixed-point check and structures betterment competently.