For the phenomenon of widespread and serious cavitation damage in the throttling section of pressure reducing valve under high temperature and high pressure in the chemical technology process of petroleum and coal, according to actual coordination structure widely applied between the valve core and valve seat, the cavitation throttling section with symmetrical contraction and expansion was made, and the visualized cavitation water tunnel experimental apparatus was designed and constructed. The cavitation evolution process with time under different cavitation numbers σ was recorded by the highspeed photography, the variation law of cavitation damage length and area with time was investigated by using aluminum film as cavitation damage carrier. Based on the experimental cavitation characteristic length L*, the evaporation coefficient F v , and condensation coefficient F c in the Zwart-Gerber-Belamri cavitation numerical model were modified, and the cavitation damage region was predicted by the gas phase condensation rate of numerical simulation. The results show that with the decrease of cavitation number, the characteristic length of cavitation strip increases; the cavitation characteristic length fluctuates greatly at σ = 1.22, and there are cavitation cloud periodic formation, shedding, collapse, and disappearance at the tail of the cavitation strip on the upper valve seat; the cavitation damage length of the upper and lower valve seat remains unchanged with time, and the cavitation damage area increases approximately linearly with time; the initial position and length of cavitation damage predicted by the gas phase condensation rate are basically consistent with the experimental results, which verifies the accuracy of the modified numerical simulation.

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As the transportation pipeline of adsorbent in S Zorb regeneration system, due to large mass flow rate of particle and gas, it is often seriously worn, and even perforated, resulting in the leakage of adsorbent. It brings great inconvenience to the transportation of regenerated adsorbent and threats its long-term operation. Therefore, it is essential to study the erosion characteristic of Y-shaped adsorbent transportation pipe. It was studied by computational fluid dynamics (CFD) numerical simulation and the calculation results were validated by actual erosion profile. The results show that the high velocity of nitrogen and the high weight-fraction adsorbent particles accumulation is the key factor leading to severe erosion. It is also found that the small angle cutting is the erosion form. The effects of the intersection angle between the transportation pipe and feed pipe and the gas inlet velocity on the particle motion and erosion characteristics turn out to be significant. The research on the wear characteristics of adsorbent transportation pipeline can provide a certain reference for erosion prevention and optimization.