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.

Bubble cap structures are researched for the particle erosion wear of the distribution plate (tray for short) in an S Zorb desulfurization reactor. The semi-empirical model of erosion wear prediction of gas–solid two-phase flow is revised by means of erosion wear experiments at high temperature and high speed. According to the revised erosion wear, the influence of the h0 (the distance from the bottom of the bubble cap to the tray), h1 (distance from the outlet of the lifting pipe to the top of the bubble cap interface), N (the number of cavities), d0 (the inner diameter of bubble cap) on erosion wear of trays are studied. The results show that a smaller h0 will make the erosion degree of the tray more serious; it is recommended to keep h0 = 17 mm. A larger h1 will alleviate the erosion wear degree of adsorbent particles on the tray, but considering the efficiency of the reaction, h1 = 36 mm is more appropriate. The increase of N reduces the erosion wear less but enhances the fluid disturbance and makes the erosion wear area unstable; so, N should be kept at 10. The increase of d0 reduces the velocity and density of fluid impacting the tray, thus reducing the erosion wear degree, which is an effective means.

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.

In the process of petrochemical production, the catalyst particles in the hydraulic conveying pipeline often cause wear failure accidents due to collisions with wall. Compared with spherical particles, non-spherical particles' trajectory would be different due to its geometric shape, and thereby affecting the flow wear characteristics. In this paper, the shape of catalyst particle model with real aspect ratio was constructed by using multi-cluster method, and a CFD-DEM coupling method was adopted by considering the interaction between particle-particle and particle-wall. The study focuses on the effect of particle shape, radius of curvature and angle of bend in terms of the wear characteristics of liquid-solid two-phase flow. The results indicate that with the increase of the particle aspect ratio, the wear rate and the impact density of particles decrease while the impact velocity increases, the wear area of the elbow mainly distributes in the middle part of the outer wall, and its maximum position appears between 78° and 90° in polar coordinates; With the increase of pipe's curvature radius, the main wear area changes due to the direct collision and the sliding friction of the particles along the pipe wall, and its maximum wear rate shows a downward trend due to the reinforce of buffering effect; With the decrease of bending angle, The main wear area decrease because of the changes in particle flow patterns and it is mainly located in the center of the outer wall.