جستجوی مقالات مرتبط با کلیدواژه « erosion » در نشریات گروه « مکانیک »

As a common industrial valve solution in slurry pipeline systems, Y-type slurry valves must be designed with properly shaped valve seat sealing rings to alleviate particle erosion and keep the valve operating in optimal condition. In this study, we investigate four different valve seat shapes with varying inner angles to understand the effect of the seat structure on particle erosion in Y-type slurry valves. We conducted computation fluid dynamics discrete element method simulations to analyze the impact of different valve seat shapes on the characteristics of particle–liquid two-phase flows and erosion. We also performed a detailed analysis of velocity and pressure distributions for liquid phase and particle velocity distributions as well as surface erosion on key valve components. We observed the primary erosion areas to be the back surface of the valve body, the inner surface of the valve seat, and the front surface of the valve disc, and as a result, we investigated the erosion distribution in these areas with different valve seat structures. Our simulation results indicate that the variation in particle diameter and the inner angle of the valve seat sealing ring have significant impacts on erosion in the studied areas.

To address the issue of erosion in the control valves of blackwater flash systems in the coal chemical industry, this study investigates the dynamic erosion characteristics of one such control valve. Computational fluid dynamics is employed to compare the results obtained with a static mesh and an erosion-coupled dynamic mesh, and the valve erosion is investigated by analyzing the erosion rate, the particle impact velocity, trajectories and angle. Moreover, the relationship between the deformation caused by erosion and the dispersion of the flash vapor phase in the valve is studied, focusing on the flow resistance coefficient. The results indicate that over a period of 9 × 106 s, the impact velocity and subsequent collisions of particles reduce, and the impact angle decreases with the accumulated deformation of the valve core. Notably, the valve core is influenced primarily by the cutting that results from low impact angles, leading to a substantial decrease in the overall erosion rate of the valve, amounting to a reduction of 56.4%. The region facing the flow is at significant risk of erosion, and as the opening decreases, the erosion zone extends gradually to the annular region of the valve core and valve head, leading to increased erosion deformation. Furthermore, as the flow resistance coefficient decreases, so does the vapor volume fraction inside the valve. This study provides a theoretical basis for predicting faults and developing online monitoring solutions for high-differential-pressure control valves in blackwater flashing systems.

In the routine maintenance of each main pump in the oil transmission station plant, abnormal erosion wear was found at the flushing port of the mechanical seal of Sulzer pump casing. For the sake of stable and safe unit operation, this study explored the mechanism and process of erosion formation in the pump casing at the microscopic level using SEM (scanning electron microscope) and EDS (energy dispersive spectrometer) techniques. And ANSYS Fluent was used to numerically simulate the unconventional turbulent flow in the special location of Sulzer pump to obtain its flow field characteristics. The trajectory tracking of solid phase particles based on Finnie erosion model was also carried out to obtain the influence law of different particle sizes on the wear degree of each area of the pump casing, and to point out the influence of the motion behavior of particles at the flushing port position on the erosion. The results show that there is unconventional turbulence in the flushing port of the Sulzer pump mechanical seal, and the solid particles are affected by turbulent diffusion and fluid adhesion, and some particles deviate from the velocity direction and continuously impact the surface of the pump casing, which is the direct cause of the erosion wear here. By optimizing the location of the flushing port, severe erosion wear at the flushing port can be avoided. This study can provide guidance and recommendations for the production, operational stability and wear protection of Sulzer pumps.

Ball valve is one of valves that have many applications in industry especially in gas delivery systems. This kind of valve is categorized in the on - off flow control valve. This study aims to investigate unusual application of ball valve to control fluid flow in industry and its destructive effect including erosion of ball and body of valve. Simulation of industrial ball valve is done using ANSYS Fluent software and effect of erosion on it is investigated in different working conditions. In this article, working condition is performed regarding 2 different concentrations for suspended particles as well as four positions of ball in different angles. We assess the effect of increased particle diameter on the rate of erosion for three diameters (3.86e-6 m , 267.45e-6 m and 531.03e-6 m) in four conditions of valve (25%, 50%, 75% and 100%) and two different concentrations of particle (3% and 6%). It is shown that rate of erosion is increased with increased particle diameters in 25%, 50% and 75% open state of valve. On the contrary, the results show that opposite rule governs complete open state. Furthermore, it is demonstrated that increase in particle diameter decreases the area of erosion in four conditions of valve.

Ball valve is one of valves that have many applications in industry especially in gas delivery systems. This kind of valve is categorized in the on- off flow control valve. This study aims to investigate unusual application of ball valve to control fluid flow in the oil and gas industry and its destructive effect including erosion of ball and body of valve. Simulation of industrial ball valve is done using ANSYS Fluent software and effect of erosion on it is investigated in different working conditions. In this study, working condition is performed regarding 3 different concentrations for suspended particles as well as four positions of ball in different angles. It is shown that rate of erosion for 25% open state of valve is increased to about 15000 times of complete open state of valve, and rate of erosion is increased to about 3500 times for half open state (50% open state); and rate of erosion is increased to about 220 times for 75% open state of valve.

One of the most valid and efficient models of long rod projectile penetration in homogeneous targets is Tate and Alekseevskii’s (A&t) model. Based on Tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. The proposed collision speed-penetration depth diagrams are developed using Tate’s model. In this way, various collision speed-penetration depth diagrams for different projectile dynamic resistances and targets are calculated and the optimum speed envelope is derived. According to Tate’s diagrams, the increase of collision speed is not followed by the increase of penetration depth; instead, it causes erosion phenomenon to happen. The comparison of the resulted optimum penetration speeds and the available data confirms the findings. Speed and rigidity both have a positive impact on the increase of penetration depth. With the increase of speed, the erosion issue finds a higher significance due to the increase of pressure on the projectile tip. Therefore, higher speed and erosion are opposed to each other; for the case of Y>R, there are some maximum points which indicate the optimum reciprocity of the two mentioned factors to obtain a maximum penetration depth. In the present research, an equation is developed indicating the optimum speeds resulting in the maximum penetration rate in the case of Y>R. For the reciprocity of speed and erosion, the target resistance against an erosive projectile should be 4 to 5 fold higher than the same target resistance against a rigid projectile penetration. [1]