Study On Flow Erosion Characteristics Of Salt Mud In Horizontal 316L Bend

The brine purification process in industrial salt production will produce salt sludge.The direct discharge of salt sludge will pollute the environment and waste resources,and it is necessary to carry out harmless resource treatment of salt sludge.The salt slurry treatment process relies on pipeline transportation.Due to the high solid content of salt slurry,the salt slurry flowing through the elbow will have an erosion effect on the elbow.In this paper,the horizontal layout of 316 L elbow is taken as the research object to study the erosion characteristics of the elbow when transporting salt slurry.The main work of this paper is as follows :(1)The simulation model of salt mud flow in the horizontal elbow was established to simulate the flow field and motion trajectory of salt mud particles in the elbow.It was found that the pressure outside the elbow was large and the pressure inside the elbow was small,while the velocity field was opposite.The first collision between salt mud particles and the inner wall of the elbow is at the outlet section outside the elbow,and some particles will collide twice or even three times after the first collision with the wall.(2)E/CRC wall erosion model and Grant and Tabaoff wall collision recovery function were used to explore the erosion rate of salt mud particles on the inner wall of horizontal 316 L elbow.It is found that the most serious erosion of salt mud on the inner wall of the elbow is also at the outlet section outside the elbow,especially near the elbow angle of20° from the outlet.(3)To explore the influence of different single factor changes on the inner wall of salt mud erosion elbow.The results show that the erosion rate increases with the increase of conveying speed,particle mass flow rate and elbow bending angle,and decreases with the increase of elbow diameter and elbow bending diameter ratio.When the particle size of salt mud increases gradually,the erosion degree of salt mud on the inner wall of elbow will first increase and then decrease.(4)By using the orthogonal experimental analysis method,the influence order of multi-factors on the inner wall rate of salt mud erosion elbow was obtained : elbow diameter > salt mud flow rate,particle mass flow rate > salt mud particle size > elbow diameter ratio.(5)The experimental platform is built using the existing experimental equipment to verify the feasibility of the numerical simulation.The multi-point thickness reduction rate of the inner wall of the tube in multiple normal planes of the central line of the elbow was measured,and the interference of salt mud on the corrosion and thickness reduction of the inner wall of the elbow was eliminated through the weight loss method test to obtain the erosion amount of the corresponding parts.The maximum error rate between the simulation value and the experimental value was 20.09%,which verified the reliability of the erosion numerical simulation.The research results of this paper can provide basis for the design of salt slurry pipeline transportation system,and provide reference for the use and maintenance of pipeline system.