Study On Delamination Of Particle System In Liquid Under Vibration Condition

Granular materials can be seen everywhere in nature and in our production and life which have great scientific research value and practical application value.There are many researches on particle systems,such as the capillary effect of particles,the migration of particles in a vibrating U-shaped tube,and the phenomenon of particle size separation.The more common phenomenon of particle size separation mainly includes Brazil nut(BNE)separation,anti-Brazil nut(RBNE)separation and so on.The research on particle size separation mainly focuses on two aspects.One is to find out various factors that affect its separation efficiency through experiments and numerical calculations;the other is to explore the internal mechanism that leads to its separation from the perspective of its separation mechanism.However,most of the research on particle systems is aimed at the particle system in the air,and the research on the mixed system composed of liquid and particles is rarely involved.In many scenarios,the application of the combination of liquid and particle systems is involved,such as mudslides and the application of drilling vibrating screen in industrial production.Therefore,it has important engineering application value for the research of particle system in liquid.This article takes the application of drilling vibrating screen in industry as the background,and will study the movement of the particle system in the liquid under the action of external excitation force.This article will study the motion state of the particle system in the liquid through a combination of theory and experiment.First,analyze the force of a single particle in the liquid,and find out the main influencing factors of the force of a particle in the liquid.Then,experiments are used to study the movement layering law of the particle system in the liquid,and a set of comparative experiments are set up to explore the similarities and differences between the particle system in the air and the particle system with clean water under the same conditions.It was found that the particle system in the air will present three phases of Brazil nut layering,vertical Brazil nut,and mixed during the process of changing the external vibration frequency and acceleration,while the binary mixed particles in the water change with the vibration frequency and acceleration,but there is no size segregation.In order to continue to explore the influence of the law of particle system movement in the liquid by those factors,suitable experimental materials were selected,and the single variable method was used to explore the influence of the particle size ratio,the density ratio and the viscosity of the liquid on the movement of the particle system.Through the observation of the experimental process and the recorded data to make the f-Γ phase diagram,analysis found that under the experimental conditions,the larger the particle size ratio of small particles,the more obvious the leakage of small particles,and the particles are more prone to size separation.The larger the density ratio of the large and small particles,the more unfavorable the size separation of the particles.The greater the viscosity of the liquid,the greater the viscous resistance of the liquid when the particles move,and therefore the more difficult it is for the particles to form a size separation.