Study Of Flow Characteristic In Liquid-Solid Fluidized Bed With Uniform Magnetic Field

Liquid-solid fluidized bed with a good heat transfer, mass transfer and liquid-solid mixing and other characteristics, has been used in metallurgy and mining, wastewater treatment, and pharmaceutical production, biotechnology and chemical fields have very good application. But the liquid-solid two-phase flow in fluidized bed is complexity of the structure, not a sound theory to a detailed description of the fluidized bed properties of liquid-solid two-phase flow.The flow characteristics for the liquid-solid fluidized bed is stuided by means of Eulerian two-fluid model, to simulate the macro order of magnitude for granular, but can not track the particles motion information in detail. The Euler-Lagrange model is with solid particles for a discrete phase and the liquid as the continuous phase, through the numerical solution of the Lagrange coordinates for the movement of discrete particles and the Euler coordinates for the movement of liquid. Discrete particle model is to describe the macroscopic state of the flow field, and can be traced the particle-particle collision to simulate the interaction between particles.This paper introduces the liquid-solid fluidized bed under the external magnetic field. Discrete element model (DEM) is introduced into the numerical simulation of liquid-solid two-phase flow. Computational fluid dynamics method, soft sphere model of particles are discussed with the coupling between the two phases taking into account the external uniform magnetic field on the mechanical model of particle impact. The magnetic field in the liquid-solid two-phase flow model is established. Using the above simulation apparoch, a hydroynamics of liquid-solid fluidized bed is simulated to understand the typical flow phenomena.Consider the impact of lubrication force, the instantaneous distributions, particle concentration, particle trajectory, bed layer expansion height, pressure drop in a liquid-solid fluidized bed are simulate. The influence of superficial liquid velocity, liquid viscosity, liquid density, particle density, particle size and other conditions on the particle velocity and liquid velocity variations are studied.The liquid-solid two-phase flow characteristics are studied in a liquid-solid fluidized bed flow at the external uniform magnetic force with the axial and transverse uniform magnetic field. By changing the magnetic field strength and the ratio of non-magnetic the distribution of particles is studied within the bed. The concentration and velocity is predicted at the different voltage variations, temperature and other parameters, and the mechanical analysis of magnetic particles is peformed. Simulations show that the magnetic field affects the motion of magnetic particles within the bed, and is linked into a flux. With the increase of magnetic field strength, the flux gradually becames longer and the velocity is decreased. The drag force of gas-particles is dominated by the subject gradually transformed into particles, which hindered the movement of particles.