Experiment And Mathematical Model Research On The Flow Of Granular Materials In Packed Bed

The phenomenon of material flow is widely exist in the material manufacturing process. Such as, rare earth oxides oxide preparation and the shaft furnace and blast furnace process of the steel material preparation. The material flow phenomenon in the shaft furnace is closely related to the operating performance, the production efficiency and the quality of the product of the shaft furnace. Master the rule of the material flow is very important to realize the characteristics, operating and controlling of the reactor. Study the material flow at the indoor temperature is the foundation to know the rule of the material flow in the shaft furnace. This paper mainly took experimental and mathematical model study on the material flow in the quasi-two-dimensional packed-bed.The tracer particles on different residence time of contour line plot out the steady material flow field of the center and eccentric discharge experiment. And studied the discharging speed takes effect to the material flow field. The new model based on proper material flow apparent driving force, material flow resistance and the viscous force of material flow, set up a new model which could be used to research two-dimensional steady flow field of granular material flow. Using the SIMPLE algorithm to solve the new numerical model equation in disunion type. And verify the reliability of the new model with the experiment results.The results of experimental and theory as follows:(1) There is obvious flowing area and stagnant zone in the packed-bed. The distribution of lateral velocity on any level height the material flow is not uniform. The material flow along the vertical line of the outlet is faster in center discharge experiment. In the eccentric discharge experiment, there is obvious boundary layer of material flow phenomenon close to the wall. The shape of flowing area isn’t change with the variation of the discharge flow.(2) The expression of the apparent driving force on the volume force direction reflect that the material flow field have a strong bearing corresponding relations with the volume force field and the co-existence of the flowing area and the stagnant zone. The expression of the material flow resistance shows that the material apparent velocity increases, the material liquidity becoming better. That means the status of material flows maintaining by inertial becomes stronger.(3) The new model predicted the flowing area and stagnant zone successfully, and the boundary layer of material flow in eccentric discharging. The results of numerical calculation well conform to the results experiment. This paper established a continuum model. Compare with other mathematical models, continuum model have a good further development space. Lay the foundation for the next step to researching the gas-solid two phase coupling in the packed-bed, the phenomenon of material flow bypassing obstacles and the unsteady discharging.In this paper, the research work provides a relatively simple mathematical simulation method to understand the rule of granular material, and provides a possible means to study the simulation and optimization of shaft furnace and blast furnace in the further.