CFD Simulation And Experimental Study On Fluidization Velocity Of Bubbling Fluidized Beds With Iron Ore Fines

Ironmaking process longer rely coke and high energy consumption and seriousenvironmental pollution. With increasingly scarce and increasingly stringentenvironmental requirements of coking coal resources can be used directly in thefluidized bed reactor powder ore more attention and become one of the importantdirections of development of low-carbon ironmaking technology.gradually attractingwide attention. Among various non-blast furnace iron-making processes, the fluidizedbed reavtor technology is likely to be an important future development direction fordirect iron reduction because of its direct use of fines ores.Firstly, the establishment of a fluidized bed cold model experimental apparatus andexperimental systems; comparison hydrodynamic characteristic of iron ore particles andglass beads with class B in bubbling fluidized bed. Studied the pressure drop at differentsuperficial gas velocity and bubble dynamics behavioral characteristics in iron ore andglass beads bubbling bed bed, Class B discovered iron ore particles and glass beadsgeneral nature of the bubbling fluidized bed similarities and differences, as well as ironore particles easily pulverization phenomenon. Experienced initial fluidization(microbubble layer formed on the surface of the bed, with the superficial gas velocitygradually increases and down), the transition fluidization (distribution of bubblesformed on the surface plate, grown to increased fracture surface) and stable fluidization(bubble generation, grew to rupture cyclical changes) in three stages;pulverization for iron ore in bubbling fluidized bed experiments, andnon-spherical particles of iron ore, based on the experimental methods and empiricalformula to determine the minimum fluidization velocity and the traditional fullfluidization velocity, it can not accurately predict iron ore bubbling fluidized bed criticalvelocity, Therefore, this paper base on bed pressure drop diagram of partial pressurefluctuation analysis and related gas velocity obtained under experimental method fordetermining iron ore bubbling fluidized bed critical velocity judged on the basis oftraditional experimental methods, relevant experience while using predictive formula aphased basis to redefine the critical flow velocity (including the initial flow rate and thesteady flow velocity) is calculated critical parameter calculation methods and formulasof transition flow velocity (Grace formula), and gives consideration pulverizationcalculation methods such as particle size bed impact equivalent; using Brazilian and Australian iron ore slag bubbling bed different sizes were applied and experimentalvalidation of critical flow velocity is calculated, to achieve the desired effect;Consider the reality of the particle size distribution of the particles in the reactoriron ore, were studied experimentally wide particle size distribution on thecharacteristics of bubbling fluidized bed of particles of different proportions of the ClassB mix different size ranges, and B, D mixed in different proportions of two kinds ofparticles of different particle size and the nature of the two Brazilian and Australian ironore slag bubbling bed study results show that: iron ore bubbling fluidized bed features awide particle size distribution fluidization characteristics of fine particles in addition toa high proportion of minority groups have mixed differences, class B mixed groups offluidized particles other features with a single particle of iron ore bubbling fluidized bedcharacteristics were similar, indicating that the iron ore pink bubbling bed mainlynon-wide particle size distribution of the particles spherical shaped bed features as itsbasic characteristics fluidized; critical flow velocity while the modified formula is alsosuitable for predicting the particle size of the iron ore mixed bubbling bed critical flowvelocity.On the basis of experimental studies on the combination of characteristics of ironore bubbling fluidized bed, a mathematical model based on iron ore bubbling bed Fluentsoftware, through the bubbling bed mathematical model of iron ore recovery factor anddrag function important parameters such as research, the introduction of a customfunction optimization model, and the time step, meshing, optimization, etc.; value ofiron ore bubbling fluidized bed initial phase and the steady flow stage fluidized processthe simulation results are consistent with the experimental results, and numericalsimulation of the behavior characteristics of bubbles and solid particles velocity vectoris also associated with literature findings have the same law, the validity of themathematical model describes the method established in order to further explore theiron ore bubbling bed two-phase flow characteristics of the powder, a reactor designedto provide a means.