Investigation Of Hydrodynamic And Heat-Transfer Characteristic In Fluidized-Moving Combination Bed

Fluidized-moving combination bed is combining fluidized bed with moving bed, t ake full advantage of high efficient heat transfer of fluidized bed and continuous oper ation. The article studies on and analyzes the hydrodynamic and heat transfer of comb ination bed by experiment.At first, study on hydrodynamic and heat transfer by using glass beads, investigat ing the classification and heat transfer of combination bed on the basis of fluidization condition and heat transfer coefficients. In experiment, research on the hydrodynamic o f glass beads in terms of particle size, bed height, classification efficiency, fluidization velocity factors. Fluidization velocity increase with the increase of particle size, pressu re drop increase with the bed height. Along with the increase of gas velocity, classific ation efficiency will reach the maximum. At some extend, increasing with gas velocity, there is an exponential growth in elutriation, but classification efficiency decrease. In heat transfer experiment, research on the gas-solid heat transfer coefficient in terms of gas velocity, air temperature, particle size and bed height. Gas-solid heat transfer empi rical equation is obtained by orthogonal analyses on the data of heat transfer experime nt in fluidized-moving combination bed:Fluidization part:Moving part:On the basis of experiments with glass beads, carry on drying experiments with c oal. From the aspects of operating air velocity, the temperature of air flow and bed m ovement rate, investigate the coal drying process. There are constant rate stage and de celerated stage in coal drying, temperature of coal has smaller change in constant stag e. With the increase of air inlet temperature and operate velocity, the drying velocity of combination bed is accelerated. Equilibrium moisture content has the difference und er the different temperature and gas velocity. When air temperature is 120℃ and flow rate is 24m3/h, critical moisture content of coal is at around 2%.