Application Of Microwave Fluidized Bed In Grain Drying

A microwave fluidized bed is a fluidized bed with a microwave heating device in the body range.Both its heater and mass transfer performance are improved.Microwave fluidized bed drying combines the advantages of fluidized bed drying and microwave drying,Can get good quality product with low energy-consuming.B Experiments in this paper were carried out in a microwave fluidized bed withΦ（140）,with rice as the research object,the intermittent drying mode,the fluidized bed drying and microwave fluidized bed drying experiments.The effects of the inlet temperature,microwave power density,fluidized gas velocity and other parameters on the drying time,the condition of the explosive waist and the energy consumption of the unit were studied by single factor experiment.The optimum technological conditions for the combined drying of rice paddy microwave fluidized bed were studied by orthogonal experiment.Based on the experimental data combined with the theory of drying kinetics,the combined drying kinetics of rice paddy microwave fluidized bed was studied,and the optimum drying kinetics model was selected.The experimental results show that the influence of inlet temperature,microwave output power density and fluidized gas velocity on rice drying process is significant.Compared with traditional fluidized bed drying,microwave fluidized bed drying can greatly improve the drying rate and the quality of drying products,and reduce the energy consumption of unit dehumidification in the drying process to a certain extent.With the drying time,waist blasting capacity,unit energy consumption for the comprehensive evaluation index of rice combination microwave fluidized bed dry optimum process conditions is the inlet air temperature of 70℃,the microwave output power density of 1.375 W/g,fluidizing gas velocity 1.62 m/s;The drying processcanbeexpressedinthediffusionmodel,MR=exp[-π²D₀/r₀²exp（Ea/RT）],D₀=0.041 m²/s,r₀=0.0193 m,The relationship between microwave power density P and dry activation energy in experimental conditions can be expressed as Ea=Ea₀(1-0.27P^0.34).Compared with the conventional fluidized bed equipment,microwave fluidized bed under the condition of low microwave power density,can make drying activation energy is reduced by 2.3%³%,the drying time reduced by 18%²4%.This model can be used to simulate the variation of rice moisture over time in the range of this research.