Numerical Simulation Of The Drying Process Of Typical MSW Matrix On Incinerator-like Conditions

Waste incineration is an effective processing method for waste endlessly, which can rapidly radioes the volume and mass of waste and make waste innoxious. The drying process of waste is important, because water in waste would reduce its caloric and buring efficiency.Two diffrent mathematical models have been chosen to solve the heat and mass transfer equations for convective drying of biologic-waste and abiological-waste.In biologic-waste model, heat and mass transfer inside the waste as well as between the waste and hot air is studied according to the similarity between waste and porous media. The model takes into account shrinkage of material , and moisture content and shrinkage dependant effective diffusivity. Moisture content, temperature , drying speed and shrinkage speed have been described by the model. It can be seen that when drying temperature changes by every 20℃, drying speed of the biologic-waste will be 1.25 times of the inicial; shrinkage speed will be 1.27 times of the inicial, and drying speed of the abiological-waste will be 1.3 times of the inicial. Maximal drying speed of the inner nodes will appear later than the outside ones. Different kinds of biologic-waste have some same characteristics during drying. Biologic-waste which has lower capillary pressure and moisture content will be good for drying . When takes shrinkage into account, the error of the moddle will only be 46.43% as the non-shringkage moddle . The shrinkage will at first arrest the drying process. When it comes into speed-decline period, shrinkage will accelerate drying.Radiation coefficient of potato slices and watermelon peel both change from 10 W/m²Â·K to 17 W/m²Â·K. When drying temperature changes by every 20℃, h_sh will change by 1.4 W/m²Â·K. Radiation coefficient has more infection in watermelon peel than potato slices and wet cardboard.This paper summarized 100℃～200℃nondimensional relationship between M and b/b₀ of potato slices. It can be showen that temperature has little effect on this nondimensional relationship.