Numerical Simulation Based on Low-Temperature Sludge Drying Test
Drying treatment can effectively reduce the amount of sludge,and low-temperature drying technology has attracted much attention in the field of sludge treatment with the advantages of low energy consumption and low pollution.The changes of specific volume and porosity during sludge drying were investigated through experiments,and a mathematical model was established to carry out numerical simulation of sludge drying.In this paper,the drying characteristics in the sludge drying process were described,the influencing factors of sludge drying were studied,and the flipping situation of sludge in the actual drying process was discussed.The results showed that the simulation results after considering the volume shrinkage were closer to the real situation,and the influencing factors of sludge drying such as moisture content,solar radiation intensity and humidity had a significant effect,while the influence of wind speed and temperature was relative small.The drying conditions directly affected the moisture content distribution of the sludge.When the drying was violent,the moisture distribution of the sludge was uneven and the phenomenon of"evaporation front"appears,while moisture of the sludge was evenly distributed when the drying rate was small.The distribution of moisture determines the frequency of sludge flipping.The more uneven moisture distribution was,the more obvious the effect of flipping on drying was.
low temperature sludge dryingnumerical simulationinfluence factordrying characteristicsmoisture content distribution