Microwave Drying Characteristics and Kinetics of Yellow phosphorus-like material

In this paper, the effects of initial mass, initial moisture content, and microwave power on the drying process were investigated, and microwave drying experiments were carried out on materials using microwave drying technology. The effects of different initial mass, moisture content, and microwave power on the drying characteristics of the materials were explored, and the microwave drying efficiency (η) and unit energy consumption (Qs) were calculated under different conditions. The results show that with an increase in initial mass and initial moisture content, the microwave drying efficiency (η) increases and the unit energy consumption (Qs) decreases. However, with the increase in microwave power, the microwave drying efficiency (η) gradually decreased and the unit energy consumption (Qs) gradually increased. When the initial mass is 50 g, the initial moisture content is 40%, and the microwave power is 360 W, the microwave drying efficiency (η) is the largest and the unit energy consumption (Qs) is the lowest. Therefore, the initial mass and initial moisture content can be increased appropriately, and the microwave power can be reduced to improve the microwave drying efficiency (η) and reduce the unit energy consumption (Qs) to achieve the purpose of energy saving. Four thin-layer drying kinetic models were used to fit the relevant experimental data, and the results showed that Modified Page was most suitable for describing the material microwave drying process. The surface diffusion coefficients of water molecules under different conditions were also calculated, and the activation energy was further calculated through the diffusion coefficients. The maximum diffusion coefficient was 1.29×10-10 m2·s-1 for an initial mass of 40 g. The maximum diffusion coefficient was 1.53×10-10 m2·s-1 for an initial moisture content of 30%, and the maximum diffusion coefficient was 1.64×10-10 m2·s-1 for a microwave power of 900 W. The activation energy was calculated to be 5.95 W·g-1. COMSOL was used to model the microwave electric field strength and tangential resistance loss at 2.45 GHz for a range of power levels and layer thicknesses. The findings demonstrate that when microwave power increases, the electric field strength rises as well, from 8.13×104 V·m-1 to 9.96×104 V·m-1 and finally to 1.15×104 V·m-1. The electric field distribution in the cavity is more uniform, and the field strengths at the microwave feeder and the X-Y plane are higher. As layer thickness grows, the electric field strength rises as well, from 5.89×104 V·m-1 to 5.99×104 V·m-1 and finally to 8.13×104 V·m-1. It demonstrates how the microwave field intensity is affected by varying microwave powers and layer thicknesses. The temperature difference and temperature field distribution can be displayed by the temperature field simulation of materials with varying layer thicknesses under various microwave power settings.