Experimental and modeling study of RDX in a novel continuous dryer

The drying of energetic materials is an essential and hazardous process involving complicated heat and mass transfer. In this paper, the drying properties of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) are investigated using a novel developed continuous dryer which can be applied for the drying of both hazardous powders and ordinary powders. The results reveal that a distinct falling rate period occurs following a short increasing rate period with no any constant rate drying period, greatly shortening the drying time. Ten different thin-drying mathematical models are tested by the drying curve fitting and Midilli-Kucuk model with the higher R, EF and the lower MBE, RMSE and χ 2 is selected as the most adequate model for describing the thin layer drying of RDX. Effective moisture diffusivities are in the range of 3.16 × 10−8–3.46 × 10−8 m2/s. It is confirmed that drying monitoring values are well inside the security perimeter with lower temperature (less than 90 °C), electrostatic charge (at a desired level) and dust (reduced by 85.6%). Compared to the original static tray drying, the continuous drying of RDX in the novel dryer exhibits a great superiority for energy saving and cost saving with the falls of 59.7% and 13.7% respectively.