Smoldering of Storage Rice: Effect of Moldy Degree and Moisture Content

Rice, as one of the most valuable bio-resources, is combustible in nature, which poses an inevitable fire risk for the storage and transport processes. The propensity of rice mold could change the fire hazard and endangers the food security of human beings. In this work, the smoldering spread of normal rice, mildly and severely molded rice were studied under the forced opposed airflow. As the rice molding degree increased, the particle pore surface area increased to enhance the char oxidation. Consequently, the smoldering temperature was higher, the propagation rate became larger, and smoldering was more likely to transition to flame, showing a significant fire hazard and explosion risk. Results also showed that as the moisture content increased, both the smoldering temperature and the propensity to flaming increased, probably because of the increased airflow speed after the expansion of rice particles. This research proves that the molding degree has a significant impact on the fire risk and hazard of rice storage and drying process, thus helping provide a scientific guideline for the safe storage and transportation of rice.