3D Flexible Ribbon Chain Model for Simulating Dynamic Behaviors of Flexible Ribbon Particles in a Pneumatic Conveying Dryer

Abstract

The pneumatic conveying drying process is widely used due to the high mass-and heat-transfer efficiency between the gas and solid phases, large dehydration rate, and wide range of operation conditions. The flexible ribbon particles are often involved in the pneumatic conveying drying of agricultural products, food, and biological products. These types of particles are easy to hold together due to the flexibility and the nonuniformity of ribbon shape. It is important to understand the dynamic behaviors of flexible ribbon particles in a pneumatic conveying dryer. Therefore, research on flexible ribbon particles in a pneumatic conveying dryer is necessary. However, previous studies were scarcely concerned about the particle of this special type. The flexible ribbon particles in the gas−solid fluidized bed would exist in the form of single discrete particles or clusters. Moreover, the hydrodynamic characteristics were impacted by the inhomogeneity of particle flow, which affected the performance of the pneumatic conveying dryer. In this paper, the flexible ribbon chain model was proposed, and the 3D flexible ribbon particle computing method with GPU was established. The dynamic behavior of the flexible ribbon particles was investigated in a pneumatic conveying dryer. Specially, the effects of particle flow rate, superficial gas velocity, and other parameters on the dynamic behavior of flexible ribbon particles were analyzed. The experimental verification was also performed by a fluidization test of cut tobacco particles. The results provide guidance for the further study of ribbon particles.