Particles flowing process across aligned tubes in a moving bed

Many solid particles in industrial processes require heating or cooling, such as calcinated petroleum coke, blast furnace slag, and steel slag. A moving bed with tubes is a viable design for facilitating such complex heat transfer processes. As particles are the primary heat carriers in this flow, the flow pattern of particles across the tubes in a moving bed is the main determinant of the heattransfer mechanism. The characteristics of particle flows across a tube structure are vastly different from those of a continuous-medium flow. Therefore, the flow pattern of particles moving across a bed of tubes must be studied prior to the heat-transfer mechanism. A simple pseudo-funnel flow model that can calculate parameters such as velocity field and residence time was established in this study for particle-flow modeling, and the range of parameters required to describe particles flowing across tubes was discussed. Using a movingbed test device made of transparent PMMA material, the flow of particles across aligned tubes banks was measured and a set of experimental results were obtained. Simultaneously, the discrete element method (DEM) was used for numerical simulations of the particleflow distribution in the system, and the obtained results were compared and verified by experimental results. Computational results from the quasi-funnel flow model were then compared with the DEM numerical simulation results to find the set of parameters required to describe particles flowing across aligned tube banks in the pseudo-funnel flow model. By setting appropriate values of the abovementioned parameters, the relative error between the two models could be reduced to 3%. This study provides a foundation for future studies on heat transfer processes in moving granular beds and the design and optimization of similar heat exchange devices.