Computational fluid dynamics (CFD) analysis of pipeline in the food pellets cooling system

Pellet cooling-drying machine with a pneumatic conveying system is used to transfer heat and moisture of hot and moist pellets in the food and animal feed plants. During heat transfer along the pipeline, very fine pellets and flour is sucked in to the pipe and settling phenomenon is accrued. The sediment of fine particles and pellets leads to the erosion and wear in the pipeline especially at the warm and humid condition. In the present research, the reported problem in Faradane Feed Processing Company, consisting of the erosion of facilities and settling in the pipeline of pellet cooling-drying system was analyzed. A computational fluid dynamics modeling (CFD) based on the Euler-Euler method was developed to investigate the particle distribution and settling inside the vertical and horizontal pipeline as a function of pipeline diameter, particle size, flow velocity, and inlet volume fraction of particles. The results indicated that, the particle sediment along the vertical pipeline was lower than the horizontal pipeline and particle size had the greatest influence on the distribution and position of settling. Increasing of particle size from 62 μm to 250 μm was leaded to the rise in the particle sediment up to 54%.