Experimental and Numerical Study of Silo Filling Using Pellets

Abstract

At present, different biological materials, agricultural crops or forest products are susceptible to be industriallytransformed to be used as solid biofuels. The most common presentation for these materials is in the form of pellets,whose storage is carried out mainly in hoppers, silos or bunkers. However, there is an important lack of knowledgeabout the mechanical behaviour of these stored materials, what causes difficulties in the structural silo design.Numerical models have proved to be a useful tool to analyse this phenomenon and even for the design of silos.However, numerical models need parameters that must be experimentally obtained and finally they must be validatedby experimental assays.The objective of this work is to present a finite element model developed by the authors to simulate the mechanicalbehaviour of pellets that have been stored in a silo. This model has been compared with the experimental resultsobtained using a real scale silo test.The experimental analysis was performed at the experimental station located at the University of León, designed andbuilt by Couto, Ruiz & Aguado (Couto et al., 2012; Ruiz et al., 2012). The parameters such: specific weight, modulus ofelasticity, internal friction angle, wall friction coefficient, angle of repose and Poisson’s ratio were determinedexperimentally.The numerical model was made in 3D, using Ansys 2021R1 software. For simulate the filling stage all nodes placedat the hopper shell of the silo were totally restricted. The behaviour of the pressures in the silo and hopper were verified,as well as the displacement of the grains and the directions of the main stresses.