1. General information on silo flow

Technologically speaking, a silo is one of the simplest devices imaginable for storing bulk products. It consists of an often cylindrical tank, mounted on a section of reduced cross-section in the shape of an inverted conical or pyramidal segment (figure 1 ). At the base of this section, called the discharge hopper or hopper, is an opening for product extraction. Industrial silos come in a wide range of sizes. Their diameter can vary from one metre to several dozen metres, and the height/diameter ratio from 1 to 10 (or even more).