Pretreatment process for improving the filling of a chamber with solid particles

A pretreatment process for improving the filling of a chamber with solid particles, comprising mixing said solid particles, before loading of said solid particles into the chamber, with at least one lubricant that is solid at ambient temperature chosen from saturated fatty acids having 14 or more carbon atoms, metal salts of saturated fatty acids having 14 or more carbon atoms, esters of fatty acids having 14 or more carbon atoms, fatty alcohols having 14 or more carbon atoms, linear N-alkanes having 16 or more carbon atoms in solid form, fumaric acid, talc or sodium stearoyl fumarate, the lubricant being introduced at a content of between 0.01% and 1% relative to the total weight of the mixture of solid particles and lubricant, and then loading the solid particles mixed with lubricant into the chamber, the loading being carried out manually with the aid of a flexible hose or the loading being carried out with the aid of a functional device internal to the chamber which may be introduced into and/or withdrawn from said chamber.