Abstract: A method of fabricating a double-walled shell of fiber reinforced plastic material is by centrifuging. The outer wall of the shell is made by projecting glass fibers and resin in a liquid phase against an inside face of a cylindrical mold rotating about its horizontal axis. A section member is then applied against the inside face of the outer wall by a plurality of turns having a diameter substantially equal to the inside diameter of the outer wall and separated from one another by a distance substantially equal to the thickness of the outer wall. The section member has a channel section with a web and two flanges extending radially outward, defining a sealed helical duct. The space between the turns is filled with resin by centrifuging, forming a helical spacer, and the inner wall is formed by centrifuging.

Abstract: The invention relates to a method of fabricating double-walled shells of fiber reinforced plastic material by centrifuging, in which method the outer wall (18) is made by projecting glass fibers and resin in the liquid face against the inside face of a cylindrical mold (2) rotating about its axis (X) which is horizontal, the method being characterized by the fact that after the outer wall (18) of the shell (16) has been made, a metal section-member (21) constituted by a plurality of turns having a diameter substantially equal to the inside diameter of the outer wall (18) and separated from one another by a distance substantially equal to the thickness of the outer wall is applied against the inside face (18a) of said outer wall (18), said section member having a channel section with a web (22) and two flanges (23a, 23b) extending radially outwards, with their free edges penetrating into the material constituting said outer wall (18) so as to define a helical duct (20) that is sealed and that extends from one

Abstract: Devices for emptying a cylindrical or prismatic silo of ensilaged granular and/or pulverulent material, said devices embodying (a) a conical or pyramidal deflector, located at the lower part of silo, its axis 4 converging perceptibly with that of the silo, its apex directed upwards, and its base, together with interior silo wall, defining a horizontal annular corridor (b) at least one scraper which, guided by a drive system along and above the corridor, displaces the products toward a discharge outlet for the products, this outlet opening into the corridor through an opening located at a right angle with the zone swept by the scraper.