Abstract: The invention relates to a cathode rod permitting extraction of the current from a cell for the production of aluminum by electrolysis according to the Hall-Heroult process, which is sealed in at least one groove which is open at the base of each of the carbonated blocks 1 forming the cathode of the electrolysis cell.According to the invention, the cathode rod 2 is extended by a metal sole 5 in electrical contact with the base of the carbonated blocks 1 over at least 20% of the total surface area of this base. The sole 5 is constituted by a metal sheet which is at least 4 mm thick and preferably at least 10 mm thick and is soldered to the cathode rod 2 before the carbonated block 1 is positioned in the cell.To prevent infiltration of electrolyte into the subcathode space, the lower face of the sole 5 is placed in a superimposed relationship and in electrical contact with a thick, continuous metal screen 26 arranged at the top of the thermally insulating lining.

Abstract: The invention relates to an electrolysis tank for production of aluminum by electrolysis of alumina dissolved in a molten cryolite bath, by the Hall-Heroult process, between at least a carbon anode and an aluminum sheet covering a carbon cathode substrate. At the interface of the aluminum sheet and molten cryolite bath it comprises a floating screen, which is conductive of electric current, not connected to the carbon cathode substrate and free to move at least in the vertical direction.The floating conductive screen can extend over the entire interface or be limited to being perpendicular to each anode.The distance between each anode and the floating conductive screen can be reduced to about 20 mm.

Abstract: The invention concerns floating cathode elements which are intended for the electrolytic production of aluminum using the Hall-Heroult process in an electrolysis tank comprising a molten cryolite-base bath, between a carbon anode, and a cathodic layer of molten aluminum, said elements comprising at least one active cathode element (30) formed of electrically conductive refractory material such as titanium diboride and supported by an intermediate support (31) which is inert with respect to the liquid aluminum and the electrolyte, the mean relative density of the assembly of the acitve cathode element and the inert intermediate support being lower than the relative density of the liquid aluminum under the normal conditions of operation of the electrolysis tank.

Abstract: A subcathodic shield for use with Hall-Heroult electrolysis cells. The shield, which is located below the carbonaceous blocks which make up the cathode, and above the cell housing, comprises at least one continuous steel sheet at least 5 mm thick extending substantially over the total area between the base of the cathode and the base of the housing, and which has at least one deformable zone for absorbing thermal stresses caused by differences in temperatures between the shield section situated below the central area of the cathode and the shield section situated below the peripheral areas of the cathode.

Abstract: A recovery-type furnace for the indirect transfer of heat between two gaseous fluids flowing in opposite directions comprises two heat exchanging units which function alternately as a heating and a heated unit and which operate on a reversing cycle of a few seconds to several minutes. Each exchanging unit is packed with at least one bed of ceramic particles that rest on a metal or ceramic support. The direction of gas flow is controlled by reversing devices so that the hot gaseous fluid flows to the top of the particle bed of the heated unit and, upon cooling, passes through the bed support and from the bottom of the particle bed downwardly through the unit.

Abstract: The present invention relates to relaxing furniture particularly for the ventral and/or dorsal decubitus comprising a rest surface which is substantially flat and adapted to receive the body in stretched out position and comprising, in a zone substantially situated in the upper part of its middle third, a swell which is adapted to support the periumbilical and subumbilical zones. The invention is more particularly applied to a piece of garden or beach furniture.