Apparatus for gas collection in aluminum smelting furnaces

Abstract

A gas collection apparatus for use in electrical smelting furnaces, especially those for the production of aluminum is disclosed. The apparatus comprises a substantially annular body positioned beyond the outer circumference of the furnace at its lower edge and tapering towards the anode carrier at its upper edge. A space at the bottom is left between the wall of the gas collection apparatus and the furnace to permit introduction of air resulting in a chimney effect in the gas collecting apparatus of the present invention.

What is claimed is: 
     
       1. In an electric smelting furnace for the melt electrolytic production of aluminum including a furnace .[.post.]. .Iadd.pot .Iaddend.having an .[.annular.]. outer side wall and .[.generally cylindrical.]. anode section disposed above the furnace pot and being of lesser .[.diameter.]. .Iadd.dimensions .Iaddend.than the .[.diameter.]. .Iadd.dimensions .Iaddend.of the furnace pot the improvement comprising .[.an annular.]. .Iadd.a .Iaddend.gas collecting hood, said gas collecting hood comprising upper and lower portions each of which comprises a plurality of sections and each plurality of sections in combination forming .[.an annular.]. .Iadd.a closed .Iaddend.shape and each said section of each plurality of sections being movable with respect to any other section independently of the other to permit access to said furnace pot, each of said sections in the lower portion having a slope upwardly towards the anode section and the lower end of the lower portion being of greater  .[.diameter.]. .Iadd.dimensions .Iaddend.than the .[.diameter.]. .Iadd.dimensions .Iaddend.of the outer wall of the furnace pot and being spaced .[.radially.]. outward from the outer wall of the furnace pot to permit entry of air, the upper portion being disposed at least in part .[.radially.]. outward from the anode section and being spaced along its length from the anode section to permit upward egress of gases evolved from the smelting process. 
     
     
       2. The apparatus of claim 1 wherein the sections of the upper and lower portions are articulated. 
     
     
       3. The apparatus of claim 1 wherein the sections of the upper and lower portions are slidable with respect to each other. 
     
     
       4. The apparatus of claim 1 wherein each lower section is in the shape of a truncated triangle.