Device for distributing gas in a gas processing vessel comprising a particulate material

A gas processing vessel of cylindrical shape with a vertical axis, comprising a cylindrical shell, the cylindrical shell having a shell diameter DR, an upper end wall, a lower end wall, an inlet orifice, an outlet orifice, a gas distribution device and a first particulate material, the distribution device being fixed in said vessel next to the gas inlet or outlet orifice and is recessed into the lower end wall, the distribution device comprising:

• a gas-permeable cover covering said inlet or outlet orifice and having a wall with a substantially circular base, the gas-permeable cover having cover openings, the cover being designed to be in contact without a weld with the lower end wall and having a diameter greater than or equal to one third of the shell diameter,
• a second particulate material with an equivalent diameter De greater than or equal to 10 mm and greater than the dimensions of the cover openings, the second particulate material being accommodated around the cover at least to a height corresponding to an upper end of the cover, and
• a means for centering the cover above the inlet or outlet orifice, said means being fixed to a pipe that is connected to the inlet or outlet orifice,
• wherein the centering means is made up of a rod, an upper end of which is fixed to the cover, and of a means for maintaining said rod at a center of the pipe.