Patent ID: 6210549
Filing Date: 2001-04-03
Classification: C25B

Abstract:
A system for the electrolysis of fluorine gas comprising:an electrolytic cell comprising a reservoir of electrolytes containing a hydrogen-fluoride solution and having a melt surface;a cell case having a sidewall, an upper portion, a lower portion and a cell case flange;a cell head plate having an underside surface and attached to said cell case at said upper portion, cell head plate flange on said lower portion;a cell floor attached to said cell case at said lower portion;at least one independently mounted anode having flat surfaces and aligned in a vertical direction from the upper portion of said case to the lower portion of said cell case, whereby said anode is electrically isolated from the cell head plate and capable of being interchangeably dropped into said electrolytic cell;at least one anode mounting plate bolted to said cell head plate, wherein said anode mounting plate is attached to an anode support hanger and said anode support hanger corresponds to and is attached to said independently mounted anode;said anode support hanger is positioned in parallel alignment with the cathode means and positioned above the melt surface of the electrolytes;a cathode box having cathode grid plates arranged in a grid pattern located inside said cell case about a vertical axis and positioned parallel to said anode and mounted to a cathode support flange via a cathode support assembly, wherein said cathode support flange is mounted to said cell case flange;said cathode box is electrically isolated from the cell case and the cell head plate flange and located radially inside said cell;said reservoir of electrolytes comes in contact with the anode and the cathode;a gas separation skirting arrangement located on the underside surface of said cell head plate with the cell head plate nested radially about a vertical axis between the cathode and the anode, said gas separation skirting arrangement forming at least two isolation chambers comprising a fluorine gas chamber and a hydrogen gas chamber, wherein said isolation chambers provide a barrier for separating fluorine gas evolved from said anode in said fluorine gas chamber and hydrogen gas evolved from said cathode in said hydrogen gas chamber;said hydrogen gas chamber, which is completely separated from said fluorine gas chamber, substantially surrounds said fluorine gas chamber;said gas separation skirting arrangement has a bottom edge which is level and positioned above and at an equal distance from said cathode box at all points but one, wherein that one point is an edge high point forming a notch in the gas separation skirting arrangement, said edge high point extending below the melt surface and permitting a recombination of gases from a higher pressure chamber to a lower pressure chamber via said notch;wherein said gas separation skirting arrangement extends below the melt level of said electrolytes in the cell directing an electrolyte flow within the electrolytes above the cathode box and against the sidewall of the cell case, said gas separation skirt arrangement is positioned to enable the electrolytes to be pushed upward towards the cell head plate by gases evolved at the cathode box and in a downward flow path to circulate past the cathode box on the side opposite of each anode, the gas separation skirting arrangement is positioned to deflect a flow path for the electrolytes circulating radially outward past the top of the cathode box, down the cell wall on the opposite of the cathode box from each anode, and inward below the cathode box, thereby inducing an electrolyte circulation flow path into both the fluorine gas chamber and the hydrogen gas chamber;said gas separation skirting arrangement is positioned to deflect a flow path for the electrolyte circulating radially outward past the top of the cathode box, down the cell wall on the opposite of the cathode box from each anode, and inward below the cathode box;said gas separation skirting arrangement further comprises a series of hydrogen channels located above said cathode means and sloped upward and outward toward the hydrogen gas chamber so that an upward rise in evolved hydrogen gas can push the electrolytes toward the sidewall of the cell; anda power connection lug located on the cathode support flange connects said cathode box to a power supply.