Aluminum shield for a roll in continuous strip apparatus

Claim 1

A molten salt bath electrolytic descaling apparatus comprising, in combination: a ferrous metal tank adapted to contain electrolyte of molten salt; a ferrous metal exit roll positioned to be partly immersed in said electrolyte and insulatedly mounted on its ends in said tank; means adapted for directing a ferrous metal strip to be descaled first into said electrolyte and then over an unimmersed part of said exit roll and thus out of said electrolyte and said tank; electrode means in said electrolyte near said roll for charging said strip as it approaches said roll; an aluminum shield in the form of an open top tub under and around the lower surface of the roll adjacent but spaced from it, and adapted to be filled at least partly with electrolyte; and means for positively charging said shield in a manner to cause the formation of an inert film on the shield whereby to prevent current flow from said electrode means to the electrolyte through the strip and the roll; with said shield charging means being arranged to charge the shield oppositely from the charge on said electrode means.