GB241461A - Improvements in or relating to furnace electrodes - Google Patents

Abstract

241,461. Becker, C. W. April 15, 1925. Furnace details. - A furnace electrode comprises a carbon core a, an outer carbon portion b surrounded by wire netting c, and metal pieces f<1> situated between the inner and outer portions and connected to the electrode mount m, so that in the part of the electrode above the furnace cover k the core carries nearly all the current. The pieces f<1> are coupled to the mount m by water-cooled conductors f. The electrode material may consist of anthracite, graphite and coke with a suitable admixture of tar and pitch. The cross-sectional area of the core may be from one-fourth to one-fifth of the total cross-sectional area of the electrode. The core is burnt at a high temperature and the outer portion is then formed by ramming unburnt material introduced into the space between the core and the wire sheathing. The complete electrode is then burnt in a furnace which may be heated by hot gases from the furnace in which the electrode is used at about 400‹ C. to 500‹ C. The metal pieces f<1> melt on entering the furnace and the outer and inner portions a, b sinter together so that the current is shared between them. The electrodes may be made in sections coupled together by nipples h and dovetail joints h<1>, the bottom g<1> of the latter lying in approximately the same plane as the bottom of the hole for the nipple. In the case of sectional electrodes the burnt-out stump is removed from the furnace and the new section is then built thereon. The mount m and the conductors f are generally removed before adding a new section and are placed at the top of the latter, or the heavy conductors f are replaced by lighter ones.