Coil Repair

in the installed condition is only possible in the case of a few furnace manufac- turers. This must be an open cage construction, in which the iron piles can if nec- essary be detached from the outside and moved to the side. The coil jacket is then cut open at the damaged point of the coil. The coil can then be exposed from the inside by removing the coil plastering or smooth coil coating. The damaged intermediate layer insulation is removed, and the defective coil copper cleaned and repaired. After the water pressure test, the intermediate layer insulation is installed, the coil copper painted and the repair spot dried with hot air for approx. 15 min. The plastering can then be applied again. Before lining the cru- cible, the repair spot should be allowed to dry for 4 to 12 hours, depending on the thickness and density of the coil plastering. The coil jacket is glued back on again from outside, and the cut areas sealed off with glass fibre material. The iron pile or piles are replaced in position and attached using the press-screws.