Electric Arc Furnace (EAF) Components
Electric arc furnace upper shell — custom-engineered to client drawings, with water-cooled panel integration and EN ISO 3834-2 certified welding quality. In addition to upper shell manufacturing, we also produce EAF center rings. The center ring is the transition component between the upper and lower segments of the furnace shell.
| Custom manufacturing to furnace diameter (Ø3,000 mm – Ø10,000 mm) |
| Material: structural steel + water-cooled panel combination |
| Welding standard: EN ISO 3834-2 (TÜV NORD supervision) |
| Pre-delivery hydraulic pressure and leak test |
| Warranty period: 12 months |
It is a welded steel structure that carries the water-cooled sidewall panels. US patent 12,181,221 describes the common upper shell design as a structure manufactured from plate, large-diameter pipe, or a combination of the two, which hangs the panels from the inner diameter of the upper ring. DNL Mühendislik manufactures the upper shell according to furnace diameter and panel layout.
By fasteners fixed to the cold outer face of the panel. The same patent lists an upper plate flange, intermediate flanges, T-irons, pins, and brackets, all of which attach to matching brackets on the shell. The patent also notes a known weakness of this arrangement: in an unplanned failure, removing the panels is difficult, and repair often requires personnel to access the furnace from inside, causing significant downtime and production loss.
A structure in which the furnace is divided into three main sections. US patent 4,091,228 describes these sections as the upper section, the upper shell, and the lower shell with the hearth; a separation line exists between the upper shell and the lower shell. This line allows the upper shell to be removed and replaced as a single unit.
At the junction between the water-cooled shell and the refractory lower shell. US patents 5,743,729, 5,772,430, and 6,249,538 make the same observation: as melting cycles progress, one of the greatest weaknesses is wear of the lower shell refractory in the circumferential band at the upper edge of the slag level. The slag layer that adheres to the panels is not enough to protect this region from thermal and chemical stress, which is why separate cooling arrangements acting directly on the lower shell refractory have been developed.
From a circumferential water channel running along the furnace's upper flange. US patent 6,084,902 states that water pressure at the panel outlet must be kept above 20 psi; otherwise some panels fail to receive sufficient water and flow distribution becomes uneven. DNL Mühendislik designs the shell and the water distribution arrangement together.
