The sloping bearing surface at each side of a sprung arch, built from skew bricks with one angled face and backed by a steel skewback channel tied to the furnace binding. The arch thrust runs into the skewback, so its angle must match the rise of the arch and its steel must hold as the roof expands. Furnace operators adjust the binding tie rods during heat-up to let the arch grow without lifting or dropping.
Skewback channel on the north side has rolled, the crown's been dropping since last campaign.
Watch the tie rods during heat-up. As the arch grows they are backed off in steps, and forgetting them can crack or lift the crown.
Also heard as
- skew
- skew brick
- skewback channel
Related terms
Arch brick
Tapered brick whose thickness narrows across its width, used to turn thin arches and rings.
Crown
Arched refractory roof of a glass furnace or other large furnace, often built of silica brick.
Expansion joint
Gap deliberately left in a lining so bricks or castable can grow with heat without crushing or lifting.