replacement of brick Lining support angles in a 166' x 16' id STEEL STACK
The Unit #3 stack at the Perry K Generating Sta. is roof-mounted steel stack with an internal brick lining which consists of (10) brick liner sections supported by steel shelf/support angles welded to the interior shell plate.
An inspection identified that the support angles at (7) lining sections were heavily corroded and the initial signs of lining failure were evident. To avoid having to replace the whole liner sections, a piecemeal replacement plan was developed, removing and replacing the shelf angles and 4-courses of brick lining in the region above and beneath the shelf angles.
The plan required localized replacement in four regions of brick at 90 apart, in 4' arc lengths and rotating around the circumference of the stack after the new brickwork was set. The work also included:
- Sandblasting to an SSPC-6 Commercial Blast finish all exposed surfaces of the interior steel shell and shelf angles.
- Coating all steel with a heat and acid resistant mastic coating.
- Filling the gap between the top course of brick and shelf angle with a flexible heat resistant resin compound.
- The application of a 2" thick gunite lining (complete with mastic and reinforcing anchors) over limited regions of the interior surface.