STEEL STACK LINER REPLACEMENT

A steel exhaust stack was experiencing decline in its structural integrity as a result of liner deterioration. Industrial Access provided existing liner demolition and new refractory installation services utilizing custom-engineered access methods. The team identified the best liner replacement solution that would fit the client’s needs and maximize the structure’s longevity.

A power plant in the southern United States was in need of interior repair services for their 120’ tall steel exhaust stack. The existing liner had spalled and deteriorated, and the shell of the stack began showing signs of thinning and wear as a result. The structure was progressively in higher risk of complete failure, so the facility contracted Industrial Access (IA) to perform complete liner replacement.

In order to conveniently access the 12’ inner diameter stack interior, IA’s expert engineers designed and built a custom dance floor. It was built 18” smaller in diameter than the stack to leave room for gunite removal and new liner installation. This platform provided access to the full height of stack interior and maximized the crew’s work efficiency.

In order to determine the best solution for this type of stack, IA had proposed three different liner options, detailing the advantages and conditions of each one and offering expert recommendations. The client ended up choosing the 2” LHV 1:2:4 liner solution best suited to the structure specifications listed by the stack manufacturer. This cementitious refractory solution is lightweight and provides excellent high temperature resistance, protection from both abrasion and corrosion, with great insulating properties.

IA began the repair process by removing the existing reinforced gunite liner and old wire mesh, then emptying the debris. The interior surface of the steel stack was sandblasted in preparation for the new refractory. New stainless steel anchors were welded to the stainless steel wire mesh sheets according to the unique specifications provided by the client. The mesh was then welded to the stack interior, thus providing support for the new refractory. LHV material was pre-mixed, then sprayed in multiple layers over the mesh using gunite machines.

The installation of the new refractory system was completed successfully and on time. This repair will help ensure the longevity of the structure and maximize operational efficiency. The crew also made some non-scope observations of staining and corrosion on the exterior shell of the stack and its platforms. Future repair recommendations were made to enable the facility to stay one step ahead in the maintenance of their structures.