DRY STACK DRAINAGE SYSTEM REPAIR & REPLACEMENT

A power plant was dealing with severe clogging and corrosion in their boiler stack drain cones. The client decided upon a new drainage system, and Industrial Access was contracted to demolish the damaged cones, replace them with new drainage containment, and upgrade the overall piping system. With limited time available, IA’s rope access expertise maximized work efficiency and safety.

A power plant in the southern United States retained Industrial Access to perform demolition and repair services for their failed dry stack drainage system. Two chimneys inside the boiler had steel collection cones installed at each base, which ended up clogged with hardened coal deposits reaching 100 tons each. Over time, the acidic debris had corroded through the steel, leaving the structures severely damaged and in urgent need of repair.

Since the client’s fuel source had changed from coal to natural gas, a different drainage system was recommended to manage condensation. IA engineers proposed retrofitting the base from a collection cone to a sloped drainage floor for each of the two chimneys.

Additionally, the client had a very short scheduled outage window, and part of the work was planned to be completed during an extended outage. However, in order to minimize the outage, the team worked in longer shifts, and a strategy was developed to accommodate the client and ensure that the crew was always prepared to put the boiler back online if necessary.

IA’s highly trained, SPRAT certified technicians utilized rope techniques as the primary method of access for most of the tasks carried out in this project. This is the most recommended access approach that requires less setup time, less equipment, and fewer workers than other alternatives, like scaffolding.

In order to begin clearing the cones and building the new drainage surface, it was necessary to first eliminate any overhead safety hazards. Since the turning vanes directly above the cone sections were covered in coal debris deposits, the crew first cleaned off the buildup. Only when the turning vanes were washed and cleared of falling object hazards could the team access the cones safely.

Firstly, the new drainage containments were built in both chimneys. The crew installed false floor beams and plates, welded them, and inserted drains. The surface was designed to be slightly sloped, and the drain was positioned on a side for a unidirectional flow of condensation.

Then, IA loosened the buildup in the cones using an air chisel and hand tools, then removed all of it via a vacuum truck. When the cones were empty, the crew began the demolition work by torch-cutting the steel plates of the cones into sections. Sections were lowered down with a crane, and insulation was later installed below the new false floor.

On the boiler exterior, old piping was demolished with the help of rope rigging and a crane. New drain pipes were designed and installed in the interior and exterior of the stack. This updated piping system was developed to better suit a power plant specifically fueled by natural gas.

The project was completed on time and within budget. These repairs will enable the power plant to run at full capacity, restoring its efficiency and preventing any further related damage. After the work was finished, the crew performed a washdown of both false floors and disposed all debris from the area at an authorized dumpsite, leaving the site in an “As Found” or better condition.