Power Generation

Subcategory: Scheduled Outages & Maintenance Contracts

Xcel Energy – Boiler Coutant Bottom Installation

Client: Xcel Energy

Location: Becker, Minnesota

Project: Boiler tube panel removal and replacement

Scope: During the Unit 1 two month outage at Sherco, the coutant bottom of the boiler was removed and replaced on a 650MW coal-fired boiler with a new set of boiler tube panels. Each coutant panel was installed in two pre-fabricated sections. The 32 vertical slope sections were 35 feet long and approximately 5,000 lbs. each; the 32 horizontal sections were 10 feet long and approximately 1,600 lbs. each. To aid in the construction process, AZCO installed a temporary engineered boom system serving as a way to carry the loads from a series of monorails used to remove and replace the coutant panels while also supporting the full firebox scaffolding required to perform routine maintenance on the remainder of the boiler walls and elements.

Work included removal of the old tube panel sections, support beams, seals, drip screens, trough plates, support steel, casing and refractory. Installation included support steel, new gas seals and slope support beams in dead air space, temporary rigging, hoists, and chain falls, refractory and anchors, and all new tube panel sections.