Structural repairs to a sponge coker unit at this CITGO petroleum refinery required years of planning because of a narrow window of just 30 days to execute the $9.4-million project, which involved modifications to coke chutes, coke pit walls and floors, and head decks as well as supporting columns and beams.
Preparations included extensive training for each crew member—from labor to management—in the key areas of safety, task training and execution.
Elgin, Ill.-based concrete contractor STRUCTURAL commandeered more than 200 repair specialists, dividing work into two 12-hour shifts that operated for 30 consecutive days, logging zero safety incidents during more than 67,000 man-hours.
Among other initiatives, STRUCTURAL encouraged workers to submit observation reports documenting unsafe conditions.
As work progressed, crews repaired and strengthened more than 900 sq ft of support columns and beams on coking unit head decks, a task involving about 30 yd of concrete. Four of the six decks were completely removed and replaced with about 120 yd of concrete. Full-depth repairs were completed on angled coke chutes for six drums.
Crews repaired the coke pit by first pouring a leveling mud slab, then installing an under-drain system topped by a new reinforced concrete slab. A transition slab was built to join the new slab to the existing coke pit ramp.
One of the more significant challenges involved access to the top and bottom of head decks and angled coke chutes directly below them, circumstances that prompted deployment of a suspended deck system to access head deck beams and slabs, including swing stages with angular stirrup brackets to repair the chutes. Both systems served to protect crews at work in chute and pit areas below.
Each work area, including head decks, coke chutes, pit floors and pit walls, was assigned a dedicated project management team to develop related safety, execution and QA/QC plans.
CITGO Lemont Refinery Coker Turnaround, Lemont, Ill. Key Players
Owner: CITGO Petroleum Corp. Inc., Lemont, Ill.