Stack problems and consequential costs
I.G. Standish
CICIND REPORT Vol. 11, No. 2, 1995
Order No: CR-009
Dr. Standish describes a survey made of tall concrete chimneys at 12 of BP's refineries, world-wide. Commentaries were received on problems in 23 chimneys. None had fallen down, but one was in such bad shape that a replacement was built alongside and it was demolished. Most of the difficult and expensive problems related to failures of the liners. They found, for instance that lifts of brickwork liner were being rebuilt every 7-10 years. Also they have experienced problems with high temperatures and guide failures in steel liners. Refinery operation requires that units run non-stop for 3-4 years. They are then taken out of service for a few weeks for maintenance. Chimney repair costs are typically in the order of $30,000 to $300,000, depending on complexity. These costs are, however, totally overshadowed by production losses if they extend the shut-down period beyond the minimum period necessary or, worse, if they require an emergency, unplanned, shut-down. In these circumstances, costs escalate to anything between $100,000/day and $300,000/day, depending on the profitability of the unit served.