Coker Heater Health Monitoring for Maximum Throughput and Reliability
Here’s an excerpt from the Inspectioneering Journal July/August 2024 issue. https://inspectioneering.com/journal/2024/07
Modern delayed coker heaters provide the energy to drive the coking process with challenging feeds, wide temperature cycles, and operating constraints. The balancing act maintained by the operations team to hit the correct coil outlet temperature, maintain an even heat fl ux, manage drum swaps, and remain vigilant
to comply with decoke timing can be quite challenging.
Fired heaters in coking units can be single or double-fi red configurations, typically with multiple cells and many burners. Most recent designs favor the dual-fi red approach, in which -burners are configured on each side of the process tubes. Keeping the heater radiant tubes healthy is critical to maintaining safe and reliable operations of the full coker unit. Three key enemies of the tubes are time, pressure, and temperature. Each should have
properly specified parameters identified for corrosion, velocity, etc. Time and pressure are readily quantifiable parameters that allow for accurate and repeatable direct measurement possible. Temperature, however, can be tricky due to the possibility of internal tube fouling. I will generally refer to this fouling as “coke,” but please be aware that it is not always an organic formation. While coke is typically an organic formation, it can also bepresent as a non-organic compound. Our enemy, tube temperature, is critical to how long tubes will last and the economic considerations that should be considered.
Over the course of many years, a 50°F difference in operating temperature can reduce tube life by decades. Put another way, a 4-5% change in a tube’s maximum operating temperature can significantly change how long it can survive its environment. As delayed coker operators and support teams, how do we manage this risk reasonably while providing as much flexibility to push unit rate and severity?
Available Methods
What tools do delayed coker practitioners have to protect our heater tubes? How can we find and manage something so elusive as coke? Thankfully, several reliable methods exist to manage these risks. It is important to use these methods in combination to maximize value.
Technology and methods available to help manage delayed coker heater tube reliability can be viewed in the full article in Inspectioneering Journal July/August 2024 issue. https://inspectioneering.com/journal/2024/07