CO Boiler Convection Replacement
The refinery had a carbon monoxide (CO) boiler in their Fluid Catalytic Cracking (FCC) Unit. The CO boiler was more than 40 years old. The CO boiler’s convection section is used to preheat the FCC charge and also generate superheated steam at 600 psig/710°F. The boiler had three problems: (1) low economizer tube metal temperatures were reaching dew point levels (2) high super heated steam temperature (3) problems with tube supports in the hottest zones.
The refinery approached Furnace Improvements to provide thermal design for replacing the convection section of the CO boiler. Furnace Improvements carried out the engineering study for replacing the convection section. We conducted a detailed operation analysis of the existing CO boiler and built a model of the existing design. With the model built, we were able to simulate the current operating conditions and predict the heater performance for the future operating conditions. We developed a better design overcoming the drawbacks in the existing CO heaters. The convection section was redesigned to: