Has anyone had experience performing on-line spalling on a 2-pass furance? We have always steam-air decoked our heaters; however, this requires a complete heater shutdown every 2.5-3 months. We would like to perform on-line spalling as a more efficient decoking method, but were always told only 4-pass furnaces can be spalled on-line. What issues could we experience in on-line spalling a two-pass furnace vs. a four-pass furnace?
We have two cabin style heaters (one heater for each pair of coke drums). Each heater has two-passes with a common convection section and a brick dividing wall in the middle of the firebox. The burners are along each side of the middle brick wall firing vertically. 600# steam is used as the velocity media and enters at the convection inlets only. Any help is appreciated. Thank you.
