Low NOx Burner Replacement for FCCU Feed Preheater
FCCU Feed Preheater located in a refinery in Texas is a natural draft cabin heater with horizontal tubes, a horizontal convection section and two top mounted stacks. The firing rate of the heater is 39.35 MMBtu/hr. The heater originally had 13 burners with the design heat release of 9.23 MMBtu/hr. The refinery wanted to reuse the existing shutdown Crude Heater Unit C burners in FCCU Feed Preheater service and reduce the NOx emissions to 0.06 lb/MMBtu.
Furnace Improvements (FIS) was awarded the job of checking the suitability of the burners to be reused and preparation of documents for procurement of one new burner. The revamp scheme consisted of following:
The burners were sized for design heat release of 39.35 MMBtu/hr.
The FCCU feed preheater required 7 burners to achieve this heat release.
Six burners were exported from the shutdown crude heater and additional one burner was procured new.
The existing thirteen burners were removed, and alternate burner slots were filled by seven burners as described above.
The rest of six burner slots were patched by refractory.
The new burner was designed with higher pressure loss of 0.4-inch WC at design conditions, to match the draft loss of existing six crude heater burners.