Complete CFD study of a suspension preheater’s riser duct
The main target of the project is to confirm:
- If an increase in clinker production (or a decrease in the specific fuel consumption) can be possible by injecting natural gas into the riser duct.
- The impact if any, on the NOx emissions and/or ammonia consumption (relative to the current clinker production) when firing natural gas.
Fives first developed a complete C.F.D model involving natural gas combustion, raw meal decarbonation, urea injection and NOx calculation.
The C.F.D results with the addition of natural gas injectors inside the riser duct showed that the pre-calcination rate increased (from 52.5% to 75%) resulting in a higher clinker production and a better system efficiency.
The NOX reduction also improved (71% vs 68%) with natural gas injection for the same Molar Ratio (NH3/NOX).