Cement Case: Thought on Kiln Burner Momentum
A recent deep-dive into our kiln burner performance revealed an interesting paradox:
- High velocities, but low flame momentum (7.44 N/MW vs 9–11 target)
- Primary air higher than optimum (10–11% vs 8%)
We are operating jet air vel 290 m/s as against ideal > 250 m/s and coal injection velocity 68 m/s although high as against the standard 35 m/s.
Coal conveying highly dilute (low density ~2.9 kg/m³) although guide value 3- 5. We don’t want to reduce to avoid coal dosing pulsating and CO affect.
What’s happening? We are operating a high-velocity, low-density system → leading to:
- Weak flame push
- Over-mixing near burner tip
- Higher heat consumption (~695 kcal/kg clinker) , potential < 680
- CO risk at kiln inlet
Key Learning: Momentum is not just velocity — it’s density + balance.
Way Forward:
- Increase coal conveying density (critical lever)
- Gradually reduce primary air from 10 to 8%
- Optimize coal & jet velocities (balanced, not maximum)
Outcome Expected: Stronger flame, better stability, and improved thermal efficiency.
Original source: #cementindustry #kilnoperation #processoptimization #energyefficiency #manufacturingexcelle | Swapan Roy