Why Doesn’t All of the Carbon Burn in the Furnace?
From our experience, there are three major factors that prevent complete burnout of carbon before it reaches the furnace exit: • Insufficient furnace oxygen. • Particle size that is too large (coal fineness is too coarse). • Poor fuel and air distribution in the burner belt. If there is insufficient well-distributed oxygen in the furnace to mix proportional amounts of fuel, it doesn’t matter what the furnace temperature is, the carbon will not burn. It’s important to remember the fundamentals such as ignition temperature, fuel, and oxygen that are required for combustion. Lack of oxygen in the furnace can be the root cause for one of three reasons: • Insufficient total airflow. • Fuel and air imbalance in the furnace (there may be an adequate oxygen level on an average basis, but some areas may have pockets of low oxygen levels). • Falsely high oxygen indications from air in-leakage. Side-to-side imbalances may be determined by taking fly ash samples from both the left and right sides
