Anthracite ignition characteristics in an arch-fired boiler with slot burners

Experimental studies were conducted on the anthracite ignition characteristics under different conditions in a 600 MW supercritical arch-fired boiler equipped with slot burners. The experimental measurements reveal that the igni- tion distance of the pulverized coal flows is affected by the air distribution of the burner and pulverized coal concentra- tion. The ignition distance of the fuel-rich flows become remarkably shorter under the low primary velocity. The fuel- rich flows could be ignited at about 1 meter away from the burner. The secondary air should be added into the primary flows after being ignited and it is ease for the excess or deficiency of secondary air to cause the deterioration of com- bustion. A higher concentration of pulverized coal is favorable for anthracite ignition. Ignition of the fuel-rich flows be- come more stable after rising the concentration of pulverized coal to 1. 0 kg / kg. Appropriate ignition distance of pulver- ized coal flows is very important to the operation of arch-fired boilers. The delayed ignition distance of pulverized coal could lower the flame center and cause the high temperature of the hopper region.