Our UNICAL calciner burners are designed to be operated with traditional and different alternative fuels. Burners are available for high and low performances, for single or multi fuel operation.
Fuel is taken in for combustion perpendicularly to direction of raw meal flow. The design changes in dependence of the fuel or combinations of fuels are fired.
Example: 60 MW, Coal, Petcoke, Natural gas (drying)
Fuel is introduced along the direction of raw meal flow which has been taken in via a swirl chamber. The burner is designed like a three channel kiln burner to ensure best fuel distribution into the rotating raw meal flow.
Example: 165 MW, Coal, Petcoke, Natural gas
The oxygen required for ignition and combustion of the fuel is supplied either through the kiln or the tertiary air duct. A minimum amount (percentage) of O2 must be available to ensure the ignition of the fuel.
Fresh air is added for cooling of the burner and to support combustion at the flame root. Only about 5 per cent of the stoichiometric air quantity is used to prevent unnecessary cooling of the calciner.
Inside the calciner temperature ranges roughly from 800°C up to 900°C. The temperature must be at a level to ensure self ignition of the fuel.
The passing raw meal takes the partially burnt fuel along until it has been burnt out completely in dependene of O2-content an temperature level. The velocity inside the channel should not be lower than 25 m/s at horizontal installed calciner burners.
The necessary residence time in the calciner depends on the fuel fired, the temperature level and transport velocity of raw meal.