Design of the calciner is quite crucial for complete combustion and calcination. Generally with simulations and low CAPEX process modifications, alternative fuels substitution rates of 70% in the burner and calciner are readily possible, with up to 100% in the calciner depending on the alternative fuel type and specification.
For the calciner to perform well, DTM considers the parameters below to achieve the desired output and efficiency:
- Fuel type (natural gas, alternative fuel, coal, petcoke etc.)
- Capacity
- Velocity distribution
- Residence Time
- Mixing Properties
- Combustion and Calcination Profiles
- Low NOx and low carbon emissions
DTM will analyze the calciner together with TAD in a CFD software to determine flow patterns of the solid-gas mixture and pressure drops to achieve an optimized calciner design. The simulations run in our CFD department using equipment with high-end technology. CPFD Barracuda Virtual Reactor® is being used to optimize the calciner.
For a more complete combustion, optimization of the kiln gas, the tertiary air, residence time and the fuel mixing are important. Alternative fuels such as Tire Derived Fuel or Refused Derived Fuel require more time to reach complete combustion, therefore the design of the calciner should allow for enough residence time.
The location of the tertiary ducts directly affects the location of the combustion zone. In addition, a good mixing property can be supported with a well-located tertiary air pipe.
DAL provides cyclonic Tertiary Air Inlet for proper mixture of the Tertiary Air with fuel, and kiln gas. Beside this, at calciner turn a swirl top is applied to further mix the gas upcoming from the first combustion zone.
