Peter Priesching

Numerical analysis of cement calciner fuel efficiency and pollutant emissions

Efficient mixing of pulverized fuel and limestone particles inside cement calciners is important due to the reason that the calcination process directly affects the final fuel consumption. The focus of this paper is on the numerical analysis of cement calciner’s operating conditions and pollutant emissions. The paper analyzes the influence of different amounts of fuel, mass flow of the tertiary air and the adiabatic wall condition on the decomposition rate of limestone particles, burnout rate of coal particles, and pollutant emissions of a newly designed cement calciner. Numerical models of calcination process and pulverized coal combustion were developed and implemented into a commercial computational fluid dynamics code, which was then used for the analysis. This code was used to simulate turbulent flow field, interaction of particles with the gas phase, temperature field, and concentrations of the reactants and products, by solving the set of conservation equations for mass, momentum, and enthalpy that govern these processes. A three-dimensional geometry of a real industrial cement calciner was used for numerical simulations. The results gained by these numerical simulations can be used for the optimization of cement calciner’s operating conditions, and for the reducing of its pollutant emissions.

CFD analysis of a cement calciner for a cleaner cement production

Cement calciners are pyroprocessing units found in modern cement plants. Inside of them occurs a strong endothermic reaction known as the calcination process, and the combustion of pulverized solid fuels. Controlling the mixing of limestone and pulverized fuel particles is of particular importance because it directly affects the energy consumption. The paper analyzes the impact of an axial and a swirl burner on the mixing of the particles, pollutant emissions and the operating conditions of a newly designed cement calciner. All necessary numerical models were developed and implemented into a commercial computational fluid dynamics code FIRE, which is then used for the analysis. This code is used to simulate turbulent flow field, temperature field, concentrations of the reactants and products as well as the interaction of particles with the gas phase, by solving the set of conservation equations for mass, momentum and enthalpy governing these processes. The results gained by these simulations can be used for the optimization of cement calciner’s operating conditions.