Numerical analysis of cement calciner fuel efficiency and pollutant emissions

Abstract

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 threedimensional 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.

Numerical study of co-firing pulverized coal and biomass inside a cement calciner

“…This is due to the calcination process, which is a strong endothermic reaction. Furthermore, when comparing the co-firing cases with the case where only the coal was combusted (Mikulčić et al, 2013c), it can be observed that in the co-firing cases in the near burner region the temperatures are roughly 100 K lower. Figure 3 shows the CO 2 mole fraction inside the calciner for the three calculated co-firing cases.…”

“…A detailed description of the geometry and the boundary conditions of the modelled calciner can be found in our previous study (Mikulčić et al, 2013c).…”

“…Furthermore, for consistency and better understanding of the amount of fuel that was substituted, in Table 1 the boundary conditions used for the reference coal combustion case are summarized. The values for the reference coal combustion case were the input data that were provided to the authors (Mikulčić et al, 2013c). The proximate and ultimate analyses of the used coal and biomass are tabulated in Table 2.…”

Numerical modeling of urea water based selective catalytic reduction for mitigation of NOx from transport sector

“…The motion and the transport of the parcels are tracked through the flow field using a Lagrangian formulation, while the gas phase is described by solving conservation equations using an Eulerian formulation. The coupling between the liquid and the gaseous phase is taken into account by introducing appropriate source terms for interfacial mass, momentum, and energy exchange (Mikul ci c et al, 2013).…”

Numerical modelling of diesel spray using the Eulerian multiphase approach

“…In general, most of these strategies have fallen into two basic formulation methods that are commonly used for coupling the dynamics of the liquid and the gaseous phase: the Euler-Lagrangian method and the Euler-Eulerian method. The Euler-Lagrangian [16] method has been used by many researchers and various improvements to the basic scheme have been proposed [17][18][19][20][21]. Over recent years the Discrete Droplet Model (DDM) within the Euler-Lagrangian framework has dominated in predicting the behaviour of the spray process.…”