A discrete-continuous approach to describe CaCO3 decarbonation in non-steady thermal conditions

Abstract

In cement production, direct measurements of thermal and chemical variables are often unfeasible as a consequence of aggressive environments, moving parts and physical inaccessibility, and therefore prediction models are essential tools in these types of industrial applications. This article addresses the problem of the numerical prediction of the CaCO 3 calcination process, which is the first and the most energy expensive process in clinker production. This study was conducted using the Extended Discrete Element Method (XDEM), a framework which allows a Eulerian approach for the gas phase to be combined with a Lagrange one for the powder phase. A detailed validation of the numerical model was performed by comparison to non-isothermal TG curves for mass loss during the CaCO 3 decarbonation process. The complex three-dimensional predictions for solid and gas phases are believed to represent a first step towards a new insight into the cement production process. Thus, the high accuracy and detailed description of the problem addressed, serve as a basis to assess the uncertainty of more simplified models such as those used in soft sensors.

XDEM for Tuning Lumped Models of Thermochemical Processes Involving Materials in the Powder State

“…The N2 flow of the CFD domain continuously removes the CO2 expelled from the particles. A validation of the model discussed so far is reported in [15].…”

“…The comparison between results of the two models, when applied to a test involving a higher number of particles with respect to the one reported in [15], shows how the tuned lumped model can provide a high level of accuracy with less computational effort, thus making it suitable both for virtual sensing and feed-forward control strategies.…”

“…The XDEM simulation associated to such process has been already validated by the authors in [15] on the basis of experimental data documented by Gieorgieva et al [16].…”

Preliminary Investigation on the Capability of eXtended Discrete Element Method for Treating the Dripping Zone of a Blast Furnace

“…The XDEM has been developed by Peters 21) and applied to many Multiphysics applications such as combustion, 22,23) heat up processes, 24) drying, [25][26][27] pyrolysis [28][29][30][31] as well as reduction [32][33][34][35] and many other applications. [36][37][38] So far, the upper part of the blast furnace known as the shaft, where the reducing gas is the only fluid phase was modeled by XDEM method. This method has been validated not only for the rheology of the gas phase through layered packed bed of iron ores and coke particles in the shaft of a blast furnace but also for the drying and different reduction of iron ores.…”

Modelagem matemática dos perfis de temperatura do gás, do sólido e da parede do forno e dos perfis de concentração das principais espécies químicas presentes no interior do forno rotativo empregado na produção de clínquer

“…Dessa forma, há um grande interesse na otimização do processo de produção de cimento [6,7]. O tipo mais comum de cimento é o cimento Portland, definido como um aglomerado hidráulico, que é obtido basicamente pela trituração de uma mistura de gesso e clínquer [7].…”