Modeling of Pulverized Coal Combustion in Cement Rotary Kiln
In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rotary kiln were obtained by numerical simulation of a 3000 t/d rotary kiln with a four-channel burner. The predicted results indicated that the improved model accounts for the thermal enthalpy of the clinker formation process and can give more insight (such as fluid flow, temperature, etc,) from within the cement rotary kiln, which is a benefit to better understanding of combustion behavior and an improvement of burner and rotary kiln technology.
"Hot Rotary Kiln Deformability for Cement Plant, Experimentation, and Numerical Simulation"
The goal of this work is the study of mechanical behavior and ferrule deformability under the heat effect, for a cement plant’s rotary kiln. This study is within the scope of preventive maintenance for these kilns more specification precisely. It’s about the finite element model validation, which simulates the kiln’s elastoplastic behavior. This work is based on the case study of a cement plant’s rotary kiln of a Moroccan industrial group. First, we take experimental measurements for the kiln distortions in the presence of heat. The, we use the numerical finite element method to simulate the ferrule and the refractory wall, this simulation is obtained by the use the of commercial software PATRAN-NASTRAN. Finally For a better reality approach of the kiln behavior, our finite element method results are compared with those obtained by the experimental tests.
The calculation of radiative heat flux in a cylindrical furnace using the Monte Carlo Method
Abstract The temperature profiles and heat flux distributions in an end-fired right cylindrical furnace with circumferential sink surfaces were calculated by the Monte Carlo Method, for various flow patterns. The combustion pattern was determined from precise experimental data taken on cold ducted jets and its calculation included the effect of turbulent fluctuations of the fuel and oxygen concentrations as well as the mean values. The results compared favorably with previous calculations for identical conditions using the classical interchange method for the radiative terms. The Monte Carlo Method proved to be more flexible than the classical method in handling concentration variations in the radiating gases and changes in volume element geometry to conform more closely with jet structure. Various suggestions are proposed to circumvent the use of random numbers which lead to statistical errors, the major disadvantage of the Monte Carlo Method.