Study of Parameters Influencing Fluid Flow and Wall Hot Spots in Rotary Kilns using CFD

Elattar, H.F.; Specht, Eckehard; Fouda, A.; Bin‐Mahfouz, Abdullah S.

doi:10.1002/cjce.22392

Cited by 20 publications

(18 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, rotary kilns are the most popular equipment dedicated to the drying, heating and coating of granular materials. A better understanding of the physical mechanisms [37,38,39] occurring within a rotary kiln is therefore crucial to optimize the industrial plants [40] in the context of sustainability, efficient energy use and reduction of toxic gases like polycyclic aromatic hydrocarbons. Here, we aim to model such a typical industrial equipment.…”

Section: Rotary Kilnmentioning

confidence: 99%

Heat convection and radiation in flighted rotary kilns: A minimal model

et al. 2016

View full text Add to dashboard Cite

We propose a minimal model aiming to describe heat transfer between particles (i.e. grains) and gases in a model of flighted rotary kilns. It considers a channel in which a convective gas interacts with a granular suspension and a granular bed. Despite its simplicity it captures the main experimental findings in the case of dilute suspension of heavy grains typical of what can be observed in many industrial rotary kilns. Energy balance between each phase takes into account the main heat transfer mechanisms between the transverse granular motion and the convective gas. In the absence of radiation heat transfer, the model predicts exponential variations of the temperatures characterized by a length which depends on the granular and gas heat flow rates as well as on the exchange areas. When radiation is taken into account, the model can be solved numerically. For this case, the temperature variations can be fitted by stretched exponentials whose parameters are found to be independent of the studied phases. Finally, an efficiency criterion is proposed to optimize the length of the system

show abstract

Section: Rotary Kilnmentioning

confidence: 99%

Heat convection and radiation in flighted rotary kilns: A minimal model

et al. 2016

View full text Add to dashboard Cite

show abstract

“…With the increased pulverized coal concentration, the high‐temperature combustion zone gradually moves toward the kiln hood with the average temperature of the flue gas increasing. The flame temperature also increases due to the lower primary air ratio . At a lower pulverized coal concentration, the temperature of the sintering zone is correspondingly low, which is not good for cement production.…”

Section: Simulation Results and Discussionmentioning

confidence: 99%

Experimental research and numerical analysis on thermal dynamic characteristics of rotary kiln

Wang

Cheng

2019

Can J Chem Eng

View full text Add to dashboard Cite

The rotary kiln is a piece of equipment that consumes an extensive amount of energy. The thermal dynamic characteristics of the rotary kiln include conduction, convection, radiation, and combustion characteristics, which are closely bound up with the energy consumption of the kiln. In this paper, both experimental and numerical studies are performed to understand the relationship between the thermal dynamic characteristics of the rotary kiln and the factors that affect them. In the experimental section, the shell temperature and coating thickness of the kiln cylinder were measured, which shows the thermal dynamic characteristics of the rotary kiln. In the numerical section, a three-dimensional numerical model with ANSYS software is set up to research the fluid flow, combustion, and heat transfer characteristics of the rotary kiln under different working conditions. The numerical simulation results presented reasonable agreement with the experimental data. The results indicate that coating thickness affects the heat transfer conduction of the kiln and the burner structure affects the combustion and convection heat transfer in a kiln. Fugitive constituents of coal, pulverized coal concentration, excess air ratio, and oxygen content can influence the characteristics of the combustion and heat transfer processes.

show abstract

“…Computational Fluid Dynamics (CFD) packages have been used to study different aspects of the rotary kiln. E.g., in [4] we see how CFD can aid in the operation and design of a kiln to meet the specified requirements. We extended this model in [5] by adding the refractory lining, to allow the wall temperature to develop more realistically.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Variable Air–Fuel Ratio on Thermal NOx Emissions and Numerical Flow Stability in Rotary Kilns Using Non-Premixed Combustion

2021

View full text Add to dashboard Cite

One of the quickest ways to influence both the wall temperature and thermal NOx emissions in rotary kilns is to change the air–fuel ratio (AFR). The normalized counterpart of the AFR, the equivalence ratio, is usually associated with premixed flames and studies of its influence on diffusion flames are inconsistent, depending on the application. In this paper, the influence of the AFR is investigated numerically for rotary kilns by conducting steady-state simulations. We first conduct three-dimensional simulations where we encounter statistically unstable flow at high inflow conditions, which may be caused by vortex stretching. As vortex stretching vanishes in two-dimensional flow, the 2D simulations no longer encounter convergence problems. The impact of this simplification is shown to be acceptable for the thermal behaviour. It is shown that both the wall temperature and thermal NOx emissions peak at the fuel-rich and fuel-lean side of the stoichiometric AFR, respectively. If the AFR continues to increase, the wall temperature decreases significantly and thermal NOx emissions drop dramatically. The NOx validation, however, shows different results and indicates that the simulation model is simplified too much, as the measured NOx formation peaks at significantly fuel-lean conditions.

show abstract

Study of Parameters Influencing Fluid Flow and Wall Hot Spots in Rotary Kilns using CFD

Cited by 20 publications

References 16 publications

Heat convection and radiation in flighted rotary kilns: A minimal model

Heat convection and radiation in flighted rotary kilns: A minimal model

Experimental research and numerical analysis on thermal dynamic characteristics of rotary kiln

The Effect of Variable Air–Fuel Ratio on Thermal NOx Emissions and Numerical Flow Stability in Rotary Kilns Using Non-Premixed Combustion

Contact Info

Product

Resources

About