Skip to Main content Skip to Navigation
Theses

Modélisation de la combustion en fours rotatifs d'incinération de déchets

Abstract : Rotary kilns are effective tools for waste incineration. They offer good possibilities for treatment and energy recovery for solid, liquid or gaseous waste. In order to design at best the kiln length, it is necessary that the time scale of the waste reduction be closest to the time residence time of the particles. The rotation speed and the slope of the kiln are two operating conditions that determine the solid bed flow and the mixing efficiency. The dynamic angle of repose and the angle of descent are solid phase parameters that characterise its fluidity. The dynamic model developed studies the influence of the operating conditions and rheological properties on the residence time of the solid load and the filling degree, that have consequences on the heat and mass transfer in rotary kilns. The model has been validated through comparisons between numerical results and experimental data. Experimental measurements were made in a pilot rotary kiln and an industrial kiln. A relation for the residence time was proposed which depends on the type of waste and the kind of installation. The second part of the work deals with the development of the chemical decomposition through pyrolysis-devolatilization of the solid load. The numerical results were then used as boundary conditions for CFD simulation that enables the computation of the flow and combustion of volatile matter. After an elementary analysis of the two kinds of waste tested, which are shredded tyre and crushed wood, the experimental data have enabled the study of the influence of the controlling parameters such as the preheating temperature, the primary air flow, and the waste moisture content on the combustion efficiency and the pollutant nature. The numerical simulations and the experimental data have enabled to identify the different zones of the transformation of the solid load which are the drying, pyrolysis, devolatilization, and combustion of volatile matter and carbon residue. An overall assessment leads to a first kiln device analysis.
Complete list of metadatas

https://hal-uphf.archives-ouvertes.fr/tel-03025584
Contributor : Julie Cagniard <>
Submitted on : Thursday, November 26, 2020 - 12:33:05 PM
Last modification on : Sunday, November 29, 2020 - 3:04:22 AM

File

2009VALE0015_NDIAYE_LAT GRAND....
Files produced by the author(s)

Identifiers

  • HAL Id : tel-03025584, version 1

Citation

Lat Grand Ndiaye. Modélisation de la combustion en fours rotatifs d'incinération de déchets. Génie mécanique [physics.class-ph]. Université de Valenciennes et du Hainaut-Cambrésis, 2009. Français. ⟨NNT : 2009VALE0015⟩. ⟨tel-03025584⟩

Share

Metrics

Record views

16

Files downloads

10