| 초록 |
This study investigates the combustion of carbon during the production of sintered fly ash aggregates. The objective of the research is to develop a single particle model for carbon combustion which is applicable to the large scale production process of light weight sintered fly ash. The model includes the mole balance of O2, diffusing into a porous spherical particle while reacting with the carbon. A separate heat balance was formed including the conduction and heat generation by the combustion reaction. In order to model the combustion rate, two kinetic models are used: one is Freundlich model which is mathematically simple with one kinetic constant, and the other is the Langmuir model which is the most commonly used model for the carbon combustion. The models were used to predict the oxygen gradient, temperature gradient, and the amount of remaining carbon as a function of time and the position in the pellet. The kinetic parameters in model were obtained by fitting the model into the fly ash powder experiments data which were not limited by the mass transfer of O2. For combustion experiments, the apparatus equipped with an O2 flow controller, a temp. controller and recorder was set up. |
