Mathematical Model of the Aluminum Oxide Rotary Kiln

Abstract

A steady-state model of the rotary kiln used for calcination of basic ammonium aluminum sulfate In production of aluminum oxide Is described. Carrying away of solid particles by gas stream and chokes In the inner kiln wall are specific features of the kiln considered. The model consists of a set of ordinary differential equations describing reaction kinetics and mass and heat balances, a set of algebraic equations for space-depending parameters, and a set of two-point boundary conditions. An algorithm for a numerical solution of the model equations with two point boundary conditions is described along with a method for computation of the kiln with and without chokes. Computational results for the kiln with and without chokes are presented, and a comparison of computed and experimental data for a kiln with chokes Is given.

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

“…A possible explanation is that the flame radiation heat flux depends on the flame temperature; therefore, Figure 7a has similar trends to Figure 6a. The local radiative heat transfer coefficient between the flame and the walls can be calculated based on Equation (20) which is presented by Manitius et al [5] as follows.…”

“…[2] This is related to the rotary kilns being able to work at a high burning zone temperature, such as lime burning (1200 8C), [3] cement clinker burning (2000 8C), calcination of petroleum coke (1100 8C), [4] and calcination of aluminum oxide (1300 8C). [5,6] However, cement industries are considered the essential applications of rotary kilns. [7] Rotary kilns are used extensively for incinerating waste materials, since they can handle various feed materials with variable calorific values and effectively burn the solid wastes on the way out.…”

Coal pyrolysis in a rotary kiln: Part II. Overall model of the furnace

“…We calculated the values of these ciently complete to take into account all the phenomena coefficients using different correlations. [1,11,[16][17][18] We commentioned previously, while remaining simple enough to be pared the quantity of heat radiated toward the charge calcureadily used in the overall model of the rotary kiln. This lated from these values to that given by the more-rigorous part of the study makes use of the abundant results available model of Gorog et al [12] The expressions given by in the literature on heat-transfer phenomena.…”

“…published in the literature, [1][2][3][4][5] none applies specifically to the pyrolysis of coal. Another point which distinguishes the ROTARY kilns are widely employed in the cement, present study from previous work is that the description of metallurgical, and chemical industries due to their simplicity the conversion of an individual coal grain to coke led us to of use and their ability to continuously treat granular or develop a specific kinetic and thermal model, which has powder solids with excellent heat and matter transfer been termed the grain model.…”

“…was measured in the pilot furnace by filming the successive The use of Eqs. [1] through [7] has been validated by appearances and disappearances of the painted grains, while comparing their results to measurements made in a pilot the axial profile of the charge was established with the aid furnace.…”