Simulating the process of carbon anode baking used in the aluminum industry

Abstract

A simulation scheme for the baking process of carbon anodes as practiced in the aluminum industry is presented. Despite the very complex nature of the process, the proposed scheme is simple enough to be readily implemented on the computer yet takes into account all the important aspects of anode baking: the infiltration of air, the control of depression in the flues, the release and burning of volatiles, and the heat loss to the atmosphere and to the furnace foundation. Emphasis in this paper is laid on the design of the simulation algorithm, more than on the detailed arguments behind the development of the model equations. Two interesting features are worth mentioning. First, the modular structure adopted for the algorithm helps increase its clarity. Second, in executing a simulation run on the computer, the analyst actually “adjusts” the depression in the flues and the fuel flow at the burners the same way a human operator does in the real process. Test runs are made, first to reproduce the existing operating conditions, then to study the effects of various parameter changes on the process. Most of the time this cannot be done on the real facility due to the costs and risks involved. Results show that the proposed model is a reliable tool for process evaluation and improvement.