Date of Graduation

2003

Document Type

Thesis

Degree Type

MS

Committee Chair

Larry E. Banta

Abstract

The Aluminum reduction process is a nonlinear, time varying electro-chemical process, during which alumina is electrolyzed to produce molten aluminum. Al2O3 A main concern of the aluminum reduction process is the ‘Current Efficiency’-an indicator of the productivity of aluminum reduction cells. How to achieve higher current efficiency with lower energy consumption has always been a central objective of aluminum reduction process control in aluminum reduction industry. Noise is generally considered hostile to cell Current Efficiency. Therefore noise control is an important issue in commercial cell automatic control system. A key contribution of this research is the examination of the effects of “noise” from different sources on the cell efficiency, and the effectiveness of standard control measures in abating this noise. Three types of noise generated during the aluminum reduction process are discussed, and a set of mathematical metrics has been developed to isolate and quantify the levels of each type of noise present in the cell. Real-time algorithms have been implemented to allow on-line estimation of the noise sources and intensities. Simulation tests of the algorithms have been conducted, and the results are presented. ii An advanced data acquisition system using fiber optic communications was built for the purpose of capturing the data required for the noise studies. The hardware and software implementations of the data acquisition system are discussed in detail.

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