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Alumina Production Carbonation Decomposition Process Operating Parameters To Optimize Settings And Control Strategy

Posted on:2012-06-28Degree:MasterType:Thesis
Country:ChinaCandidate:Y HuFull Text:PDF
GTID:2211330335490053Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
In the process of sintering alumina production, the alumina continuous carbonation decomposition process (ACCDP) is a critical procedure, combination reaction of the sodium aluminate solution produced by upstream desiliconization process and carbon dioxide gas is occurred, and aluminium hydroxide with certain quality index is produced. ACCDP has many characteristics such as multivariable, nonlinear, strong-coupling, large inertia, large delay where complex multi-phase chemical reactions are involved.The ACCDP is composed of six series decomposition tanks, the decomposition ratio of each tank increases gradually, formed decomposition ratio gradient, which is the important process index in the ACCDP. The operating parameters must be optimized to ensure decomposition ratio is met. On the basis of analyzing the decomposition mechanism of the ACCDP, the model of decomposition ratio is established by neural network, using the measuring data from industrial field. The variables are reduced by principal component analysis(PCA), makes the model more accurate and reasonable. The operating parameters which influence the decomposition ratio are adjusted to make sure the ratio of intermediate tank within the target range, and the ratio of the last tank is maximum. The optimization settings are obtained by the Genetic Algorithm(GA).The ACCDP is a complex process involving multiple-phrase reaction, which has properties like nonlinear, strong-coupling, large delay, leading the decomposition ratio is difficult to control. Expert control system is used because of these characteristics, which makes optimization settings of the parameters are adjust according the components of sodium aluminate solution. Therefore, both the quality and the output of aluminum hydroxide are improved. The expert rules library of control circuit are established, and the optimal control of decomposition ratio is realized.
Keywords/Search Tags:continuous carbonation decomposition, decomposition ratio gradient, neural network model, optimization of operating parameters, expert control
PDF Full Text Request
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