METHOD FOR CONTROLLING THE ALUMINA FEED TO REDUCTION CELLS FOR THE PRODUCTION OF ALUMINIUM

摘要

PCT No. PCT/NO86/00017 Sec. 371 Date Dec. 17, 1986 Sec. 102(e) Date Dec. 17, 1986 PCT Filed Feb. 17, 1986 PCT Pub. No. WO86/05008 PCT Pub. Date Aug. 28, 1986.Method for controlling the alumina feed to reduction cells for the production of aluminum. There is employed an adaptive control with parameter estimation (3) and controller calculation (2) based upon the separation theorem. As a process model there is used a linear model having two inputs and one output. One input (u1) is in the form of alumina feeding minus assumed alumina consumption. Another input (u2) is in the form of movements of the reduction cell anode. The output (y) is in the form of the change in electric resistance across the reduction cell concerned. The model is of the first order in u1 and u2 whereas it is of the order zero in y. An estimated parameter (b1) represents the slope of the curve for resistance as a function of alumina concentration in the electrolytic bath, and the controller (2) controls the addition of alumina to the electrolytic bath in response to the value of b1.