PROCESS OF CONTROL OVER ELECTROLYZERS WINNING ALUMINUM AND GEAR FOR ITS IMPLEMENTATION Russian patent published in 2002 - IPC

FIELD: non-ferrous metallurgy, winning of aluminum from alumina by electrolytic process. SUBSTANCE: process of control over electrolyzers winning aluminum consists in keeping of temperature condition in electrolyzer by way of adjustment of distance between poles and of concentration of alumina within specified limits of alternation of conditions of excessive and deficient supply and includes measurement of voltage across electrolyzer and of current of series, computation of present values of reduced voltage U_red and rate of its change in time dU_red, comparison of obtained values with preset values and making decision on adjustment of distance between poles and transfer to condition of excessive or deficient supply of alumina according to comparison results. Transfer from condition of deficient supply to condition of excessive supply is conducted when rate of change of reduced voltage in time reaches value U_red, transfer from condition of excessive supply to condition of deficient supply is conducted when rate of change of reduced voltage in time reaches value dU_red/dt>G₁, where dU_red/dt<G₂ are threshold values of rate of change of reduced voltage determined experimentally. Distance between poles is adjusted at moment of transfer from condition of excessive supply to condition of deficient supply provided that G₁,G₂, where /U_red-U₀/>ΔU, is rated value of reduced voltage; U₀ is insensitivity zone specified by technological requirements. Description presents functional circuit of gear. EFFECT: raised quality of control over electrolyzers fitted with ΔU systems. 9 cl, 7 dwg