Electrolysis control apparatus and method

A method for controlling an electrolysis reaction in an apparatus having a plurality of anode units positioned above at least one cathode where current is conducted between each anode unit and a cathode comprising the steps of,

• generating a plurality of current measurement signals, one for each of said anode units, where each of said current measurement signals is proportional to the current in a different one of said anode units,
• detecting each of said current measurement signals to detect changes in current with respect to time in any of said anode units which exhibit oscillations having a frequency of less than approximately one cycle per second,
• generating an oscillation alarm signal in response to detection of said oscillations,
• generating a plurality of voltage measurement signals, one of each of said anode units, where each of said voltage measurement signals is proportional to the voltage between a different one of said anode units and a cathode,
• comparing each of said voltage measurement signals with a voltage limit signal to provide a limit alarm signal whenever any of said voltage measurement signals exceeds said voltage limit signal.

A method for controlling an electrolysis reaction in an apparatus having a plurality of anode units positioned above at least one cathode where current is conducted between each anode unit and a cathode comprising for each of said anode units the steps of,

• generating a current measurement signal proportional to the current in a different one of said anode units,
• generating periodically each increment of time a current change signal as a function of said current measurement signal,
• comparing said current change signal with a predetermined constant change signal,
• storing an accumulated measurement signal,
• incrementing or decrementing said accumulated measurement signal as a function of whether said current change signal is greater than or less than, respectively, said predetermined constant change signal,
• comparing said accumulated measurement signal with a predetermined measurement constant to form an indication that oscillations are present when said accumulated measurement signal exceeds said predetermined measurement constant.

The method for controlling an electrolysis reaction with apparatus including a power supply, a plurality of buses, a plurality of anode units where each anode unit is connected to a different bus, where the andoe units are positioned in proximity to a cathode and immersed in an electrolyte and where current is conducted from the power supply through the buses, from anode to cathode through the electrolyte, the steps comprising,

• sensing the current in each of said buses to form, for each anode unit, a current measurement signal having an amplitude proportional to the current in the respective anode unit,
• periodically sampling, for each anode unit, said current measurement signal to form a first sampled current measurement signal each increment of time, .DELTA.t, and where each first sampled current measurement signal becomes a second sampled current measurement signal after an increment of time, .DELTA.t,
• generating periodically each increment of time .DELTA.t a current change signal, .DELTA.Ib, for each anode unit, where .DELTA.Ib is equal to the difference between the first sampled current measurement signal and the second sampled current measurement signal,
• comparing each current change signal, .DELTA.Ib, with a predetermined constant signal, .epsilon., for each anode unit,
• storing an accumulated measurement signal, Xb, for each anode unit,
• adding, for each anode unit, said accumulated measurement signal, Xb, to an incremental quantity, Yb, where Yb varies as a function of whether said current change signal is greater than or less than said predetermined constant signal, .epsilon.,
• comparing, for each anode unit said accumulated measurement signal, Xb, with a predetermined measurement constant to form an indication of oscillation when said accumulated measurement signal, Xb, exceeds said predetermined measurement constant,
• changing the spacing between the anodes and cathode in response to said indication of oscillation.

A method for controlling an electrolysis reaction with apparatus including a power supply, a plurality of cells, a plurality of buses where each bus connects to each cell, a plurality of anode units in each cell where each anode unit is connected to a different bus, where the anode units in each cell are positioned in proximity to a cathode and are immersed in an electrolyte and where current is conducted from the power supply through the buses, from anode to cathode through the electrolyte, comprising sequentially for each cell the steps of,

• sensing the current in each of said buses to form, for each anode unit, a current measurement signal having an amplitude proportional to the current in the respective anode unit,
• periodically sampling for each anode unit, said current measurement signal to form a first sampled current measurement signal each increment of time, .DELTA.t, and where each first sampled current measurement signal becomes a second sampled current measurement signal after an increment of time, .DELTA.t,
• generating periodically each increment of time, .DELTA.t, a current change signal, .DELTA.Ib, for each anode unit, where .DELTA.Ib is equal to the difference between the first sampled current measurement signal and the second sampled current measurement signal,
• comparing each current change signal, .DELTA.Ib, with a predetermined constant signal, .epsilon., for each anode unit,
• storing an accumulated measurement signal, Xb, for each anode unit,
• adding, for each anode unit, said accumulated measurement signal, Xb, to an incremental quantity, Yb, where Yb varies as a function of whether said current change signal is greater than or less than said predetermined constant signal, .epsilon.,
• comparing, for each anode unit said accumulated measurement signal, Xb, with a predetermined measurement constant to form an indication of oscillation when said accumulated measurement signal, Xb, exceeds said predetermined measurement constant,
• changing the spacing between the anodes and cathode in response to said indication of oscillation.

An apparatus providing alarm signals for monitoring an electrolysis reaction comprising,

• an electrolysis cell having a plurality of anode units, having a cathode and adapted to have an electrolyte where anode current is conducted from the plurality of anode units through the electrolyte to the cathode,
• means for generating a plurality of measurement signals, at least one for each of said anode units, where each of said measurement signals is proportional to an electrical parameter of a different one of said anode units,
• detecting means, detecting said measurement signals as current measurement signals, for detecting for each of said anode units changes in anode current with respect to time exhibiting oscillations having a frequency which is less than one cycle per second,
• first means for generating an oscillation alarm signal in response to detection of said oscillations by said detecting means, and
• second means for generating a limit alarm signal in response to one or more of said measurement signals exceeding a limit signal.

In an electrolysis apparatus including a power supply, a plurality of buses, a plurality of anode units where each anode unit is connected to a different bus, where the anode units are positioned in proximity to a cathode and immersed in an electrolyte and where current is conducted from the power supply through the buses, from anode to cathode through the electrolyte, the apparatus for controlling an electrolysis reaction comprising,

• means for sensing the current in each of said buses to form, for each anode unit, a current meansurement signal having an amplitude proportional to the current in the respective anode unit,
• means for periodically sampling, for each anode unit, said current measurement signal to form a first sampled current measurement signal each increment of time, .DELTA.t, and where each first sampled current measurement signal becomes a second sampled current measurement signal after an increment of time, .DELTA.t,
• means for generating periodically each increment of time .DELTA.t a current change signal, .DELTA.Ib, for each anode units, where .DELTA.Ib is equal to the difference between the first sampled current measurement signal and the second sampled current measurement signal,
• means for comparing each current change signal, .DELTA.Ib, with a predetermined constant signal, .epsilon., for each anode unit,
• means for storing an accumulated measurement signal, Xb, for each anode unit,
• means for adding, for each anode unit, said accumulated measurement signal, Xb, to an incremental quantity, Yb, where Yb varies as a function of whether said current change signal is greater than or less than said predetermined constant signal, .epsilon.,
• means for comparing, for each anode unit said accumulated measurement signal, Xb with a predetermined measurement constant to form an indication of oscillation when said accumulated measurement signal, Xb, exceeds said predetermined measurement constant,
• means for changing the spacing between the anodes and cathode in response to said indication of oscillation.

An apparatus for controlling a plurality of electrolysis cells where each cell includes a plurality of anode units, where anode units from different cells are connected to a plurality of current buses, and where each cell includes a cathode, the control apparatus, comprising,

• a plurality of cell instrumentation packages, one for each of said cells, each of said cell instrumentation packages including a plurality of current sensing means, one for each of said current buses, addressable multiplexer means for multiplexing current measurement signals from each of said current sensing means, an analog-to-digital converter for converting multiplexed current measurement signals from said multiplexer means into digital current measurement signals, transmitter and receiver means connected to said analog-to-digital converter for transmitting said digital current measurement signals as a data output, and receiver means for receiving addresses for controlling said multiplexer means,
• data processing means including means for generating addresses for said multiplexer means in each of said cell instrumentation packages, means for receiving and storing said digital current measurement signals at locations curresponding to said addresses, means for processing said digital current measurement signals to determine when current in any of said current buses has changes with respect to time that exhibit oscillations,
• means for generating an oscillation alarm whenever said oscillations are detected.