Patent ID: 6065867
Filing Date: 2000-05-23
Classification: C25C

Abstract:
A method for measuring temperature and electrolyte level of a molten electrolysis bath in a cell for production of aluminum by electrolysis of alumina dissolved in said electrolyte, said electrolyte being in contact with carbonaceous anodes and resting on a sheet of liquid metal formed on a cathodic substrate, the surface of said electrolyte being in contact with air in an upper part of the cell and covered by a crust of solidified bath, comprising the steps of:a) piercing of the crust of solidified bath with a crust breaker and immersing into the electrolyte, through an aperture thereby created, an extremity of a temperature probe to a sufficient depth until an initial temperature reading of at least 850.degree. C. is measured, then maintaining the immersion of the probe, measuring additional temperature values over time, in said electrolyte for a length of time, which is less than the time taken to establish the thermal equilibrium of the probe in the electrolyte,b) withdrawing the probe and determining a temperature of the electrolyte by extrapolation of the additional temperature values measured by the probe by comparison with pre-established calibration data,c) measurement of the level of electrolyte in the cell by moving the lower extremity of the probe into contact with the electrolyte while recording potential signals between the cathodic substrate and the probe, and recording position signals corresponding to the position of the probe,d) determining the level of the electrolyte by comparison of recorded potential and position signals.