Patent ID: 7429314
Filing Date: 2008-09-30
Classification: C25C

Abstract:
1. Device for controlling the travel distance of a chisel for a feeding system of an electrolytic cell for aluminum production, the cell containing an electrolytic bath covered with a crust, where the chisel is carried by a rod fixed to a rod of an actuator controlling vertical displacement of the chisel between a high position in which it is above the crust and a low position in which the crust is perforated and in which contact is made with the bath, the device comprising: an electrical circuit comprising means for measuring an electrical parameter between the chisel and a point in the cell used as an electrical reference; a first connection means for electrically connecting the circuit and the chisel; a second connection means for electrically connecting the circuit and the point in the cell; and means for causing the actuator to provide immediate vertical upwards displacement of the chisel when a predetermined value of the electrical parameter is measured, indicating that the chisel is in contact with the bath; wherein the first connection means comprises a conducting part, in electrical connection with the circuit, and means for elastically urging the conducting part into direct mechanical contact with at least one point on the chisel, the rod of the chisel or the actuator rod, resulting thereby in a point contact with the chisel, the chisel rod or the actuator rod.