Mould for making carbon electrodes by compacting pasty material - with automatic control of vibration rate and electrode height, maximising manufacturing efficiency

摘要

A process and a machine for making carbon electrodes esp for use in Al prodn. by compacting incorporates controlling the rate of vibration and the height of the electrode to increase the rate of mfr. The process consists of compacting a pasty material by vibration in a mould fixed to a vibratory table. The mould is open at thet op for filling and a heavy plate forming a cover is put in from above, after the mould has been filled, and bears on the material during the compacting. Increasing the rate of mfr. comprises effecting the rebounds of the cover regularly and at a frequency which is a fraction of the fundamental frequency of the vibration of the mould, and stopping the compacting automatically when the electrode has the desired height. For frequencies of vibration of the mould between 1100 and 1300 and between 1200 and 1500 per minute, the frequencies of rebounds of the cover will be respectively equal to a half and two thirds of the fundamental frequency of the vibration of the mould. The speed is regulated form analysis of the signal delivered by an accelerometer placed on the cover. The height of all the electrodes is controlled and rate of rejections in reduced. Machine operations is improved and supervision facilitated.