
134 Control for Aluminum Production
Needless to say, the above control action does not address the cause
of the noise and it, therefore, returns in many cases when the voltage is
returned to normal. This is particularly the case if the noise is not due to
any lack of heat input to the bath and cathode (which is addressed by the
increase in voltage).
“Seems like there’s something going on with the noise, Rob. There’s a lot
of extra voltage on a lot of pots, due to high noise. However, some are getting
a lot more than others, and it doesn’t correspond to a particular crew, or with
particular anode setting groups, or anything else obvious.”
Rob sa ...