|
(11) | EP 0 203 026 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|||||||||||||||
| (54) | Rock crusher including improved feeder control |
| (57) A method and apparatus for controlling the operation of a rock crusher and feeder
such that the rate of supply by the feeder to the crusher hopper is kept within carefully
controlled parameters and such that the power level at which the crusher operates
is maintained within a narrow range at the optimum operating range of the rock crusher.
A microporces- sor having a first PID control loop receives an input signal from a
transducer sensing the power draw by the crusher motor and a second PID control loop
receives a signal from an analog level sensor measuring the level of rock in the hopper.
The first PID compares the sensed power draw with a selected maximum power draw and
produces an output signal proportional to the difference between the sensed power
draw and the selected power draw. The second PID compares the sensed level in the
hopper to a selected or desired level in the hopper and produces a signal proportional
to this measured difference. The signal from the first PID and the signal from the
second PID are transmitted to an arbitration routine for comparing the signals. The
first or second signal calling for the lower feeder speed will be transmitted to the
feeder variable speed drive. |