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How to Improve the Iron Removal Effect of Electromagnetic Iron
Remover
In recent years, a method to improve the efficiency of iron
removal has been developed, which implements "short-term strong
excitation" for electromagnets, i.e. installing a sensor at the
front of the electromagnet pole boot and at the bottom of the
conveyor belt. Its purpose is to use the sensor to detect the
magnetic material farthest from the pole boot and weakest
attraction effect, and then transmit the detected signal to the
strong excitation rectifier through the sensor to make the
magnetic material. Then, when passing under the pole boot, a
high supply voltage is applied to the magnet coil for a short
time, resulting in a strong magnetic force flow, which makes the
electromagnetic attraction increase sharply in a short time, so
that the magnetic material buried in the depth can be sucked
out, and then the voltage will be restored to the normal supply
state. The purpose of the sensor installed in front of the pole
boot is to avoid the interference of electromagnetic field.
Generally, when iron is in the upper or middle part of the coal
seam, the sensor is not allowed to send effective signals. Only
when iron is buried in the bottom of the coal seam, can it send
effective signals.
The sensor has the following links:
Normal Excitation Trigger Control Link
Mainly for the normal excitation control of the electromagnet,
it is necessary to have the function of trigger pulse phase
shifting adjustment to control the main and the same circuit
thyristor KP1 and KP2 to achieve the normal excitation current
regulation.
Intensive Excitation Delay Control Link
It provides the time delay from the detection of ferrous signal
to the time when ferrous material just runs to the front end of
electromagnet pole boot, then starts the strong excitation
control signal, starts the strong excitation trigger link, and
carries on the strong excitation at a good time, and reduces the
strong excitation time as much as possible, so as not to miss
the purpose of catching the good opportunity. Strong Excitation
Time Control Link The main purpose is to control the duration of
the forced excitation, control the time of the forced excitation
at the front of the front pole boot and at the back of the rear
pole boot, and control the time of the forced excitation within
a good range. Strong Excitation Trigger Control Link Under the
control of the time delay and the time of the strong excitation,
it sends out the trigger pulses to the controllable silicon KP3
and KP4 of the main circuit of the strong excitation at the
right time to carry out the strong excitation. In addition, the
trigger pulse need not be controlled by phase shifting, only the
trigger angle can be controlled to a minimum, so as to obtain a
larger excitation current.
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