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| Introduction
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The
System was
designed to
provide a accurate
simultaneous
measurement
of |
|
the
individual Contact
Pad kilo amps
& summated
electrode current
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This
has not been
possible in the
past.
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|
H.V.
Test cc in South
Africa have
developed a unique
system for
the
|
|
measurement
of these currents.
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A
number of these
systems have been
successfully
operating on
submerged
arc
|
|
closed
top furnaces since
1998
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System
Goal
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The
measurement of the
individual electrode
contact pad currents
using |
|
current
transducers, signal
processing,
isolation and a
monitoring system |
|
The
system can be
integrated into the
existing PLC furnace
control system |
|
The
goal is to monitor
each contact pad to
determine when
overloading |
|
&
under loading occurs
due to poor contact
or green electrode
problems. |
|
The
System can record
trends predicting
contact pad
problems,
electrode |
|
slipping
changes and possible
green electrode
changes |
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|
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The
System
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Each
set of bustubes is
monitored by the system
and individual signals are
transferred to the control
room. The signals can be
incorporated in the
existing monitoring and
recording system or a
dedicated PC. The PC will
present a visual picture
of the furnace, the
contact pads and the
electrodes. When a Contact
Pad is been overloaded or
underloaded the screen
will alarm red or green
together with a audible
alarm.
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Next
to each contact shoe, the
current in KA will be
reflected together with
the phase
current/transformer as
well as the victory
summated electrode current
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Should
the current on the contact
pads vary dramatically
this could be an
indication of:
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Poor
Contact pad service
pressure problems |
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Overslipping
of the electrode and
that a green
electrode is eminent |
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Indication
of furnace mix
problems |
|
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Electrode
Breakages |
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Secondary
Transformer winding
overloading |
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Cooling
water temparature
problems |
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Electrode
casing problems |
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Cavitation
in the electrode |
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Conclusion
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We
believe that this
monitoring system will
provide the furnace
operators with valuable
information allowing
optimised operation of the
furnace
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