Blowers in modern blast furnaces must deliver air
volumes of up to 400,000 m³/h at about 4 bar–huge
volumes that can only be handled with electrical
power levels far above 30 MW. In most cases, it is
not possible to start such large synchronous
machines directly on the power supply network: Even
in the very powerful supply networks of a steel
plant, this would cause an excessive voltage dip and
put too much mechanical stress on the blower.
With the SIMOVERT S drive system, we offer a
convincing alternative to conventional motor
generator units. It is “convincing” primarily
because of the elegant and safe method to start such
large motors both, smoothly and quickly – without
causing power-on surges or excessive mechanical
stress.
Our solution can dramatically shorten the start-up
times to only one or two minutes. Another advantage
is the fast, nearly bumpless transfer of the motor
to the power supply network. Many plants have a
successful start-up rate of over 99%. This is
crucial for the safety of your blast furnace – after
all, the worst-case scenario of an aborted start is
a furnace that cools down in the charged condition
and is out of operation for up to 10 days.
Siemens Metals Technologies
Blast Furnace