Actuators help cut emissions
November 1st 2008 ABB has supplied six rotary
actuators worth £40k+ to
Halifax Fan as part of a
project to cut emissions of
NOx from three boilers at a
2000MW coal-fired power
station. The project, known
as BOFA, or Boosted Over
Fire Air, cuts NOx released
to atmosphere by enabling
the power station to burn
coal at a lower temperature.
Over fire' air is injected
into the boiler above the
main burner.It mixes with
the tails of the flames to
cool the gases. Boosted air
is transported from the
secondary air duct to the air
duct at the top of the boiler
by two fans at the base of
each boiler.
The six ABB RHD800
Contrac electric part-turn
actuators control the pitch
of the vanes on the BOFA.
They apply a force of up to
800Nm to move the fan
vanes fans by up to 9°/sec
and are well suited to
operating this type of
control element, which has
a 90° rotary movement. More articles from ABB Ltd: | 
