AUTUMN 2019
WELDING
What a
wonderful weld
Automated weld overlay repair improves
efficiency for biomass power plant.
stations as well as ensure plant
availability, performance and
efficiency.
In an effort to increase the
durability of its essential assets,
maintenance planners at the power
station wanted to repair the boiler walls
with a long-lasting solution that could be
completed with minimal disruption.
Fuelling plant effi ciency
The plant, located in Londonderry, was
built and is operated by Burmeister & Wain
Scandinavian Contractor A/S (BWSC), a
provider of medium-sized commercial scale
power plants. The facility uses recycled
wood as the main feedstock to generate
six megawatts of heat (MWth) and 18.2
megawatts of power (MWe), 15.8 MWe of
which is then used to power 30,000 local
homes and businesses.
The key piece of equipment at the
Lisahally plant is the two-pass biomass grate
boiler, which generates high-temperature,
high-pressure steam by combusting the
wood-based material fed to its furnace. >>
The steam is then transferred to a turbine,
coupled with a generator to produce
electricity. Waste steam is condensed into
water and fed back to the boiler via a closed
loop system.
As corrosion and erosion were affecting
the integrity of Lisahally Power Station’s heat
exchange system, i.e. boiler furnace and wall
tubing, plant managers contacted Sulzer to
help them conduct the necessary repair work.
The company’s Tower Field Service group
provides specialised field services with over
40 years of experience in tower, drum and
Biomass is becoming an increasingly
popular fuel solution for power
generation. It is one of several
technologies being implemented to
improve the sustainability of power
supplies as demand continues to
increase. As with all facilities, regular
maintenance is required to ensure
operability and any repairs need to
be carried out quickly and to a high
standard. When the walls of the boiler
in Lisahally Power Station, in Northern
Ireland, had sustained erosion and
corrosion damage, Sulzer used its
automated weld overlay technology to
extend the service life of the boiler and
ensure that the plant could continue to
run at peak performance.
The fuels used to operate biomass power
plants cause corrosion and erosive wear
in boilers. In fact, biomass can release
contaminants, such as alkali metals, chlorine,
sulphur and other corrosive chemicals, when
burned. As a result, regular maintenance
is fundamental to maximise the lifespan
and reliability of equipment in these power
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