Dealing with fly ash
Putzmeister outlines how its pumps have helped save
resources at Europe's largest coal power station
he Belchatow power station in the Polish
province of Łódź has a capacity of 5,420
MW, making it Europe's largest brown coal
power station. It is considered the third largest
coal power station in the world. Some 28 TWh of
electrical energy, equivalent to around 20% of
Poland's entire power requirement, are
produced every year. The operator is PGE GieK,
a company of the PGE Group, Poland's largest
energy supplier. PGE produces electricity and
thermal energy, primarily for the central and
western parts of the country. Most of this energy
comes from fossil fuels, but some also comes
from renewable resources.
As it combusts coal, this colossal power
station produces an enormous amount of fly
ash. However, the construction materials
industry has only a few customers for this
product. The fly ash from brown coal
combustion is lower grade than that from hard
coal. The vast majority, therefore, is landfilled or
used as backfilling material. If the landfill site is
full, it is re-cultivated at a later time.
T
much as that required for the old pump variant.
At around 8,000 hours of continuous operation
per year, this is no mean amount. For around
two years now, the Putzmeister pumps have
operated reliably 24 hours a day, 7 days a week.
They are equipped with high-performance Duro
26 components. Their service life has doubled
from the original design of 2,000 hours to a
genuine 4,000 hours. This significantly reduces
maintenance costs compared to conventional
wearing parts and improves the availability of
the plant as a whole.
Pressure fluctuations in the material
optimally mastered with PCF
The PCF control is important for trouble-free
operation: pressure fluctuations are reduced,
the pipeline is protected
the power station to shut down. The
consequences do not even bear thinking about.
The reliability of the pump system, then, is
paramount. That's where Putzmeister came in.
In 2013, a total of six HSP 25150 HP seat valve
pumps featuring the Putzmeister PCF system,
The ash slurry is conveyed eight
kilometres to the landfill site
Reliability key to success
The landfill site for the ash slurry is around 8 km
away from the power station unit itself. The
former system with centrifugal pumps was
overburdened by both the volume and also the
long pumping distance. The wear rate increased
drastically. Failure of the pumps, and hence no
removal of the fly ash, would effectively cause
each driven by a 800 kW hydraulic unit, were
installed for transporting the fly ash of the
entire power station. Currently, there are three
pump lines in operation and three on stand-by.
Some 600 m 3 of fly ash slurry are pumped every
hour.
Six individual DN 200 PN 100 delivery lines
(maximum 100 bar), each 8 km long, lead from
the pumps to the landfill site. Each pump can be
connected to each of the pipelines via a
coupling station – a kind of "shunting yard".
Pressures may vary in the delivery lines, since
the fly ash itself has different compositions –
depending on the seam from which the coal
comes. In order to protect the long pipelines
from wear, PCF controls are installed at the
Putzmeister pumps. The so-called Putzmeister
Constant Flow control reduces the pressure
differences that occur during the pumping
switchover process and
creates a more
consistent flow in the
pipeline. This is
extremely important,
since the long
conveyor line could
experience vibrations if
the pressure were to
vary constantly. In this
case, the pipeline
would be at risk of
blocking and even
breaking. The plan is to expand the power
station with a new modern unit with a capacity
of approximately 800 MW. This is to have two
further identical pump lines for transporting the
fly ash. IM
Water and power consumption
drastically reduced
Two of the six HSP 25150 HP pumps in
Belchatow power station
Because Putzmeister pumps are capable of
conveying much drier material, the water
consumption is considerably less. The HSP
pumps manage a 1:1 mixture of fly ash and
water, relative to weight. The old centrifugal
pumps required a mixture of 1:10. Previously, the
420 t of fly ash accumulating per hour had to be
mixed with 4,200 t of water. Today, only 10% of
this water quantity is required and so the
volume flow rate is drastically reduced. As a
result, the power consumption is around half as
The fly ash mixture conveyed by the
Putzmeister pumps contains only a tenth of the
water compared to previously