How to save energy up to 30-70% in paper machine vacuum system? - Paper Technology International 2023 - Paper Technology International 2023 - Flipbook - Page 43

How to save energy up to 30-70% in paper machine vacuum system? - Paper Technology International 2023

PAPERTECHNOLOGYINTERNATIONAL How to save energy up to 30-70% in paper machine vacuum system? - Paper Technology International 2023
Figure 4: EcoFlow is the only reliable and accurate online
dewatering measurement system for water that contains lot of
air. When you measure the water flow accurately, you can adjust
the vacuum optimally and reach high energy efficiency.
increased dewatering, an online dewatering monitoring, efficient
water discharge and rewet prevention are necessary. Runtech
Ecoflow, save-alls and double doctors can perfectly match these
needs.
There are some additional ways to ensure optimal vacuum
levels and thus save energy. By using nip dewatering instead of
uhle box dewatering, you get better profiles and improve dewatering
without vacuum.
Here are some things to pay attention to:
•
Felt moisture ratio has to be high enough.
•
You need to have right type of felts.
•
Roll covers need to have grooves instead of blind
drillings.
•
Well-functioning save-alls and doctors are a must to
prevent rewetting. A doctor rebuild can reduce the need
for vacuum by up to 50%.
•
AirBlades are suitable for lower machine speeds.
Optimized doctoring and dewatering improve process
performance and dryness after press, lowering the need for steam
(1% dryness means 4% steam savings). This, in turn, results in
electrical and steam energy savings.
Recover and reuse exhaust heat
The EP Turbo blower produces approximately from 5 to 20
m3 of exhaust heat per second. By recovering this 100–180°C heat,
you will be able to lower steam consumption at your paper machine.
Recovered exhaust heat can be used, for example, to warm up
shower waters or dryer hoods.
Since steam is one of the most expensive components in
papermaking, heat recovery will lead to significant cost savings.
Reusing exhaust heat boosts sustainability, too. Replacing primary
energy sources by heat recovery reduces your carbon footprint as
in many places steam is produced by combusting fossil fuels that
cause CO2 emissions.
Figure 5: A well-designed and operated dewatering and
doctoring system is one of the key issues to a well-performing
and energy-efficient machine.
Figure 6: Heat recovery, as an important part of the RunEco
solution, cuts down papermaking energy costs radically because
the system reuses heat to replace primary energy sources.
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