Paper Technology International 2024 - Journal - Page 91
PAPERTECHNOLOGYINTERNATIONAL
Maximizing e昀케ciency through
M
vacuum optimization
Anna-Riina Ahonen, Marketing Manager, Runtech Systems
INTRODUCTION:
By optimizing vacuum usage, strategically measuring water 昀氀ow, and implementing EP Turbo Blowers, mills can reduce energy
consumption by 30-70%. Furthermore, exhaust heat recovery, regular maintenance, and tailored dewatering solutions help achieve
remarkable energy savings, ultimately bene昀椀ting both the environment and operational ef昀椀ciency.
Runtech Systems developed the
EcoFlow dewatering measurement system
already in the 1980s as a tool to better
understand forming and press section
dewatering. Measuring water 昀氀ow accurately
is essential for optimizing vacuum levels.
Many paper mills tend to use excessively
high vacuum levels due to missing or
inaccurate water 昀氀ow data. EcoFlow
dewatering meters are designed to address
this challenge by measuring water 昀氀ow
across mechanical restrictions, unaffected
by entrained air or foaming. Accurate online
water 昀氀ow measurement empowers you to
昀椀ne-tune vacuum levels, ensuring they are
neither excessive nor wasteful.
For substantial energy savings, it’s
essential to use vacuum only where it’s most
critical. By deploying vacuum strategically, you can enhance your nip
dewatering strategy and reduce overall energy consumption.
Nip Dewatering for Enhanced Ef昀椀ciency
The most ef昀椀cient and economical method of water removal
in the press section is nip dewatering. When upgrading the vacuum
system may bring the biggest energy savings, optimized dewatering
with doctoring and save-alls provides often very good results with
a small investment effort, and is an important step in optimizing the
ef昀椀ciency of the paper machine.
Nip dewatering, combined with doctoring, signi昀椀cantly
improves energy ef昀椀ciency and machine performance. A welldesigned and operated dewatering and doctoring system is crucial
for both energy consumption and paper quality. Runtech’s EcoFlow,
save-alls, and double doctors offer a tailored approach to meet
these needs. Combining dewatering improvement with vacuum
system rebuild can bring the biggest bene昀椀ts, especially if the mill is
still using conventional vacuum pumps.
Well-designed and built save-alls with integrated doctoring
are essential to get the full bene昀椀ts from increased dewatering
and ensure ef昀椀cient water discharge with perfect rewet prevention.
Correctly designed Save-Alls are capable of handling 100% nip
dewatering without rewetting. Runtech save-alls are specially
designed for AirBlades and EcoFlow dewatering measurement
systems. They deliver reliable operation in all press and wire section
positions and press section rebuild packages.
Optimized doctoring leads to increased dryness after the
press section. Savings in dryer section steam usage are notable.
Runtech’s offering includes CompoAdapt, a hose loaded blade
holder providing easy maintenance and trouble-free operation and
CompoDoc carbon 昀椀ber doctor beams with excellent doctoring
performance. Double doctors provide optimal doctoring for suction
couch and press rolls. AirBlades are air assisted doctor blades
for the press rolls that enable high nip dewatering even with low
machine speeds, help with roll cleanliness problems, improve
moisture pro昀椀les and have a positive effect on machine speed.
Changing Conditions Call for a Flexible Vacuum System
After digging deeper into the impact on dewatering, we
realized that the vacuum system needs to be 昀氀exible, as paper
machine conditions change all the time. For example, the machine
speed can easily vary from 200 to 1,100 m/min depending on basis
weight, furnish and felt condition changes over time. This means
it is not optimal to have the same amount of vacuum (kPa and/or
air 昀氀ow) in different conditions. Our over 30-year experience in the
昀椀eld has taught us the importance of measuring water removal and
controlling vacuum levels.
Traditional vacuum technologies proved unsuitable when the
target was to optimize vacuum levels, minimize energy consumption
and adapt to changing conditions.
91
