PAPER TECHNOLOGY INTERNATIONAL Runtech introduces new EP AMB Turbo Blower: High efficiency meets high reliability. Anna-Riina Ahonen, Marketing Manager, Runtech Systems

PAPERTECHNOLOGYINTERNATIONAL
Image 2: The open (shroudless) impeller design was developed
to meet two critical needs: lower maintenance requirements
and reduced energy consumption per ton.
“The tolerance against the build-up can be increased but it
means re-thinking the bearing system to make it non-昀椀xed. This is
how we ended up developing AMB turbo blowers. As rotor position
is controllable in AMB system, both static and dynamic positions can
be controlled. In AMB system rotor can be rotated around center
point of mass. So geometrically rotor orbits, resulting in no vibration
and capability to handle high unbalance force. Limiting factor is orbit
size.”
Example of AMB–rotor system
•
Rotating speed 9,600 rpm
•
5 kN unbalance force can be compensated with 15.5
µm orbit
•
In this example, alarm limit for orbit is 80 µm so there is
much more window to operate still
•
Correlation between unbalance and orbit size is linear.
This way turbo blower can be 昀氀exible not only for the
changing conditions of paper making process but also tolerant for its
side effects like dirt and other harsh conditions.
Figure 1 shows unbalance magnitude values in micrometers
from one year time period from EP1000 AMB Turbo Blower.
Beyond the mechanical bene昀椀ts, the AMB system
incorporates built in position sensors and an advanced digital
controller, opening new opportunities for condition monitoring
and predictive maintenance. Because the bearings continuously
measure rotor position and magnetic forces, the blower becomes
a source of diagnostic data rather than a passive component. This
capability complements Runtech’s broader focus on measurementled vacuum control and supports mills in further optimizing
performance.
“Based on our 昀椀eld experience, conventional high-precision
ball bearings can typically tolerate vibration levels equivalent to
roughly 40 µm of unbalance magnitude. When vibration exceeds
this threshold for extended periods, the resulting loads can
accelerate wear and eventually damage the bearings. Situation
changes fundamentally with AMB turbo blowers,” says Aleksi and
explains why: “Because the rotor position is actively controlled, the
system can operate with much higher unbalance forces, meaning
higher unbalance magnitudes, without affecting performance or
reducing lifetime. The primary limits to allowable unbalance are the
clearance of the safety bearings, usually around 200–300 µm, and
the linearity and force capacity of the AMB actuators. Even within
these constraints, the maximum permissible orbit in an AMB system
is signi昀椀cantly greater than what a conventional ball-bearing unit
can tolerate. In the EP1000, for example, the allowed unbalance
magnitude reaches 110 µm, enabling stable operation even under
substantial contamination or material build-up.”
Adjustable vacuum aligns capacity to real operating needs
EP technology utilizes variable-speed turbo blowers
as an ef昀椀cient alternative to conventional vacuum systems in
paper machines, delivering signi昀椀cant energy reductions typically
between 30% and 70%. Because the blowers operate without
water, water handling and treatment infrastructure, such as cooling
towers, associated with traditional systems, is eliminated. Their
variable-speed capability provides precise control of vacuum
levels, allowing the system to respond directly to changing process
conditions and maintain high operational ef昀椀ciency.
The EP Turbo Blowers use high-speed motors controlled
by frequency converters, enabling accurate adjustment of rotational
speed and vacuum output. This level of control is particularly
valuable in new installations where actual vacuum demand often
becomes clear only during early production. By adjusting speed
together with throttling, the system avoids common sources of
inef昀椀ciency and minimizes air losses.
Mechanically, the EP design
is intentionally simple. The impeller
is mounted directly on the motor
shaft, requiring only two bearings and
contributing to higher reliability and
easier installation. With the addition of
Active Magnetic Bearings, the system
removes all mechanical contact
between moving parts, reducing
maintenance needs. These features
support long-term stability and help
lower overall lifecycle costs.
Papermaking environments
are dynamic, and machine speed,
basis weight, and felt condition
昀氀uctuate throughout production.
Figure 1: Unbalance magnitude values in micrometers from one year time period from EP1000 AMB turbo blower.
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