Case study – MDF refiner plates

Case study
Lower energy consumption and high fiber quality
ANDRITZ MDF Spiral refiner plates
www.andritz.com
We accept the challenge!
The challenge: Reduce energy costs and
increase fiber quality
Current
situation
MDF producers are facing a situation with
That is why there is no alternative but to
considerably more competitive pressure
make more efficient use of existing refiner
globally, while being confronted at the
plants.
same time with a drop in raw material
With these requirements, ANDRITZ refin-
quality and higher demands on the qual-
er plate technology is also breaking new
ity of the final product. Rising energy costs
ground and presenting important innova-
always account for a large part of the
tions for energy-efficient operation of ex-
manufacturing costs in MDF production.
isting refiner units.
Fiber samples from refining with standard plates
Parallel design
Ro
ion
tat
70°
Rota
tion
The ANDRITZ solution: MDF Spiral
refiner plate technology
Before the innovative ANDRITZ MDF Spi-
constant breaks in the fiber pad. In addi-
ral design was developed, all models had
tion, the following was noted: the smaller
parallel bars with varying cutting angles
the cutting angle, the higher the number
depending on the current position of the
of fiber cuts. And the larger the cutting
fibers on the refiner plate. Parallel bars
angle, the higher the fines content. This
do have an average cutting angle of 30°
means that the fibers are treated differ-
between rotor and stator, however the
ently depending on their position on the
range can fluctuate between 17° and 38°.
refiner plate.
The parallel refiner plate design is accompanied by erratic raw material feed and
Crossing angle in course of
sweeping process
76°
55°
34°
38°
17°
Bar angle
Ro
n
tatio
58°
Rotat
ion
Analysis and
evaluation
The challenge: Reduce energy costs and
increase fiber quality
ANDRITZ
innovation
The diagram shows how the cutting angle
the outer sector it is produced more by
thus tapers from the inner diameter out-
crushing in the refiner gap. This is why
wards as the rotor rotates against the sta-
short, broad fibers are produced in the in-
tor. This reduction in cutting angle has a
ner sector and long, thin fibers in the outer
negative impact on the fiber quality and
sector. Due to the varying cutting angles
on energy consumption. In the inner sec-
in parallel bar refiner plates, the load on
tor of the refining zone the fiber is pro-
the cutting edges varies, which can lead
duced more by the cutting effect, while in
to higher energy consumption.
Fiber samples from refining with ANDRITZ MDF Spiral plates
ANDRITZ Spiral design
ta
Ro
tion
58°
Rotat
ion
The ANDRITZ solution: MDF Spiral
refiner plate technology
Unlike the parallel bar refiner plates, the
The cutting angle zones can also be il-
Spiral refiner plate has a constant cutting
lustrated in a graph of the cutting angle
angle formed by the logarithmic shape of
spectrum. This shows the angle of the re-
the bars, and fiberizing takes place with
finer plate and the cutting angle applied
the same angle over the entire refining
as the rotor rotates. The constant angle of
zone. Due to the constant cutting angle,
the refiner bars on the Spiral refiner plate
a homogenous fiber spectrum is created.
and the constant cutting angle are illus-
The energy consumption can be reduced
trated as one single point in the diagram.
by up to 20% compared to conventional
By contrast, the parallel bar refiner plate
designs due to the high fiberizing intensity
with its refiner bars at varying angles and
of this design. A further positive aspect of
changes in cutting angle as the rotor ro-
the Spiral refiner plates is the reduction in
tates is displayed as a wider spectrum in
vibrations achieved by even fiber trans-
the diagram.
port in the refining zone
50°
Crossing angle in course of
sweeping process 40°
30°
20°
10°
0°
10° 15° 20° 25°30°35° 40° 45° 50°
Bar angle
R
io
otat
n
58°
R o tati
on
ANDRITZ
innovation
The challenge: Reduce energy costs and
increase fiber quality
ANDRITZ
innovation
Spiral (top) vs. standard pattern (bottom)
In the meantime, the new Spiral refiner
MDF producers are also facing a situa-
plate technology is available for all types
tion with considerably more competitive
and sizes of refiner. It has been tested
pressure globally, while being confronted
successfully on all continents and has
at the same time with a drop in raw ma-
already become established as standard
terial quality and higher demands on the
plate equipment in many mills. Depending
quality of the final product. Rising energy
on the process requirements and charac-
costs always account for a large part of
teristic production data (throughput, re-
the manufacturing costs in MDF produc-
quired fiber quality, specific energy con-
tion. That is why there is no alternative but
sumption, quality of raw material, etc.),
to make more efficient use of existing re-
ANDRITZ develops a refiner disc design
finer plants.
to suit a specific customer’s needs and
With these requirements, ANDRITZ refin-
then assesses the result. If necessary, the
er plate technology is also breaking new
refiner disc design is then adapted to suit
ground and presenting important innova-
specific customer requirements.
tions for energy-efficient operation of existing refiner units.
The ANDRITZ solution: MDF Spiral
refiner plate technology
Customer
references
SEC (kWh/t)
Energy savings: 4%
ANDRITZ MDF Spiral 58" plate Ø
105 kWh/t
ANDRITZ 58" Parallel plate
Ø 109 kWh/t
PLT (Days)
In one test series the 58” MDF Spiral re-
In this case, the specific refining energy
finer plate design was compared with
was 4% less, whereas the fiber quality
the 58” ANDRITZ parallel bar design.
showed an improvement.
SEC (kWh/t)
Energy savings: 7%
ANDRITZ MDF Spiral 48" plate
Ø 135 kWh/t
Competitor 48" plate
Ø 145 kWh/t
PLT (Days)
The second example shows a 48” ­Spiral
The comparison of refiner plate lifetimes
refiner plate (48SD801/811) i­n a compari-
(PLT) shows that there are no differences
son with a plate from a different manufac-
when using MDF Spiral refiner plates. The
turer. Here, too, 7% of the specific energy
service lifetime of the refiner plate is de-
could be saved, while maintaining the
pending on its design and intensity.
same fiber quality.
In both of the examples shown above
there was a positive increase in the PLT.
If savings of 10 kWh/t at an output of 20 t/hr are assumed and the energy costs are
calculated at 0.07 €/kWh, the annual savings potential is as follows:
10 kWh/t x 20 t/hr x 24 hrs/day x 365 days/year x 90% availability x 0.07 €/kWh
≈ 110,000 € per year
Benefit &
savings
Expert support
for the MDF industry
Production reliability, reduced energy
Our process experts can help you opti-
costs, consistent quality, and maintenance
mize your refining process to keep pro-
efficiency are the key challenges facing
ductivity and quality at a high level. Fol-
MDF manufacturers. To ensure that you
lowing a thorough analysis of your refining
meet these challenges, ANDRITZ offers
process, we offer advice on how you can
a portfolio of technologies, services, and
reduce the amount of energy required to
process experts who can help you extract
manufacture your fiberboard product and
the maximum productivity from your refin-
increase refining quality.
ing system.
Technology and service are the highest
priorities at ANDRITZ. We provide the
world’s best plate designs to meet your
demands for lower energy consumption
Kastamonu Entegre Agaç San.Tic.A.S.
and improved fiber quality (or lower resin
in Turkey is already using the MDF Spiral
usage) due to longer average fiber length.
refiner plate technology successfully in its
Adaptations to general plate designs can
48” and 66” lines.
be tailored to your individual application.
Andritz Inc.
Tualatin, OR, USA
Phone +1 (503) 691-5106
Andritz AG
Vienna, Austria
Phone +43 (1) 81195 6288
www.andritz.com
MDF_Plates@andritz.com
All data, information, statements, photographs and graphic illustrations made in this leaflet are without any obligation and raise no liabilities to or from part of any sales contracts of Andritz
AG or any affiliates for equipment and/or systems referred to herein. © Andritz AG 2011. All rights reserved. No part of this copyrighted work may be reproduced, modified or distributed
in any form or by any means, or stored in any database or retrieval system, without the prior written permission of Andritz AG or its affiliates. Any such unauthorized use for any purpose
is a violation of the relevant copyright laws. Andritz AG, Stattegger Strasse 18, A-8045 Graz, Austria
PW.MDFcs1.02.eng.03.12
Case study
Lower energy consumption and high fiber quality
ANDRITZ MDF Spiral refiner plates
www.andritz.com
We accept the challenge!