Paper Technology Journal 19 - Voith

6
Fig. 4: Reel section with Janus MK 2
and Sirius reel.
Fig. 5: TopDuoRun dryer section.
Fig. 6: The EcoCell primary cells for
post-flotation in DIP 3.
Based on this, the rebuild concept for
them was prepared.
For the capacity increase not only the existing
machines but also all the peripherals
had to be taken into consideration.
This was undertaken within the framework
of the basic and detail engineering,
also carried out by Voith.
The major bottlenecks in DIP 1 were
pulping, MC slotted screening and thickening,
in DIP 3 thick stock cleaning,
pre- and post-flotation and likewise thickening.
By re-arranging the process layout and
modifications to existing machines, the
extent of new investment has been
reduced to a minimum. Voith supplied a
Fiberizer for DIP 1 to assist pulper discharge
operations as well as a vat thickener
which was installed in parallel with
the existing thickener. The supply for
DIP 3 mainly consisted of an EcoCell
primary flotation stage for post-flotation,
consisting of five cells and the recently
developed EcoGaus foam killer, which
effectively destroys the foam directly in
the foam collecting channel. The existing
flotation cells that became free were split
up and installed in parallel with the
primary cells in the pre-flotation stage as
well as providing a new secondary stage
for post-flotation. This now allows the
mill to operate a separate loop layout.
As part of the expansion of the deinking
plants DIP 1 and DIP 3, Voith Paper
Automation provided the entire control
and instrumentation engineering, including
the logic diagrams. The new components
have been seamlessly integrated
into the existing process control system
and the group controls for new and old
conponents optimally combined. In DIP 1
the old process control system has been
completely exchanged for a new one.
Installation and start-up were also carried
out by Voith.
The results are convincing: both the contractually
agreed production increases
and also the promised quality parameters
were reached shortly after start-up of DIP
1 and 3.
Carsten
Wenk
Production
Manager
Stora Enso
Maxau Mill
23
“With a great deal of commitment and
competence on the part of all those
involved, the time pressure was successfully
withstood. Even if the originally
planned deadline for ,Paper on
Pope‘ was delayed by three days, the
start-up team brought forward by two
days the goal of producing salable
paper by September 24 at the latest.
From ,Stock on Wire‘ up to the first
salable roll in eleven days – that is top
performance. A good quality approved
by our customers has been uninterruptedly
produced since September 24,
2004.“
By modifying the pulper helix and installing
the additional Fiberizer in DIP 1,
pulping capacity significantly increased
and pulping quality as well as contaminants
discharge were further improved.
Initial stickies tests showed a 50% reduction
of the stickies content in the finished
stock, – a factor mainly attributable
to the modifications in the individual
screening stages.
Although the production of both DIP
plants was significantly increased, brightness
of the finished stock has been maintained
at a high level. In addition, by rearranging
the pre- and post-flotation
stages in DIP 3, bleaching chemicals
have been significantly reduced. Achieving
the required objectives in such a
short time was only possible thanks to a
smooth and close cooperation between
supplier and customer.
19/05