ATMOS Premium Tissue I Energy efficiency – A challenge for ... - Voith

RESEARCH AND DEVELOPMENT
36
New speed record prospects – with the HiDryer HiDryer – Impingement drying directly
after the press (patent pending)
Innovative drying technology enabling speeds
in excess of 2,000 m/min –
HiDryer: the speed and quality module
One of the main goals of paper machine development has always
been higher production speeds. Impressive advances have been
made in this respect thanks to improved press technology, optimized
felts for high solids content, and efficient stabilizers in the
dryer section for reducing draws. But breaking the “speed barrier”
of 2,000 m/min is only possible if the web already has a high solids
content before entering the dryer section. And this is exactly what
the Voith HiDryer makes possible. It is in fact a breakthrough development
for wide and high-speed paper machines making them
more profitable in the future.
As proven with the Hürth PM 1 newsprint
machine, high quality newsprint
can be produced at speeds in excess
of 2,000 m/min. Further speed increases
are however limited by the
initial wet strength of the web, which
dictates the maximum web tension
that the wet paper can withstand
after the press section. Excellent machine
runnability requires adequate
tension in order to release the web
from the smooth dryers.
To attain speeds significantly higher
than 2,000 m/min high web strength
at the first dryer is required. The
HiDryer ensures this by drying the
web with high-performance impingement
hoods to give it the necessary
strength before entering the dryer
section. In this way the HiDryer enables
speeds 200 m/min higher than
with conventional technology, thus
making modern paper machines
more productive and more profitable.
24 I 2007 I Voith Paper I twogether