Paper Technology International 2020 - Journal - Page 38

PAPERTECHNOLOGYINTERNATIONAL
When the existing vacuum pump or blower reaches the end
of life, there are several options for how to go forward. Units can be
replaced with new ones or be upgraded to the latest or a different
model, depending on the process requirements. In some cases, a
complete rebuild is needed to gain better energy efficiency or cut
down on water consumption. We are the only company in the world
that can supply both liquid ring pumps and dry vacuum systems, or
a combination of them, for a so-called hybrid system. In addition, we
offer doctors and save-alls, making our offering complete for paper
machine dewatering. With this unique portfolio, we can always find a
perfect fit for our customer’s demands, needs and budget.
At Smurfit Kappa Ania in Italy, both its PM2 and PM3
have been rebuilt after Runtech audits. Total energy savings in
the vacuum system alone have amounted to 9 GWh per year,
equaling EUR 700,000 in electricity savings annually. Additionally, as
production increased by 2%, the payback time was approximately
one year. According to Mill Manager Massimiliano Listi, it was
shocking to learn how much vacuum they had been using for
nothing. For example, the suction couch roll vacuum was removed
after the forming section optimization. EcoFlows now provide a
window to the process.
The next step is replacing the remaining water ring pumps
with an EP Turbo Blower. This rebuild will bring the PM2 to a world
record level in the specific energy consumption (SEC) of the vacuum
systems.
Forming and press section audits
Forming section audits analyze and troubleshoot the
machine’s forming section. They specifically seek to optimize energy
consumption and cleanliness. A forming section audit would typically
consist of a dewatering analysis and exhaust air measurements.
The cleanliness of the wet end is inspected and reasons for any dirt
buildups are uncovered. The audit also includes the optimization
of high-pressure and low-pressure showers and an edge trimming
survey.
Press section audits analyze a variety of elements, such
as doctoring and save-alls, to optimize the dewatering of the press
section. Press section audits normally focus on analyzing the
operation of the save-alls and doctoring equipment. Dewatering
profile measurements are taken and machine cleanliness and
runnability are inspected.
Both audits aim to optimize the dry content.
CASE: Forming section and wet end ventilation on a board machine
Kartonsan Karton Sanayi ve Ticaret A.S., Turkey, suffered
from excess mist and flooding of the shower water back to the wire
on their BM2. A study revealed that the existing exhaust system
was insufficient and out of order. The type of existing fans and
water separators were not optimal. The wet-end fan did not create
adequate vacuum or air flow. The dry-end fan was not even running.
To correct the situation, Runtech proposed an exhaust
ventilation system for the forming section, including exhaust below
the breast rolls/below the headboxes to the suction stocks across
the wire where the showers are installed and to the area of highpressure showers where mist catchers need to be installed.
The new exhaust system proposed included
centrifugal fans, ductworks, mist catchers, water
separators with cleaning hatches and manual
dampers. New fans were installed on the foundations
of the old fans. Also, ducting routes were reused
whenever suitable to minimize dismantling and
installation work.
Today, there is clearly less mist inside the
wires, and it does not spread out from the forming
section. Mist coming from the low-pressure and
high-pressure showers does not reach the hall
ceiling or spread out to the hall anymore. This project
had a major effect on operator safety and working
conditions – it is easy to breathe the air in the
machine hall again, and the floor is not wet or slippery
anymore.
Figure 2 and 3: The machine hall before and
after forming section and wet end ventilation
at Kartonsan BM2.
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