Energy costs pure squeezed
January 1st 2008
PET bottling production at Tropicana's purpose-built
facility in Zeebrugge, Belgium is making significant
energy savings following the installation of one of the
first new generation of ZD compressor and booster
combinations – a concept that provides a 40bar, oilfree
air facility for Europe's drink and beverage sector
Tropicana, a division of Pepsico
International, has taken delivery of
one of the first of Atlas Copco's new
generation combined ZD 1400 VSD oilfree
compressor and a 40 bar booster in
Europe for PET bottling
production in the drink and
beverage industry.
For the first time, the Atlas
Copco ZD combination features
a Z rotary screw, oil-free air
compressor that delivers quality
dry air at 10.5bar and a D
booster, raising the oil-free air
pressure to 40bar for the PET
blow moulding machines. The
ZD combination has been
developed as a complete
integrated package and the
installation incorporates Atlas
Copco's Variable Speed Drive
(VSD) technology, Electronikon
and AirOptimizer control
system, designed for multicompressor
installations to
provide significant regulated
energy savings.
Quayside operation
The Tropicana facility was
opened in 2002 with production
of blown PET bottles and
carton filling with fresh chilled
juice commencing the following
year. Its quayside location in
the Port of Zeebrugge, Belgium was
purpose-selected to eliminate large
movements of bulk tankers on the busy
highways. Fresh juice is unloaded directly
from the ships into the plant's tank farm,
under aseptic
conditions. This tank
farm is kept
refrigerated just above
freezing point in order
to retain maximum
freshness in the juice
before being passed
through to the
blending and filling
area, and finally to the
packaging and
automatic palleting
process.
The filling area today
features four carton
lines and a PET bottle
blowing line. The
carton area is
maintained as an ultra
clean production
facility while the PET
facility is maintained
under aseptic
conditions. The facility
also features a high
speed Procomac PET
line producing a range
of bottles from 250ml
up to 1.5 litre capacity.
PET air power
Initially two Atlas Copco ZT 110 rotary
screw, oil-free compressors were installed
in the utility plant room to meet basic
loads for carton filling. As production
output increased, and with the
introduction of PET bottles blown on-site,
a ZT 160 VSD FF was installed to meet
increased loads for oil-free air. Although
the Z compressor and D booster have
been designed to stand alongside each
other as a combined installation,
Tropicana engineers recognised that the
initial phase of the operation only required
the ZT 160 VSD compressor to operate
until the PET moulding machine was
delivered and commissioned.
Once the blow moulding plant had
been installed, the D booster was
subsequently sited in a separate plant
room some 60m from the Z compressor
but just 20m from the moulding room;
thereby eliminating possible losses of air
pressure in the airnet.
Energy savings
Recognising that energy consumption is
an increasingly major factor in a
compressor's life cycle, Atlas Copco has
designed the VSD option to maximise
energy savings.
In a typical blowing operation, the
moulding machine forms the production
centrepiece, but it is surrounded by equally
important peripheral equipment such as
cappers, labelers and instrumentation – all
requiring a reliable oil-free air supply. The
VSD continually adjusts the speed of the
motor load to match load requirements in
the PET bottling plant. If the air demand
drops, the motor slows and in doing so,
uses less electrical energy. With VSD
technology, energy consumption is
reduced by up to 35% compared to a
load/no load operation.
The Tropicana installation also features
Atlas Copco's AIROptimizer package that
regulates the three compressors.
Operational data measurements at
Tropicana showed that without the
regulating package, the specific energy
requirement was 663J/l and an energy
consumption of 24,371kW/h over one
week. With the AIROptimizer, the specific
energy requirement decreased to 603J/l
and energy consumed fell to 22,165kW/h.
ZD installation benefits
Commenting on the choice of an Atlas
Copco's compressor system, Tropicana's
maintenance manager, Mr StijnVan
Paemelen said: "An important factor in
opting for the ZD combination was the
ease of installation. It is equipment that
requires no special foundations or fixing
systems; installation was just a simple
'plug in and play' operation and relocation
in the future is also very simple". Adding,
"Availability of service and support from
Atlas Copco were also other key
considerations in choosing the ZD option". More articles from Atlas Copco Compressors Ltd: | 
