EVENTS AND EXHIBITIONS
INCORPORATING COLD CHAIN
a preferred option to more and more
customers in commercial refrigeration.
On a P-H diagram, Fuhrer demonstrated
the gains in cooling performance by the
intermediate compression of flash gas in a
trans-critical CO 2 system.
The high volumetric efficiency of CO 2
and good heat transfer coefficient have the
benefit of reducing the required refrigerant
mass flow rate and small-bore piping
compared with most commonly used
refrigerants. CO 2 is also freely available and
at a low price. Fuhrer said that although
the CO 2 system was not much different in
basic principles to a conventional vapour
compression system, it did require special
skills to install and maintain. He further said
that electronic controls were essential in
all CO 2 systems for optimum performance.
The Bitzer SL semi-hermetic range has been
designed specifically for CO 2 sub-critical
systems and the new T series for trans-critical
with permissible suction pressures of 100 bar
and 160 bar on the discharge.
The options of Bitzer equipment for CO 2
applications, sub-critical or trans-critical,
are not limited to compressors, but include
oil separators and liquid receivers.
Bitzer has to date supplied over 65 000
compressors for trans-critical CO 2 systems
and over 60 000 for sub-critical. In South
Africa, Bitzer has 117 semi-hermetic
compressors operating on CO 2 systems,
predominantly in the retail sector.
Keeping pace with the demand for
natural refrigerant systems, Bitzer has
extended the range of screw compressors
for ammonia to a volumetric capacity of
1 015m 3 /h (at 2 900rpm) and added their
innovative double slider technology.
NATURAL REFRIGERANTS
Before leaving the discussion on
refrigerants, Fuhrer had some valuable
The three Bitzer presenters, from left: Torsten Steinborn (Cape Town); Tobias Fuhrer
(Sindelfingen, Germany); and Bernhard Blaeser (Cape Town).
advice. Delegates learnt about natural
refrigerants, in particular the safe handling
of and the safety standards for flammable
refrigerants, for example R290, NH 3 , and
HFOs. They looked at designing systems
with the smallest possible refrigerant
charge. He advised that the change
to mini channel condenser coils will
certainly be of value to reduce refrigerant
charge. “Give attention to the reduction
of possible refrigerant leaks in the
design of new systems and when doing
maintenance and repairs. Recovery and
recycling should always be an option to
reduce usage of synthetic refrigerants.”
DETECTING PIRATE PARTS
Support services and spare parts were
dealt with by Blaeser. The use of pirate
parts is of growing concern to Bitzer, as it
impacts on the performance and lifespan
of compressors. Blaeser demonstrated
Bitzer South Africa has passed the 25-year milestone
as a foreign subsidiary serving countries across
Africa.
the use of the free Bitzer Spot app to
authenticate the origin of Bitzer spares.
By scanning the outside of the spare
package with one’s mobile phone, one
can verify the content of the package
before opening and once opened, can
compare the content with what was
previously shown in the scan. A similar
system is used to authenticate whether
supplied oil is a genuine Bitzer product.
He also gave insight to the Green
Point service centre. The Green Point
service centre in Johannesburg now
offers users the option to hire service
exchange compressors on a daily basis,
while their own compressor is being
rebuilt to original specification with
genuine Bitzer replacement parts. A
similar Green Point service centre is to be
established in Senegal.
New features in the range of shell
and tube condensers, the Orbit scroll
COLD LINK AFRICA • May 2019
compressors with variable speed drives
(VSD), and Flexible Injection Technology
(FIT) for chiller and heat pump applications,
the commissioning assistance service, the
digitisation of documentation, comparison
of life cycle costs, the Line Start Permanent
Magnet Motors (LSPM) for higher efficiency
and compliance with the safety standards
required in different countries, were some
of the other topics covered during the BSA
regional conference.
Each delegate had their own
expectations of the conference as
to what they hoped to achieve. The
programme was certainly varied and
the transfer of product knowledge
was comprehensive. What remained
unquestionable, was the opportunity of
networking and establishing contacts
across the African continent and forging
stronger links with the Bitzer global
organisation. CLA
www.coldlinkafrica.co.za
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