FEATURE
INCORPORATING COLD CHAIN
Locally, there seems to be a growing
interest in trans-critical CO 2 installations,
according to La Grange. Clients are
putting large trans-critical installations
in place of what might have been
ammonia installations traditionally. In such
cases, the capital outlay of the trans-
critical CO 2 systems compare favourably
to a more costly ammonia installations.
CO 2 trans-critical installations are
also favoured in terms of cost over an
ammonia/CO 2 cascade systems in some
cases. Having one refrigerant on site does
have its advantages. The cost of CO 2
Staff should always wear the correct personal protective equipment (PPE) in cold store
environments.
SPEED, EFFICIENCY AND SAFETY
Speed and efficiency of the loading
and unloading process should also be
taken into consideration. Hydraulically
operated dock levellers operate much
faster and more reliably than their air-
powered counterparts. With the standard,
integrated stop-valve in the cylinders the
hydraulic units also offer superior safety
which prevents the unit from falling down
in case the truck accidentally drives/rolls
away during the loading and unloading
32
process. Besides less maintenance, fewer
parts underneath the hydraulic dock
leveller also aids in keeping hygiene to
a maximum as debris and dirt are easily
visible and accessible to clean.
A LOOK AT TRENDS
Being environmentally friendly is one of
the biggest trends currently, explains
Ford. “Environmentally aware products
such as CO 2 are slowly becoming more
cost effective to use too.”
trans-critical systems is likely to always be
higher than any HFC or HC solutions due
to the higher operating pressures.
Globally, the use of hydrocarbons like
R290 and R600a is growing dramatically,
according to La Grange. “The skills
required to design and build systems using
hydrocarbons are very similar to the skills
needed for HFC systems. The HC systems
of course being less costly than CO 2 .”
On the industrial side, a lot of R&D has
gone into alternatives to modulate the
capacity that screw compressors offer on
the larger systems, says La Grange. Most
compressor manufacturers have invested
heavily into this.
“It is generally a stable industry and
change is a gradual process,” says Van
www.coldlinkafrica.co.za
der Merwe. But he has noticed a move
towards installing more electronics for
plant monitoring, data logging, and
off site access to plant operational
information. “The available solutions are
becoming more affordable while offering
similar levels of information and storage.”
In addition, the industry is becoming
more cost conscious and this is putting
pressure on quoting for a good technical
solution with redundancy and providing
some form of back-up for equipment
failure versus equipment selections that
are marginal and possibly undersized,
says Van der Merwe.
“It should be borne in mind that if an
air-conditioning system fails to perform
then the people may complain that is
warm but it will still be more comfortable
than the outside ambient conditions,” says
Van der Merwe. “If a cold store installation
fails to perform as required, then the
client’s operational requirements may be
compromised and product quality and
shelf life could be negatively affected.”
Executive summary? Look at future-
proofing in terms of refrigerants as well.
You don’t want to put in a system run on
refrigerant gas that will be phased out
soon. If you’re going to build a cold store,
do it right, or it’s going to cost the client a
lot of money in the long run. CLA
COLD LINK AFRICA • July/August 2019