FEATURE
INCORPORATING COLD CHAIN
Cold storage facilities are regularly being built across the country to ensure perishable products
are kept at the right temperature before distribution. Pictured: Idube.
solar installations (Alternative Refrigeration
Technologies: Reinaldo Maykot, Gustavo
C. Weber, Ricard A. Maciel). “With a well-
developed and competitive solar solutions
market customers have many to choose
from to suit their needs,” says La Grange.
“Energy savings is probably the most
important factor right now, especially
in South Africa with the price of power
constantly increasing,” says Ford. “You
can achieve efficiency simply by lowering
your operating pressures using quality
electronic control systems. Installing soft
starters and variable speed drives on the
compressors is also a good idea.”
RACKING SOLUTIONS
No large cold store is complete without
racking, but it wasn’t always so. Cold stores
with insulated sandwich panel construction
became popular in the 1970s, explains
James Cunningham of Barpro Storage.
Prior to that, they were insulated with
cork and low in height. As clear heights
30
increased, so did capacities and pallet
access problems began. The norm in
relatively low cork stores was to block-stack
product, sometimes not even on pallets. As
store heights increased, converters or steel
frames were introduced to improve stability
and prevent crushing to the lower layers
of boxed product. Capacity utilisation was
good, but access to product and stock
control accuracy were terrible. In freezers
of 2 000 tons plus, stock could be lost for
years, hence the acronym FISH – First In
Still Here.
Fixed selective pallet racking was
initially introduced in higher volume
throughput distribution freezers with high
numbers of stock-keeping units (SKUs)
and an element of case picking. Fixed
selective racking was great for pallet
access but bad for holding capacity
as half the expensive volume was lost
to access aisles. Since then, racking
developments are designed either for
high density or pallet access. “Drive-in”
racking is high density as is “push back”
and “flow racking”. “Fixed selective”,
“narrow aisle” and “high bay crane
racking” are geared for individual 3. Not nearly enough attention is paid
to racking inspections and repairs.
Freezer stores are uncomfortable
places, so there is even less incentive
pallet access.
But modern freezers are expensive
– both to build and to operate. “And
given the growth in product lines, racking
systems must offer both high capacity
and great access,” says Cunningham.
This is what mobile racking achieves.
Mobile racking was first installed in 1990
at Hermanus Seafoods, and has become
almost standard in new freezers since the
early 2000s.
Cunningham looks at things to consider
when choosing and operating your
freezer racking system:
1. Don’t compare racking costs in
isolation. Fixed selective racking may
be “cheaper” than mobile racking
but the effective storage capacity
of the store will be halved. When you
divide the total capital cost of the
freezer (including the racking cost) by
the number of usable pallet locations,
more expensive racking types can be
surprisingly cost effective.
2. As freezer stores are rarely turned
off, consider allocating a bit more to
the initial racking budget to increase
flexibility later. This can pay dividends
in the future. Design the racking
to carry heavier pallets than are
initially expected. Consider installing
mobile rails and mobile-friendly fixed
selective racking so that your freezer
capacity can be quickly doubled
when required. Consider the use of
pallet support beams on higher pallet
levels. There is nothing more difficult
than trying to remove a broken but
wedged pallet at 9m in -25°C. to spend time checking for rack
damage. Rack inspections should be
carried out weekly on site by trained
personnel and by an external expert
once every six months. All rack repairs
in freezers should be inspected by
a third party and signed off before
being used.
4. Don’t make access aisles too narrow.
Squeezing them may allow for an
additional run of racking, but the
additional storage capacity will be
accompanied by increased rack
damage.
5. Make sure your freezer store drivers
are well protected from the cold.
Reach trucks and forklifts without
heated cold store cabs may be
cheaper, but semi-frozen drivers are
more likely to damage racking. At
least spend a bit more clothing wise
to protect them from hypothermia.
6. Always maintain clear spaces
between the rack frames and the
loaded pallets as well as between the
pallets themselves. Leaning pallets,
especially when in contact with rack
frames, are particularly dangerous.
Removing such pallets from the
racking at high level can result in
falling product while also exerting
negative forces on the rack frames.
www.coldlinkafrica.co.za
DOORS AND LOADING DOCK
EQUIPMENT
Doors and loading dock equipment are
another key component of any cold store.
If these don’t function properly, product
can be compromised and potentially
COLD LINK AFRICA • July/August 2019