PROJECT
INCORPORATING COLD CHAIN
3
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chiller to handle an average of 800 tonnes of
raspberries or 124 tonnes of blueberries, has
exceeded all expectations since commissioning,”
says Kevin Schlemmer of Coolcheck.
The new rack to handle the higher cooling
load, has two Bitzer six cylinder semi-hermetics
with a nominal capacity of 250kWR at -9°C/35°C.
The chiller has two refrigeration circuits which
feed a common buffer tank with glycol at -5°C.
After the packing line, the cartons are
palletised in a newly revamped insulated area
with two rapid batch coolers, each cooling four
pallets of berries to 1°C in one hour. Humidity
levels of 95% are maintained to maximise shelf life.
Two new Colcoil blower coils, each with
two 0.65kW fan motors, are installed in the
prepacking area. In the open receiving platform,
evaporative coolers are also installed to start
the cooling of the berries from the very outer
perimeter of the pack house.
As a backup, the newly installed evaporative
condenser has a buffer tank of makeup water and
a standby pump. “Backup of the water supply to
the evaporative condenser is essential. Any outage
of water supply brings the entire packing operation
to a standstill,” emphasises Schlemmer.
The chiller plant, manufactured by Phoenix
Racks and the remainder of the refrigeration
plant was installed by Ronald Giles and his team
of DRS Air Conditioning, based in Paarl. The
polystyrene panels were installed by Evercool.
Power saving was a prime consideration in
the redesign of the refrigeration system. Both
compressors are fitted with variable frequency
drives and ebmPapst EC fan motors are fitted to
all blower coils and on the Evapco evaporative
condensers. “All these power saving features
and accurate temperature control has paid
dividends,” says Schlemmer.
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1. Custom made imported fabric ducting
maintain the air temperature in the picking line
at comfort levels for the packers.
2. Berries are received on the far left and
dispatched from the insulated bay on the right.
3. Energy usage is further reduced with ebmPapst
EC fans on the new evaporative condenser.
4. Trays of berries from the field are stacked
on skids.
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COLD LINK AFRICA • May | June 2017
www.coldlinkafrica.co.za
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