Cold Link Africa Cold Link AfricaOctober 2018_digital | Page 26

PROJECT
INCORPORATING COLD CHAIN
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5
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of product weight loss, by keeping the log
mean temperature difference (LMTD) as low
as possible while ensuring that the required
cooling profiles are achieved.
COMPRESSORS
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Four-off Mycom N8M reciprocating
compressors were installed and operate at
-8°C/+34°C, as mentioned. The compressors
are direct-driven by a 220kW, 400V four-pole
motor. The capacity at -8°C/+34°C and
1 450rpm, is 827kWr with an absorbed power
of 188kW.
All four compressors are star-delta
started. Since the N8M compressors
all allow for four stages of loading, this
allows for sufficient scaling of the applied
refrigeration power, based on the
1. The facility’s airlock where product
enters and exits the facility.
2. Ambient temperature area that can
also serve as a dispatch floor when
required.
3. The temperatures, operational status,
and plant issues in the facility are easily
monitored using a Carel Plantvisor.
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4. Part of the client’s (GoChill’s)
temperature logging apparatus.
5. Mobile racking inside the second chiller.
6. The airlock coolers.
facility’s demands. During the off-peak
season, there is a special control feature
installed that prevents nuisance trips due
to boiling in the accumulator. “These
are the subtle control aspects that we
focus on to deliver an extremely robust
and reliable plant to our client,” explains
Joshua Pinkerton of MRE.
The rapid cooling
tunnels make use of
proportional suction
control valves to maintain
temperatures for export
goods accurately.
The compressor packages from MRE were
delivered complete with oil separator,
pressure gauges, and the full complement
of hard-wired safety accessories. The
packages also feature what they consider
to be essential safety requirements, such
as internal pressure relief valves, coupling
covers, and isolation valves.
The N8M compressor has four capacity
steps —25, 50, 75, and 100% — which is
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COLD LINK AFRICA • October 2018