Cold Link Africa Cold Link AfricaOctober 2018_digital | Page 35

PROJECT
INCORPORATING COLD CHAIN
Drinkrow. “To become familiar, we installed
our own training system in our workshop
and developed as we became more
confident with the high pressures and the
unique condensing requirements. Our
in-house training has proved invaluable to
provide technicians with the required skills
and confidence. With each new plant
that we have installed, we have tried new
innovations to improve efficiency and
reduce energy usage. The BM plant, being
our first industrial plant, compared with our
previous plants mainly in the retail sector,
required a greater focus on the recovery of
heat for hot water production and water
treatment to prevent possible scaling.”
The flash gas from the top of the CO 2
receiver is piped to the suction of the
two parallel compressors to improve the
coefficient of performance (COP) of the
plant and prevent any flash gas at the
inlet to the DX coils, which are all fitted with
electronic expansion valves.
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INNOVATIVE WATER TREATMENT
The large volumes of hot water used
requires make-up from the municipal
mains, and scaling in the plate heat
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exchanger (CO 2 /water) was of prime
concern. To prevent scaling, an
electronic ‘descaler’ was installed on
the outside of the water feed to the
heat exchanger. The operation of the
device is based on creating a magnetic
field, which assists in the ionisation of the
water. “For some unknown reason, since
commissioning the CO 2 plant, the scaling
in the water feed to a steam generation
plant elsewhere on the site has reduced
significantly,” says Drinkrow.
With the low ambient temperature in
winter, the plant is often just idling and has
excess capacity. The plant was designed to
handle the required duty when the ambient
is above 38°C, as can occur in the summer
months in Cape Town.
“Until we commissioned the CO 2
plant, our production was limited by our
refrigeration capacity and availability
of hot water. With the new plant, this
has been reversed and our production
capacity now lags our cooling capacity.
We also are confident that the CO 2 plant
will cope on the days when temperatures
in Cape Town are above 38°C in summer,”
says Vayanos.
BM Food Manufacturers has two
manufacturing facilities, one in
Johannesburg with a staff of 250 and
one in Cape Town with a staff of 280.
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The business was started by Vayanos’s
uncle, who is now 87. Vayanos joined the
company as the accountant and later
took over the reins as CEO when his uncle
retired.
“Our refrigeration plant has undergone
a massive shift from having many simplex
units to the high-capacity, environmentally
friendly CO 2 plant. Before commissioning
the CO 2 plant, there would be a
noticeable rise in the air temperature of
the blast chillers as we pushed in trolleys of
warm product that still had to be cooled.
With the CO 2 plant, the air temperature
follows virtually a straight line. The quicker
the warm product is cooled, the longer the
shelf life,” says Vayanos.
BM Food Manufacturers supply to
retailers, food service, and fast-food outlets
across the entire market. As far as possible,
ingredients are sourced locally and only
those that cannot be sourced from South
Africa or that are in short supply, are
imported. “Quality of ingredients are of
utmost importance, as they impact on the
reputation of our brand name.”
REDUCED CARBON FOOTPRINT
“The CO 2 plant is another step towards
our drive in saving the natural resources
of our planet for future generations,” says
Vayanos. At the 18 000m 2 site in Montague
Gardens, rainwater is harvested for the
washing of vehicles, large areas of the
extensive roof space are fitted with solar
panels for power generation, and all
recyclable materials are hand sorted and
sent to a recycling plant in Philippi, where
methane gas is produced and used for
power generation.
“BM Foods is excited about our new CO 2
plant, not only to improve product quality
and production, but also because of its very
low impact on the environment. All future
refrigeration plants on our sites will be CO 2 ,”
concludes Vayanos. CLA
1. The pressure vent on the low-
temperature room safeguards against
a pressure build-up when temperature is
rapidly reduced.
2. The new CO 2 plant is housed in one
of three buildings on the Montague
Gardens site.
3. The water/CO 2 plate heat exchanger
with vertical oil separator behind.
4. A two-stage chiller with provision to
convert to a three stage later on.
5. Control panels for blast chillers are all
located in a single area.
COLD LINK AFRICA • October 2018
www.coldlinkafrica.co.za
35