Bottle & jar cooling system
Practical Action
Obviously, if this external medium is contaminated, the contents will become liable to spoilage.
Hence, the necessity for immersing the packs in the well-chlorinated water. To avoid corrosion of
the metal cap caused by chlorine, it is recommended that its level be controlled at 1ppm. In Figure
1, it can be seen that the chlorine solution is metered from a small feeder tank with an adjustment
clip and it is necessary to carry out periodic free chlorine checks using readily available and simple
to use kits.
The system suffers from one slight inconvenience in that at the start of the day the tank has to be
filled with warmed chlorinated water to avoid damage to the first packs of the day that enter. The
cold main is then turned on and adjusted to give a steady overflow from the shallow end of the tank.
Hot bottles can then be placed in the tank. Within a few minutes the system will stabilise and it
will be found that the deep end of the tank is cool and the water leaving the shallow end hot.
It is more convenient to remove the packs
when they are still slightly warm to the touch
as the residual heat will cause rapid drying of
the glass surface and reduce the time delay
before labelling. The cooling of jams and
jellies requires a somewhat different
technique as they need to remain steady and
upright while cooling so as to allow gel
formation. To overcome this problem, a
series of wooden carriages were used in St
Vincent that were simply pulled through the
tank by means of a metal hook. A typical
Figure 2: A typical carriage
carriage is shown in Figure 2.
Figure 2: A Typical Carriage
References and further reading
Food Packaging a selection of Practical Action Technical Briefs
Appropriate Food Packaging by Peter Fellows & Barry Axtell, Practical Action Publishing ILO/TOOL
1993
Packaging UNIFEM Practical Action Publishing 1996
Small-scale Food Processing: A guide to appropriate equipment, Edited by Peter Fellows & Ann
Hampton, Practical Action Publishing/CTA 1992
Useful organisations and contacts
The Technical Centre
for Agricultural and Rural Cooperation
C.T.A
P.O. Box 380
6700 AJ Wageningen
The Netherlands
Tel: +31 (0) 317 467100
Fax: +31 (0) 317 460 067
E-mail: cta@cta.nl
Website: http://www.cta.int/
Midway Technology
Dr. Peter Fellows
19 High Street
Bonsall
Derbyshire
DE4 2AS
United Kingdom
E-mail: peterfellows@freeserve.com
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