The Britvic factory in Great Britain handles a range of fruit juices. The juices are pasteurised prior to filling to
temperatures in the region of 80C; glass bottles arrive on the line at ambient temperatures. When filling glass bottles,
there is a significant danger of sufficient thermal shock to cause cracking/bottle failure if the temperature difference
between fluid and glass is greater than around 42ºC.
Historically to ensure that the bottle/juice temperature difference was maintained below this critical level, the bottles to
be filled would be first subjected to a hot rinse and then passed through a steam oven to complete their heating to
around 55°C. The hot water was then allowed to drai n, with associated energy losses. The steam oven was also energy
intensive and could not be switched off quickly in the event of line stoppage.
The production facility finally installed at Britvic consists of a 4m long infrared oven of total power of 109.2kW, split into
three zones. The first two zones are each fitted with two 15.6kW carbon infrared modules and the final heating zone is
equipped with two 23.4kW modules. The final zone also features PID control to ensure that the bottles emerge at the
correct temperature for filling. The carbon infrared emitters offer virtually instant response, so that bottles are not
overheated in the event of line stoppage.
Since installation, the new medium wave infrared system has proved very successful, providing huge energy savings.
Apart from that, the new system also allows Britvic to cold rinse bottles before heating. This is important as it means that
the rinse line can now be shared with the carbonated drinks line without major modifications, and cost, as it is impossible
to fill carbonated drinks into heated bottles.