User:MattAldred/TunnelPasteurisation
Tunnel pasteurisation, is a method of heat pasteurisation of perishable beverages like fruit and vegetable juices, beer, and dairy products. Compared to other pasteurisation processes, it is simpler, more consistent and product stability is easy to confirm.[1]
In tunnel pasteurisation bottles or cans are filled and closed in the normal way, then funnelled into the pasteuriser 'tunnel' before any labelling is added. The tunnel has a low ceiling with spray heads at regular intervals. Temperature controlled water is sprayed down on to the packages. The bottles or cans move through the pasteuriser slowly on either a walking beam or conveyor belt. The tunnel is divided into many temperature zones to slowly bring the product up to temperature, keep them at a specified holding temperature and then bring them back down to room temperature.
Modern tunnel pasteurisers contain sophisticated control systems to manage the temperatures, deal with line hold-ups and slow-downs in a way to prevent over or under pasteurisation of the product. Water is normally recirculated to improve energy efficiency. A run through the pasteuriser takes between 20-50 minutes at temperatures from 60°C to 90°C. Due to the length of time the bottles must be heated, tunnel pasteurisers can be extremely large. However, solutions are available with double deck designs to optimise the use of space.
In order to control and monitor the pasteurisation process a travelling recorder or /PUMonitor is used.