A video camera based fire detection system for cacao ovens. Fire in cacao ovens is a major problem in this type of production process. Once the fire
starts it needs to be controlled rapidly otherwise it can’t be stopped and it may cause a total loss of the production facilities. Studies and tests showed that detecting fire in a
greasy cacao oven is not an easy job. The pollution in the oven seemed to be a bigger problem then detecting fire with the camera. Solving the visibility problem for the camera
was quite a challenge.
Conventional water-cooled and air-pressured camera housings could not be used because of the difficult environmental conditions.
Tests showed that the camera window of these type of housings got polluted by the greasy substance in less then 2 hours when the oven was in full operation.
The pollution blocked the camera view totally.
The special designed construction of the Firewatcher I housing looks after conventional cooling (without water cooling) and compressed air) using a vacuum created by the
under-pressure in the oven. The advantage of the construction is that pollution can’t settle and the camera window remains absolutely clean for a full production run of 6 days and
Using a special infrared sensitive camera the system is able to spot the start of a possible fire half an hour before the human eye can even see it.
The camera is connected to an image processing system “Astraguard” that looks after automatic fire detection and early warning showing the alarms on
a monitor to the process operator.
Because of the early warning of the system the start of a possible fire will be eliminated in a very premature stage before it can cause any damage. In the event of an alarm,
supervised by the operator in de control room watching the Astraguard monitor, a second operator removes the hazardous substance from the oven and production
continues without being stopped.