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Backfire Detection

Spark detection technology for backfire detection of boilers

A backfire is an event where the fire moves from the fire box into the fuel transmission system and sometimes all the way into the fuel depot. The traditional way to prevent backfires is to use a heat-sensitive AVTA valve.

Atexon® optic backfire detectors offer superior detection speed and sensitivity compared with heat-responsive fire extinguishing systems.

More information:perties:

+358 (0)10 325 3581


Faster and more sensitive backfire detection with the optic spark detection technology

A fire box that does not burn properly causes vapours and flames to appear in the fire box. Sparks and heat from coal enter the feed screw and pass through heat sensors without being detected. Atexon® backfire detectors detect sparks that fly by in a millisecond and extinguishes them with a small amount of water.


– Optic spark detection technology
– Optimised amount of water used for extinguishing
– Battery back-up

Optional features include a GSM alarm, a pulse cooling feature, a screw control feature and a screw heat monitoring feature.

Mounting principle of the backfire detector

1. The backfire detector is mounted on a screw or a release point between two screws.
2. The fire extinguisher unit is mounted approx. 0.5 metres away from the backfire detector.
3. The screw control output of the backfire guard is attached to the boiler’s automation system
4. The backfire guard has a 230Vac power supply
5. Depending on the case, a pressure increase station or at least a water tank is installed
6. The heat sensors of the backfire guard are mounted 0.5-1 metres away from the combustion head.

The backfire detection triggers the water extinguishing sequence that typically last for 10 seconds after the last detected spark. The extinguishing sequence will stop automatically. The temperature sensors measure the temperature of the combustion head and control the extinguishing unit with pulses if the temperature rises above 75 degrees. At 95 degrees, continuous extinguishing is triggered. The extinguishing sequence will stop when the temperature drops below 75 degrees.

Backfire danger solved by using spark detection and extinguishing system in wood chip heating boiler

Atexon® fire extinguishing systems are extremely reliable. We have protected over 2,500 targets against dust explosions. View our references