The Logic Behind The Magic. “IR Flame Detectors" The Logic Behind The Magic. “IR Flame Detector”. ”.

Fire detection is required for process equipment and heat generating utilities, specifically where liquid hydrocarbons may accumulate.  For areas where there is a significant fire risk, additional detectors employing diverse techniques may be considered.

The fire detectors should be selected to suit the conditions and to provide the earliest reliable warning. The suitability of the fire detector is dependant upon the characteristics of the fire, which are determined by the materials involved and their rate of combustion.

Triple Band IR Flame Detectors are considered best practice for flame detection.

Sample of IR Flame Detectors criteria and requirement is shown below.

 

These type of detector usually have 6 signals and status that are shown in the control room,

1. Faulty Status
2. Short Faulty
3. Warning Alarm
4. Confirmed Alarm
5. Trip Signal
6. Inhibit signal

The logic are:

1. If the Flame detector is in the faulty status (open loop or short). Faulty signal will appear and trip signal will be disable until the reset command is activated.
2. If the Flame detector is in the optical fault.Alarm and Trip signal will be disable.
3. If the Flame detector is in the inhibit status. None of the other signals will be executed until the reset command is activated.
4. Warning signal will appear if IR detectors transmit 10mA current value, and will be confirmed in 16 mA. Confimed alarm will trigger the trip signal.
   Sample of the logic is shown below: