IRIS 500 Flame Monitoring System
- Category: Flame Monitoring Systems
- Written by Super User
The IRIS 500 is a sophisticated flame monitoring system having a variety of applications, but is particularly successful in the more difficult situations, where discrimination proves to be a problem. The flame amplifier comprises a mother board, an analogue signal processor board and a digital signal processor.
- The analogue board contains the circuitry required to produce a flame on/off output, an analogue flame signal intensity meter, hysteresis ratio selection switch and flame out delay timing, adjustable 1 to 6 seconds.
- The digital board is composed of a 4 digit LED display, and two 4 digit set point switches -- one for flame on threshold and one for flame off. The function of the analogue board is to provide the flame on/off safety channel.
The digital board, which is not required for the basic operation of the system, can be used in conjunction with, or separate to, the analogue board to provide diagnostic or additional control functions.
Viewing Heads
Three viewing heads are available. The UV head, in which self checking is accomplished by a mechanical shutter, this is suitable for use on gas and light oil flames. Its spectral response is 185 to 300nm. In the IR and IRX2 viewing heads, the self checking is achieved by using an electronic switch – hence there are no moving parts
Failure of a component in any mode, will cause the output relay to de-energise. Both respond to the high flicker frequency of the flame. It is this AC flicker which generates the signal which is essential if good discrimination is to be achieved. The IR viewing head employs a silicon photodiode, and has a spectral response of 200 to 1080 nm.
Its primary function is for use on large multi burner boilers firing heavy oil and coal.
The IRX2 twin channel viewing head uses a silicon/lead sulphide two colour detector, having a wide spectral response of 350 to 3000 nm. It is particularly successful in detecting difficult fuels, such as H2S, where masking of the lower frequencies can cause nuisance shutdowns. By using the IRX2 on dual fuel fired multi burner boilers, considerable savings can be achieved, as only one viewing head is required for oil or gas flames.
