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PROGRAMMING THE 45FS1/45UVFS1 FLAME SIGNATURE SCANNER
Information on the setup procedure and programming for the 45FS1/45UVFS1 flame
Signature
Scanner
can be found later in this bulletin, as well as the programming primer (CU-33).
OPERATION
The 45FS1/45UVFS1 flame scanner utilizes a microcomputer which continually monitors the fre-
quency spectrum of the sensed flame and compares it against the flame signature that is stored in its
memory. The degree of uniformity of the measured flame to its signature determines the flames sta-
bility.
A Setup procedure in which the 45FS1/45UVFS1 scanner “Learns” the various conditions (e.g.
burner on, burner off, etc.) is required for the proper operation of the scanner. See
Programming the
Flame Signature Scanner and the Programming Primer (CU-33).
The 45FS1/45UVFS1 flame scanners are compatible with the following Flame Safeguard controls:
— Fireye Type 25SU3, Model -2000, -2100, 4170, 4172, 5166, 5168, 5172, 5173
— Fireye Type 25SU5, Model 5011, 5012
(Refer to Figures 19, 20, and 21 for wiring diagrams).
APPLICATION
The type of burner and fuel will affect the frequency and amplitude characteristics of the flame. Gas-
eous flames (propane, methane, natural gas) tend to have a low flame amplitude, while solid pulver-
ized (coal) and liquid (oil) flames have a high flame amplitude. The type of burner will affect the
frequency of the flame (gun type = high flame frequency, low nox = low flame frequency).
A further explanation of the nature of flames will also assist in scanner selection.
Oil and coal
flames
produce soot and flash respectively during the combustion process which makes these flames
opaque in the infra-red range. An infra-red detector will recognize the infra-red radiation in the target
flame but will not see through the flame to detect the infra-red radiation associated with the opposed
flame. In the event of a flame out condition, the flame signature of the background radiation (e.g.
opposed flame tips) should be unique enough to provide proper discrimination (See “Learn Flame
On/Off - Setpoints Menu” and “Discrimination - Status Menu”).
A
gas flame
is a very clean burning fuel that is mostly transparent to an infra-red detector. This
means an infra-red detector will detect the infra-red radiation in the target flame but will also see
directly through the flame and pick up any infra-red radiation associated with an opposed flame.
Consequently, when an infra-red detector is used on a gas flame, care should be taken so the line of
sight of the scanner does not pick up any other source of infra-red radiation (e.g. single burner or
front fired applications are acceptable, opposed fired may cause discrimination problems).
A
gas flame
also emits a large amount of ultra-violet radiation. However, during the combustion pro-
cess, water vapor is also produced at the leading edge of the gas flame. This water vapor will absorb
most of the UV radiation. The water vapor now makes a gas flame opaque to an ultra-violet detector,
allowing the UV detector to pick up the UV radiation within the target flame, but not see through the
flame (due to the water vapor) to pick up UV radiation from opposed flames in an opposed fired
burner. In the event of a flame out condition, the flame signature of the background radiation (e.g.
opposed flame tips) should be unique enough to provide proper discrimination (See “Learn Flame
On/Off - Setpoints Menu” and “Discrimination - Status Menu”).
The
45FS1
scanner with its lead sulfide cell (infra-red detector) is best suited for providing reliable
flame detection and discrimination on coal and/or oil flames, as well as single burner or front fired
gas flames.
The
45UVFS1
scanner with its super-blue silicon cell (ultra-violet) sensitive to UV radiation preva-
lent in gaseous flames. In addition, the 45UVFS1 scanner possesses an automatic signal amplifica-
tion circuitry to adjust for both high (coal and oil) and low (gas) amplitude flames. These two factors
