Real-time alkali monitoring system
- Christiansburg, VA
- Prosperity, PA
- Morgantown, WV
A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium emission line, may be detected in the presence of interfering background radiation. A combustion flame is fed by a diverted portion of a process stream and the common end of a bifurcated or quadfurcated fiber optic light guide is adapted to collect light from the flame. The light is guided through the branches of the fiber optic cable to bandpass filters, one of which is adapted to each of the branches of the fiber optic light guide. The bandpass filters are centered at wavelengths corresponding to the emission lines to be detected and two separate filters are required for each species being detected. The first filter has a bandwidth of about 3 nms and the second filter has a bandwidth of about 10 nms. Light detectors are located to view the light passing through the bandpass filters and amplifiers are connected to receive signals from the light detectors. The amplifier corresponding to the bandpass filter having the narrower bandwidth is preset to scale the signal by a factor equal to the ratio of the wide and narrow bandwidths of the bandpass filters. This scaling produces a scaled signal from which the difference between the scaled signal on the other signal can be calculated to produce a signal having an amplitude directly proportional to the concentration of the species of interest and independent of background radiation.
- Research Organization:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 4896965
- OSTI ID:
- 867255
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
alkali
monitoring
fiber
optics
based
optical
emission
line
provided
selected
spectral
lines
sodium
detected
presence
interfering
background
radiation
combustion
flame
fed
diverted
portion
process
stream
common
bifurcated
quadfurcated
optic
light
guide
adapted
collect
guided
branches
cable
bandpass
filters
centered
wavelengths
corresponding
separate
required
species
filter
bandwidth
nms
10
detectors
located
view
passing
amplifiers
connected
receive
signals
amplifier
narrower
preset
scale
signal
factor
equal
ratio
wide
narrow
bandwidths
scaling
produces
scaled
difference
calculated
produce
amplitude
directly
proportional
concentration
independent
narrow bandwidth
background radiation
pass filters
selected spectral
light detectors
bandpass filter
fiber optics
process stream
fiber optic
light guide
optic cable
emission line
optic light
narrow band
bandpass filters
directly proportional
light detector
pass filter
light passing
receive signals
spectral emission
collect light
optical emission
emission lines
real-time alkali
receive signal
optics based
alkali monitor
based optical
line monitoring
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