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Title: Real-time alkali monitoring system

Abstract

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 ofmore » 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.

Inventors:
 [1];  [2];  [3]
  1. Christiansburg, VA
  2. Prosperity, PA
  3. Morgantown, WV
Issue Date:
Research Org.:
National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
OSTI Identifier:
867255
Patent Number(s):
4896965
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01J - MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
real-time; 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; /356/250/

Citation Formats

Goff, David R, Romanosky, Robert R, and Hensel, Peter. Real-time alkali monitoring system. United States: N. p., 1990. Web.
Goff, David R, Romanosky, Robert R, & Hensel, Peter. Real-time alkali monitoring system. United States.
Goff, David R, Romanosky, Robert R, and Hensel, Peter. Mon . "Real-time alkali monitoring system". United States. https://www.osti.gov/servlets/purl/867255.
@article{osti_867255,
title = {Real-time alkali monitoring system},
author = {Goff, David R and Romanosky, Robert R and Hensel, Peter},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 1990},
month = {Mon Jan 01 00:00:00 EST 1990}
}