Abstract

The monitoring of the effluent of a rotary dryer has been developed and implemented. The vapor stream between the dryer and the vacuum is monitored in real time by a process fiber-optic coupled near-infrared (NIR) spectrometer. A partial least-squares (PLS) calibration model was developed on the basis of solvents typically used in a chemical pilot plant and uploaded to an acousto-optic tunable filter NIR (AOTF-NIR). The AOTF-NIR is well suited to process monitoring as it electrically scans a crystal and hence has no moving parts. The AOTF-NIR continuously fits the PLS model to the currently collected spectrum. The returned values can be used to follow the drying process and determine when the material can be unloaded from the dryer. The effluent stream was monitored by placing a gas cell in-line with the vapor stream. The gas cell is fiber-optic coupled to a NIR instrument located 20 m away. The results indicate that the percent vapor in the effluent stream can be monitored in real time and thus be used to determine when the product is free of solvent.

Particulate-matter distribution and its flow from power plants using infrared spectrometry and thermodynamics for in situ continuous emissions monitoring

Alex Shlifshteyn, Fred D. Lang, and Robert Ayrapetian
Appl. Opt. 35(3) 351-363 (1996)

Near-infrared spectroscopy for monitoring water permeability of optical coatings on plastics

Ulrike Schulz and Norbert Kaiser
Appl. Opt. 36(4) 862-865 (1997)

Remote observations of effluents from small building smokestacks using FTIR spectroscopy

Ronald C. Carlson, Andreas F. Hayden, and William B. Telfair
Appl. Opt. 27(23) 4952-4959 (1988)

Fiber-optic Sagnac interferometer for noncontact structural monitoring in power plant applications

T. A. Carolan, R. L. Reuben, J. S. Barton, and J. D. C. Jones
Appl. Opt. 36(1) 380-385 (1997)

Assessment of the brain ischemia during orthostatic stress and lower body negative pressure in air force pilots by near-infrared spectroscopy

Anna Gerega, Stanislaw Wojtkiewicz, Piotr Sawosz, Michal Kacprzak, Beata Toczylowska, Karolina Bejm, Franciszek Skibniewski, Aleksander Sobotnicki, Adam Gacek, Roman Maniewski, and Adam Liebert
Biomed. Opt. Express 11(2) 1043-1060 (2020)