Mid-infrared laser absorption spectroscopy for process and emission control in the glass melting industry : Part 1. Potentials

Abstract

Laser spectroscopic diagnostics of combustion species at elevated temperature has shown considerable progress during the last years and decades. Particularly, techniques of mid-infrared absorption spectroscopy using fundamental rotational/vibrational transitions offer potentially great sensitivity and selectivity for combustion control. However, applications are still limited to mostly laboratoryscale investigations, which is mainly due to drawbacks of light sources and beam guidance materials. On the other band, many efforts are made to facilitate industrial application. In this context, the relevance of mid-infrared absorption spectroscopy for in situ monitoring of minor species in glass melting furnaces is obvious, too. The present paper gives a general review of available techniques and their impact on emission diagnostics in the glass industry, considering conventional as well as emerging light sources, detectors, peripheral devices and spectroscopic techniques.