On-Line Determination of Unburned Carbon in Airborne Fly Ash

[+] Author and Article Information
R. C. Brown, A. R. Dona

Department of Mechanical Engineering, Iowa State University, Ames, IA 50011

J. Eng. Gas Turbines Power 112(4), 597-601 (Oct 01, 1990) (5 pages) doi:10.1115/1.2906211 History: Received February 01, 1989; Online April 24, 2008


Knowledge of the carbon content of fly ash is important for calculating combustion efficiency in coal-fired boilers. However, present methods of measuring carbon content of fly ash are tedious and time consuming. Thus, we are investigating photoacoustic absorption spectroscopy (PAS) as a method for on-line monitoring of carbon in fly ash. Photoacustic absorption spectroscopy is capable of detecting very weak absorptions and is unaffected by light scattering in a particulate-laden gas flow. Accordingly, PAS has good potential for distinguishing small amounts of carbon from mineral matter suspended in flue gas. Experiments have been performed on fly ash samples of variable carbon content suspended in a gas flow. A 35-mW HeNe laser was able to detect carbon loadings of 0.75 g/m3 . Order-of-magnitude improvements in detection sensitivity are expected with higher power lasers or improved PAS cell design.

Copyright © 1990 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In