Microwave Technique for On-Line Determination of Unburnt Carbon in Fly Ash

Evans, T.G.; Yip, V.; Cutmore, N.G.; McEwan, A.J.

doi:10.1109/apmc.1992.672104

Cited by 4 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[7][8][9] The microwave-based method has been used widely in coal-fired power plants, but the measurement accuracy is significantly affected by the fluctuation of power load and the characters of coal. With this method, sample fly ash is taken from the exhaust of a boiler and heated in a muffle furnace for several hours at 815 C, and the loss in weight is assumed to be the UC present in the sample.…”

Section: Introductionmentioning

confidence: 99%

“…Several on-line measurement techniques have been proposed to determine UC in fly ash, such as those based on the principle of photoacoustic effect, 2-4 optical dispersion-reflection, 1,5 backscattering of polarized light, 6 and microwaves absorption. [7][8][9] The microwave-based method has been used widely in coal-fired power plants, but the measurement accuracy is significantly affected by the fluctuation of power load and the characters of coal.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analyzing unburned carbon in fly ash using laser-induced breakdown spectroscopy with multivariate calibration method

Yao

Lü

Zheng

et al. 2012

J. Anal. At. Spectrom.

View full text Add to dashboard Cite

This paper presents an alternate calibration method for measurement of the unburned carbon (UC) in fly ash using laser-induced breakdown spectroscopy (LIBS). Fly ashes studied in this research were produced from pulverized coal in a muffle furnace and the UC was determined by a loss-on-ignition (LOI) test. We apply both univariate calibration and multivariate calibration methods to LIBS data to establish the calibration curve of the UC in measured samples, and the performance of these two approaches was compared. Our analysis shows that traditionally used univariate calibration in LIBS does not qualify quantitative analysis of fly ashes from different kinds of coal due to the presence of matrix effects. Instead, multivariate calibration has a better performance as the matrix effects can be taken into account with the influence of the spectroscopic signals of other components in fly ash. The correlation coefficients R 2 of multivariate calibration reach 0.994 (fly ashes from one kind of coal) and 0.981 (fly ashes from different kinds of coal), which is significantly improved compared with univariate calibration.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%