Investigation of unburned carbon particles in fly ash by means of laser light scattering

Iannone, Rosario; Morlacchi, Roberto; Calabria, R.; Massoli, Patrizio

doi:10.1007/s00340-010-4315-0

Cited by 6 publications

(4 citation statements)

References 18 publications

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“…The major advantage of light scattering methods is in the possibility of determining simultaneously several unknown quantities -e.g., size, velocity, composition (i.e., refractive index), temperature, and roundness [124][125][126]. In this method, measurements of the polarization ratio (the ratio between the scattering intensities polarized in the horizontal and vertical plane) is used for the calculation of UC content in coal ash.…”

Section: Determination Of Uc Levels In Ashmentioning

confidence: 99%

“…-Photoacoustic absorption spectroscopy [111][112][113] -Microwave attenuation/resonance measurements [114,115] -Laser-induced breakdown spectroscopy [116,117] -Measurement of thermal effects [118] -Measurement of ash color [119,120] -Nuclear techniques [121][122][123] -Optical methods [108,[124][125][126][127][128] -Capacity measurements [129].…”

Section: Determination Of Uc Levels In Ashmentioning

confidence: 99%

See 1 more Smart Citation

Unburned carbon from coal combustion ash: An overview

Bartoňová

2015

Fuel Processing Technology

144

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Section: Determination Of Uc Levels In Ashmentioning

confidence: 99%

Section: Determination Of Uc Levels In Ashmentioning

confidence: 99%

Unburned carbon from coal combustion ash: An overview

Bartoňová

2015

Fuel Processing Technology

144

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“…However, in this technique, the use of radiation sources requires maintenance of certain operating procedures that may pose a barrier to install this type of equipment in some power plants. It is also possible to use photo-acoustic techniques or laser light scattering [3][4][5]. A photo-acoustic signal is generated by the absorption of radiation by the sample placed in a sealed chamber filled with gas (nitrogen, helium).…”

Section: Introductionmentioning

confidence: 99%

Inspecting the Quality of Fly Ash and the Identification of Areas of their Economic Utilisation

Molenda

2015

SSP

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The content of unburned carbon in the fly ash is one of the indicators that allow the assessment of the correctness of the process of the combustion of pulverized coal in conventional power plants, as well as the identification of emerging economic usefulness of ash by-products, which are used, among others, as additives for cements [1]. This forces constant quality checks of generated fly ash. Routinely such tests are carried out periodically with use of laboratory equipment. However, technological progress allows the measurements in semi-real-time on the samples of ash taken directly from a stream of air-ash aerosol. Often used methods in commercial analytical equipment are the microwave methods [2]. Other solutions, currently used in conventional power measurement systems, are devices using x-ray and dielectric methods. X-rays and the measurement of the dielectric parameters of the carbon in the ash are used in, for example, SYSKON 201. The method employed in this solution allows the detection of carbon in the ash in the concentration range from 0 to 16%. However, in this technique, the use of radiation sources requires maintenance of certain operating procedures that may pose a barrier to install this type of equipment in some power plants. It is also possible to use photo-acoustic techniques or laser light scattering [3-5]. A photo-acoustic signal is generated by the absorption of radiation by the sample placed in a sealed chamber filled with gas (nitrogen, helium). Radiation absorbed by the sample causes it to heat up and expand the surrounding gas. The heat wave penetrates the surrounding gas, generates heat at a frequency fluctuation in accordance with the frequency modulation of radiation, and causes changes in gas pressure and, consequently, the formation of the acoustic wave recorded by a highly sensitive microphone [6]. Important limitations of the industrial application of this method is the problem of placing the sample in the measuring chamber filled with an inert gas and the high sensitivity of the measuring equipment to external vibration. The presented characteristics of current methods of monitoring the quality of fly ash directly in technological conditions shows that every solution has some limitations that hinder the application in technological lines. Therefore, development work is carried out to develop other simple and effective methods for monitoring the carbon content of fly ash [7, 8].

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“…The assessment of the instrument performance is discussed in depth in the review paper by P. Werle about the effects of optical fringes and turbulence on accuracy and precision of spectroscopic measurements [7]. Three papers deal with applications to combustion diagnostics: the paper by Löhden and coworkers describe advantages of intracavity absorption spectroscopy for trace gas detection in a combustion process [8]; the paper by Porter, Jeffries and Hanson describes a dual-wavelength mid-infrared laser diagnostic approach for the simultaneous measurements of vapor-phase fuel mole fraction and liquid fuel film thickness in hydrocarbon flames [9]; Iannone and coworkers deal with combustion optimization by measuring the fraction of unburned carbon with respect to ashes in the exhaust gas [10]. A particular kind of OPO source, suitable for cavity ringdown spectroscopy of isotopic species, especially for breath analysis, is described in the paper by Rihan and coworkers [11].…”

mentioning

confidence: 99%