This note presents results of a theoretical and experimental investigation on the emittance of particulate deposits. A simple model based on independent and multiple scattering and using discrete ordinate method has been developed to predict the spectral hemispherical and normal emittance of particulate deposits. The model predictions are compared with measurements carried out under this study-controlled spectral emission measurements between wavelengths of 2 and 12 μm on deposits of ground synthetic ash particles having known composition and particle size. The trends from the predictions matched well with the measured values, except for some differences in the wavelength region below 4 μm, and between 8 μm and 12 μm wavelength. Possible reasons for these differences are discussed.

1.
Elliston
,
D. G.
,
Gray
,
W. A.
,
Hibberd
,
D. F.
,
Ho
,
T. Y.
, and
Williams
,
A.
,
1987
, “
The Effect of Surface Emissivity on Furnace Performance
,”
J. Inst. Energy
,
pp.
155
167
.
2.
Debellis, C. L., 1991, “Effect of Refractory Emittance in Industrial Furnaces,” Fundamentals of Radiative Heat Transfer, HTD Vol. 160., pp. 104–115.
3.
Wall
,
T. F.
, and
Becker
,
H.
,
1984
, “
Total Absorptivities and Emissivities of Particulate Coal Ash from Spectral Band Emissivity Measurements
,”
ASME J. Eng. Gas Turbines Power
,
106
, pp.
771
776
.
4.
Boow
,
J.
, and
Goard
,
P. R. C.
,
1969
, “
Fireside Deposits and Their Effect on Heat Transfer in a Pulverised Fuel Fired Boiler
,”
Fuel
,
pp.
412
418
.
5.
Brajuskovic, B., Uchiyama, M., and Makino, T., 1991, “Experimental Investigation of Total Emittance of Power Plant Boiler Ash Deposits,” Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics, J. F. Keffer et al., eds., Elsevier.
6.
Markham
,
J. R.
,
Solomon
,
P. R.
,
Best
,
P. E.
, and
Yu
,
Z. Z.
,
1992
, “
Measurement of Radiative Properties of Ash and Slag by FT-IR Emission and Reflection Spectroscopy
,”
ASME J. of Heat Transfer
,
114
, pp.
458
464
.
7.
Wall
,
T. F.
,
Bhattacharya
,
S. P.
,
Zhang
,
D. K.
,
Gupta
,
R. P.
, and
He
,
X.
,
1993
, “
The Properties and Thermal Effects of Ash Deposits in Coal Fired Furnaces
,”
Prog. Energy Combust. Sci.
,
19
, pp.
487
504
.
8.
Bhattacharya
,
S. P.
,
Wall
,
T. F.
, and
Schuster
,
M. A.
,
1997
, “
A Study on the Importance of Dependent Radiative Effects in Determining the Spectral and Total Emittance of Particulate Ash Deposits in Pulverised Fuel Fired Furnaces
,”
J. of Chemical Engineering and Processing
,
36
(
6
), pp.
423
432
.
9.
Bhattacharya
,
S. P.
,
2000
, “
A Theoretical Investigation of the Influence of Optical Constants and Particle Size on the Radiative Properties and Heat Transfer Involving Ash Clouds and Deposits
,”
J. of Chemical Engineering and Processing
,
39
(
5
), pp.
471
483
.
10.
Siegel, R., and Howell, J. R., 1992, Thermal Radiation Heat Transfer, Hemisphere Publishing, Washington.
11.
Chandrasekhar, S., 1960, Radiative Transfer, Dover Publications, NY.
12.
Bohren, C. F., and Huffman, D. R., 1983, Absorption and Scattering of Light by Small Particles, John Wiley and Sons.
13.
Bhattacharya, S. P., 1995, “The Radiative Properties and Thermal Effects of Ash Clouds and Deposits in Pulverised Fuel Fired Furnaces,” Ph.D. Thesis, The University of Newcastle, Australia.
14.
Goodwin, D. G., 1986, “Infrared Optical Constants of Coal Slags,” Ph.D. thesis, Stanford University.
15.
Vassallo
,
A. M.
,
Cole-Clarke
,
P. A.
,
Pang
,
L. S. K.
, and
Palmisano
,
A. J.
,
1992
, “
Infrared Emission Spectroscopy of Coal Minerals and Their Thermal Transformations
,”
Appl. Spectrosc.
,
46
(
1
), pp.
73
78
.
16.
Vassallo
,
A. M.
, and
Finnie
,
K. S.
,
1992
, “
Infrared Emission Spectroscopy of Some Sulfate Minerals
,”
Appl. Spectrosc.
,
46
(
10
), pp.
1477
1482
.
17.
Touloukian, Y. S., and Ho, C. J., 1989, Thermal Radiative Properties of Nonmetallic Solids, 8, Plenum Press, New York.
18.
Coleman, W., and Steele, G., 1989, Experimentation and Uncertainty Analysis for Engineers, John Wiley, NY
19.
Viskanta
,
R.
, and
Menguc
,
M.
,
1987
, “
Radiation Heat Transfer in Combustion Systems
,”
Prog. Energy Combust. Sci.
,
pp.
97
160
.
20.
Wenlan
,
X.
, and
Shen
,
S. C.
,
1997
, “
Infrared Emittance of Medium Containing Nonsphere-Shaped Particles
,”
Applied Optics
,
36
(
7
), pp.
1644
1649
.
21.
Carter, H. R., Kokdsal, C. G., and Garabrant, M. A., 1992, “Furnace Cleaning in Utility Boilers Burning Powder River Basin Coals,” Proc. International Power Generation Conference, Atlanta.
22.
Baxter, L. L., 1993, “In Situ Real Time Emission FTIR Spectroscopy as a Diagnostic for Ash Deposition During Coal Combustion,” Proc. Engineering Foundation Conference, Solihull, UK.
23.
Hottel, H. C., and Sarofim, A. F., 1967, Radiative Transfer, McGraw Hill.
24.
Yamada
,
Y.
,
Cartigny
,
J. D.
, and
Tien
,
C. L.
,
1986
, “
Radiative Transfer With Dependent Scattering by Particles: Part 2—Experimental Investigation
,”
J. Heat Transfer
,
108
, pp.
608
613
.
25.
Kumar
,
S.
, and
Tien
,
C. L.
,
1990
, “
Dependent Absorption and Extinction of Radiation by Small Particles
,”
J. Heat Transfer.
,
112
, pp.
178
185
.
26.
Mazza
,
G. D.
,
Berto
,
C. A.
, and
Barreto
,
G. F.
,
1991
, “
Evaluation of Radiative Heat Transfer Properties in Dense Particulate Media
,”
Powder Technol.
,
67
, pp.
137
144
.
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