TY - JOUR
T1 - Flame-spreading Process over Thin Aluminum Sheets in Oxygen-enriched Environments
AU - Yeh, C. L.
AU - Johnson, D. K.
AU - Kuo, K. K.
AU - Mench, M. M.
N1 - Funding Information:
This work presents the results obtained from the research project sponsored by Praxair, Inc. and Air Products and Chemicals, Inc. The authors are grateful to R. A. Van Slooten, R. Zawierucha, and J. F. Million of Praxair, Inc. and J. G. Hansel, P. A. Houghton, and E. C. Rogusky of Air Products and Chemicals, Inc. for their input and support of this project.
PY - 1998
Y1 - 1998
N2 - An experimental study of flame-spreading process over thin aluminum (99% Al and 1% Mn) sheets was investigated in oxygen-enriched environments. The objective of this study was to determine the dependency of flame-spreading rate over aluminum sheets as a function of initial chamber pressure, sample thickness, oxygen purity, oxygen flow condition, and sample orientation. The reaction mechanism of aluminum in oxygen was also studied by examining the recovered partially-burned sample using a scanning electron microscope (SEM) coupled with an energy dispersive spectrometer (EDS). The flame-spreading rate over aluminum sheets was measured by an array of fast-response lead-selenide (Pb-Se) IR photodetectors. The initial chamber pressure was varied from 0.1 to 6.3 MPa. Two grades of oxygen gas were used with purities of 99.996% and 99.75%. In terms of the effect of pressure on the flame-spreading rate, as the initial chamber pressure was increased, the flame-spreading rate was found to increase to a maximum, decrease to a minimum, and then increase again. Based upon the comparison of flame-spreading rates in horizontal, upward, and downward orientation, the flame-spreading process over aluminum sheets was found to be dominated by the solid-phase heat conduction mechanism. The continuous oxygen flow showed a strong influence on the flame-spreading behavior, and it was demonstrated that the flame can be blown off when the counter-current flow velocity exceeds a critical value. The flame-spreading rates under high-purity (∼99.996%) oxygen environments were found to be significantly greater than those in commercial grade (∼99.75%) oxygen. In addition, the oxygen content in the white ceramic-type nodules formed on the burned edge of the recovered partially-burned sample is much higher than that on the unburned surface. These imply that there exist heterogeneous reactions between aluminum and either oxygen or gaseous aluminum sub-oxides on the burning surface.
AB - An experimental study of flame-spreading process over thin aluminum (99% Al and 1% Mn) sheets was investigated in oxygen-enriched environments. The objective of this study was to determine the dependency of flame-spreading rate over aluminum sheets as a function of initial chamber pressure, sample thickness, oxygen purity, oxygen flow condition, and sample orientation. The reaction mechanism of aluminum in oxygen was also studied by examining the recovered partially-burned sample using a scanning electron microscope (SEM) coupled with an energy dispersive spectrometer (EDS). The flame-spreading rate over aluminum sheets was measured by an array of fast-response lead-selenide (Pb-Se) IR photodetectors. The initial chamber pressure was varied from 0.1 to 6.3 MPa. Two grades of oxygen gas were used with purities of 99.996% and 99.75%. In terms of the effect of pressure on the flame-spreading rate, as the initial chamber pressure was increased, the flame-spreading rate was found to increase to a maximum, decrease to a minimum, and then increase again. Based upon the comparison of flame-spreading rates in horizontal, upward, and downward orientation, the flame-spreading process over aluminum sheets was found to be dominated by the solid-phase heat conduction mechanism. The continuous oxygen flow showed a strong influence on the flame-spreading behavior, and it was demonstrated that the flame can be blown off when the counter-current flow velocity exceeds a critical value. The flame-spreading rates under high-purity (∼99.996%) oxygen environments were found to be significantly greater than those in commercial grade (∼99.75%) oxygen. In addition, the oxygen content in the white ceramic-type nodules formed on the burned edge of the recovered partially-burned sample is much higher than that on the unburned surface. These imply that there exist heterogeneous reactions between aluminum and either oxygen or gaseous aluminum sub-oxides on the burning surface.
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U2 - 10.1080/00102209808952051
DO - 10.1080/00102209808952051
M3 - Article
AN - SCOPUS:0347493382
VL - 137
SP - 195
EP - 216
JO - Combustion Science and Technology
JF - Combustion Science and Technology
SN - 0010-2202
IS - 1-6
ER -