Review of flashback reported in prevaporizing/premixing combustors

• Published in: Combustion and flame 1978-01, Vol.32, p.193-203
• Main Authors: Plee, S.L., Mellor, A.M.
• Format: Article
• Language: English
• ISSN: 0010-2180; 1556-2921
• DOI: 10.1016/0010-2180(78)90093-7

Flame flashback into the fuel preparation tube of advanced prevaporizing/premixing gas turbine combustors is considered. Evidence in the literature indicates that classical flashback, which results from the flame velocity exceeding the fuel/air velocity in either the tube boundary layer or in the free stream, has not been observed in noncatalytic combustion systems burning hydrocarbon fuels. Instead, autoignition of the air stream, flame propagation through reversed flow fields, and preignition of the fuel/air mixture in separated flow regions of the mixing tube are responsible for the reported phenomena. The latter two mechanisms may be caused by either small details in the geometry of the premixing tube such as steps, diverging sections, or surface discontinuities, or by methods of fuel injection, such as contraflow injection. Only catalytic combustors operating at very low reference velocities appear capable of experiencing classical flashback; however, flashback and autoignition must be differentiated even under these conditions.