GB758678A - Elimination of carbon in jet combustors - Google Patents

Abstract

A process for eliminating carbonaceous deposits in a gas turbine engine burning a hydrocarbon fuel boiling in the range 100-600 DEG F., comprises introducing into the combustion section of the engine an alkaline earth metal compound and an amphoteric metal compound. The atomic ratio of the alkaline earth metal compound to the amphoteric compound is at least 1/1 , and the metal compounds are present in amounts of 0.00001 to 0.1 per cent calculated on the metals. By alkaline earth metals is meant Ba, Ca, and Sr and by amphoteric metals, Pb, Zn, Mn, Cr, Va, Al, Bi, and Mo. Mixtures of more than one alkaline earth metal may be used. Compounds referred to are salts of aliphatic acids, e.g. those containing 8-22 carbon atoms, salts of aromatic acids, e.g. those containing 7-12 carbon atoms, and naphthenates, e.g. those of M.W. 150-300; acetates, formates and lactates are referred to, and these may be dissolved in water or water-alcohol mixtures. Metal alkyls, carbonyls, aryls and alcoholates are also mentioned. Oxides, hydroxides and carbonates, of particle size less than 10m , may also be used. The atomic ratio of alkaline earth metal/amphoteric metal is preferably 1/1 -\ba5/1 . The compounds may be introduced into the combustion section as a solution or suspension in the fuel. The hydrocarbon fuels may contain lead alkyl, e.g. tetraethyl lead, scavenging agents such as ethylene dibromide and dichloride, ignition promoters such as amyl nitrate, corrosion inhibitors and oxidation inhibitors.