Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/12—Inorganic compounds

Definitions

• This invention relates to a method for preventing or reducing the deterioration of a gas turbine engine, operating on a mineral oil residual fuel, particularly a petroleum residual 'fuel. This invention also relates to an improved fuel composition for use in gas turbine engines.
• Residual fuels employed in the compositions of this invention have a small content of vanadium which, under the conditions existing in a gas turbine engine and in the absence of additives, are converted to corrosive vanadium compounds.
• vanadium which, under the conditions existing in a gas turbine engine and in the absence of additives, are converted to corrosive vanadium compounds.
• the preferred micas are muscovite (potassium mica) and phlogopite (magnesium mica); other micas which may be employed are:
• the .mica will normally be incorporated, in the fuel, in finely divided form whereby a. suspension is formed. Clearly the stability of the suspension will depend, among other factors, upon particle size, and preferably stirring means will be provided to maintain the composition.
• a method of operating a gas turbine. engine upon a residual fuel, of petroleum origin contain ing vanadium, by which damage or decline in efficiency during the operation of the engine on said fuel, a mica,
• the improved compositions when used in gas turbine engines, give a reduced rate of corrosion of internal surfaces of the turbine in comparison with the untreated fuel and also in comparison with compositions derived by the use of additives which, while being complex aluminium silicates, do not lie within the sub-class of compounds in'accordance with the invention. It is an objectof this'invention to provide an improved fuel composition for use. in gas turbine engines. lt fis another objectiof thisiny'ention to provide an improved metho d' of opei atinga gas turbine engine upon a residual fuel, of. petroleum origin, containing vanadium. Other objects will appear hereinafter. f
• a fuel composition suitable for use in gas turbine engines: containing a major proportion of a vanadium containing tently, into the combustion chamber of said engine.
• the optimum rate of feed of mica to the engine depend upon both the rate of feed of the fuel and upon the proportion of vanadium contained in the fuel.
• greater amounts will usually be added during the period of injection but normally the amount so addedfwhen averaged, over the injection cycle will not exceed 3% by weight of the fuel fed during this period.
• the mica may be introduced into the engine by any desired method, including: a v
• the additive may be introduced into the engine in intermittent manner.
• the mica will be introduced over a period of hours by one or other of the methods described and thereafter a substantial measure of protection from corrosion will be achieved notwithstanding that residual fuel free of corrosion preventing additive is employed.
• the cycle will be repeated.
• i t V Preferably in a cycle of operations the mica is introduced for a period not exceeding 20 hours and thereafter the engine is operated without introduction of mica for a period of at least 80 hours.
• the cycle may consist of 12 hours operation with injection of mica at the rate of (ll-1.0% by weight of the residual fuel followed by 88 hours operation using residual fuel without mica injection to the engine.
• the combustion rig was of the following construction:
• test blade section consisting of four turbine stator blades arranged to simulate the first row of turbine blading.
• test blades were descaled in the following manner:
• the blades were immersed in a boiling mixture of 30 percent weight caustic soda, 2 percent weight potassium permanganate and 68 percent water for one hour after which they were scrubbed under running water with a brass wire brush. The blades were then replaced in the mixture for a second hour and the scrubbing treatment repeated. Water vaporisation losses from the mixture were made good by topping up with distilled water. After the second scrubbing treatment the blades were replaced for two minutes in a mixture of 1 part concentrated nitric acid and 3 parts water to which had been added 1 percent volume of volume hydrogen peroxide. The temperature of this mixture was maintained at '60 C. On removal the blades were Washed under running water, then in acetone and dried ready for weighing.
• Tests 1 and 2 are provided by way of comparison.
• the fuel employed was a kerosine distillate fraction of petroleum origin.
• the fuel employed was an Admiralty Reference Fuel, having the code name Mothball, of the following characteristics:
• Viscosity (Redwood No. 1 at 100 F.) secs 635 Ash percent 0.058 Vanadium content "ppm..- 258 Sodium content p.p.m 1
• test 3 mica was injected into the total air supply to the combustion chamber.
• the mica used was muscovite (potassium aluminium silicate complex) and had a particle size such that 80% passed through a 200 British Standard mesh. 7
• Example 2 vided a preheating chamber through which 'the flow of compressed air passed before reaching the main 'combustion chamber; the preheating "chamber was in the.
• test'bl'ade holder A jig, hereinafter referred to as the test'bl'ade holder, and constructed to locate four turbine blades in therelative positions in which they' would be mounted in a paratus described in Example 1.
• the blade'holder was brought into position for test urposes after steady operating conditionsfhad been,estab lished.
• To measure fouling the inner blade s w s weighed both before and after exposurejto-the' exhaust test-blades and of the weight of theblades aftercleaning. Results are expressed as (a) percentage difference (increase or decrease) in fouling, in relation to fouling obtained using fuel Without additive and (b) percentage reduction in corrosion (loss of weight of; the blades after cleaning) in relation to corrosion obtained; using fuel withoutadditive.
• the referen cefuel was thefuel knownas Admiralty Reference Fuel "Vanilla which has an ash content of 0.08% by weight, a vanadium content of 360 parts per million and a viscosity (Redwood No; 1 at 100 F.) .of 650 seconds.
• vite Mica weight on Fuel Flow. 294 12 .do Primary Zone. 1.70% by 575.0 Increase... 50.

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Liquid Carbonaceous Fuels (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10272073

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (5)

Family Cites Families (11)

• 0
  • BE BE570953D patent/BE570953A/xx unknown
• 1957
  • 1957-09-06 GB GB28211/57A patent/GB837831A/en not_active Expired
• 1958
  • 1958-09-03 US US758668A patent/US2993336A/en not_active Expired - Lifetime
  • 1958-09-05 DE DEB50243A patent/DE1157031B/de active Pending

Patent Citations (5)

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