Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B27/00—Compositions containing a metal, boron, silicon, selenium or tellurium or mixtures, intercompounds or hydrides thereof, and hydrocarbons or halogenated hydrocarbons
• • 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 OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/30—Organic compounds compounds not mentioned before (complexes)
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K7/00—Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof
  • F02K7/08—Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof the jet being continuous
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• This. invention relates to power plants of the type known as jet engines, their operation and hydrocarbon fuel compositions therefor. More particularly this invention relates to improved hydrocarbon fuel compositions for jet engines and the improved method of operation resulting therefrom. In one of its more specific aspects the invention relates to improved fuels for ram jet en gines.
• turbo jets there are three types of jet engines falling into categories known as turbo jets, ram jets, and pulse jets.
• the leastcomplicated of these power plants is the ram jet engine. While it is similar in operation to the turbo jet with respect to its working cycle, the two engines differ in compression steps. "Whereas compression for the turbo jet engine is provided by a gas turbine driven compressor which provides a stream of air to the combustion chamber at a desired controlled .velocity, air iiow through the combustion chamber of the ram jet engine is controlled only by the speed ofthe ram jet engine moving through-the air. Compression :for the ram jet engine is produced by the ramming effect of .the oncoming air.
• One of the principal objectives in thedevelopment of ram jet engines is to provide a design which develops sufiicient; thrust to extend the present level to flight speed. Other important objectives are better fuel utilization, efficiency of fuel utilization being a function of speed of flight, and motor weight reduction.
• the thermal efficiency of ram jet engines operating at current flight levels is approximately 40%. Lower ignition temperatures and extended fuel to air ratio limits are to a great extent properties required in a fuel to reach these objectives.
• One of the primary objects of this invention is to provide a fuel capable of developing a higher percentage increase in thermal efiiciency at present flight speed levels and greater thrust for a given motor design.
• Another important object of this invention is to provide hydrocarbon fuel compositions for jet engines having lower ignition temperatures.
• Still another object of this invention is to provide a fuel capable of use under extended fuel to air ratio limits and having higher heats of combustion than fuels now avail able.
• a still further object is to provide a new and novel igniter for hydrocarbon fuels and a new method of ignition.
• the overall search for fuel compositions capable of giving the optimum in engine operation has centered about additives whose properties in the combustion processgive (111) high. heat of, combustion, (2) highflame .speed and;having (3) high density, (4) .low-toxicityand (5) low volatility.
• invention resides in novel hydrocarbon fuel compositions containing as additives varying percentages of certain aluminum compounds more commonly known as aluminum alkyls. These compounds may be represented by the formula (R),,Alll wherein R is ahydrocarbon radical and n is an integer of 1, 2 or 3.
• Illustrative, but not-limitative, of the aluminum alkyl additives which maybe employed to advantage in the fuel compositions of this invention are trimethyl aluminum, dimethyl aluminum hydride, methyl aluminum dihydride, triethyl aluminum, diethyl aluminum hydride, ethyl aluminum dihydride, tributyl aluminum, dibutyl aluminum hydride, butyl aluminum dihydride, tri-isobutyl aluminum, di-isobutyl aluminum, isobutyl aluminum dihydride, and higher homologous aluminum alkyls andtheir hydrides.
• the additives above-described are very useful as igniters for hydrocarbon fuels, particularly in jet engine operation.
• a small quantity of the aluminum alkyl is injected into the combustion such as conventional petroleum hydrocarbon jet engine fuels including kerosene and aviation gasoline.
• hydrocarbon fractions which may be employed boil in the range of 200 to700 F.
• a preferred fuel in accordance with this invention comprises a hydrocarbon fraction boiling in the range of 250 to 600 F. and containing the above-designated portions of an aluminum alkyl.
• the fuels disclosed herein can be used in continuous type jet engines of the class known as turbo jet, ram jet, and pulse jet in which an atomizing type system for supplying fuel to the combustion chamber of the engine is employed.
• these engines are operated by injecting the fuel and air into the combustion chamber of a jet engine in certain predetermined fuel-air ratios and igniting the fuel so as to heat the air and combustion gases, thus increasing the volume of gas mass which is exhausted through the exhaust zone of the jet engine.
• the exit of the gas mass from the rearwardly extending exhaust duct or jet nozzle is at a velocity higher than the 'fiying speed of the engine.
• the thrust produced thereby equals the gas mass flowing through the exhaust duct times its increase in speed, according to the law of momentum.
• the decrease in ignition temperature is of the order of 800.
• COMBUSTION TESTS Example II fuel feed rate was decreased over a period. of to 15 seconds until the flame went out. To determine the rich limit, the fuel feed rate was gradually increased until the In thefollowing table. are given the re- The nozzles were uniformly In the foregoing combustion tests the fuel flows given are those flows at which the flame blew out. Each value given is theaverage of 3 to 4 determinations.
• the aluminum alkyls in anj or start-up ignition or for reigniting following blow out. Whereas ignition times in the neighborhood of 20 milliseconds is considered excellent, each of the aluminum alkyls tested in accordance with the invention gave ignition times of the order of 10 milliseconds. Specific ones of the aluminum alkyls which have given such reduced ignition times include triethyl aluminum, triisobutyl aluminum, diethyl aluminum hydride and diisobutyl aluminum hydride. These tests were performed under normal operating conditions with a small quantity of. the ignite'r being injected into the combustion zone of an, engine containing the preheated fuel-air mixture and the ignition time recorded.
• the method of operating a jet engine which comprises supplying to the combustion zone of said jet engine a hydrocarbon fuel boiling in the range of 200 to 700 F. containing between 5 and 30% by weight of an aluminum compound having the formula (R),,AlH
• R is a lower alkyl radical and n is an integer equal to from 1 to 3, burning said fuel in the combustion zone; of said engine and exhausting resulting gases from said enginefso as to impart thrust thereto.
• the method of igniting a jet fuel which comprises injecting an aluminum compound having the formula (R),,AlI-I wherein R is a lower alkyl radical and n is an integer equal to from 1 to 3 into the combustion zone of a jet engine containing a normally liquid hydrocarbon boiling in the range of 200 to 700 F. and preheated to a temperature of about 800 to'1000 F.; said aluminum compound being introduced in an amount equal to from about 5% to 30% by weight of said hydrocarbon.
• a jet engine fuel consisting essentially of a normally liquid hydrocarbon boiling in the range of 200 to 700 F. and about 5% to 30% by weight of an aluminum compound having the formula (R),,AlH wherein R is a lower alkyl radical and n is an integer equal to from 1 to 3.
• the method of operating a ram jet engine which comprises supplying to the combustion zone thereof a hydrocarbon fuel igniting in the range of about 800 to 1000 F. and boiling in the range of 250 to 600 F. containing between about 5% and 10% by weight of an aluminum compound having the formula: (R),,AlH wherein R is a lower alkyl radical and n is an integer of at least one and not more than three, burning said fuel in the combustion zone of said jet engine and exhausting the resulting gases from said engine so as to impart thrust thereto.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Liquid Carbonaceous Fuels (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (5)

Cited By (6)

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Citations (3)

• 0
  • NL NL102142D patent/NL102142C/xx active
  • BE BE558133D patent/BE558133A/xx unknown
  • NL NL217788D patent/NL217788A/xx unknown
• 1956
  • 1956-06-07 US US589861A patent/US2867081A/en not_active Expired - Lifetime
• 1957
  • 1957-05-20 GB GB15963/57A patent/GB809728A/en not_active Expired
  • 1957-05-23 DE DEK32016A patent/DE1049160B/de active Pending

Patent Citations (3)

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