Патент USA US3021677код для вставки
Unite rates 3,021,667 ‘lice atet Patented Feb. 20, 1962 Table I 3,021,667 Sample METHOD FOR INlTiATlNG THE CGMBUSTIQN 0F HYDRAZHNE Donald N. Griiiin, Niagara Falls, and Donald R. Feller, Grand island, NFL, assignors to Olin Mathieson Chern ical Corporation, a corporation of Virginia No Drawing. Filed June 2, 1953, Ser. No. 359,294 5 Claims. (£1. ?ll-35.4) 10 Our invention relates to the ignition of monopropel 65% X2134, 30% 2% H2O M115 >1‘ 0;, 2% 2% H20 62% Nz?l, 33% NgHr \: O3, 8% H20 Yes. Slow e Yes. Detonates.-No Slow _ Yes-_ No AgNOzh Yes. A ___ AggOrOi __________ __ Yes _______ __ Yes ___________ __ No. Noru.—“Yes” indicates prompt ?aming ignition. “Slow” indicates ?aming ignition after slight delay. .lant hydrazine by means of solid materials which are spontaneously reactive with hydrazine. 93% NHL, 15 We have also conducted numerous tests in a small It is known in the art that hydrazine possesses utility as a liquid propellant for rockets and other applications. caliber gun in which monopropellant hydrazine charges have been ignited successfully by the injection into the alent salts of other common metals. In accordance with our present invention, we have discovered that the silver salts of oxidizing acids are reduced by hydrazine, and ignitor would be more suitable than a solid ignitor mate rial. However, if the ignitor charge were to be carried in gun chamber of very small quantities of the silver salts Its use as a bipropellant with liquid oxidizers such as employed in accordance with our invention, particularly nitric acid or hydrogen peroxide has been under investi 20 silver chlorate, silver perchlorate and silver bromate. In gation for several years. With such oxidizers hydrazine these tests the weight of the salt amounted to approxi displays excellent self-igniting characteristics. In fact, mately 1 percent of the total charge in the gun chamber. hydrazine has been employed as a starting-fuel to ignite Our invention ?nds utility in any case where an ignitor such fuel systems as gasoline-nitric acid by injecting a is used in conjunction with monopropellant hydrazine, for small quantity of hydrazine into the rocket motor along 25 example, rockets, gas generators and liquid propellant with or ahead of the main fuel system during start-up. guns. For instance, in the ignition of a hydrazine mono The use of hydrazine as a monopropellant presents a propellant gas generator of the ?xed catalyst bed type, a generator having a catalyst bed containing a silver sal. special ignition problem. An external source of energy useful in our invention either as a top layer, dispersed may be used to initiate the monopropellant decomposi tion reaction. This would include an electric spark or 30 through the bed, or at some other suitable location, will be self-starting upon contact of the hydrazine with the glow-plug system, or injection of a liquid oxidizer during silver salt. This type of starting is satisfactory for a start-up. “single‘shot” application Where the generator is to be Solid materials which display satisfactory self-ignition operated only once, as in a rocket or guided missile. characteristics with hydrazine have advantages, over other 35 Our invention can also be employed in a caseless liquid ignition methods, when used for the ignition of mono monopropellant hydrazine gun. In a liquid propellant propellant hydrazine in certain applications as mono caseless gun in which the propellant is pumped directly propellant rockets, gas-generators, or liquid propellant into the gun chamber, some separate source for ignition guns. is required, since elimination of the shell case also Silver salts are reduced by hydrazine, and their re eliminates the conventional primer. it the ignitor mate~ action with hydrazine is usually more rapid than equiv rial is injected into the chamber to accomplish ignition of the monopropellant charge, it is likely that a liquid the presence of the oxidizing radical simultaneously pro 45 or on the base of the projectile, or in some other similar arrangement, it is likely that a solid ignitor would be duces a vigorous oxidation of the hydrazine with the more suitable than a liquid. A small charge of one of liberation of energy. This overall reaction produces a the solid silver salts which we use can be employed in ?aming or explosive ignition of the hydrazine. The such an arrangement, causing ignition when it is con presence of the silver ion alone, or the oxidizing radical tacted with the hydrazine charge. 50 alone, is not sufficient to produce the ignition reaction We claim: described. 1. A method for initiating the combustion of hydrazine We have tested the following silver compounds and which comprises reacting the hydrazine with a solid silver have found them to be e?ective in producing ?aming salt of an oxidizing acid to produce a ?aming ignition ignition of hydrazine and various hydrazine propellant 55 of the hydrazine, the reaction system consisting essen mixtures: AgClO2, AgClO3, AgClO4, AgBrO3, AgNO2, tially of the reactants and the resultants of reaction. AgNO3 and Ag2CrO4. Thus, one aspect of our inven 2. A method according to claim 1 in which said silver tion is a combustible mixture containing hydrazine and salt is silver chlorite. also containing a silver salt of an oxidizing acid as a 3. A method according to claim 1 in which said silver combustion initiator for the hydrazine, and another aspect 60 salt is silver chlorate. 4. A method according to claim 1 in which said silver of our invention is a new method for initiating combus salt is silver perchlorate. tion of hydrazine by admixing the hydrazine with one of 5. A method according to claim 1 in which said silver the aforementioned silver salts. salt is silver chromate. In order to test the utility of various silver compounds as ignitors for hydrazine, we performed a series of tests 65 References Cited in the ?le of this patent involving dropping a small quantity of hydrazine or Friederich et al.: Zeitschrift fur das Gesarnte Schies hydrazine-containing mixture onto small samples of such sund Sprengstotiwesen, vol. 21, pp. 49-52, 65—69, 84-87, compounds in air. The reaction was observed visually. 103-105, 143-146 (1926). , Table I sets forth the results obtained using a variety of Audrieth: The Chemistry of Hydrazine, John Wiley & 70 silver compounds with three di?erent hydrazine-contain ing mixtures. Sons, Inc., New York (1951), pp. 135, 138, 163, 183, 189, 199, 225, 227, 228.