Explosive and thermic compositions or charges – Containing liquefied gaseous fuel or liquefied oxygen...
Reexamination Certificate
1999-05-21
2001-04-03
Jordan, Charles T. (Department: 3641)
Explosive and thermic compositions or charges
Containing liquefied gaseous fuel or liquefied oxygen...
C149S017000, C149S045000, C149S074000, C149S109400, C060S211000
Reexamination Certificate
active
06210504
ABSTRACT:
BACKGROUND OF THE INVENTION
A liquid or gel bipropellant rocket propulsion system consists of gas generators, oxidizer and fuel propellant tanks, plumbing, oxidizer and fuel valves, and an engine. This propulsion unit begins operation when the gas generators have been initiated and the gases from the gas generator pressurize oxidizer and fuel propellant tanks. When the oxidizer and fuel valves open, the pressurized oxidizer and fuel tanks then force the propellants through the plumbing into the engine where the propellants are mixed and ignited. The propellants can be ignited by either ignition aids or by hypergolic chemical reaction. Ignition aids can take up valuable space in the propulsion system so a hypergolic chemical reaction is the preferred ignition method. Inhibited Red Fuming Nitric Acid (IRFNA) type IIIB and monomethyl hydrazine (MMH) ignite when contacted with each other because of a hypergolic chemical reaction and are the preferred oxidizer and fuel for bipropellant rocket propulsion systems. These propellants can deliver a specific impulse of 284 lbf sec/Ibm and density impulse of 13.36 lbf sec/cubic inch when the engine operating pressure is 2000 psi. Special precautions must be used when handling because of its toxic properties.
If a liquid gas generator is used excess pressurizing gases do not have to be dumped overboard to prevent overpressurization that can result from a solid gas generator formulation. A solid gas generator formulation once ignited cannot be stopped; however, a liquid gas generator system supplies gas pressure only when it is needed. Hydrazine and hydrazine blends have been considered for liquid gas generators because of their ability to decompose at ambient conditions on an iridium catalyst preheated to above 350° F. to form warm (1000° F. to 1500° F.) gases. Hydrazine is undesirable because of its toxicity and high melting point (34° F.).
An object of this invention is to provide a less toxic liquid/gas generator propellant that is a suitable replacement for hydrazine or hydrazine blends.
Another object of this invention is to provide less toxic fuel gel propellants which are good candidates for gas generators because of their exothermic decomposition.
A further object of this invention is to provide an alternate less toxic fuel gel propellant which decomposes exothermically to release enough heat to sustain decomposition in a thermal reactor bed.
A further object of this invention is to provide gas generators as alternative fuels selected from tertiary amine azides that can function also as hypergolic fuels in a bipropellant propulsion system to meet the above conditions as further described hereinbelow.
SUMMARY OF THE INVENTION
The tertiary amine azides which are defined below are non-carcinogenic alternatives to hydrazine in liquid gas generator systems or monopropellant thruster propulsion systems. The tertiary amine azides which are defined below are non-carcinogenic alternative for use with a thermal reactor bed where exothermic reaction releases enough heat to sustain decomposition for furnishing gases for gas generator systems employed. Calorimetry methods have been used to determine the heat of formation of these compounds since this information has not been published in the open literature. The heat of formation data has been used to determine the specific impulse and density impulse of the respective formulations. A tertiary amine typically has three hydrocarbon moieties attached to the nitrogen atom. The tertiary amine azides of this invention can have no more than seven carbon atoms in the molecules.
Further, these tertiary amine azides can contain no more than two azide moieties which are attached at the opposite end of the hydrocarbon portions from the amine nitrogen atom. A special case that still meet these requirements is a pyrollidine moiety (five atom cyclic structure wherein each end of a linear four carbon atom structure is attached to a common nitrogen atom), and the common nitrogen atom has an attached ethyl azide moiety.
Pyrollidinylethylazide (PYAZ) has the following structure:
wherein R
3
is as
previously defined and wherein R
4
is —CH
2
.
Three compounds meeting the specified requirements have been synthesized and their physical and ballistic properties are evaluated herein as shown in Table 1. The chemical names for these compounds are dimethylaminoethylamine (DMAZ), pyrollidinylethylazide (PYAZ), and bis(ethyl azide)methylamine (BAZ). The structural formulae for these compounds are defined hereinbelow.
Dimethylaminoethylamine (DMAZ) has the following structure:
wherein R
1
=—CH
3
,
R
2
=—CH
3
,
R
3
=—CH
2
CH
2
N.
Bis(ethylazide)methylamine (BAZ) has the following structure:
and wherein
R
1
and R
3
are as previously defined.
REFERENCES:
patent: 4012384 (1977-03-01), Nielson
patent: 4499723 (1985-02-01), Frankel et al.
patent: 5133183 (1992-07-01), Asaoka et al.
patent: 5152136 (1992-10-01), Chew et al.
patent: 5621156 (1997-04-01), Thompson
patent: 6013143 (2000-01-01), Thompson
Baker Aileen J.
Bush Freddie M.
Jordan Charles T.
The United States of America as represented by the Secretary of
Tischer Arthur H.
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