Liquid Oxidants

The Fire Triangle The well-known/i/ g triangle (see Fig. 26-33) is used to represent the three conditions necessary for a fire (1) fuel, (2) oxygen or other oxidizer (a gaseous oxidizer such as chlorine, a liquid oxidizer such as bromine, or a solid oxidizer such as sodium bro-mate), and (3) heat (energy). 

Yellowish, volatile, toxic liquid, oxidizes in air and explodes at 60°C Confirmed carcinogen... 

The formation of molten M0O3 above 815°C results in a catastrophically accelerating effect due to the following factors (a) the liquid oxide flows off the metal surface, (b) the rate of diffusion of oxygen through the liquid phase is high, and (c) the molten oxide can also act as a flux. 

The very powerful liquid oxidant explodes when vigorously shaken, or immediately on contact with alcohol, ether, aniline or grease. It is also sensitive in the vapour or solid state (but see reference 3 above). 

Ramsay, J. B. et al., Proc. 6th Int. Symp. Detonation, 1976, 723-728 Liquid nitrogen oxide and other cryogenic oxidisers (ozone, fluorine in presence of water) are very sensitive to detonation in absence of fuel, and can be initiated as readily as glyceryl nitrate [1,2]. Detonation of the endothermic liquid oxide close to its b.p. (-152°C) generated a 100 kbar pulse and fragmented the test equipment. It is the simplest molecule that is capable of detonation in all 3 phases [3], The liquid oxide is sensitive and may explode dining distillation [4],... 

Heterocyclic bases Mellor, 1940, Vol. 8, 543 Pyridine and quinoline are attacked violently by the liquid oxide. 

The oxide ignites immediately with ethanol at ambient temperature [1]. The liquid oxide (above 24°C) reacts very violently with methanol, dimethylformamide, dimethyl sulfite or dimethyl sulfoxide (also with arsenic trifluoride) and charring may occur [2],... 

Also, the spontaneous ignition temperature for liquid or volatile oxidizers can be investigated by testing [157]. Here, a predetermined quantity of sawdust (12 to 50 mesh) is added to a reaction vessel and brought to the desired test temperature. The liquid oxidizer is then cautiously injected with a long hypodermic syringe into the vessel. The extent of reaction is determined from continuous temperature measurements and by visual observations. 

Propellant chemists have proposed a new high energy liquid oxidizer, penta-oxygen 05, which is also a monopropellant. Calculate the monopropellant decomposition temperature at a chamber pressure of 10 atm if it assumed the only products are O atoms and 02 molecules. The heat of formation of the new oxidizer is estimated to be very high, +1025 kJ/mol. Obviously, the amounts of 02 and O must be calculated for one mole of 05 decomposing. The 05 enters the system at 298 K. Hint The answer will lie somewhere between 4000 and 5000 K. 

Half of the more strongly acidic groups present on the liquid oxidized carbons were destroyed on vacuum outga.s.sing at ca. 200°. At... 

As shown in Fig. 14.24, a self-regulating oxidizer feeding mechanism is used to eliminate the liquid oxidizer pumping system. A flow of the pressurized fuel-rich gas generated in tlie primary combustor forces the oxidizer tank to supply the liquid oxidizer to the secondary combustor. Simultaneously, the fuel-rich gas is injected into the secondary combustor and reacts with the atomized oxidizer. The fuel-rich gas is injected from the primary combustor into the secondary combustor through the fuel gas injector under condihons of a choked gas flow. The pressure in the primary combustor is approximately double that in the secondary combustor. This system is termed a gas-pressurized system. 

Blends of perchloryl fluoride with halogen fluorides are homogeneous and stable. When these are used as storable liquid oxidizers for rocket propulsion, the halogen fluoride usually confers hypergolicity, increased density, and lowered vapor pressure whereas the perchloryl fluoride provides oxygen needed for efficient combustion of carbon in the fuel or of certain metal additives. The mixtures are thermally stable and their... 

Unlike some liquid oxidants, ozone readily disperses through soil. 

Hybrid Rocket Propellants. A special proplnt combination of unlike materials, particularly of unlike physical characteristics. Typical hybrid proplnt combinations are a solid fuel (or oxidizer) in combination with a liquid oxidizer (or fuel) in tjiat order. Sometimes a grain of solid fuel is encased in the combustion chamber of a rocket engine and burned in combination with liq oxygen. Similarly, a liq fuel may be injected into a combustion chamber in contact with a solid oxidizer. Another example is the use of concentrated hydrogen peroxide and a hydrocarbon fuel. In this case, the hydrogen peroxide is converted by decompn into a hot gas contg oxygen. The fuel is injected downstream of the first reaction, mixed with the hot oxidizer-rich gas, and burns (Ref 1)... 

Primarily because of industrial interests in glass and slags, and, to a less extent, of the relative ease of experimentation, most of the binary liquid oxide systems studied have been silicates and borates. Hence these will be the only systems to be discussed in this section. 

Polycomponcnt systems of liquid oxides studied have mostly been silicates. Detailed discussions of these systems are beyond the scope of the present review. Perhaps the most important feature regarding polycomponcnt liquid silicates is their ionic nature. This may be conveniently illustrated by recent studies on the viscosity of some of these melts. 

Polycomponent liquid oxides containing A1203, however, are not amenable to such simple treatment on account of the possibility of the formation of both AIO4 and A10 groups (25). No hypothesis regarding the nature and molecular structure of such anions has been made. 

Nitric Acid and Nitrates. The use of nitric acid as a major component in liquid oxidizers dates back to at least World War II when it was used in a mixture with oleum (88 wt. % white fuming nitric acid and 12 wt. % oleum) and was denoted as mixed acid. In later years its use as white fuming nitric acid (WFNA) and inhibited white fuming nitric acid (IWFNA) developed because of its higher performance capabilities in these forms. These acids are fairly pure nitric acid WFNA contains a maximum of 2 wt. % H20 and 0.5 wt. % N02 IWFNA addi-... 

Nitromethane (Vol. I, p. 579) may be used as a monergol propellant. However its negative oxygen balance may be reduced by the addition of liquid oxidants, e.g. of tetranitromethane to form a bipropellant. In practice, however, nitromethane decomposes too slowly, and it is difficult therefore to obtain hypergolic mixtures from it. To facilitate and accelerate the decomposition of mixtures with nitromethane it is necessary to add a catalyst, such as a salt of chromic acid. 

A disadvantage of liquid oxygen is that its boiling point is very low (— 183°C), an so is its specific gravity at this temperature (1.14). In view of the low boiling point rockets should be filled with this liquid oxidant just before use. 

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