Application of Propellants

Special slow burning cool propellants can be used to generate gas under pressures suitable for the operation of mechanical devices. Perhaps the most important of these applications is in cartridge starting of jet engines for aircraft. The principles involved in this application of propellent explosives are illustrated in Fig. 19.7. 

In this chapter, applications of the calculation methods used to predict the hazards of BLEVEs, as described in Chapter 6, are demonstrated in the solution of sample problems. Fire-induced BLEVEs are often accompanied by fireballs hence, problems include calculation of radiation effects. A BLEVE may also produce blast waves and propel vessel fragments for long distances. The problems include calculations for estimating these effects as well. Calculation methods for addressing each of these hazards will be demonstrated separately in the following order radiation, blast effects, and fragmentation effects. 

Propellers for the marine environment appeared first in the eighteenth centui y. The French mathematician and founder of hydrodynamics, Daniel Bernoulli, proposed steam propulsion with screw propellers as early as 1752. However, the first application of the marine propeller was the hand-cranked screw on American inventor David Bushnell s submarine, Turtle in 1776. Also, many experimenters, such as steamboat inventor Robert Fulton, incorporated marine propellers into their designs. 

Installation of propeller-type mixers varies greatly, depending on the specific application. Top-entering mixers utilize either a clamp- or flange-type mounting. It is important that the mixer be installed so the propeller or paddle placement is at a point within the tank, vessel, or piping that assures proper mixing. Vendor recommendations found in O M manuals should be followed to ensure proper operation of the mixer. 

Copper alloys in wrought or cast form are used for other purposes in ships and other marine installations, such as for propellers bearings, valves and pumps. One widespread application of aluminium-brass is its use for heating coils in tankers carrying crude oil or petroleum products. Some corrosion problems encountered in this and other applications on board ship have been described by Gilbert and Jenner . 

External jackets, 326-328 Helical coils, 312, 326, 327 Vertical coils, 326, 327 Mixing impellers, 290-297 Anchor, 290-329 Blending, 324, 326 Characteristic curves, 306 Chart to examine turbine applications, 296 Efficiency of propellers, 299 Flow of propellers. 298, 299 Flow patterns, 309-312 Gas-Liquid contacting, 324, 326 General list impellers, 291 Helical, 290, 329 Liquid-liquid dispersion, 326 Multiple, 297... 

Sweeney K.W. Bills, Application of Nitro-polymers to Smokeless Propellants , Report No 1104, Aerojet-General Corp, Azusa, Calif ... 

Madison, Application of Large Vertical Helical Mixer for Mixing Composite Propellants , Paper AlChE 60th Meeting, Atlantic City, NJ... 

Two observations on the correlations can be made. First, these results tend to invalidate one of the major objections to the application of the thermal-ignition theory to composite propellants, namely that heterogeneous interfacial reactions within the solid phase are not possible. Secondly, the effect of pressure on propellant ignitability can be qualitatively explained. 

Equations (21)-(24) permit the temperature history of the propellant grain during ignition to be calculated. Ignition of any point on the surface is assumed to occur when the propellant autoignition temperature is reached at that point. The propagation rate can then be predicted from the different times at which the different positions on the propellant surface are ignited. The important basic assumption in this approach is the applicability of the... 

A comparison of Horton s data for composite propellants with the theoretical results of Hart and Friedly is difficult. The theoretical studies are based on premixed flames, which are more appropriate for double-base propellants. The applicability of premixed flames to composite propellants is open to question, as indicated in Section II. Brown et al. (B13) have indicated that the data are consistent with the expected contributions of surface reactions in the transient combustion process. These comparisons are preliminary, however, and more research is required to study these observations in detail. 

There has been increase in the application of these componnds since the synthesis of flnorinated alkanes and related componnds in the 1930s. These include flnorinated hydrocarbons that were formerly nsed as propellants, polymerized tetraflnoroethene, and the polyflnorinated C -Cg carboxyl-ates and snlfonates. All of them are notable for their inertness under normal conditions. Aromatic flnorinated componnds are discnssed in Chapter 9, Part 3. 

Specific objectives and results of propellant grinding tests performed in support of the EDS II program for the Eco Logic technology package are discussed in detail in Chapter 4. The description of the tests and the committee s evaluation of the results presented in Chapter 4 are also applicable to the use of this unit operation in the SILVER II technology package. 

Chinese chemists have reported the synthesis of pentacyclo[4.3.0.0 , 0 ]nonane-2,4-bis(trinitroethyl ester) (88). This compound may find potential use as an energetic plastisizer in futuristic explosive and propellant formulations. The synthesis of (88) uses widely available hydroquinone (81) as a starting material. Thus, bromination of (81), followed by oxidation, Diels-Alder cycloaddition with cyclopentadiene, and photochemical [2 - - 2] cycloaddition, yields the dione (85) as a mixture of diastereoisomers, (85a) and (85b). Favorskii rearrangement of this mixture yields the dicarboxylic acid as a mixture of isomers, (86a) and (86b), which on further reaction with thionyl chloride, followed by treating the resulting acid chlorides with 2,2,2-trinitroethanol, gives the energetic plastisizer (88) as a mixture of isomers, (88a) and (88b). Improvements in the synthesis of nitroform, and hence 2,2,2-trinitroethanol, makes the future application of this product attractive. 

A practical application of dinitrogen pentoxide in methylene chloride reagent involves the nitration of either ammonium carbamate or nitrourethane, followed by ammonolysis to yield ammonium dinitramide, an energetic oxidizer with enormous potential for use in future high performance propellant compositions. This important reaction is discussed in more detail in Chapter 9. 

ANTA (114) readily forms a stable anion on reaction with bases like sodium ethoxide and this anion has been used as a nucleophile for the synthesis of many ANTA derivatives. Laval and co-workers synthesizedDANTNP (116) (calculated VOD 8120 m/s, = 1.84 g/cm, m.p. > 330 °C) from the reaction of 4,6-dichloro-5-nitropyrimidine (115) with two equivalents of ANTA (114) in the presence of sodium ethoxide. Agrawal and co-workers studied the thermal and explosive properties of both ANTA and DANTNP and suggested their use for applications in propellant/explosive formulations where insensitivity coupled with thermal stability is of prime importance. The activation energies of ANTA and DANTNP indicate that DANTNP is more thermally stable than ANTA. 

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