Detonation process

Safety has been greatly increased by use of the continuous nitration processes. The quantity of nitroglycerin in process at any one time is greatly reduced, and emulsification of nitroglycerin with water decreases the likelihood of detonation. Process sensors (qv) and automatic controls minimize the likelihood of mnaway reactions. Detonation traps may be used to decrease the likelihood of propagation of an accidental initiation eg, a tank of water into which the nitrated product flows and settles on the bottom. 

Properties of Detonation Processes. See under Detonation, Explosion and Related Subjects in Vol 4, D137-L to D732-R... 

Chemical equilibrium methods provide useful predictions of the EOS of detonation processes and the product molecules formed, but no details of the atomistic mechanisms in the detonation are revealed. We now discuss condensed-phase detonation simulations using atomistic modeling techniques to evaluate reaction mechanisms on the microscopic level. 

A pure form of sp3 hybridized carbon is known as diamond and this may also be synthesized at the nanoscale via detonation processing. Depending on their sizes, these are classified as nanocrystalline diamond (10 nm 100 nm), ultrananocrystalline diamond (< 10 nm) and diamondoids (hydrogenated molecules, 1 nm-2 nm). Nanodiamond exhibits low electron mobility, high thermal conductivity and its transparency allows spectro-electrochemistry [20,21]. However, ultrananocrystalline diamond exhibits poor electron mobility, poor thermal conductivity and redox activity [21,22]. 

Understanding the complex physical, chemical, and thermodynamic phenomena associated with liquid-phase injection, mixing and ignition, those which influence rapid development of detonation waves, and the role of transverse waves in the detonation process. 

The fuels area offers significant future opportunities for the synthetic chemists and combustion scientists. A tailored fuel may be in order since fuels that exhibit rapid initiation and rapid development of chemical reactions can significantly influence the detonation process. 

In contrast to the detonation of gaseous materials, the detonation process of explosives composed of energetic solid materials involves phase changes from solid to liquid and to gas, which encompass thermal decomposition and diffusional processes of the oxidizer and fuel components in the gas phase. Thus, the precise details of a detonation process depend on the physicochemical properties of the explosive, such as its chemical structure and the particle sizes of the oxidizer and fuel components. The detonation phenomena are not thermal equilibrium processes and the thickness of the reachon zone of the detonation wave of an explosive is too thin to identify its detailed structure.[i- i Therefore, the detonation processes of explosives are characterized through the details of gas-phase detonation phenomena. 

In the detonation process, temperatures reach 3000 to 4000 K so that residue, if any, consists of unreacted explosive and, possibly, carbon if the explosive is... 

Characteristics of Explosives and Propellants. See Vol 2, p C149-L and the following Addnl Refs A) W.M. Evans, PrRoySoc 204A, 12-17(1950) CA 45, 10587(1951) (Some characteristics of detonation) B) W.H. Anderson R.B. Parlin, "New Approaches to the Determination of the Thermodynamic-Hydrodynamic Properties of Detonation Processes", Univ of Utah, Inst for Study of Rate Processes, TechRept XXVIII(I953), Contract N7-onr-45107 C) W. Fickett ... 

Ordnance Explosive Train Designers Handbook , NOLR 1111 (1952), p G1 2a) C.G. Dunkle, "Introduction to Theory of Detonation of Explosives , Lecture delivered at PicArsn on 13 Dec 1955, pp 1-14 (Definitions of detonation, detonation process and other terms) 3) Clark Hawley (1957), pp 293-95 ("Detonation , by W.H. Rtnkenbach) 370-71 (Explosives and Detonation, by M.A. Cook)... 

Vol 1 (1946), Chapter 5, "The Theory of Detonation Process (Based on Summary by S.R. Brinkley, Jr) lh) G.J. Su C.H. Chang, JACS 68, 1080-83 (1946) (Equation of state for real gases) li) Ibid, IEC 38, 800-02 802-03(1946) (Equations of state for real gases) lj) M.A. Cook, jChemPhys 15, 518-24(1947 (An equation of state at extremely high temperatures and pressures from the hydrodynamic theory of detonation)... 

G.J. Mueller, Equipment for the Study of Detonation Process , PATR 1465 (1945)... 

Dunkle s Syllabus (1957-1958) Shock Tube Studies in Detonation (pp 123-25) Determination of Pressure Effect (144-45) Geometrical and Mechanical Influences (145-48) Statistical Effects of Sensitivity Discussion on Impact Sensitivity Evaluation (148-49) Pressure in the Detonation Head (175) Temperature of Detonation (176) Charge Density, Porosity, and Granulation (Factors Affecting the Detonation Process) (212-16) Heats of Explosion and Detonation (243-46) Pressures of Detonation (262-63) A brief description of Trauzl Block Test, Sand Test, Plate Dent Test, Fragmentation Test, Hess Test (Lead Block Crushing Test), Kast Test (Copper Cylinder Compression Test), Quinan. Test and Hop-kinson Pressure Bar Test (264-67) Detonation Calorimeters (277-78) Measurements... 

CA 59, 3711(1963) Engl Translation Russ JPhysChem 37, 631-34(1963) "A Technique for Investigating Transient Detonation Processes ... 

Expansion of the expln products in the forward direction in a cylinder is accompanied by compression of new layers previously undisturbed in the xplosion and this causes some loss of energy, which is considered, however, not as a loss, but as a normal part of the detonation process. Expansion of the expln products in the rearward direction proceeds more slowly as the path traversed by the wave in the explosive becomes greater, i.e., the thicker the layer of compressed expln products behind the wave becomes, the more slowly the expansion proceeds. Thus for a large chge diam, the more powerful is the initiator causing the initial wave, the smaller are the losses at the origin of propagation of detonation. 

Holland et al (Ref 11) reported that when single crysts of PETN were initiated by means of a chge of Comp B, the velocity started at 5560m/sec and then suddenly changed to 10450 while accompanied by observable radiation in the interior of the crystal. Then a final, apparently steady vel was established at 8280 m/sec. The "dark waves" observed in deton of single crysts of PETN arose at the periphery of the deton wave and preceded failures of the deton process. In a typical experiment a rod of PETN of diam 0.252 inch and 0.438 inch long was wrapped with brass foil for a distance of 0.287 inch from the boostered end. The foil seemed to prevent the occurrence of dark waves in the 1st part of the stick, but.when the deton wave passed the foil, it was choked off by dark waves (See also Ref 13, p 202)... 

Fig 3 Various Stages of Detonation Process in Lined-Cavity Charge... 

Ubbelohde J. Copp, "Detonation Processes in Gases, Liquids and Solids , pp 577-609 of the book "Combustion Processes , edited by B. Lewis et al, Prince-tonUnivPress, Princeton, NJ (1956), 84 refs 38) W.E. Deal, JChemPhys 27, 796-800(1957) (Measurement of Chapman-Jouguet pressure of expls) 38a) D.R. White, JFluidMech 2, 513-14(1957) (On the existence of higher than normal deton pressures) 39) J.F. Roth, Explosivst 1957, 161-76 (Ballistic Methods for Measuring Explosive Power and Detonation Shock) 40) Dunkle s Syllabus, (1957-1958), pp 1-3 (Measurement of detonation pressure) 1 78-81 (Calcn of detonation pressures and densities) ... 

Detonation Processes Properties of Explosive Affecting Them. This is a very broad subject and might include Chapman-Jouguet parameters (See Table under "Detonation, Chapman-Jouguet Parameters in ), thermohydrodynamic properties, brisance, density, power or strength, pressure of detonation, temperature of detonation, sensitivity to impact, sensitivity to initiation and detonation velocity... 

Detonation, Properties of Explosives Affecting Processes of. See Detonation Processes, Properties of Explosives Affecting Them... 

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