Detonation temperature

Gibson et al, Use of an Electrooptical Method to Determine Detonation Temperature In High Explosives , JApplFhys 29,628—32, (1958)... 

Pure silver azide explodes at 340°C, but presence of below 10% of copper(I) or (II) oxides or sulfides, copper(I) selenide or bismuth(III) sulfide reduces the detonation temperature to 235°C. Concentrations of 10% of copper(II) oxide, copper(I) selenide or sulfide further reduced it to 200, 190 and 170°C, respectively. 

Compare and discuss the results for these deflagration and detonation temperatures. 

Detonation Temperature Determination. See under Ignition (or Explosion) Temperature in Vol 1, pp XVI-XVII... 

Ignition (or Explosion) Temperature Tests, also called Deflagration Temperature, Detonation Temperature and Flash Point Tests. 

F.C. Gibson et al, "Detonation - Temperature Measurements , Encyclopedia of Spectroscopy, G,L. Clark, ed, Reinhold Pub Co, New York, NY (i960), pp 134-38 (Describes a method of measuring temps of deton in HE s by means of a modified grating spectrograph. Temps of deton of several expls are as follows EDNA 5500°, PETN ca 5000°, NG 4000°, Permissible Dynamite 2600°K) 44a) Dunkle s Syllabus (1960-... 

A "parameter is a quantity which may have various values each fixed within the limits of a stated case or discussion (Ref 4a). Detonation parameters are density, heat of detonation, pressure developed on deton, temperature developed on detonation, detonation velocity, energy, propagation velocity, brisance, impetus (power), specific impulse, etc. These values seem to be identical with those called "Caracteris-tiques des Explosifs et de Poudres by French scientists. Some of them are listed in Vol 2 of this Encycl, p C149-L as "Characteristics of Explosives and Propellants . Some scientists list parameters... 

Note Accdg to C.G. Dunkle, Unlike detonation pressure, detonation temperature shows no definite trend with density, and the agreement among the values of it reported by different investigators is poorer He also suggested addg the following references ... 

F.C. Gibson et al, "Use of an Electro-Optical Method to Determine Detonation Temperatures in High Explosives , JAppl-Phys 29, 628-32(1958) 8) A.N. Dremin... 

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 (and Explosion), Spectra and Spectrographic Measurements in. Studies have been made for determination of spectra produced by flames,shock waves and detonation waves and spectrographic measurements have been made for approximate determination of temperature developed on detonation (or explosion). We call this temperature of detonation, while the term "detonation temperature we reserve for the "temperature required to cause a detonation ... 

Dunkle (Refs 7 11) and Cook (Ref 8) mentioned several methods and listed refs Refs 1) J.G. Fox, "Spectrographic Measurement of Detonation Temperature ,... 

Equation (6) is used to calibrate the apparatus and determine the detonation temperature Baum et al (Ref 44, p 97) described the spectroscope method developed in Russia in 1945 by Alentsev, Belyaev, Sobolev Stepanov, which was applicable only to transparent liquid expls, such as NG, NGc, etc. In order to elimi-. nate luminosity caused by shock wave in the atmosphere, the authors immersed the test tube with. sample in water. For a more detailed description of the method, see Ref 16 and pp 98-100 of Ref 44. The values obtd by this method are considerably lower than the calcd values. For example, for NG the exptl value was only 3150CK vs 4520°K obtd by calcn and for NGc. 3160 vs 4700... 

Detn of temp of deton by calcn) 429-30 (Experimental methods for detn of temp of deton) (See in the text) 48) Dunkle s Syllabus (1960-1961), p 15a (Discussion on the paper of Lochte-Holtgreven, listed here as Ref 43a) and 25a-b (Detonation temperature)... 

Azotidrato d argento (Silver Azide—SA) o Acido d argento, AgN 3, is described in Belgrano (Ref 31, pp 449—51). Trauzl value for 2g sample 22.5cc, Detonation Velocity 5700m/sec, Temperature of Explosion 3545° Detonation Temperature 297° (Ref 31, pp 447 451). 

The last column of Table 1 lists some experimental detonation temperatures (T j) obtained by optical methods. Although there is considerable disagreement between measurements made by different investigators, these TCJ values are probably the best that are now available. Detonation temperature is a very important parameter in detonation theory, inasmuch as it provides 1) the best test for the validity of an equation of state of the detonation products (See Vol 4, pp D268—298) and 2) insight into the chemical reaction rates in the detonation process... 

Detonation Temperature. See Explosion (Deflagration or Ignition) Temperature. Not to be confused with Temperarure Developed on Detonation or Explosion... 

Three significant consequences in regard to detonation calculations on C-H-N-0 compositions derive from the present K-W parameters and covolume factors the predicted detonation temperature is quite low the predominant carbon-oxygen product is CO2 rather than CO over a wide range of compositions at the higher loading densities the detonation pressure and velocity are reasonably close to experiment where experimental data are available. Whether the result on CO is correct or not, it has served as one point of departure for the discussion which follows. 

Since most detonation temperatures calculated by ruby fall within the range 2000°-4000°K, it is apparent from Table Al that an estimate of the detonation temperature to within 10% at the lower densities would fix Pj to within about 2-3%, and at higher densities the error would become progressively smaller. 

The detonation temperature computed from the heat of explosion and from the average specific heat of the products must not exceed 1900°C for explosives intended for penetrating rock and 1500°C for those to be used in coal mines. 

The theoretical calculation of the detonation temperature as a safety criterion was adopted only in France. In all other countries (and more recently also in France) a practical criterion has been introduced based on an experimental evaluation of the effect of explosion of a sample of the explosive on a mixture of air and methane, or on a suspension of coal-dust in air, under conditions similar to those existing in mines. For this purpose testing galleries were devised, simulating the conditions of mine galleries. 

Sulphur dust is more dangerous than coal-dust, because of the low ignition temperature of sulphur suspensions in air. According to Dubnov [53] 100 g charges of the U.S.S.R. explosives Ammonit No. 1 and 8 ignited sulphur dust. The same explosives did not ignite a methane-air mixture when the quantities were 400 and 500-650 g respectively. In sulphur mines explosives of very low detonation temperature should be used. 

Table 1. Detonation Temperatures of (Dialkylamino)trifluoro-24-sulfanes8...

Dialkylamino)trifluoro-24-sulfanes Detonation Temperature CQ Comments... 

The author believes the present experimental work confirms the view previously expressed, that the detonation in an engine using liquid fuel is due to the formation of organic peroxides, which become concentrated in the nuclear drops during compression and ignite them simultaneously where the detonation temperature is reached. The addition of detonation inducers such as nitro derivatives, amyl nitrite, and benzoyl peroxide to a variety of fuels shows that the temperature of spontaneous ignition is lowered in all cases and detonation preventors, such as organometallic compounds, have the opposite effect. 

---