Temperature explosions

Explosion Temperature The explosion temperature is a qualitative term and depends upon several factors, similar to explosion delay. It is measured mainly for a comparative study. In the present work, it is defined as the temperature necessary to cause explosion in exactly 10 or 5 seconds, that is, 10-/5-second time-to-explosion while determining explosion delay with a few milligrams of an explosive. 

A Wood s metal bath is constructed as follows a solid mild steel block 30 cm long, 

The test is performed with 20 mg of a sample, ground and dried. When the temperature of the bath is 300 °C, a test tube with the sample is immersed in the Wood s metal bath and a stopwatch is switched on simultaneously. When explosion of the sample occurs, the time is recorded by the stopwatch, that is, the time interval between the moment of insertion and the moment of explosion is noted. This period is the explosion delay (J D) or induction period at that temperature. In order to eliminate accidental variations, the mean of three readings is taken in all cases. The bath temperature may be decided depending upon the value of f D, that is, if value of ED is too high, the bath temperature may be increased whereas if it is too low, bath temperature may be decreased in order to improve the accuracy of the determination. 

Using this apparatus, it is also possible to determine the 10-/5-second time-to-explosion temperature, as follows. 

A Beckman thermometer is used to read the temperature of the bath. When the temperature of the Wood s metal bath is -300 °C, a test tube with a sample is immersed in it. A stopwatch is used to record the time interval between the moment of immersion of sample in the bath and the moment of its explosion. If the explosion delay (ED) is more than 10/5 seconds, the temperature of the bath is increased by 10 °C and the experiment is repeated with a fresh sample. This exercise is repeated with incremental temperature changes (higher or lower) until an exact ED of 10-/5- seconds is obtained. This method is similar to that described by Weber in the literature [24]. 

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Output Tests, Calculated Explosion Temperatures, and Results of... 

Explosion Temperature. At 430° it expls in 5sec (Ref 36). The crit temp for expl was found to be 599°F and the crit press 915psi (Ref 52). Pure NMe under air or N was found to deton betw 500 and 720°F. Ten additives in varying concns were tried as desensitizers, but there was no change in the temp range (Ref 14) Flammability. The flash point is 112°F (Ref 50) in the Abel-Pensky app it is 35—37° and by Marcusson s method it is 42—43°. The autoignition Doint by Constam Schlaepfer s method was found to be 440° (Ref 48)... 

Explosion Temperature, Ignited above 240° Heat of Combustion. Q 531,4kcal/mole Impact Sensitivity 11cm with BurMines app with 2kg wt (less sensitive than NG)... 

Explosion Temperature. 1 Osec at 435 ° (Ref 11) Flammability. The flammability of AP, as measured by the min weight of a primer which will ignite it, was found to lie betw Xylyl (a Russian expl) and TNT (Ref 38)... 

Explosion Temperature. The expln temp of 80/20 mixts of K perchlorate with org compds was found to be ethylene glycol, 240° polyester resin, 290° and cotton linters, 245°. 

Explosive Properties ofTetra-ammoniate. Explosion Temperature. 305° (Ref 5)... 

Ballistic Strength. 100% T NT (BuM ine s) Explosion Temperature. Does not expld or ignite at 360° or below Heat of Combustion. 8l8.1kcal/mole Hygroscopicity. Practically none Impact Sensitivity. Comparable to TNT Power. By Trauzl test, 103% TNT Rifle Bullet Test. No detonations from impact of. 30 cal bullet at 90 ft Thermal Stability. Unsatisfactory, loses 49% of wt in 48 hrs at 75° (International Test) Velocity of Detonation. No information Salts of (m-Nitrophenyll-dinitromethane. Milone and Massa (Ref 2) prepd several metallic salts and found that their expl power decreased with increasing atomic v/t of the metal Following are some of the expl salts K salt—yel crysts ... 

Brisance. Sand Test, 200g bomb 37.5 to 39.5g sand crushed vs 48.0g for TNT (78 to 82.5% TMT) PIsts Dgjjj Test Method A for pressed confined charge, 91% of TNT at d 1.50g/cc Explosion Temperature. 

Heat Sensitivity. Henkin McGill (Ref 29) report the following explosion temperatures for FA ... 

Brisance. Sand test, 58.5g vs 43.0 for TNT Detonation velocity. 7910m/sec for a cast, unconfined sample 1.0/ diam at d 1.60g/cc Explosion temperature. No cap used 375°... 

A bearing assembly from a sodium bromate crusher had been degreased at 120°C, and while still hot the sleeve was hammered to free it. The assembly exploded violently, probably because of the presence of a hot mixture of sodium bromate and a grease component (possibly a sulfurised derivative). It is known that mixtures of bromates and organic or sulfurous matter are heat- and friction-sensitive [1]. The energy of decomposition of the likely components has been calculated as 1.93 kJ/g, with an explosion temperature above 2000°C [2],... 

Above 140°C its exothermic decomposition to metal and carbon dioxide readily becomes explosive [1], A 1 kg batch which had been thoroughly dried at 50°C exploded violently when mechanical grinding in an end-runner mill was attempted [2], Explosions have been experienced when drying the oxalate as low as 80°C [6], It is a compound of zero oxygen balance. The explosion temperature of the pure oxalate is lowered appreciably (from 143 to 122°C) by application of an electric field [3], The salt prepared from silver nitrate with excess of sodium oxalate is much less stable than that from excess nitrate [4], Decomposition at 125°C in glycerol prevents explosion in the preparation of silver powder [5],... 

An explosion temperature has been published, but a solvent-free sample standing... 

During investigation of elfect of 1% of added impurities on the thermal explosion temperature of TNT (297°C), it was found that fresh red lead, sodium carbonate and potassium hydroxide reduced the explosion temperatures to 192, 218, and 192°C, respectively. 

TNT and potassium hydroxide in methanol will interact even at —65°C to give explosive acz -nitro salts (presumably o-quinonoid, or possibly Meisenheimer complexes). The explosion temperature is lowered to 160°C by the presence of a little potassium hydroxide. 

Solutions of 4-nitrotoluene in 93% sulfuric acid decompose very violently if heated to 160°C. This happened on plant-scale when automatic temperature control failed [1], but the temperature was erroneously abstracted as 135°C [2], The explosion temperature of 160°C for the mixture (presumably containing a high proportion of 4-nitrotoluene-2-sulfonic acid) is 22°C lower than that observed for onset of decomposition when 4-nitrotoluene and 93% sulfuric acid are heated at a rate of 100°C/h [3], Mixtures of 4-nitrotoluene with 98% acid or 20% oleum begin to decompose at 180 and 190°C, respectively [3,4], Thereafter, decomposition accelerates (190-224° in 14 min, 224-270 in 1.5 min) until eruption occurs with evolution of much gas [4],... 

Calcium, strontium and barium azides are not shock-sensitive, but explode on heating at about 150, 170 and 225 (or 152)°C, respectively. In sealed tubes, the explosion temperatures are higher [1], Although calcium azide is rather mildly endothermic (AH°f (s) +46 kJ/mol, 0.37 kJ/g), it can decompose much more exothermally to the nitride (189.9 kJ/mol, 1.53 kJ/g) than to the elements [2],... 

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

Explosion temperatures were determined for a wide range of combustible liquid and solid organic materials sealed into glass tubes with potassium perchlorate. The lowest temperatures were shown by mixtures with ethylene glycol (240°), cotton Enters (245°) and furfural (270°C). 

In the MBR, the applicator of plate steel was an important safety feature in the possible event of vessel rupture or explosion. Temperature and pressure measurements, stirring, infinitely variable control of microwave power input, the cold-finger, as well as a pressure relief valve, have all contributed significantly to the safety and reliability of the system. 

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