Explosion Temperature Test Apparatus

For initiating expls only 0.01 g samples are prescribed. When the metal in the crucible reaches the desired temp, place the shatterproof-glass barricade in front of the apparatus, and lower (by means of a lever) the clamp to a point corresponding to the fixed depth of immersion of the cap in the molten metal. 

Wait until, the sample puffs off (or flashes, or explodes) and record the bath temp and the time of immersion. Vary the metal temp in the bath betw detons so as to have the 10 flashes or explns occur over a time interval range of 2 to 10 secs. Plot a time-temp curve and select from this curve the temp necessary to cause the expl to flash. or explode after immersion for 5 seconds. Record this temp as the expln (ignition, etc) temp 

In the table which. follows are listed the temps in °C which were detd in the USA by means of apparatus similar to the one described in Ref 28. The values are taken from PATR 1740, Rev (1958) and from the table entitled Military Explosives compiled at PicArsn. The temps detd in Russia for some expls and reported in Ref 24, p 29 and Ref 25, pp 326-27 are given here for comparison Most of the apparatuses used in foreign countries employ heated baths either filled with Wood s metal or with. some liquid of high bp, such as in apparatus of Kostevitch (Refs 5 24). Exceptions are the apparatus of Lang-hans, briefly described in Ref 4, which employs a metal block and the apparatus of Belgrano (Ref 18) which employs an iron plate and is of very simple construction 

C = constant depending on compn of expl e=base of natural logarithms (2.718) 

E = energy of activation of expl, in cal/mole R = gas constant (1.986 cal/mole °K) 

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Rev 1(1958) (Expln temp test) 23) Cook (1958), 39 41 (Brief descriptions of explosion temperature tests) 24) Baum, Stanyukovich Shekhter (1959), 24-28 [Temperatura vspyshki (flash.temp) and "period zaderghki (period of delay) relationships] 28-29 (Description of closed bath, apparatus and of app designed by Kostevitch, Figs 3 4) 29-30 (Method of Bowden Yoffe ) 25) Andreev Belyaev (I960), 325-28 (Detn of expln temp by the methods similar to those described in Ref 24, p 28-30) 26) PATR 2700,... 

Nj. The following tests are described Impact Test with PicArsn Apparatus (pp 2 to 4 with Figs 1, 2, 3 4 on pp 32 to 35) Impact Test with USBurMines App (4 to 7 with Figs 5, 6 7 on pp 36 to 38) Modified Impact Tests for Liquid Explosive Made with BurMinesApp and with PicArsnApp (7) Explosion Temperature Test (7 to 8 with... 

NJ. The following tests are described Impact Test with PicArsn Apparatus (pp 2 to 4 with Figs 1, 2, 3 4 on pp 32 to 35) Impact Test with USBurMines App (4 to 7 with Figs 5, 6 7 on pp 36 to 38) Modified Impact Tests for Liquid Explosive Made with BurMinesApp and with PicArsnApp (7) Explosion Temperature Test (7 to 8 with Fig 8 on p 39) Decomposition Temperature Test (8) Sensitivity to Initiation as Determined by Sand Test (9—II with Figs 9, 10, 11 12 oh pp 40—3) Modified Sand Test for Liquid Explosives (12—14) Electrostatic Sensitivity Test (14—15 and Figs 13 14 on pp 44 45) Brisance by Sand Tests (16—17) Initiation Efficiency by Sand Test (17) Stability Tests, which include 75°C International Test (18) 82.2°C KI Test (19) 100° Heat Test (19) 90°, 100° 120°C Vacuum Stability Tests (19—22 and Figs 15, 16 17 on pp 46—8) 65.5°C Surveillance Test (22—3 and Fig 18 on p 49) ... 

The Bureau of Mines impact apparatus indicates TMETN is as sensitive as nitroglycerin, with a drop height of four centimeters for a two kilogram weight. The five second explosion temperature test value is 235°C and TMETN detonates with both the metal and fiber shoe in the pendulum friction test. 

Two types of results are obtained from mechanical sensitivity tests (1) no reaction, or (2) decomposition with or without an explosion. The magnitude of friction and the impact sensitivity reported is the smallest load at which a positive result has been noted. The objective of mechanical sensitivity testing is to establish whether or not the substance is sensitive under normal handling conditions. However, this objective may not be reached. The test results may not truly reflect process conditions because most testing is carried out at ambient temperature and pressure. Since results are dependent on the type of test apparatus used, the interpretation of the results for use in practical applications requires much experience in this field of testing. 

The lowest ambient temperature for explosion protected electrical apparatus is normally rated at -20°C or T2 = 253 K. Compared with the type test conditions (see Section 8.1) for reference pressure determination in a laboratory at +20°C or % = 293 K, the explosion pressure is increased by 16% only. 

An additional test is done with this same apparatus, the 0.1 second test. In this test, a pinch (yep, that s right, a pinch ) of high explosive is thrown onto the surface of the melted Wood s Metal. If it does not react immediately, then the bath temperature is raised, and the test is repeated until the temperature is found that causes the thrown sample to pop on contact with the bath surface. This is reported as the explosion temperature at 0.1 s. ... 

JPut on hot plate with temperature above explosion temperature. Samples tested at 100 cm with NOL apparatus. 

Horsley s Apparatus—Table of Firing Points—The Government Heat Test Apparatus, c., for Dynamites, Nitro-Glycerine, Nitro-Cotton, and Smokeless Powders—Guttmann s Heat Test—Liquefaction and Exudation Tests— Page s Regulator for Heat Test Apparatus—Specific Gravities of Explosives—Will s Test for Nitro-Cellulose-Table of Temperature of Detonation, Sensitiveness, c. 

An additional classification test is sometimes used. This is simply a test for explosibility in the test apparatus, classifying the dust as able or unable to ignite and propagate a flame in air at room temperature under test conditions. This test in itself is not very useful particularly if the test conditions differ significantly from the plant conditions. 

The apparatus used to determine the explosive nature of vapors is shown in Figure 6-14. The test procedure includes (1) evacuating the vessel, (2) adjusting the temperature, (3) metering in the gases to obtain the proper mixture, (4) igniting the gas by a spark, and (5) measuring the pressure as a function of time. 

Henry and McUmber (1977) reported on the systems R-22 -water and R-22-oil. They constructed an apparatus in which R-22 could be poured into water or mineral oil at various ambient pressures controlled by the pressure of argon gas in the system. Separate units were used for the water and oil tests. They demonstrated that they could achieve thermal explosions at 1 bar, in agreement with earlier tests (see Section VII). However, no such events were observed at system pressures of 2.2 or 8 bar even though the hot liquid temperature was varied over a wide range. 

Heats of Formation and of Explosion (33-41) Temperature of Explosion (41-8) Pressure of Explosion (49-58) Power by Trauzl Test (58-63) Brisance by Crusher Test (Stauchapparat) (64-5) Testing of Blasting Caps by Lead Plate Test (155-57) Testing of Blasting Caps by Pendulum Apparatus (157-59) Determination of Burning Time of Safety Fuses (163-65) ... 

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