Electrical ignition

Tayout also has a significant role in minimizing the probability of ignition of a flammable release. Area electrical classification provides the basis for the control of electrical ignition sources. This classification is also used to determine the areas that require protection from vehicular access, etc. Frequently, highly hazardous processes that can result in overpressure (e.g., hydrogenation) are placed behind blast resistant structures/walls. 

If no gas is detected, light and then insert the poker (or switch on the electric igniter). 

For a Source of Ignition to occur, there must be an Open Flame or an Electrical Ignition or Mechanical Ignition must be present. Therefore, box 3 is an or gate since only one situation need occur. 

Gluh-verlust, m. loss on ignition, -waohs, n. gilder s wax. -wem, m. mulled wine, -zone, /. zone of incandescence, -ziinder, m. electric igniter. 

Kerzen-docht, m. candle wick, -filter, n. candle filter, filter candle, -masse, /. candle composition. -nuss, /. candlenut. -nussol, n. candlenut oil. -stUrke, /. candle power, zundung,/. electric ignition,... 

Photo flash powders are loose mixts of powdered oxidizers such as Ba nitrate and K perchlorates with metallic fuels, principally Mg, A1 and Zr. These ingredients have such small particle sizes that they bum with expl violence for durations of less than 0.1 sec. At present photoflash powders are used exclusively in military aerial photography, whereas civilian applications are served by electrically ignited Zr or Hf wire containing flashbulbs. Since 1970. non-electric, pyrotechnically functioned, flash cubes have appeared on the market (USPs 3535063,3540813 3674411)... 

A 4.9 g sample of the liquid siloxane in a glass dish was put into a bomb calorimeter (on an open bench) containing 5 ml of sodium hydroxide solution to absorb combustion gases. The electric igniter system consisted of a metal wire in contact with a cotton-wool wick which dipped into the siloxane sample. The bomb was sealed, pressured up to 39-44 bar with oxygen, and the igniter was fired. A violent explosion blew the lid off the bomb (rated at 190 bar working, 250 bar test), and examination of the deformed bomb indicated that a maximum detonation pressure of around 900 bar had been attained. 

The overall intent of electrical area classification is to provide for safety of personnel and equipment. This is achieved by the elimination of electrical ignition sources near combustible gases or vapors that could explode or bum. The specific reasons for classifying facilities into electrical hazardous areas typically are ... 

Given the unreliability of the stab-initiated tests, a second round of testing was performed using a hot nichrome wire to initiate the detonators in place of the NOL-130 stab mix and firing pin. This test was successful and all nine detonators functioned, showing that DBX-1 is more susceptible to this method of initiation. Figure 8 shows the electrical ignition setup. 

Both 2,4-dinitrosoresorcinol (23) and 2,4-dinitroresorcinol (24) are important in the explosives industry. The lead salt of 2,4-dinitrosoresorcinol has a low ignition temperature and finds use in priming compositions and in electrical igniters. The lead salt of 2,4-dinitroresorcinol is a weak initiator but is found to exhibit high sensitivity to friction and stab action without being highly sensitive to impact, and as such, this compound has found use in primers. 

Each water resistant tubular unit contains an open ended piped match holder, a time delay element and a holder at the opposite end of the tube for an electric igniter (or a second PYROCLOCK element). 

The DuPont Co makes also electric igniting devices, called electric squibs (Ref 50, pp 94-5). Three types of US electric squibs patented by Burrows et al, are described in Ref 44, pp B212 to B214... 

In addition to matches and other scratch sensitive materials, prime ignition of pyrotechnic and other ordnance items can be achieved by stab, percussion or electrically ignited primer (or squib)... 

Investigations of direct electric ignition of secondary expls such as PETN and RDX were carried out for more than 15 years, especially wirh exploding u/ires, where thin wires were rapidly evaporated under formation of a shock wave, thru abrupt application of high electric energy produced for example by a capacitor (condenser) discharge... 

On p 210 is mentioned USP 2103014 (1937) by M. Palmieri S.D. Ehrlich, in which an electrically ignited heat source transmits its heat to a metallic rod or cup that on reaching a certain temperature sets off a heat sensitive charge... 

Ger 9-10 (Antiwithdrawal fuzes) Ger 20 (Bomb high-explosive train) Ger 33 (Delay compns) Ger 33-34 (Delay elements) Ger 34-35 (Detonators blasting caps) Ger 38 39 (Dust fuze) Ger 40-41 (Electric fuzes) Ger 41-2 (Electric igniters and primers) Ger 42 (Electric matchhead) Ger 44 (Eschbach igniter) Ger 53-54 (Fuseheads and their manuf) Ger 54-56 (Bomb fuzes) ... 

Uses The possibility of using Ni nitrohydrazinate in commercial detonators was investigated by loading Cu caps of 5mmdiam with 2.5g of Ni complex and trying to detonate them by means of a fuse, or an electric igniter. No detonations were produced unless the substance was primed by ca 1.5g of Black Powder... 

Ignition Delay. If the igniter is of the delay type, it is necessary to determine the time elapsed from the start of current flow to the rupture of the igniter case. For instance, the M12 electric igniter has an ignition delay not exceeding 100 milliseconds (Ref 2)... 

The primary igniting mixture in the Ml9 electric igniter (used for simulating gunflash) contains dinitrodiazophenol 40 3, potassium chlorate 58 3 and nitrostarch 2 0.5%. This mixture is ignited by heat produced by incandescent resistance wire and in turn ignites the charge of Black Powder placed next to it... 

Electric Igniter Cap consisted, accdg to Pian-tanida (Ref 4, p 196), of a mixture of Guncotton (dry) 50, KC103 25 Sb2S3 25%, which surrounded the Pt-Ir wire, connected to two electrodes... 

Accdg to Refs I R, Japanese Rocket Launchers were mostly wooden troughs, others were guide rails and steel barrels (tubes). Launchers were provided with some electric ignition device. The most practical launcher was used by the Japanese Army under the name Type 4 20-cm Rocket Launcher, described in Ref 1, p 204 and shown in Fig 320 on p 206. It consisted fo a metal tube on a mounting permitting fine adjustments in elevation and train. The launcher was in three parts which could easily be disassembled for transportation. A rate of fire of from 1 to 2 rounds per minute could be obtd... 

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