Coil explosion

Therefore, in the case of normal heating rates (10°C/min) the solution crystalUzed UHMW-PE crystals melt at 136°C and are consequently superheated by 8°C. At 136°C the crystal coil explodes . If melting occurs from the crystal sides by slow melting this coil explosion is circumvented. The heating rate has imphcations on the chain dynamics and consequently the rate of entanglements formation from the disentangled to the entangled state. 

Pentaerythritol may be nitrated by a batch process at 15.25°C using concentrated nitric acid in a stainless steel vessel equipped with an agitator and cooling coils to keep the reaction temperature at 15—25°C. The PETN is precipitated in a jacketed diluter by adding sufficient water to the solution to reduce the acid concentration to about 30%. The crystals are vacuum filtered and washed with water followed by washes with water containing a small amount of sodium carbonate and then cold water. The water-wet PETN is dissolved in acetone containing a small amount of sodium carbonate at 50°C and reprecipitated with water the yield is about 95%. Impurities include pentaerythritol trinitrate, dipentaerythritol hexanitrate, and tripentaerythritol acetonitrate. Pentaerythritol tetranitrate is shipped wet in water—alcohol in packing similar to that used for primary explosives. 

Pitch. Pitch used to be stored in solid form at the tar distillery in open bays, from which it was removed by small explosive charges. Loading of the lump pitch by mechanical shovel created a dust ha2ard both at the tar installation and at the customer s, where the lumps had to be ground before use. In the 1990s, pitch is stored in tanks heated by superheated steam or circulating hot-oil coils and transported in fiquid form in insulated rad, road tankers, or ships. When transport as a hot fiquid is not feasible, not acceptable by the customer, or for small amounts, the pitch is converted into a dust-free particulate form, ie, short rods termed pencils, pastilles, or flakes. 

The first tank was cleaned without incident. By the time the contractors started on the second tank, a new foreman was in charge. To soften the deposits, he disconnected the steam coil, blew live steam into the tank, and then sprayed kerosene onto the walls, section by section, using a spinner mounted on a tripod. The report does not make it clear whether or not the kerosene was heated. While men were moving the tripod, a fire started in the tank, followed by an explosion. Three men were icilled. one by the fire and tw o by falling bits of the external concrete cladding. 

The resistance of titanium in nitric acid is good at most concentrations and at temperatures up to boiling . Thus tubular heat exchangers are used in ammonium nitrate production for preheating the acid prior to its introduction into the reactor via titanium sparge pipes. In explosives manufacture, concentrated nitric acid is cooled in titanium coils and titanium tanks are... 

Decomposition and a pressure explosion occurred while a 10 kl tanker with steamheating coils was being unloaded. 

Pellistors are used to detect flammable gases like CO, NH3, CH4 or natural gas. Some flammable gases, their upper and lower explosion limits and the corresponding self-ignition temperatures are listed in Tab. 5.1. This kind of gas sensor uses the exothermicity of gas combustion on a catalytic surface. As the combustion process is activated at higher temperatures, a pellistor is equipped with a heater coil which heats up the active catalytic surface to an operative temperature of about 500 °C. Usually a Platinum coil is used as heater, embedded in an inert support structure which itself is covered by the active catalyst (see Fig. 5.33). The most frequently used catalysts are platinum, palladium, iridium and rhodium. 

Another approach to a source of vapors to calibration of instruments, and similar to that described above, was that of Davies et al. [67] who used a computer-controlled pulsed vapor generator with TNT, RDX, and PETN. The explosive solid was coated on quartz beads, which were then packed into a stainless steel tube. The tube was coiled and placed into a temperature-controlled chamber. Ultrapure air was passed through the coil at temperature and vapors of explosives were vented from the coil at rates or concentrations governed by coil temperature, airflow rate, and pulse width. Calibrations could reach the picogram to nanogram range when an IMS analyzer was used as the calibrating instrument. 

The recent explosion of information from the study of the human genome has impacted pharmacology in a big way. Genes are made up iong strings of DNA moiecuies (see below) that are highly coiled and compacted into structures called chromosomes. Humans have 23 pairs of chromosomes. 

When YBa2Cus07 x is heated to 1000°C in a flowing atmosphere containing H2, [CAUTION The H2 should be diluted with 10 volumes of Ar to reduce the hazard of an explosion. A 10-turn 5-cm-diameter coil of glass tubing should be inserted next to the H2 tank to prevent flashback of the tank. The thermal analyzer must be purged completely so there are no dead volumes of air and the exit gas must be exhausted carefully.] reduction to BaO, Y2Os and Cu occurs (10)(25)... 

Wrap a coil of Primacord explosive, sometimes covered with black grease, around the camera observation port window safety glass outside the instrument shelter. Detonation of the explosive coil creates a dense black smoke cloud. This method is usually called a smoke shutter... 

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