Pellet ignition

L. G. Herring, 56, 15720 (1962) Claims a pelleted igniter made by mixing a mixt of powd Zr Ni with a powdered inorg oxidant a small amt of Et cellulose this mixt is pelleted dried to remove excess solvent USP 3017300 (1962)... 

Chromium trioxide (chromic anhydride) [1333-82-0] M 100.0, m 197°, dec at 250° to Cr203, d 2.70 (pK 0.74, pK 6.49, for H2Cr04, chromic acid). Red crystals from water (0.5mL/g) between 100° and -5°, or from water/conc HNO3 (1 5). It separates when potassium or sodium dichromate are dissolved in cone H2SO4. Dried in a vacuum desiccator over NaOH pellets hygroscopic, powerful oxidant, can ignite with organic compounds. It is a skin and pulmonary IRRITANT. 

Smoke pellets are produced in a range of sizes and are commonly used tor the resting of household flues and chimneys. The pellet is ignited and will burn for about 10 seconds producing a dense white smoke. Because this is a combustion process there are obvious restrictions on its use (nonflammable atmo spheres, nonflammable surfaces, etc.). In addition the smoke is buoyant because of the heat generated. The smoke can also be an irritant and/or toxic. The production of smoke cannot be controlled, but pellets are inexpensive, easy to use, and readily available, and the smoke is produced in sufficient quantities to make them useful in the evaluation, for example, of fume cupboards and Ixroths. 

Pellets of the dry powder, when ignited in air, form snakelike tubes of spongy ash of unknown composition — the so-called Pharaoh s serpents . 

Moment-aufnahme, /. instantaneous exposure or photograph, -bild, n. instantaneous photograph, snapshot, -klemme, /. instantaneous clamp, -ziinder, m. instantaneous fuse, detonator, -ziindpille, /. flash pellet primer, -zundung, /. instantaneous ignition or firing. 

Igniters. A pellet composed of 26.5% K. perchlorate, 16.6% Ba nitrate, 53,9% 50/50 Zr/Ni alloy, and 3.0% et cellulose can be used to ignite solid propint grains (Ref 25), A series of mixts of K perchlorate with powd metals and other oxidizable mat were examined as substitutes for BikPdr as a gun primer. Most of the mixts tested were found to be satisfactory and to be compatible with brass and other metals (Ref 9) Incendiary Compositions. Stoichiometric mixts of K perchlorate with metals and oxidizable mat have been proposed as incendiaries of the Thermit type and have heats of reaction as follows Al dust 2504, powd Mg 2429. red P 1477, powd S 705 and powd C (lampblack) 1118cal/g (Ref 4). A mixt of 12.5% K perchlorate, 75% powd Zr, and 12,5% of a 50/50 Al/Mg alloy is reported to be a readily-ignited incendiary (Ref 20). Mixts of powd Al and/or powd Fe with K perchlorate with 1.5—2% NC as a binder are also good incendiaries (Ref 35). 

Pellets, slugs or flechettes made of U have very good powers of penetration. However, U is softer than steel so that in the process of penetrating an armored steel plate it is partially pulverized. Since in this form U is pyrophoric (self-igniting), such projectiles have an incendiary as well as a penetrating effect. According to one account of flechettes made of depleted U ... 

A pyrotechnic igniter consists of a basket of inorganic combustible materials, such as boron-potassium nitrate, which are usually in the form of pellets. This basket is also filled with a squib which provides a means of initiating the igniter. 

NaX, the same type that was used for the imaging experiments in Figure 5.3.3) and ignited above the pellets. The probe was subsequently inserted into the magnet. 

Fig. 5.3.8 Photograph of the detection region of the NMR probe with radiofrequency coil. A methane—air mixture was ignited above the zeolite pellets. The mixture also contained xenon for NMR detection. Hp-129Xe NMR spectra with 30% xenon (from high-density xenon optical pumping) in 70% methane is depicted. (1) The spectrum in the absence of combustion and (2) the spectrum during combustion. Adapted from Ref. [2],...

These experiments have revealed the possibility of the ignition of individual catalyst pellets within the bed. Such pellets can stay dry after the ignition due to the efficient progress of reaction despite the fact that they are surrounded by liquid filled pellets [Figure 5.4.4(a)], The images also reveal the presence of the beads with the characteristic concentric pattern of liquid distribution, similar to that observed earlier (Figure 5.4.2) for individual cylindrical pellets. 

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