Ignitability solids

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). 

Increasing the surface area of a combustible solid enhances the ease of ignition. Solid particles less than about 10 pm in diameter settle slowly in air and comprise float dust . Such particles behave, in some ways, similarly to gas and, if the solid is combustible, a flammable dust—air mixture containing a distribution of particle sizes can form within certain limits. 

Figure 26.2 Ignitions (solid curves), extinctions (dashed curves), HB (open circles), and HB temperatures with the heat of all reactions set to zero (open squares) as functions of inlet H2 concentration in air at 4 atm. The strain rate is 200 s ... 

USP 2900242(1959) CA 53,22957(1959) (An ignition compn suitable for igniting solid propellants consists of a mixt of polytrifluoro-ethylene 50, NH4C104 50 B 5.5-7.5ps)... 

This test enables comparative ignition experiments with easily ignitable solid inorganic substances. The sample is brought into contact with a small gas flame and one observes if ignition occurs. 

The thermite reaction (Fe203 -I- Al —> Fe -I-AI2O3) can be used to ignite solid-fuel rockets or bombs. How much aluminum is needed to react with 10.0 g of Fe203 ... 

Over the years, the thermite reaction has been used for welding railroad rails, in incendiary bombs, and to ignite solid-fuel rocket motors. The reaction is... 

The organomagnesium-halide reagents are sensitive to air and moisture and are, therefore, used directly in solution for further transformations. However, they may be isolated as white, frequently self-igniting solids that are stable to ca. 100°-150°C. Their structures in the solid state involve coordination numbers for Mg varying from three to six, but the majority of cases show Mg to be tetracoordinated, with one organic group. 

The feed, consisting of a blend of fine ore and solid fuel (coal), is first placed as uniformly as possible onto an endless perforated belt, made-up of connected and hinged cast iron or steel sections, and then passes through an ignition furnace, which is a short hood with burners inside. The flames impinge on the surface of the bed and ignite solid fuel that is close to the hot interface. From that point on, air is pulled through the completely open bed, in a downdraft fashion combustion of the solid... 

Fig. 12. Critical heat flux versus ignition temperature. Symbols are measurements at sustained ignition. Lines are calculated from abscissa for incipient ignition (solid) and incipient burning (dashed).

Ignitable solid, iiquid, or compressed gas must have a flash point less than 140 degrees F... 

Fig. 8.11 Surface coverage at ignition (solid lines) and 1 s after tjg (dashed lines) for (a) Case 5 and (b) Case 11. The coverage is provided for the catalytically coated section x > I mm. Cordierite wall material...

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