Instant ignition

In 1807 he took out a patent on his invention by which a pivoted magazine deposited a few grains at a time of mercury fulminate into a touch hole in the barrel of the firearm. The mercury fulminate was detonated by a blow from the hammer of the firearm sending flame through the touch hole to ignite the propellant. Instant ignition had been achieved. 

A lighted match can instantly ignite the gas in a Bunsen burner, but it usually cannot cause a large piece of wood to catch fire. The wood tends simply to scorch. Explain the difference in terms of collisions of gas particles. 

This is nothing but an extension or modification of the last experiment depending on the watery character of the surface of the ice, which instantly ignites a piece of potassium when the latter is brought into contact with it, Tlie writer has often amused himself by lighting a cigarette in this way. 

The examination of this model and results of numerical solutions indicate that ignition propagation is determined by the absolute value and variation of heat transfer along the surface of the grain, both before and after the first instant of ignition on the grain surface. Therefore, the important variables are (1) igniter flow rate, (2) port diameter, (3) gas temperature, (4) gas composition, and (5) motor pressure. 

The diesel fuel is ignited and spreads rapidly over the surface, reaching steady burning almost instantly. At this initial condition, compute the following ... 

Hydrocarbon releases in the petroleum industry are either gaseous, mists or liquids and are either atmospheric releases or pressurized. Gas and mist releases are considered more significant since they are readily ignitable since they are in the gas state and due to the generation of vapor clouds which if ignited are instantly destructive in a widespread nature versus liquid fires that may be less prone to ignition, generally localized and relatively controllable. 

Second, ignition must be delayed long enough for a vapor cloud of sufficient size to form. Maximum flammable cloud size is usually reached in 30 to 60 seconds, so the ignition delay is not long. If ignition occurs nearly instantly, a fire or fireball, but not a VCE, would occur. 

The fourth column presents the radius of 50% mortality by thermal burns. The fireball from a nuclear explosion can reach temperatures in the tens of millions of degrees Fahrenheit and cause thermal burns at large distances. This intense heat can also cause temporary or permanent blindness and can ignite materials far from ground zero. Heat from the fireball will be felt instantly in all directions from ground zero thus, the longer a person remains out in the open, the more intense the thermal burns will be. However, the heat from the fireball lasts only several seconds and can be shielded by solid materials like brick and earth (e.g., behind a wall or hill, in a ditch or subway tunnel, etc.). The risk of thermal burns drops with increased distance from ground zero. 

Stubington et al [6] presented a short descriptive model of how the ignition front rate and the combustion rate are determined. No mathematical models to calculate the ignition rate and the combustion rate are shown. However. As far as this author can understand, the calculation results are time average values, that is, no time instant values are obtained by the method used by Stubington. No uncertainty analysis was presented and no verification method was used. The methods used are unclearly defined. Consequently, the results would be difficult to reproduce. Nevertheless, the study includes interesting result. 

Explosion temperature explodes instantly at 200° or open flame ignites in 3 secs at 149° when thrown on a heated metallic surface explodes at 130°when heated gradually (Ref 16)... 

Lewis Von Elbe (Ref 7), in discussing the theoretical aspects of spark ignition, start with the supposition that a spark instantly establishes a small volume of gas within which the temperature is very high. The temperature within the spark volume decreases rapidly due to the flow of heat to the ambient unburned gas. In the adjacent layer of ambient gas the temperature rises and induces chemical reaction, so that a combustion wave is formed which propagates... 

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