Explosive range, definition

For any chemical reaction to take place it is known that definite quantities of constituents are necessary. The quantity of oxygen available in the air near flammable material can only oxidize/bum a certain quantity of the flammable material. A commonly known term, stoichiometric ratio, is responsible for determining the quantity of oxygen necessary to react with available flammable materials. Naturally, when the quantity of the flammable material and the available atmospheric oxygen are near to the stoichiometric ratio, the reaction will be near completion and cause an explosion with increase in temperature and pressure. The explosion will be violent. When the quantity of flammable material is too small, combustion carmot spread and may cease. The situation is similar when the quantity of flammable material is too large, because the lack of the required quantity of O2 means that the reaction carmot proceed further. As indicated in an earlier clause (Fig. X/3.1.2-1), all flammable materials have their explosion ranges and limits LEL and UEL. It may be possible to dilute flammable materials in excess air, but it is very difficult to create a situation where there is a dearth of oxygen because of the work force, hence this is only applicable inside equipment. 

The hazards of explosiveness of a liquid or a vapor can be expressed by two physical characteristics of the substance its flash point and explosive range. These are more fully covered in Chapter 16, but brief definitions follow. 

In the early days of the work on explosives the Service representatives had attitudes ranging from tolerance to definite antagonism. . . for the creation of an explosives program within NDRC. It is probable that in the large majority of cases lack of co-operation came from the sincere but smug conviction that the Services knew all that was to be known about explosives and that amateurs could not make significant contributions. [Noyes, page 20]. 

Amyl nitrite is a yellowish liquid with an ethereal odor and a pungent taste. It is volatile and inflammahle at mom temperature. Amyl nitrite vapor forms an explosive mixture in air or oxygen. Inhalation of the vapor may involve definite explosion hazards if a source of ignition is pre.sent. as both room and htxly temperatures are within the flammability range of amyl nitrite mixtures with either air or oxygen. It is nearly insoluble in water but is miscible with organic-solvents. The nitrile also will decompo.se into valeric acid and nitric acid. 

Definition of lower explosive limit (LEL), upper explosive limit (UEL), and range of... 

The definition is Atmospheric conditions exist if the absolute pressure-range is between 0.8 and 1.1 bar and the temperature is in the range from -20 to -1-60 °C. The directives to the explosion protection do not cover... 

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