Group burning

The flash point of a petroleum liquid is the temperature to which it must be brought so that the vapor evolved burns spontaneously in the presence of a flame. For diesel fuel, the test is conducted according to a closed cup technique (NF T 60-103). The French specifications stipulate that the flash point should be between 55°C and 120°C. That constitutes a safety criterion during storage and distribution operations. Moreover, from an official viewpoint, petroleum products are classified in several groups according to their flash points which should never be exceeded. 

Only thallium of the Group III elements is affected by air at room temperature and thalliumflll) oxide is slowly formed. All the elements, however, burn in air when strongly heated and, with the exception of gallium, form the oxide M2O3 gallium forms a mixed oxide of composition GaO. In addition to oxide formation, boron and aluminium react at high temperature with the nitrogen in the air to form nitrides (BN and AIN). 

Oxygen is a very reactive element and many metals and non-metals burn in it to give oxides these reactions are dealt with under the individual group headings. 

Sulfur combines direcdy and usually energetically with almost all of the elements. Exceptions include gold, platinum, iridium, and the hehum-group gases (19). In the presence of oxygen or dry air, sulfur is very slowly oxidized to sulfur dioxide. When burned in air, it forms predominantly sulfur dioxide with small amounts of sulfur trioxide. When burned in the presence of moist air, sulfurous acid and sulfuric acids are slowly generated. 

Rameshwar D. Srivastava, Ph.D., Fuels Group Manager, Burns and Roe Services Corporation, Federal Energy Technology Center (Pittsburgh) (Section 27, Energy Resources, Conversion, and Utilization)... 

A final fuels group eontains high-ash erudes and residuals. These aeeount for 5% of installed units. Residual fuel is the high-ash by-produet of distillation. Low eost makes them attraetive however, speeial equipment must always be added to a fuel system before they ean be utilized. Crude is attraetive as a fuel, sinee in pumping applieations it is burned straight from the pipeline. Table 12-2 shows data obtained from a number of users that... 

Over the years a very large number of tests have been developed to try and assess the burning behaviour of polymers, this in itself being a reflection of the difficulty of assessing the phenomenon. These tests can roughly be divided into two groups ... 

Group 1 Chlorate and metal perchlorate report or whistling compositions Dry non-gelatinized cellulose nitrates Barium peroxide/zirconium compositions Burn very violently Flash shells (maroons) Casings containing flash compositions Sealed hail-preventing rockets Mass explosion risk... 

Group 2 Nitrate/metal/sulphur compositions Compositions with >65% chlorate Black powder Nitrate/boron compositions Burn violently Large firework shells Fuse unprotected signal flares Non-pressed report bullets (bird scarers) Report cartridges (unpacked) Black matches (uncovered) Accelerating single-item explosions... 

Group 3 Nitrate/metal compositions without sulphur Compositions with <35-65% chlorate Compositions with black powder Lead oxide/silicon with >60% lead oxides Perchlorate/metal Burn fast Large firework shells Fuse protected signal flares Pressed report cartridges in primary packagings Quickmatches in transport packagings Waterfalls Silver wheels Volcanoes Black powder delays Burn very violently with single-item explosions... 

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