Explosion losses from

In the search for a better approach, investigators realized that the ignition of a combustible material requires the initiation of exothermic chemical reactions such that the rate of heat generation exceeds the rate of energy loss from the ignition reaction zone. Once this condition is achieved, the reaction rates will continue to accelerate because of the exponential dependence of reaction rate on temperature. The basic problem is then one of critical reaction rates which are determined by local reactant concentrations and local temperatures. This approach is essentially an outgrowth of the bulk thermal-explosion theory reported by Fra nk-Kamenetskii (F2). 

GP 11] ]R 19] The suppression of explosive homogeneous gas-phase reactions is not due simply to thermal quenching as a result of the heat losses from a micro reactor, but rather to radical quenching [9]. The micro reactor will therefore be safe even when heat losses from the reaction micro channel are reduced by design modifications. 

The Hydrocarbon Processing Industry (HPI), has traditionally been reluctant to invest capital where an immediate direct return on the investment to the company is not obvious, as would any business enterprise. Additionally financial fire losses in the petroleum and related industries were relatively small up to about the 1950 s. This was due to the small size of facilities and the relatively low value of oil and gas to the volume of production. Until 1950, a fire or explosion loss of more than 5 million U. S. Dollars had not occurred in the refining industry in the USA. Also in this period, the capital intensive offshore oil exploration and production industry were only just beginning. The use of gas was also limited early in the century. Consequentially its value was also very low. Typically production gas was immediately flared or the well was capped and considered as an uneconomical reservoir. Since gas development was limited, large vapor explosions were relatively rare and catastrophic destruction from petroleum incidents was essentially unheard of. The outlays for petroleum industry safety features were traditionally the absolute minimum required by governmental regulations. The development of loss prevention philosophies and practices were therefore not effectively developed within the industry. 

Combining flow manifolds, 73 272 Combipress, molecular formula and structure, 5 161t Combustible masking materials, 10 91 Combustion, See also Fire entries in diesel engines, 72 420-421 energy loss from, 70 138 of ethers, 70 579-580 explosives and propellants during, 70 719... 

U.S. Department of Transportation (DOT) statistics on liquids pipelines operated under the Code of Federal Regulations (49) indicate that corrosion was the second largest contributor to accidents and failures for the period from 1982 to 1991. These statistics covered an average of 344,575 km of liquids pipelines and were derived from required reports to DOT on all pipeline accidents involving loss of at least 7.95 m3 of liquid, death or bodily harm to any person, fire or explosion, loss of at least 0.8 m3 of highly volatile liquid, or property damage of 5000 or more (50). Similar results were also reported for 1991 in the 1992 DOT/OPS report on both oil and gas pipeline incidents 62 out of 210 oil pipeline incidents were due to corrosion, of which 74% were due to external corrosion (43). For gas pipelines, 16 of all 71 reported incidents were due to corrosion, of which 63% were reported as due to internal corrosion however, internal corrosion of gas pipelines is likely only if C02 and H20 and/or H2S are present, as with unprocessed gas in gathering lines. 

Reduce the possibility of losses from dust explosions... 

The preconcentrator efficiency 17P accounts for several factors associated with the preconcentrator performance. These factors include explosive passing through the preconcentrator during the adsorption (collection) phase, explosive loss due to adsorption on cool internal surfaces, and molecular decomposition associated with the desorption phase in the preconcentrator. The value for tjp ranges from 0 (no explosive delivered to the detector) to 1 (entire explosive sample delivered to the detector). Ideally, tjp would be 1. 

F. Reducing the Possibility of Losses from Dust Explosions (Brasie, 1986)... 

In effect, stars return between about 50% and 90% of their initial mass by winds or by explosive mass ejection. Figure 2.3 gives an overview of the relative contributions of the different stellar types to the total mass replenishment. The mass returned by the stars becomes part of the ISM and serves as raw material for the formation of the next stellar generations. In this way part of the baryonic matter in a galaxy is continuously cycled between stars and the interstellar matter. Only the very-low-mass stars (initial masses < 0.8 M0) are not involved in this matter cycle because they have lifetimes exceeding the present age of the Universe and have not yet evolved very much. Some fraction of the matter therefore accumulates in very-low-mass stars and in stellar remnants, but at least part of this loss from the matter cycle... 

Potential hydrocarbon losses from the overpressuring of operating vessels are controlled first by staged computer alerts and/or manual alarms to provide for correction of the condition. If the overpressure exceeds a second set point, pressure relief valves vent the vessel contents to a flare release system. The flare system provides a means of controlled burning of hydrocarbon vapors at a nonhazardous point to avoid fire or explosion risks. Smoke problems from flares are avoided by more efficient designs that use multiple nozzles and low pressure operation to promote clean combustion [57]. Greenhouse gas concerns should more frequently stimulate an interest in energy recovery options from flared hydrocarbons. 

At present, mine gas is the major risks affecting coal mine production safety in China, the safety problems caused by the gas accounted for over 80% of coal mine production safety accidents, and its casualties account for 90% of all serious accidents casualties (Li Jing 2007), Especially the gas explosion accidents, which have caused worst human and economic losses. From 2004 to 2009, various national coal mine accidents caused more than 10 people died approximately 225 cases, 5280 people deaths, of which including 147 gas accidents, 3,667 people deaths, accounting for 65.3% and 69.5% respectively. After restoration efforts, the industry in recent years, coal mine production safety situation in China is a little better. But the coal mine production safety situation is still grim, the total accidents is still too large, serious accidents have occurred from time to time. Based on the statistical data of the state production safety supervision and Management Bureau in 2010 and other statistical data, in 2010 China s coal mine gas accident occurred 135 cases, killed 593 people... 

All these processes must be controlled quite carefully. If water withdrawal is too fast, then there is a risk of water loss from the swollen membrane, which not only leads to a drastic raise in resistance but also to fragilization. Cracks may then develop across which the gases may mix, yielding an explosive mixture, with all the catastrophic consequences that ensue. 

The occurrence of a runaway reaction or thermal explosion depends not only on the rate of heat generation from a chemical reaction but also on the rate of heat loss from the system. Unfortunately it is therefore not possible to determine and assign a stability temperature to a substance as one can with melting points or flash points. A material which is stable at some temperature in one situation may mn away from the same temperature if the system, in particular the rate of heat loss, changes. (See also case histories Al 20-23, pages 167-168.)... 

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