Flaming combustion definition

All petroleum energy products, as distinct and dissimilar as they can be, are subjected to the process of flame combustion. It is helpful at this point to bring to mind some definitions and general laws of thermochemistry. 

The Subpart O standards apply to units that treat or destroy hazardous waste and which meet the definition of an incinerator. An incinerator is any enclosed device that uses controlled flame combustion and does not meet the criteria for classification as a boiler, sludge dryer, carbon regeneration unit, or industrial furnace. Typical incinerators1 2 3 include rotary kilns, liquid injectors, fixed hearth units, and fluidized bed incinerators (Table 23.1). The definition of an incinerator also includes units that meet the definition of an infrared incinerator or plasma arc incinerator. An infrared incinerator is any enclosed device that uses electric-powered resistance as a source of heat and which is not listed as an industrial furnace. A plasma arc incinerator is any enclosed device that uses a high-intensity electrical discharge as a source of heat and which is not listed as an industrial furnace. 

Burning and Combustion(Definition). Burning in common usage is defined, in Ref 2, as a combustion is which material is consumed by fire resulting from interaction of the material with atmospheric oxygen at high temperature and accompanied by flame and sometimes sound... 

The aforementioned definitions imply that flammabihty tests are concerned with a lower level of performance. Passing a flammability tests does not mean that a material will be less hazardous when involved in a fire. This is consistent with one definition of the term flammable, which in ASTM E176, Terminology of Fire Standards, is described as, subject to easy ignition and rapid flaming combustion (25). 

A laminar flame velocity is one of the fundamental characteristics of premixed combustible gas reactivity. It specifies an amount of mixture reacting across a unit flame front area per unit time. According to the classical definition, a laminar flame (combustion) velocity is the expansion rate of a flat one-dimensional flame front in the direction normal to the wave surface with respect to the unburned gas [1]. 

Definition of Dust E losion A dust explosion is the rapid combustion of a dust cloud. In a confined or nearly confined space, the explosion is characterized by relatively rapid development of pressure with a flame propagation and the evolution of large quantities of heat and reaction products. The required oxygen for this combustion is mostly supphed oy the combustion air. The condition necessaiy for a dust explosion is a simultaneous presence of a dust cloud of proper concentration in air that will support combustion and a suitable ignition source. 

Fundamental, laminar, and turbulent burning velocities describe three modes of flame propagation (see the Glossary for definitions). The fundamental burning velocity, S, is as its name implies, a fundamental property of a flammable mixture, and is a measure of how fast reactants are consumed and transformed into products of combustion. Fundamental burning velocity data for selected gases and vapors are listed in Appendix C of NFPA68 (1998). 

Each of these dissociation reactions also specifies a definite equilibrium concentration of each product at a given temperature consequently, the reactions are written as equilibrium reactions. In the calculation of the heat of reaction of low-temperature combustion experiments the products could be specified from the chemical stoichiometry but with dissociation, the specification of the product concentrations becomes much more complex and the s in the flame temperature equation [Eq. (1.11)] are as unknown as the flame temperature itself. In order to solve the equation for the n s and T2, it is apparent that one needs more than mass balance equations. The necessary equations are found in the equilibrium relationships that exist among the product composition in the equilibrium system. 

For those who have not studied fluid mechanics, the definition of a deflagration as a subsonic wave supported by combustion may sound over sophisticated nevertheless, it is the only precise definition. Others describe flames in a more relative context. A flame can be considered a rapid, self-sustaining chemical reaction occurring in a discrete reaction zone. Reactants may be introduced into this reaction zone, or the reaction zone may move into the reactants, depending on whether the unbumed gas velocity is greater than or less than the flame (deflagration) velocity. 

Merriam-Webster (1961) gives the following definition of fire as a noun The phenomenon of combustion as manifested in light, flame and heat and in heating, destroying and altering effects ... 

Heat Transfer by Conduction. In the theoretical analysis of steady state, heterogeneous combustion as encountered in the burning of a liquid droplet, a spherically symmetric model is employed with a finite cold boundary as a flame holder corresponding to the liquid vapor interface. To permit a detailed analysis of the combustion process the following assumptions are made in the definition of the mathematical model ... 

Flame has already been defined as a mass of gas raised to incandescence. It will be observed that this definition does not limit flame to such phenomena as are attendant upon combustion it simply postulates the existence of vapour or gas. Whilst flames may and often do exist under conditions excluding all types of combustion, as for example during the electric discharges through rarefied gases, in the majority of cases flames are the result of rapid oxidation. 

In the case of no spontaneous ignition, the evolved gas is directed at the side of a small flame to observe if it ignites to determine if the gas is combustible or not However, in the case of a definite answer in test (a), this step is unnecessary. 

Formulation of the left-hand side of Eq. (5-180) requires representative thermodynamic data and information on the combustion stoichiometry. In particular, the former includes the lower heating value of the fuel, the temperature-dependent molal heat capacity of the inlet and outlet streams, and the air preheat temperature T . It proves especially convenient now to introduce the definition of a pseudoadiabatic flame temperature Tt, which is not the true adiabatic flame temperature, but rather is an adiabatic flame temperature based on the average heat capacity of the combustion products over the temperature interval T < T < 7), The calculation of Tf does not allow for dissociation of chemical species and is a surrogate for the total enthalpy content of the input fuel-air mixture. It also proves to be an especially convenient system reference temperature. Details for the calculation of 7 are illustrated in Example 13. 

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