Burning gas

Plant Safety. Of the many ferroalloy products produced in electric furnaces, ferromanganese has the greatest potential for furnace emptions or the more serious furnace explosions. The severity of the explosions increases with the size of the furnace. Such incidents are infrequent, but can occur, and when they do are often disastrous. Explosions usually result in extensive damage to the furnace and surrounding area, and often severe injuries or death to personnel in the immediate area. An emption is the sudden ejection of soHds, Hquids, or gases from the furnace interior. A more violent and instantaneous ejection of material, accompanied by rapid expansion of burning gas, is considered an explosion (38). 

S has been approximated for flames stabili2ed by a steady uniform flow of unbumed gas from porous metal diaphragms or other flow straighteners. However, in practice, S is usually determined less directly from the speed and area of transient flames in tubes, closed vessels, soap bubbles blown with the mixture, and, most commonly, from the shape of steady Bunsen burner flames. The observed speed of a transient flame usually differs markedly from S. For example, it can be calculated that a flame spreads from a central ignition point in an unconfined explosive mixture such as a soap bubble at a speed of (p /in which the density ratio across the flame is typically 5—10. Usually, the expansion of the burning gas imparts a considerable velocity to the unbumed mixture, and the observed speed will be the sum of this velocity and S. ... 

In the reaction 2one, an increase in the intensity of the turbulence is related to the turbulent flame speed. It has been proposed that flame-generated turbulence results from shear forces within the burning gas (1,28). The existence of flame-generated turbulence is not, however, universally accepted, and in unconfined flames direct measurements of velocity indicate that there is no flame-generated turbulence (1,2). 

It is often desired to substitute directiy a more readily available fuel for the gas for which a premixed burner or torch and its associated feed system were designed. Satisfactory behavior with respect to dashback, blowoff, and heating capabiHty, or the local enthalpy dux to the work, generally requires reproduction as neady as possible of the maximum temperature and velocity of the burned gas, and of the shape or height of the dame cone. Often this must be done precisely, and with no changes in orifices or adjustments in the feed system. 

The stoichiometric flame temperature ( Tg ) is used to characterize the burning gas surrounding the droplets because combustion naturally predominates at a distance where the fastest burning mixture is produced. This mixture approximates to the stoichiometric composition. The selection of the droplet surface temperature BP is discussed below. The enthalpy change for vaporization AH is given by... 

The amount of water vapor resulting from combustion varies with composition of the burned gas. When the value is unknown, one can estimate that each cubic meter of gas burned produces 42 grams (650 grains) of water vapor. 

The heating panels can be heated with electricity, burning gas flames, or hot water. 

Rauchgas, n. smoke gas, flue gas, chimney gas, burned gas. -analyse, /. fiue-gas analysis, -vorwtlrmer, m. flue-gas preheater, economizer. 

Schwelgas, n. gas from low-temperature carbonization producer gas partially burned gas. 

Furnaces and boilers are devices that burn fuel to space heat homes, offiees, and industrial facilities. Natural gas, liquefied petroleum gas, and heating oil are the dominant fuels used for furnaces and boilers. In the United States, furnaces and boilers burning gas and oil take care of over 75 percent of all space heating. 

Transportation of natural gas through pipelines began in the United States in the early part of the nineteenth century. One of the first known uses occurred in 1821 with the building of a system of metallic lead pipes to transport natural gas from a nearby shallow well to commercial establishments in Fredonia, New York, Gas lights—burning gas made from coal—illuminated the streets of Baltimore beginning in 1816. 

This has relevance to the supply of gas and plant burning gas, in particular section 6, as amended by the Consumer Protection Act 1987. 

He considered that the rapid flame propagation could be achieved with the same mechanism as vortex breakdown. Figure 4.2.2 schematically shows his vortex bursting mechanism [4,5]. When a combustible mixture rotates, Ihe pressure on the axis of rotation becomes lower than the ambient pressure. The amount of pressure decrease is equal to max in Rankine s combined vor-fex, in which p denotes fhe unburned gas density and Vg denotes the maximum tangential velocity of the vortex. However, when combustion occurs, the pressure on the axis of rofafion increases in the burned gas owing to the decrease in the density, and becomes close to the ambient pressure. Thus, there appears a pressure jump AP across the flame on fhe axis of rotation. This pressure jump may cause a rapid movement of the hot burned gas. By considering the momentum flux conservation across the flame, fhe following expression for the burned gas speed was derived ... 

That is, once combustion is preceded, a pressure jump is invoked on the axis of rotation owing to angular momentum conservation. By further considering the pressure jump AP to be converted into the kinetic energy of the burned gas p u /l, an expression for the axial velocity of the hot gas can be obtained as ... 

After detachment of the flame from the wall and reduction of its width, three zones develop in the vessel parallel to each other a flame and burned gas zone and two zones (adjacent to the sidewalls), where no flame is present and where the gas temperatures are lower than behind the flame. All this happens in a field of very high centrifugal acceleration, which induces a free convection movement of the flame and the product zone behind it toward the... 

Units burning gas recovered from hazardous or solid waste landfills for energy recovery. 

The recombination zone falls into the burned gas or post-flame zone. Although recombination reactions are very exothermic, the radicals recombining have such low concentrations that the temperature profile does not reflect this phase of the overall flame system. Specific descriptions of hydrocarbon-air flames are shown later in this chapter. 

Figures 4.6—4.8 are the results for the stoichiometric propane-air flame. Figure 4.6 reports the variance of the major species, temperature, and heat release Figure 4.7 reports the major stable propane fragment distribution due to the proceeding reactions and Figure 4.8 shows the radical and formaldehyde distributions—all as a function of a spatial distance through the flame wave. As stated, the total wave thickness is chosen from the point at which one of the reactant mole fractions begins to decay to the point at which the heat release rate begins to taper off sharply. Since the point of initial reactant decay corresponds closely to the initial perceptive rise in temperature, the initial thermoneutral period is quite short. The heat release rate curve would ordinarily drop to zero sharply except that the recombination of the radicals in the burned gas zone contribute some energy. The choice of the position that separates the preheat zone and the reaction zone has been made to account for the slight exothermicity of the fuel attack reactions by radicals which have diffused into...

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