Vaporization mechanism

For the majority of metals, the evaporation coefficient is found to be unity, but, as mentioned before, the coefficient of many non-metallic elements with a complex vaporization mechanism such as... 

When a flammable liquid is sprayed as fine droplets into the air, a flammable mixture can result, which may burn or explode. The mist or spray may be formed by condensation of saturated vapors or by mechanical means [40]. As the particle sizes of the liquid become greater than 0.01 mm diameter, the lower flammability limit of the material becomes lower while above 0.01 mm, the LEL is about the same as the vapor. Mechanical engine crankcase explosions of oil mist in air are hazardous, and current practice is to apply explosion relief valves to the crankcase. 

A vapor mechanically separated from the liquid phase and rapidly cooled (for instance, by expansion in a cloud chamber) to a temperature Tj, at which its pressure is p and greater than the saturated vapor pressure p0 above a plane liquid sur-... 

Vaporization proceeds from the head of wire bundle. However, the vaporization mechanism of the nitride, i.e., whether the vaporization takes place through the decomposition of the nitride into metal vapor and nitrogen atoms or not, is not clear. 

From the results of Chapters 3 (see also [24]), it may be shown that for nearly all droplet vaporization mechanisms, the dependence of Rj on droplet size may be expressed approximately by the equation... 

As previously indicated (Section 11.2.2), the expression for R depends on the vaporization mechanism. An attractive formula for liquid rockets employing volatile oxidizers is that of a burning fuel droplet in an infinite quiescent oxidizing atmosphere [equation (3-58)], namely. 

The multicontact miscibility development by a vaporizing mechanism is illustrated in Fig. 1. The pseudoternary diagram shows light (L) components (CO2, CH4), intermediate (I) gases (C2-C5) and heavy (H) components (Ce+j in the vertices. The critical point on the two-phase diagram is denoted by C. Oil and solvent compositions are denoted by O and S, respectively. As oil and solvent mix at oil-solvent front, two phases form, as shown by LI and Gl. The gas moves ahead being less viscous and mixes with original oil. This produces a two-phase mixture that forms compositions shown by L2 and G2. G2 moves ahead and mixes with oil. This process repeats itself and the... 

Many relatively shallow reservoirs, especially those in Alaska and some in West Texas, are at temperatures below 50° C. In such reservoirs, three hydrocarbon fluid phases (L1-L2-V) form when oil and solvents mix.f Slim tube recoveries greater than 90% can be observed in such fluids with hydrocarbon solvents, even when three fluid phases form. Although true miscibility did not develop, high oil recovery rates were observed through the condensing-vaporizing mechanism. These solvents also had high coreflood recoveries. 

Since various other vaporization mechanics also lead to equation (67), this equation has a certain degree of generality, but it must be modified if convective corrections to R become important. Spalding s extension of this analysis [52] to account for convective effects shows that in a typical case, the present formulas overestimate x by a factor of about 2 by neglecting the increased vaporization rate and increased drag. 

A vapor-recompression evaporator is to concentrate a very dilute aqueous solution. The feed rate is to be 30,000 Ib/h the evaporation rate will be 20,000 Ib/h. The evaporator will operate at atmospheric pressure, with the vapor mechanically compressed as shown in Fig. 16.12 except that a natural-circulation calandria will be used. If steam costs 8 per 1000 lb, electricity costs 3 cents per kilowatthour, and heat-transfer surface in the heater costs 70 per square foot, calculate the optimum pressure to which the vapor should be compressed. The overall compressor efficiency is 72 percent. Assume all other costs are independent of the pressure of the compressed vapor. To how many effects will this evaporator be equivalent ... 

J.G. Davy and G.A. Somoijai. Studies of the Vaporization Mechanism of Ice Single Crystals. J. Chem. Phys. 55 3624 (1971). 

Most of the researchers in AAS, starting with [26, 27], attributed these discontinuities in plots to changes in the vaporization mechanism and/or in the chemical form of the reactant, for instance, to a transition from oxide dissociation at low temperatures to sublimation of free metal in the high-temperature domain. Interpretation of the mechanism was attempted by identifying the only measured parameter E with thermal effects of a variety of conceivable processes (or of individual steps of the whole process). In 1981, a method was proposed [25] to determine absolute vaporization rates. It included measurement of both Arrhenius parameters (see Sect. 3.6). 

Using these methods is similar to reconstructing a puzzle. How the retention and vaporization mechanisms can be quantitatively analyzed, and the predicted retention times improved, based on molecular properties calculated in silica, are fundamental questions in chromatography. In gas chromatography, no solvent is used except in special cases where water vapor and ionic gas are mixed with the carrier gas. The basic retention mechanisms depend on the strength of the molecular interaction with the stationary phase, and the vaporization mechanism depends on the properties of the analytes. 

T. Ackeman and W. Lange, Optical pattern formation in alkali metal vapors Mechanisms, phenomena and use, Appl. Phys. B, 72, 1, 2000. 

They only play a minor role on the streamer behavior. Most of the streamers are nearly the same whatever the liquid thermal properties (specific heat, heat of vaporization), mechanical properties (superficial tension, compressibility) consequently, it is almost impossible to appreciate their influence. Liquid mass per unit volume is nearly independent of pressure and temperature, and also not very different from one... 

Keywords l-Ethyl-3-methyliinidazoliuin acetate Acid-base equilibria Basic ionic liquids Carbene Catalysis CO2 capture DFT calculations Hydrogen bonding Ionic liquids Mass spectroscopy N-Heterocyclic carbenes Organocatalysis Photoelectron spectroscopy Proton transfer Synthesis Vaporization mechanism... 

Process combustion vaporization mechanical comminution Examples of pollutants emitted NO, NO2, CO, soot, SO2 hydrocarbons coarse particles, e.g. dusts, sea spray... 

In many ways condensation is just the reverse of vaporization, although some of the vaporization mechanisms cannot be mechanically duplicated in condensing equipment. Differential condensation, in which the condensate is removed as soon as it is formed, is not practiced commercially. 

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