Combustion heterogeneous

The discussion of combustion fundamentals so far has focused on homogeneous systems. Heterogeneous combustion is the terminology often used to refer to the combustion of Hquids and soHds. From a technological viewpoint, combustion of Hquid hydrocarbons, mainly in sprays, and coal combustion are of greatest interest. 

A10. Anderson, R., Brown, R. S., Thompson, G. T., and Ebeling, R. W., paper presented at AIAA Heterogeneous Combust. Conf, Palm Beach, Florida, 1963. 

Heterogeneous combustion, 7 449-454 Heterogeneous copolymerization of acrylonitrile, 11 203—204 with VDC, 25 698-699 Heterogeneous enzyme systems, 10 255-256 Heterogeneous gas-solid catalytic reactions, 21 340-341 Heterogeneous Ideal Adsorbed Solution Theory (HIAST), gas separation under, 1 628, 629... 

Not all metals bum heterogeneously. The determination of which metals will bum in a heterogeneous combustion mode can be made from a knowledge of the thermodynamic and physical properties of the metal and its oxide product [1],... 

As mentioned in the previous section, the condition for vapor phase combustion versus heterogeneous combustion may be influenced by pressure by its effect on the flame temperature (Tvol or Td) as well as by its effect on the vaporization temperature of the metal reactant (Th). For aluminum combustion in pure oxygen, combustion for all practical conditions occurs in the vapor phase. In air, this transition would be expected to occur near 200 atm as shown in Fig. 9.15 where for pressures greater than —200 atm, the vaporization temperature of pure aluminum exceeds the adiabatic flame temperature. This condition is only indicative of that which will occur in real particle combustion systems as some reactant vaporization will occur at temperatures below the boiling point... 

Brzustowski, T.A., and I. Glassman. 1964. Vapor-phase diffusion flames in the combustion of magnesium and aluminum II. Experimental observations in oxygen atmospheres. In Heterogeneous combustion. AIAA progress in astronautics and aeronautics ser. 15 117-58. 

Smirnov, N.N., and N.I. Zverev. 1992. Heterogeneous combustion. Moscow Moscow University Publ. 

Aside from thermal interactions, chemical interactions between flames and surfaces are also important. Chemical interactions are typically manifested either by radical recombination on cold (relatively inert) walls [4, 5] or by heterogeneous combustion on chemically active surfaces (catalysts). Among the available technologies, catalysts have the best potential for NO, reduction. A review on recent advances in catalytic combustion is given elsewhere [6]. The focus here is on combustion near inert surfaces. 

Kniga II. Ya.B. Zel dovich D.A. Frank-Kamenetskii, "Turbulentnoye i Geterogennoye Goreniye (Turbulent and Heterogeneous Combustion), IzdatMekhanlnst,Moscow (1947)... 

The writer echoes the wishes of many workers in the combustion field in hoping that heterogeneous combustion systems will eventually lend themselves to treatments similar to those used with the homogeneous reactor. 

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 ... 

The case of combustion of an entire spherical surface with forced convection has not yet been solved. Frossling (4) originally proposed a semi-empirical relation for the low-temperature evaporation of droplets in motion. Spalding (60) has applied the equation to his heterogeneous combustion data with some success by including the term containing the transfer number ... 

Bifurcation behavior in homogeneous-heterogeneous combustion II. Computations for stagnation-point flow (with X. Song, W.R. Williams, and L.D. Schmidt). Comb. Rome, 292-311 (1991). 

Ignition and extinction of homogeneous-heterogeneous combustion CH4 and C3H8 on Pt ... 

Zeldovich Ya. B., Frank-Kamenetskii D. A. Turbulentnoe i geterogennoe gorenie [Turbulent and Heterogeneous Combustion]. Moscow Mosk. Mekh. In-t, 251 p. (1947). 

Rastogi and Bisht (Ref 3a) made combustion studies on hybrid propints consisting of o-s m-and p-toluidine nitTates with aniline-formaldehyde polymer as solid fuels, and red fuming nitric acid as oxidizer. They found that the results fitted a burning rate equation of the type, = a (G)v, where a and v are constants and G is the mass velocity. The authors conclude that the heterogeneous combustion reaction is diffusion controlled, and its rate is dependent on particle size... 

Behrooz, G. S. Altwicker, E. R. Rapid formation of polychlorinated dioxins/furans during the heterogeneous combustion of 1,2-dichlorobenzene and 2,4-dichlorophenol, Chemosphere, 1996, 32(1), 133-144. 

Branca C, Di Blasi C, Elefante R. Devolatilization and heterogeneous combustion of wood fast pyrolysis oils. Ind Eng Chem Res. 2005 44 799-810. 

As noted in Section 2.1, polymeric materials may be burned under various conditions which affect the location of the reaction responsible for heat generation during combustion. Heterogeneous combustion of polymers is also possible. 

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