Plateau combustion

Fig. 5.6 shows the results of a set of computer calculations for the [CBTJics plant in the form of (arbitrary) overall efficiency (tjq) against pressure ratio (r) with the combustion temperature T ox as a parameter. Fig. 5.7 shows tjq plotted against T x with r as a parameter and Fig. 5.8 shows a contour plot of tjq against T ox and r. There is a flat efficiency plateau around T ox 1750°C, less than the maximum value used in these calculations, which approaches the stoichiometric limit. 

S.K. Sinha W.D. Patwardhan, Explosiv-stoffe 16 (10), 223-25 (1968) CA 70,49144 (1969) The mechanism causing the plateau effect in the combustion of proplnts with ad-mixt of Pb compds (ie, the independence of pressure of the combustion rate in a certain range) is discussed. This effect is caused by the transport of free Pb alkyl radicals from the foam zone to the fizz zone, which decomn there, causing a more efficient combustion, and increase the temp of this zone by reaction1 with NO. An increase of pressure is assumed to displace the free radicals from this zone because of the increase of the collision rate . this leads... 

Combustion Models of Super-Rate, Plateau, and Mesa Burning... 

Kubota, N., Determination of Plateau Burning Effect of Catalyzed Double-Base Propellant, 17th Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA, 1979,... 

The burning surface of an HMX propellant only becomes covered with carbonaceous materials when the propellant is catalyzed with both LiF and C. This surface structure is similar to the burning surface of an H MX propellant catalyzed with a lead compound and C. The results indicate that the combustion mode and the action of LiF are the same as those resulting from the use of lead compounds to produce super-rate and plateau burning of nitramine propellants. 

Rare-earth compounds lanthanum compounds Not only increase burn rate of DB propellants but also exhibit plateau or mesa combustion in the middle or high pressure range [244]. 

Nitrogen pressure had the same qualitative effect on the combustion characteristics for all the metals studied. As low pressures, combustion parameters increased almost linearly with increasing pressure, but at higher values of pressure they reached a plateau value, becoming independent of pressure. The results from this dependence on pressure, combined with results on the particle size, can provide fruitful ideas for the design of SHS reactors. 

The concepts discussed so far indicate that the major challenge in asymmetric operation is correct adjustment of the loci of heat release and heat consumption. A reactor concept aiming at an optimum distribution of the process heat has been proposed [25, 26] for coupling methane steam reforming and methane combustion. The primary task in this context is to define a favorable initial state and to assess the distribution of heat extraction from the fixed bed during the endothermic semicycle. An optimal initial state features cold ends and an extended temperature plateau in the catalytic part of the fixed bed. The downstream heat transfer zone is inert, in order to avoid any back-reaction (Fig. 1.13). 

In service use, the base number, or reserve alkalinity, steadily declines until a plateau is reached. At this point the higher base number of the new oil, used for topping up, balances the acidic products of combustion. The plateau is usually rather more than 50% of the original base number and must meet the minimum level set by... 

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