Concentration Limits Of Flame Propagation Research Articles

Flame propagation in mixtures of monogermane and oxygen. I. Limits, flame propagation characteristics, and gas-phase products

The concentration limits for flame propagation in GeH4−O2 (air) mixtures are determined over a wide range of initial pressures (0.7–100 kPa) at room temperature. Flame propagation is found to be of a chain-thermal character and excited intermediate particles are involved in the reactions which limit the branching rate. The gas-phase reaction products (H2O2, H2O, and H2) are determined and its is shown that the relative yields of these components and the stoichiometry, as a whole, vary with the composition of the initial gas mixture. Chemically induced decomposition of GeH4 by a branching-chain oxidation process for oxidation of the hydride by oxygen is observed.

Flame propagation in chlorine-containing combustible systems under ignition by a constant light beam

The action of the light emission of a mercury—quartz lamp on combustible mixtures of chlorine and difluoromethane and hydrogen at atmospheric pressure increases the upper concentration limit of flame propagation and flame velocity in mixtures similar in concentration to the upper concentration limit, because, during flame propagation in these mixtures, the rates of the thermal and photochemical dissociation of chlorine molecules are comparable, and the chlorine concentration behind the flame front is minimum.

Special features of combustion of propane-air and hydrogen-air mixtures in a narrow tube

The special features of combustion-wave propagation in a narrow tube have been studied experimentally in low-velocity regimes for propane-air and hydrogen-air mixtures. For propane mixtures, the increase in the curvature of the flame surface correlates with the displacement of the maximum into the region of enriched mixtures in the dependence of the combustion velocity on the mixture composition. Combustion of lean hydrogen-air mixtures is accompanied by acoustic oscillations which lead to a narrowing of the range of flame, existence relative to the combustible-gas flow rate. For enriched mixtures, the flames are stable, and they exist at a hydrogen concentration close to the value for the upper concentration limit of flame propagation.

Investigation of concentration limits of flame propagation in ammonia-based gas mixtures

The concentration limits of flame propagation inNH 3-O 2,NH 3-H 2-O 2,NH 3-O 2-N 2,and NH 3-H 2-O 2-N 2 mixtures at temperatures of up to70°C and pressures of up to1.0 MPa were studied experimentally. The lower concentration limit of propagation of ammonia flame in oxygen decreases significantly at elevated temperature and pressure, the effect of temperature being stronger than for organic combustible substances. It is shown that the Le Chatelier rule for the limits ofN 2-NH 3-O 2 mixtures is satisfied with sufficient accuracy.

Concentration limits for flame propagation in fuel-dilutent-nitrous oxide mixtures

Concentration limits for flame propagation in fuel-dilutent-nitrous oxide mixtures

Effect of temperature on the lower concentration limit of flame propagation in air suspensions

This study examines the temperature dependence on the lower concentration limit for inflammation of sulphur and benzoic acid. The experimental equipment (vessel, thermocouple, diffuser, atomizer) is specified. The experiment includes heating the vessel, atomizing and igniting the charge, and determining the flame propagation. A conditional thermo-dynamic particle combustion temperature is introduced. The constancy of thermodynamic air suspension derives a formula describing dependence of lower concentration limit on temperature. The energy balance between liberated heat and heat for inside the vessel is expressed by an equation. It is concluded that the convective-conductive heat transfer mechanism is dominant in flame propagation in air suspensions of sulphur and benzoic acid.

Determination of the concentration limits of flame propagation at elevated temperatures

Determination of the concentration limits of flame propagation at elevated temperatures

Determination of the concentration limits of flame propagation in oxyhydrogen mixtures on the initial pressure interval from 1 to 100 ATM ABS

Determination of the concentration limits of flame propagation in oxyhydrogen mixtures on the initial pressure interval from 1 to 100 ATM ABS

Concentration limits of flame propagation in mixtures of acetylene and oxygen

Concentration limits of flame propagation in mixtures of acetylene and oxygen

Effect of additions of hydrocarbons on the concentration limits for flame propagation in gas mixtures containing hydrogen

1. The concentration limits were determined for flame propagation in hydrogen-air mixtures having additions of methane, propane, butane, isobutane, and benzene, in H2 + Cl2 and H2 + NO mixtures in presence of propane, and in mixtures, diluted with hydrogen and nitrogen, of methane, propane, butane, and benzene with air. 2. It was concluded that the addition of sinall amounts of hydrocarbons to hydrogen-air mixtures results in lowering of the upper limit for flame propagation owing to chemical reaction between the inhibitor and active centers in the oxidation of hydrogen. As the amount of the addition is increased, the chain reaction of hydrogen with oxygen is suppressed to such an extent that combustion of the added hydrocarbon begins to play a determining role (hydrogen then plays the part of inert diluent).

Concentration limits for flame propagation in mixtures of hydrogen and oxides of nitrogen

The concentration limits were determined for flame propagation in mixtures of hydrogen with nitrogen oxides (N2O, NO2, NO) and an inert diluent (nitrogen), the components being taken in various proportions.