No description available.

No description available.

No description available.

No description available.

Accurate flammability limit information is necessary for safe handling of gas and liquid mixtures, and safe operation of processes using such mixtures. The flammability limit is the maximum or minimum fuel concentration at which a gas mixture is flammable in a given atmosphere. Because combustion occurs in the vapor phase, even in the case of liquids the flammability limits are applicable after calculating the vapor compositions. The body of flammability data available in the literature is often inadequate for use with the variety of conditions encountered in industrial applications. This is due to the scarcity of flammability data for fuel mixtures in non-standard atmospheric conditions, and inconsistencies in flammability values provided by different experimental methods. This work reports on the design, construction and utilization of an apparatus capable of measuring flammability limits for a range of conditions including fuel mixtures, varying oxygen concentrations, and extended pressure and temperature ranges. The flammability apparatus is a closed cylindrical reaction vessel with visual, pressure and thermal sensors. A thermal criterion was developed for use with the apparatus based on observations of combustion behavior within the reaction vessel. This criterion provides more detailed information about the combustion than is provided by the pressure criterion methods. Measured flammability limits of several hydrocarbon mixtures in air compare well with limits obtained by open glass cylinder experiments, but not with the results of counterflow apparatus experiments. The current results show that Le Chatelier’s rule describes the mixture results adequately. Minimum oxygen concentrations also were determined for methane, butane, and methane-butane mixtures and compared with values reported in the literature. Lower flammability limits were determined for an equimolar methane-butane mixture at varying oxygen concentrations. Results show that the flammability data determined with thermal criteria has an acceptable level of accuracy. Recommendations for improving apparatus are made, based upon observations made while operating the flammability apparatus.

No description available.

No description available.

No description available.

Flammability is an important factor of safe practices for handling and storage of liquid mixtures and for the evaluation of the precise level of risk. Flash point is a major property used to determine the fire and explosion hazards of a liquid, and it is defined as the minimum temperature at which the vapor present over the liquid at equilibrium forms a flammable mixture when mixed with air. Experimental tests for the complete composition range of a mixture are time consuming, whereas a mixture flash point can be estimated using a computational method and available information. The information needed for mixture flash point predictions are flashpoints, vapor pressures, and activity coefficients as functions of temperature for each mixture component. Generally, sufficient experimental data are unavailable and other ways of determining the basic information are needed. A procedure to evaluate the flash point of binary mixtures is proposed, which provides techniques that can be used to estimate a parameter that is needed for binary mixture flash point evaluations. Minimum flash point behavior (MFPB) is exhibited when the flash point of the mixture is below the flash points of the individual components of the mixture. The identification of this behavior is critical, because a hazardous situation results from taking the lowest component flash point value as the mixture flash point. Flash point predictions were performed for 14 binary mixtures using various Gex models for the activity coefficients. Quantum chemical calculations and UNIFAC, a theoretical model that does not require experimental binary interaction parameters, are employed in the mixture flash point predictions, which are validated with experimental data. MFPB is successfully predicted using the UNIFAC model when there are insufficient vapor liquid data. The identification of inherent safety principles that can be applied to the flammability of binary liquid mixtures is also studied. The effect on the flash point values of three binary mixtures in which octane is the solute is investigated to apply the inherent safety concept.

No description available.