Read in №12 of 2020 year "Experimental and Calculated Values of the Flash Point of Solvent Mixtures Used in Industry"

21 дек 2020

The experimental verification of the calculated flash point temperatures of solvent mixtures used in industry is presented, and the evaluation of the adequacy of the methods for calculating the rate of its evaporation is given. To verify these methods, acetone-benzene and acetone-chloroform mixtures were experimentally studied, for which a deviation from Raoult's law could be assumed. The dependences of the evaporated substance on time at room temperature are obtained. An increase in the saturated vapor pressure and an increase in the evaporation rate are observed in the first mixture, and a decrease in the second.  In the first case, the amount of substance that is taking part in the explosion increases and must be taken into account when calculating the room pressure increase during explosion, and the second can be used to reduce the potential explosive hazard of solvent mixtures.
The problem of predicting fire and explosion hazard of solvents is associated with the identification of the fact of the formation of explosive concentrations of their vapors and change of flash point temperatures of the mixed liquids. By the example of a number of binary mixtures of flammable liquids, the influence of the interaction of their components on the flash point is shown, the calculated and experimental (reference) data in a closed crucible are compared for the ratio of components in the range from 0 to 100 % in benzene-toluene and benzene-ethanol mixtures.
It is noted that for mixtures with a similar molecular structure, the results of calculating the flash point are in good agreement with the experiment, otherwise, the calculation gives overestimated values for liquids of various classes. Therefore, for mixtures of solvents used in industry, the number of components of which is three or more, it is required to check the flash point experimentally in order to more accurately predict their fire and explosion hazard.

  • Akinin N.I.
    Akinin N.I.
    Dr. Sci. (Eng.), Prof., Head of the Department D. Mendeleev University of Chemical Technology, Moscow, Russia
  • Melnikov N.O.
    Melnikov N.O.
    Cand. Sci. (Eng.), Assoc. Prof., D. Mendeleev University of Chemical Technology, Moscow, Russia