Establishment of the patterns of nitrogen inertization of cyclopentane vapor-air mixtures

Abstract

The object of research is the process of phlegmatization of the gaseous medium of vapor-air mixtures of cyclopentane when nitrogen is introduced into this mixture. The problem of using cyclopentane for the production of thermal insulation is to ensure explosion and fire safety, since the technology for creating foamed urethane thermal insulation includes the introduction of a liquid foaming agent, such as cyclopentane, into the reaction mass. It is characterized by a low boiling point and the creation of explosive mixtures with air. In this regard, the coordinates of the points of the phlegmatization curve were experimentally determined, the value of the lower concentration limit of flame propagation was obtained, which is 1.34% vol. of cyclopentane in a mixture with air, the upper concentration limit, which is 8.64% vol., the minimum phlegmatization concentration of nitrogen, which is 48.1% vol. and the value of the combustible substance at point D (1.45% vol.) and E (6.31% vol.). Adding a phlegmatizer to the “cyclopentane – air” system gradually increases the lower branch and lowers the upper branch of the phlegmatization curve, which converge at the point of the minimum phlegmatizing nitrogen concentration. The area intersecting the phlegmatization curve is capable of flame propagation, outside of which the gas mixture is not explosive and fire-hazardous. A method for calculating the minimum safe ratio of phlegmatizer and combustible gas (steam) in technological devices based on analytical dependencies has been developed and tested. Based on the results of determining the smallest ratio of volumetric concentrations of the phlegmatizer and the combustible substance in the gas mixture, at which it is impossible to ignite it in the environment of this oxidant, the coordinates of the contact point L (45.945% vol.; 1.7445% vol.) were established, as well as the numerical value of the coefficient k (k = 26.4). The practical significance lies in the fact that the results obtained were taken into account when creating a fire-safe technology for manufacturing thermal insulation.