Abstract: Based on the FRT explosion limit test instrument, the explosion limit of isopropanol vapor in air was tested under the initial conditions of 50 ℃ , 0.1 MPa. Experiments on explosion suppression effect of carbon dioxide or nitrogen on for isopropanol vapor were done by changing the proportions of isopropanol vapor and carbon dioxide as well as isopropanol vapor and nitrogen. The results showed that the explosion suppression volume fraction of inert gas decreases with the increase of isopropanol vapor concentration, and the carbon dioxide suppression effect is better than that of nitrogen. Under the suppression action of inert gas, when the volume fraction ratio of oxygen to vapor is less than 2.10, the mixed gas does not deflagrate. The explosion suppression triangle was drawn to describe the influence of inert gas on the explosion characteristics of isopropanol, and the difference of explosion suppression effect of different inert gases was analyzed from the aspects of activation energy theory and chain reaction theory.

Key words: isopropanol, explosion limit, inert gas, explosion suppression, volume fraction