Correlation between concentration, droplet size, turbulent intensity and explosion parameters of gas-liquid two-phase mixture

Abstract

In this study, concentration and droplet size of aerosol and turbulence distribution in the 20 L vessel over time under pneumatic pressure of 1 MPa–2MPa were observed and correlation between actual concentration, droplet size, turbulent intensity of the ethanol aerosol and pneumatic pressure were analyzed. The effect of concentration, droplet size, and turbulent intensity on aerosol explosion parameters of the ethanol aerosol were examined. The actual concentration of ethanol aerosol in the vessel is much lower than the design concentration. The ratio between the actual concentration and the designed concentration is about 65%–90% at the pneumatic pressure from 1.0 MPa to 2.0 MPa. The concentration of ethanol aerosol in the vessel increases with time from 0 ms to 50 ms, maintains a stead state from 50 ms to 100 ms and decreases gradually after 100 ms. In the initial stage of injecting, the size of aerosol droplets in the vessel changes with time sharply and tends to constant at 50 ms. The turbulence intensity from 10sm to 50 ms is higher and decreases rapidly from 50 ms to 100 ms. The effect of the pneumatic pressure on the maximum rate of explosion pressure rise of ethanol aerosol is much higher than that on the peak explosion pressure. The maximum rate of explosion pressure rise of the ethanol aerosol is lower than that of ethanol vapor/air. The explosion index of ethanol vapor/air is higher than that of ethanol aerosol. Ethanol vapor/air has a higher explosion hazard, compared with ethanol aerosol with the same concentration.