Microexplosion of aluminum slurry droplets

Abstract

The microexplosion of a slurry droplet is experimentally and theoretically investigated. The microexplosion was considered to be caused by the shell formation and the following pressure build-up in the shell which would be promoted by the suppression of evaporation, subsequent superheating and heterogeneous nucleation of a liquid carrier. Experimentally, the microexplosion phenomena was examined for various surfactant concentrations and particle loading under different ambient temperature ranges (500-900 K). To closely investigate the pressure buildup and the heterogeneous nucleation, a numerical model was introduced by considering the three stages such as the shell formation, suppression of evaporation and pressure build-up inside. The microexplosion time was estimated by postulating the limit of superheat for heterogeneous nucleation. The simulation yielded a reasonably good agreement with experimental results for Al/n-heptane slurry droplets under various solid loadings (10-40 wt.%). (C) 1999 Elsevier Science Ltd. All rights reserved.