Solid–liquid separation in suspension atomization

Abstract

The aim of this paper is to define the conditions controlling the fragmentation process within the atomization of a suspension. Correlations for the droplet diameter of a suspension spray generated by a twin-fluid nozzle have been derived. Two separate regimes in suspension atomization have been identified with respect to the solid particle size. The atomized droplets from suspensions containing relatively fine solid particles are suspension droplets (containing liquid and solid particles). In this case a correlation for the drop size distribution in the spray of a twin-fluid nozzle has been deduced. Droplet size measurements in the suspension spray with varying solid particle sizes showed that when the suspended solid particle size exceeds a critical value, solid particles and liquid will be more and more separated. This effect is indicated by a bimodal size distribution in the suspension spray. It is shown that complete solid–liquid separation in the suspension spray may be achieved, where the pure liquid drops are significantly smaller than the separated solid particles. The critical process conditions where the solid–liquid separation process is found will be derived. Depending on the operating conditions of the atomizer, the resulting pure liquid droplet size is equal or less than the hydraulic diameter.