Droplet size distribution in a full-scale rectangular self-priming Venturi scrubber with liquid film injection

Abstract

The droplet size distributions in an industrial self-priming Venturi scrubber with liquid film injection have been investigated for varying gas flow rates and different submergence levels. For this purpose, imaging method analysis, commonly applied in spray measurements, was adopted and validated by means of synthetic data. The droplet size distributions characterized by probability density functions show a unimodal shape and can be satisfactorily represented by Nukiyama–Tanasawa distribution functions. For an increase in the gas flow rate, the cumulative distribution function shifts consistently to smaller equivalent droplet diameters. On the other hand, no statistically significant difference in the droplet size distribution was found for a change in the submergence level. The present results are compared with two droplet size correlations based on spray injection and commonly applied to Venturi scrubbers. Both correlations significantly overpredict the experimental results by a wide margin. In contrast, droplet size correlations developed for annular flows in straight tubes show a superior consensus in magnitude with the experimental data. The pronounced decreasing trend in droplet size with increasing superficial gas velocity, however, is weaker in our results, possibly due to the geometry and the self-priming characteristics of the Venturi scrubber.