Axial variation of droplet distribution in a venturi scrubber

Abstract

Nowadays, a great effort has been applied into the research of pollution control devices in order to reduce the effect of gaseous emissions to the atmosphere. Amongst the various methods, the venturi scrubber is one of the most efficient processes used for removing dust particles. In this study, droplet dispersion in a large scale circular venturi scrubber, operating horizontally, was examined both theoretically and experimentally. A venturi scrubber was built consisting of a converging section 230 mm long, a throat of 300 mm in length and a diverging section 740 mm in length. The gas velocity at the throat was 34 to 70 m/s, and the liquid flow rate was set between 0.013 and 0.075 kg/s. The water is injected just upstream of the venturi and subsequently atomized into droplets of different sizes due to the influence of the turbulent gas stream. Several empirical probability distribution functions have been used to describe the spray distribution. The Rosin-Rammler function, one of the most common distributions, is suited to describe the droplet population. This is handled at each step along the venturi as a distribution of 16 size classes, whose characteristics are based on experimental data. Comparisons between the experimental data and the calculated droplet size are presented.