直接可視化法による小型ジェット式スクラバ内液滴径分布計測とスクラバ内SO₂除去解析モデルの拡張

抄録

Jet scrubbers that inject wash water in the same direction as ship exhaust gas can efficiently remove sulfur oxide (SOx), which has a high environmental impact, have attracted attention for removal of gases other than SO₂. In the previous work, the authors developed an analytical model in which the flow field in the scrubber was assumed to be a one-dimensional steady state. Although the model did not take into account the droplet size distribution of the wash water in the scrubber, it qualitatively reproduced the SO₂ concentration changes observed in the actual test. In order to evaluate the removal performance in detail, this study developed a model that takes into account the droplet size distribution in the scrubber and enables a more realistic analysis of the flow field. The characteristics of the spray nozzles used in the scrubber were investigated by direct visualization measurements to obtain droplet size distributions that vary with flow rates. Based on the obtained droplet size distributions, the flow field was solved for each droplet with a different diameter. As a result, the model reproduced the exhaust gas cooling performance of the scrubber better than the previous model. Further analysis of SO₂ gas removal obtained in actual tests using this model showed the relationship between SO₂ removal performance, the Sauter Mean Diameter (SMD) of droplet size distributions, and the wash water flow ratio.