Análise experimental sobre a probabilidade de formação de gotas compostas em um flotador modelo

Abstract

A primary oil processing plant separates surface phases (water, oil, and gas) using a set of equipment. The final water purification is done using floaters, where bubbles are injected to float the dispersed oil. After this process, the water must meet environmental disposal requirements. To make the flotation process effective, oil droplets must encounter bubbles, adhere to each other, and form a stable compound droplet. This work aims to evaluate the probability of this sequence of phenomena, called flotation probability. Experimental characterization was performed using a transparent model floater at NUEM-UTFPR. The experimental setup has dimensions of 300 mm in length, 180 mm in height, and 20 mm in thickness. A high-speed camera was used for detailed monitoring of phase interactions. At the floater inlet, there are two feeds: one with water at 25 l/h and droplets at 0.06 l/h, and the other with 30 l/h of water and 0.6 l/h of gas bubbles. Droplets are generated through shear, and bubbles through depressurization, representing dissolved gas flotation. Direct filming of three areas of interest revealed a total of 83 agglomerates structures. A detailed analysis showed the strong influence of the diameters and velocities of the structures involved in the flotation process. An induction time mathematical model was developed based on the data, which exhibited an average error of 50.31% when compared to experiments. In conclusion, under the analyzed experimental conditions, adhesion probability played a key role in flotation probability. Despite uncertainties and challenges, our findings offer a unique perspective for designing more efficient flotation units and highlighting the need to further understand adhesion probability in future research.