چكيده به لاتين
The interaction of oil droplets and gas bubbles in an aqueous media, as one of the most basic and most important sub-processes of the oil separation system from water, plays an important role in the efficiency and design of this process. During this process, oil droplets and bubbles encounter a variety of phenomena such as collision, separation, blending, and coalescence. The perfect recognition of these phenomena make the right design and optimum state to achieve the final point of the process.
To study the various aspects of this interaction, a test was designed in which the basic parameters such as fluid type, aqueous medium, bubble and drop size, collision angle and interfacial tensions (which it is one of important factor for coalescence) is extracted. Then the outputs of the problem were determined, including the ratio size of the bubble to drop, the contact angle, the collision time and the relative velocity of the collision, and their effects on the interaction. Therefore Emprical setup was desinge and Appliances needed are prepared.
In this study, by using 7 micron nozzles for silicon oil and 375 micron for produce bubble in vertical and aligned position which is controlled with XYZ stage, Various disturbances size were produced with micro syring pump from 300 to 1600 microns, and it was observed that in order to make coalescence, in addition to the importance of the size of the bubble, the Db/Do is also very important. According to observations, the scope of diameters for the Coalescence process in Db/Do <1 is 1500 micron. Also, for interactions leading to a Coalescence, the range of the angle of contact was calculated to be 150 to 160 degrees.
In summary, the process of the Coalescence was observed as follows: the approach of the bubble to the droplet; the draniage of thin film; the bubble sticking to the oil droplet; the increase of the joint surface; the oil covers on the bubble; the Coalescence and move up the bubble.
