B. The diameter of the release pipe. On the premise of determining the optimal working condition, change the diameter of the release pipe (20, 25, 32 mm) and conduct the test (the test process is the same as A). The influence of the diameter of the release pipe on the particle size distribution of microbubbles was clarified, and the diameter of the release pipe when the particle size of microbubbles was concentrated was determined.
C. The shape of the release pipe (straight or elbow). Select the optimal parameters determined in the above tests and set straight type and elbow type release pipe (with the same straight-line length) as the investigation factor for the test (the test process is the same as A). The influence of different types of release pipe on the particle size distribution of microbubbles was analyzed, and the appropriate type of release pipe was selected.
Based on the test results of A, B and C, the optimal operating conditions (pressure, gas-liquid ratio, release pipe’s length, diameter, and type) of the device were determined. The dynamic video of the floating process of microbubbles was observed under the optimal conditions. The clear single microbubble and microbubble combination were selected as the capture objects, and the floating process of the capture objects at the same time was tracked. The kinematic parameter curves (velocity, acceleration, and displacement) of the capture objects were obtained by the high-speed photography system. According to the kinematic parameter curve, the motion state of the single microbubble and the combination was analyzed, the correlation between the particle size of the microbubble and the rising rate was revealed, and the relationship between the particle size of the single microbubble, the particle size of the combination and the rising rate was established.