Prediction of Bubble Size Distribution above the Bubble-Breaking Plate

Abstract

The chord length distribution (CLD) of bubbles in the region above the bubble-breaking plate in the scrubbing−cooling chamber was studied experimentally using a conductivity probe. The predictive correlations of the shape parameters were established by fitting the CLD with a distribution function. The bubble shape was discussed, and the CLD was analytically converted to the size distribution of the direct contact of the probe. The results showed that the CLD has specific right-skewed characteristics, and the Rayleigh distribution has the best-fitting effect on the CLD. The correlation equation of the shape parameter k of the Rayleigh distribution concerning the Fr number, local gas holdup ε g , and dimensionless radius r/R was established. The predicted bubble size distributions (BSDs) based on ellipsoids are in good morphological agreement with the experimental size distributions. The relative error between the calculated and experimental values of the gas−liquid interface area was within ±20%, which verified the accuracy of the prediction of the BSD.

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

“…The liquid velocity values have an extensive fluctuation range. This is owing to the limited radial diffusion of the gas caused by the reflexive rise of the bubble plume and the relative density of bubbles in this region, which enhances the agglomeration and rupture of bubbles and increases the intensity of the fluctuations in liquid velocity . Within the immediate area of the inner wall of the liquid cell ( r / R = 0.9), with a large area of negative liquid velocity, the S and K values are almost greater than 0, i.e., the distribution curve has a ″sharp positive deviation″ pattern, indicating that the negative liquid velocity dominates.…”

Coalescence of Two Equal-Sized Bubbles with Air Injection

“…Finite-approach velocities, arbitrary surface shapes, and fluid properties contribute to the variety. − The neck formation and temporal evolution are critical features in the study of bubble coalescence. In addition to its theoretical significance, a precise understanding of bubble coalescence improves the predictive accuracy of system performance in engineering. − The neck expansion resulting from the quasi-static bubble coalescence has been extensively studied. ,, In this case, the bubbles approach each other slowly, and no gas is introduced during the merging process. In contrast, the lateral coalescence of two growing bubbles is a common phenomenon near gas distributors in industrial applications.…”