Coalescing chance

The low value of X indicates that the bed of solids is probably suspended above the coalesced jets. Therefore, the solids rarely come into contact with the grid. This type of design reduces the chances of grid pluggage due to sticky polyethylene solids. 

Let the total number of drops be N and the average volume of each drop be v, so that the total volume of dispersed phase is Nv. Then the volume of dispersed phase involved in coalescence is UiNv and the number of coalescences per unit time is w,A. Here is the coalescing rate or coalescing frequency measured in sec.-1 and the chance of having more than two drops involved in a single coalescence is assumed negligible. 

In this model the segregation is perfect isotropic microscale segregation. All drops are assumed to have the same size. The chance of coalescing with a neighboring drop is for each drop the same, and independent of time and of the concentration of the drop. Redispersion occurs immediately after coalescing and exchange of concentration. Coalescing and redispersion is assumed to have no effect on mass transfer. 

The interface becomes rigid, so the chance of coalescence decreases. 

Water Percentage. The relative proportion of oil and water affects the stability of an emulsion. In a regular emulsion, the maximum stability of an emulsion will occur at a set ratio of water to oil. Typically this maximum is found at low water percentages as these droplets have a much smaller chance of colliding with other water droplets and coalescing. Increasing the water percentage may destroy the stability of an emulsion. 

Increasing surfactant concentrations in the aeration cell has been found to decrease bubble diameter, bubble velocity, axial diffusion coefficient, but increase bubble s surface-to-volume ratio, and total bubble surface area in the system. The effect of a surface-active agent on the total surface area of the bubbles is also a function of its operating conditions. The surfactant s effect is pronounced in the case of a coarse gas diffuser where the chances of coalescence are great and the effectiveness of a surface-active solute in preventing coalescence increases with the length of its carbon chain. 

Particle or granule size Decreases chance of coalescence Increases required gas velocity to maintain fluidization... 

Some sample calculations are in Table 13.1, where both Pl and small drops and not very low interfacial tension, We < 1, except in the cream layer in a centrifuge. For large drops and small y values, We may be larger than unity. It is to be expected that for We < 1, drops are far more stable to coalescence than for We > 1, mainly because the film area is much smaller [cf. Formula (13.30)]. Moreover, small We tends to go along with relatively large y, which in itself decreases the chance of film rupture. 

GPa, cb =. 3, V = 10 A, 13 =. 1 (10% of chains in amorphous layers are taut tie molecules). It seems unlikely that the acoustic emission associated with such an elementary act could be detected. The chances are better with microcrack coalescence along the outer boundary of fibrils which involves a rapid sequence of microcracks opening and eventual full separation of the fibril from a fraction of adjacent fibrils. On the other hand one can expect that with increasing strain the frequency of microcrack formation will be so high that the cumulative acoustic emission from a finite volume of the sample will be detectable above the noise background. 

The test droplet is, respectively, attracted and repelled by the droplets above and below the critical size. This can be attributed to the action of weak fluxes sucked in by larger and blown out by smaller droplets. For a pair of droplets considered in the preceding subsection, this causes both droplets to migrate in the direction of the larger droplet. The smaller droplet moves somewhat faster due to a smaller logarithmic factor in the dissipative integral, and therefore has some chance to catch up and coalesce before disappearing. 

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