Direct droplet formation

In rotary or centrifugal atomization, droplet formation may follow several distinct mechanisms, as proposed by many research-ers 94 l09l"l, 2I on the basis of experimental observations of rotating flat disk process (Fig. 3.9) (a) Direct Droplet Formation, (b) Direct Droplet and Ligament Formation, (c) Ligament Formation, and... 

Droplet Formation in Centrifugal Atomization. The mechanisms of centrifugal atomization of liquid metals are quite similar to those for normal liquids. Three atomization modes have been identified in rotating electrode atomization process, i.e., (I) Direct Droplet Formation, (2) Ligament Disintegration, and (3) Film/Sheet Disintegration.1[189][32°] are aiso applicable to the centrifugal atomiza-... 

Table 4.11a. Correlations for Mean and Maximum Droplet Sizes Generated by Smooth Flat Vaneless Disks in Direct Droplet Formation Regime...

Ao - 3 VLPL 2KpL(7tdcorps)2sm0 1/3 Direct Droplet Formation Fraser et al. [73]... 

Figure 4.3. Regimes in centrifugal atomization of melts Direct Droplet Formation, Ligament Disintegration, and Film/Sheet Disintegration.

Figure 9 Smooth disk atomizer droplet formation mechanisms (A) direct droplet formation, (B) ligament formation, and (C) sheet formation. (From Ref. 12.)...

As ambient air pressure is increased, the mean droplet size increases 455 " 458] up to a maximum and then turns to decline with further increase in ambient air pressure. ] The initial rise in the mean droplet size with ambient pressure is attributed to the reduction of sheet breakup length and spray cone angle. The former leads to droplet formation from a thicker liquid sheet, and the latter results in an increase in the opportunity for droplet coalescence and a decrease in the relative velocity between droplets and ambient air due to rapid acceleration. At low pressures, these effects prevail. Since the mean droplet size is proportional to the square root of liquid sheet thickness and inversely proportional to the relative velocity, the initial rise in the mean droplet size can be readily explained. With increasing ambient pressure, its effect on spray cone angle diminishes, allowing disintegration forces become dominant. Consequently, the mean droplet size turns to decline. Since ambient air pressure is directly related to air density, most correlations include air density as a variable to facilitate applications. Some experiments 452] revealed that ambient air temperature has essentially no effect on the mean droplet size. 

Accordingly, for the transition from Direct Droplet to Ligament Formation regime and the reverse transition, the dimensionless transition flow rates are Q = 0.096 Re0,95/We115 and Q = 0.073 Re°-95/We115, respectively.[470]... 

We are interested in ACAT-1 inhibitors, which are expected to affect macrophages directly. In the early stages of atherosclerogenesis, macrophages penetrate the intima, efficiently take up modified LDL, store cholesterol and fatty acids as a form of neutral lipids such as CE and TG in the cytosolic lipid droplets, and are converted into foam cells, leading to the development of atherosclerosis in the arterial wall. We established an assay system of lipid droplet formation using intact mouse macrophages and searched for microbial inhibitors of the for-... 

In the premix emulsification the basic mechanism for the droplet formation is different from the direct emulsification. In fact, in this case the predominant formation mechanism is the droplet disruption within the pore. 

Both direct and premix emulsification can be obtained with a continuous phase flowing along the membrane surface (i.e., crossflow, stirring) (Figure 21.2(b)). However, it is important to distinguish between the droplet-formation mechanism and the macroscopic operation procedure. In other terms, often, in the literature, the... 

Droplet formation during direct membrane emulsification and in particular in crossflow emulsification has been described using models different in the scale and in the considered mathematical and physical phenomena, such as ... 

Both the number concentrations and sizes of aerosol particles directly affect many of their properties and effects. For example, the ability of particles to serve as nuclei for cloud droplet formation depends on their composition as a function of size, although their effectiveness in any given situation depends also on the number of particles present. Knowledge of these aerosol properties is required to evaluate the indirect effects (Section 4.04.7.3) of aerosol particles on climate, i.e., the effect of aerosol particles on cloud reflectivity and persistence. Therefore much attention has been and continues to be focused on determining particle number concentrations and size distributions. 

In this type of nozzle, spray liquid and air are mixed together as they pass through chambers in the nozzle body to form a spray that is delivered from a modified flood or reflex type nozzle. The flow of air contributes directly to the spray droplet formation process. By controlling air and liquid pressures, liquid flow rate and spray quality from the nozzle can be varied independently. Droplets generated from such nozzle designs can contain air inclusions if they are above... 

DRl (direct reduced iron) 408 drink powder 510 drive, variable speed 292 drop test 74 droplet formation 29 drugs 435, 515... 

Electrospray is viewed as the most versatile ionization technique for neutral compounds and ions in solution, and at the same time a general-purpose interface for LC-MS [14-24]. In electrospray ions are formed in solution and then transferred to the gas phase. This differs from APCI where neutral molecules are first transferred to the gas phase and then ionized by gas-phase ion-molecule reactions. The heart of the electrospray source is a metal capillary through which the sample solution flows. A potential of 3-6 kV is applied to the capillary forming a spray of fine droplets directed towards a counter electrode with a sampling orifice located about 1-3 cm from the capillary tip. A positive potential is applied to the capillary to generate positive ions, and a negative potential for negative ions. To accommodate different liquid flow rates droplet formation is assisted by optimization of the orifice diameter of the capillary sprayer, the use of a coaxial gas flow, and heat to increase the rate of solvent evaporation. 

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