Atomization quality

Rotary Atomization Spinning Disk 10-200 Spray drying. Aerial distribution of pesticides. Chemical processing Good mono-dispersity of droplets. Independent control of atomization quality and liquid flow rate Satellite droplets, 360° spray pattern... 

As mentioned in the previous section, a major drawback of the simplex atomizer is the poor atomization quality at the lowest flow rate due to too-low pressure differential if swirl ports are sized to allow the maximum flow rate at the maximum injection pressure. This problem may be resolved by using dual-orifice, duplex, or spill-return atomizers. Alternatively, the atomization processes at low injection pressures can be augmented via forced aerodynamic instabilities by using air or gas stream(s) or jet(s). This is based on the beneficial effect of flowing air in assisting the disintegration of a liquid j et or sheet, as recognized in the application of the shroud air in fan spray and pressure-swirl atomization. 

In air-assist atomization, air is needed usually to augment the atomization process only at low liquid flow rates when the pressure differential is too low to produce satisfactory pressure atomization. In some designs, however, air assistance may be required over the entire range of operating conditions if the atomization quality achieved with a pressure atomizer alone is always poor. In an air-assist atomization process, the impingement of a low-velocity liquid stream by a high-velocity air stream may occur either within or outside the... 

The studies on the performance of effervescent atomizer have been very limited as compared to those described above. However, the results of droplet size measurements made by Lefebvre et al.t87] for the effervescent atomizer provided insightful information about the effects of process parameters on droplet size. Their analysis of the experimental data suggested that the atomization quality by the effervescent atomizer is generally quite high. Better atomization may be achieved by generating small bubbles. Droplet size distribution may follow the Rosin-Rammler distribution pattern with the parameter q ranging from 1 to 2 for a gas to liquid ratio up to 0.2, and a liquid injection pressure from 34.5 to 345 kPa. The mean droplet size decreases with an increase in the gas to liquid ratio and/or liquid injection pressure. Any factor that tends to impair atomization quality, and increase the mean droplet size (for example, decreasing gas to liquid ratio and/or injection pressure) also leads to a more mono-disperse spray. 

For a constant gas flow rate, a decrease in gas density leads to an increase in mean gas velocity and/or average gas flow area. The increases in both these quantities prove to be beneficial to atomization quality. In the former case, it accelerates the liquid flow through the injector orifice so that the liquid is discharged at a higher velocity. In the latter case, it reduces the area available for the liquid flow so that the liquid is squeezed into thinner films and ligaments as it flows through the injector orifice. 

This is one of the more important properties of residual fuel oil. It is an indication of both the pumpability characteristics of the fuel and the fuel atomization quality. 

Cenospheres and oil coke are formed as a result of liquid phase cracking reactions, and, with the exception of ash, account for the major portion of the weight of particulate matter emitted when burning heavy fuel oils. Fuel composition and atomization quality appear to be the dominant parameters controlling ceno-sphere formation. 

The Sn 5 s and 5p radial functions, from a nonrelativistic calculation for the free 5sz5pz atom, are plotted in Fig. 7. Roughly 8% of the 5s charge extends outside the Wigner-Seitz radius, rws, for / —Sn the 5s orbital, with much of its density in a region in which Zen is about equal to the valence, is actually somewhat in the interior of the atom. It is not unlike the d orbitals of transition metals, which, as earlier noted, maintain much of their atomic quality in a metal. Thus it is quite plausible that the valence s character in Sn is much like the free atom 5 s, except for a renormalization within the Wigner-Seitz cell. The much more extended 5p component, on the other hand, is not subject to simple renormalization the p character near the bottom of the band takes on a form more like the dot-dash curve of Fig. 7. It nevertheless appears useful to account for charge terms of a pseudo P component and a renormalized s. 

Pure water crystallized to snow appears white, for the transparence of the separate parts makes no tansparent whole. Various crystallized salts, when deprived to a certain extent of moisture, appear as a white powder. The accidentally opaque state of a pure transparent substance might be called white thus pounded glass appears as a white powder. The cessation of a combining power, and the exhibition of the atomic quality of the substance might at the same time be taken into the account. 

The results of experiment No. 1 (hollow cone nozzle with attached swirl body) and No. 2 (removed swirl body) show that the swirl body does not affect the particle formation. The mean particle diameter ( io.s) as well as the Sauter mean diameter (SMD) are rather the same. The experiments No. 3 and No. 4 compare the atomization quality of a HCN without swirl body and a simple orifice. The orifice obviously can be used to generate powders which have particle size characteristics which are comparable to powders which are produced with a hoUow cone nozzle of the same diameter. In the experiments No. 5 and No. 6, the influence of the L/D ratio of a spray device on the particle size was investigated. On the first look, a higher L/D ratio might lead to bigger particles. 

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