Hollow-cone

Hollow-Cone Sprays. In swid atomizers, the Hquid emerges from the exit orifice ia the form of a cooical sheet. As the Hquid sheet spreads radially outward, aerodyaamic iastabiHty ioimediately takes place and leads to the formation of waves which subsequently disiategrate iato ligaments and droplets. Figure 3 illustrates the breakup process ia an annular Hquid sheet. 

Solid cone (see Fig. 14-87/ ). Similar to hollow cone hut with insert to provide even distribution. More uniform spatial pattern than hollow cone. Coarser drops for comparable flows and pressure drops. Failure to yield... 

FIG. 14-87 Charactersitic spray nozzles, a) Whirl-chamber hollow cone, (h ) Solid cone, (c) Oval-orifice fan. (d) Deflector jet. (e) Impinging jet. (/) Bypass, (g) Poppet, (h) Two-flnid. ( ) Vaned rotating wheel. 

Trichter, m, funnel hopper crater (hollow) cone horn Biol.) infundibulum Founding) gate. 

Beyer (B8) has recently reported experimental data obtained in small test motors under atmospheric and altitude conditions. At atmospheric pressure, his results showed the observed ignition delay to be a function of the delivery rate, as shown in Fig. 10. Additional data obtained in small test motors by Fullman and Nielsen (F6) are shown for comparison. These latter investigators conducted studies on the effects of various injectors, with delivery from both the head end and the aft end. Their results indicate that the hollow-cone injector is the most efficient. This subject has been treated in more detail by Miller (M7). 

Figure 1 Diagrams showing the essential electron-optical configurations used for various imaging modes in CTEM and STEM as seen by two points A and B on the sample, (a) CTEM axial bright field, (b) CTEM tilted dark field, (c) CTEM hollow cone dark field, and (d) STEM with bright field and annular dark field detectors.

A hollow-cone spray can be generated via a simplex atomizer. The spray pattern varies depending on the injection pressure. At very low pressures, liquid dribbles from the nozzle orifice. With increasing pressure, the liquid emerges from the orifice as a thin,... 

Various hollow-cone simplex atomizers (Fig. 2.1) have been developed for combustion applications, differing from each other mainly in the way that swirl is imparted to the issuing liquid jet. In these atomizers, swirl chambers may have conical slots, helical slots (or vanes), or tangential slots (or drilled holes). Using thin, removable swirl plates to cut or stamp the swirl chamber entry ports leads to economies of the atomization systems if spray uniformity is not a primary concern. Large simplex atomizers have found applications in utility boilers and industrial furnaces. Oil flow rates can be as high as 67 kg/min. 

Solid-cone spray atomizers usually generate relatively coarse droplets. In addition, the droplets in the center of the spray cone are larger than those in the periphery. In contrast, hollow-cone spray atomizers produce finer droplets, and the radial liquid distribution is also preferred for many industrial applications, particularly for combustion applications. However, in a simplex atomizer, the liquid flow rate varies as the square root of the injection pressure. To double the flow rate, a fourfold increase in the injection pressure is... 

Figure 2.1. Schematic of various types of hollow-cone simplex atomizers.

Swirl-spray nozzles Hollow cone, full 2-25 kg/kg... 

The signal to control the beam tilt angle for hollow cone. 

The primary reaction zone is a hollow cone-like zone, only lO- -lQ- m thick. The actual shape of the cone is determined largely by the velocity distribution of the gas mixture leaving the burner. While the velocity of the gases at the burner walls is virtually zero, it reaches a maximum in the centre. The rounding at the top is caused, in part, by thermal expansion of the gases, which also produces a backpressure which distorts the base... 

The working principle of hollow cone nozzles is that the liquid throughput is subjected to rotation by a tangential inlet and is then further accelerated in the conical housing toward the orifice (see the sketch in Figure 19). A liquid film with a thickness d is thereby produced, which spreads to a hollow cone sheet and disintegrates into droplets at the discharge from the orifice. 

By exceeding a certain discharge velocity, turbulence forces increase to such an extent that film disruption takes place immediately at the orifice. Now the droplet size is independent of the film thickness. This state of atomization is described by the critical Weber number. Measuring data obtained with hollow cone nozzles of different geometry and pure liquids as well as lime-water suspensions are represented in Figure 19. Wep,crit... 

Figure 19 Liquid film atomization with hollow cone nozzles by turbulent forces. Source From Ref 21.

Dahl HD, Muschelknautz E. Atomization of liquids and suspensions with hollow cone nozzles. Chem Eng Technol 1992 15 224-231. 

The conformation of the glucopyranose units results in a three-dimensional (3-D) structure best represented by a segment of a hollow cone (Fig. 4). The 3-D structure of the CD provides a cavity that is hydrophobic relative to an aqueous environment and that varies in size with a-CD being the smallest and y-CD the largest. The hydroxyls or substituents of the modified CDs provide the hydrophilic exterior responsible for the aqueous solubility of the CDs. The properties of the parent CDs that affect their use in drug complexation are (i) their maximum aqueous solubilities (Table 1) and (ii) the differences in complexation due to differences in cavity dimensions. 

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