Atomic pressures

The principal factors affecting transfer efficiency are the size and shape of the object, the type of apphcation equipment, the air pressure to the spray gun, and the distance of the spray gun from the object. The transfer efficiency becomes lower as the object becomes smaller or more complex. The transfer efficiency increases when the spray gun is brought closer to the object and when the atomizing pressure is reduced. The transfer efficiency of different types of apphcation equipment in descending relative order is manual > electrostatic spray > airless spray > conventional atomized air spray. 

FIG. 27-25a Common types of atomizers pressure atomizers. From Lefeh- ore. Atomization and Sprays, Hemisphere, New York, 1.98.9. Reproduced with permission. All rights reseroed. )... 

A. Milchev, K. Binder. Osmotic pressure, atomic pressure and the virial equation of state of polymer solutions Monte Carlo simulations of a bead-spring model. Macromol Theory Simul 5 915-929, 1994. 

Oil burners Type Size range Dual-fuel capability Fuel type Atomizing Atomizing pressure viscosity (bar) (cS) Turndown ratio Flame characteristics Main applications... 

C and 1-3 atom pressure. The gases are scrubbed with water to dissolve acrylonitrile. It is purified by... 

The three different nozzles have slight differences in the configuration of the liquid insert and air cap (the path for the atomizing air), but the largest difference is in the size of the annulus between these components to permit the higher volume of compressed air to flow at the same atomizing pressures for atomization of the liquid stream (Fig. 18). 

To maintain the same particle size the triple-headed nozzle could spray three times the pilot unit spray rate at a 2.5 atomization air pressure. However, this could result in a longer process time. Another approach to maintain the similar droplet size is to maintain the mass balance of spray rate and the atomization pressure. Thus, by increasing the atomization pressure to 5 bar, the spray rate was increased to 800g/min, keeping the same droplet size and, hence, obtaining granulation with the desired characteristics. 

Nos. 1 and 2 distillate fuels cut from catalytic gas oils are lower in both gravity and aniline point than corresponding virgin stock fuels. But the catalytic fuels have been used satisfactorily in atomizing pressure-type oil burners. 

Figure 23. Variation of the intensities and time profiles of the emission from C02 produced in the sequence (15,16) passed through filters centered at 1873 cm-1 (a) and at 2066 cm" 1(b) as a function of oxygen-atom pressure marked on the diagrams in mTorr. [CF2HC1] = 10.4 mTorr, total pressure 4 Torr, 3 time resolution, (a) Data were taken over 200 laser shots at 68 Jem-2. (b) Data for 100 laser shots at 59 J cm"2. Note the different timescales for the two sets of traces. Reproduced with permission from Ref. 82.

Anderson, IE. Boost in Atomizer Pressure Shaves Powder-Particle Sizes, Advanced Materials and Processes. 30 (July 1991). 

IS internal standard, SPE solid phase extraction, LIE liquid-liquid extraction, MTBE methyl-t-butyl-ether, MeOH methanol, EtOH ethanol, PrOH propanolol, APCI atomic pressure chemical ionization, LLOQ lower limit of quantification, F/T freeze-thaw, LT long-term... 

A visualization study of fuel atomization using a pulsed laser holography/photography technique indicates that basic spray formation processes are the same for both a coal-derived synthetic fuel (SRC-II) and comparable petroleum fuels (No. 2 and No. 6 grade). Measurements were made on both pressure swirl and air assisted atomizers in a cold spray facility having well controlled fuel temperature. Quality of the sprays formed with SRC-II was between that of the No. 2 and No. 6 fuel sprays and was consistent with measured fuel viscosity. Sauter mean droplet diameter (SMD) was found to correlate with fuel viscosity, atomization pressure, and fuel flow rate. For all three fuels, a smaller SMD could be obtained with the air assisted than with the pressure swirl atomizer. 

In 1985 McMahan and LeSar predicted that the triple bond in molecular nitrogen should be breakable under very high pressures and a solid should be formed which consists of trivalent (i.e. three-coordinate) nitrogen atoms (pressure-coordination rule). Such structures already exist at normal pressures for the other group 15 elements phosphorus, arsenic, antimony and bismuth. The transformation pressure for nitrogen should lie in a range between 500 and 940 kbar. An estimation... 

Menon et al. studied the formation of pellets by fluid-bed granulation using this design. The five factors investigated were (Xi), the binder concentration X2, the method of introducing it (dry or solution) (X3), the atomization pressure (X4), the spray rate and (X5), the inlet temperature. Particle sizes of the resulting particles are shown in Table 3. 

The coefficients of the model are calculated by linear regression (the logarithm of the particle size was used here) and then plotted as a cumulative distribution of a normal plot (Fig. 2). The important coefficients are those that are strongly positive or negative, for example, the spray rate and the interaction between atomization pressure and inlet temperature 35. Others not identified on the diagram are not considered significant and could well be representative mainly of experimental error. The equation can thus be simplified to include only the important terms. However, if interactions are included, their main... 

However, the effect of binder also interacts with two other factors, the atomization pressure and the inlet temperature. Thus, the individual variables cannot be considered separately. 

Baldwin reported the detection of the [M-I]" ion in FAB mass spectra of synthetic cyclostellettamines obtained as iodide salts. Unequivocal proof of their structures was obtained by high resolution atomic pressure chemical ionisation (APCI)-MS experiments on the [M+H] pseudo-molecular ion of the corresponding uncharged bis-tethrahydropyridine obtained by reduction of cyclostellettamines [44]. 

Spray. Direct type, continuous operation. Rotary atomizer, pressure nozzle, or two-fluid nozzle. Includes combined spray-fluid bed and spray-belt dryers Suited for large capacities. Product is usually powdery, spherical, and free-flowing. High temperatures can sometimes be used with heat-sensitive materials. Products generally have low bulk density. See comments under Liquids. Pressure-nozzle atomizers subject to erosion Requires special pumping equipment to feed the atomizer. See comments under Liquids. Not applicable unless feed is pumpable Not applicable Not applicable Not applicable Not applicable... 

Atomization Rotary atomization Pressure nozzle atomization Two-fluid nozzle atomization... 

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