Atomizing nozzles, structure

Atomizers nozzle (air, pressure position, number) rotary, etc. Shape/size, size distribution of drops Trajectory of drops Flow rate/pressure drying air Temperature air inlet/outlet Flow rate/temperature product Powder yield (TS), sticking Water content, aw composition, retention, degradation,% surface structure (amorphous, crystallized) Size, density, wettability, flowabiUty, surface state Temperature, Tg, MP... 

Santangelo, P. J., Sojka, P. E. (1995). A holographic investigation of the nea-nozzle structure of an effervescent atomizer-produced spray. Atomization and Sprays, 5(2), 137-155. 

Eor air-assisted atomizer nozzles the interaction of the gas and liquid phases, gas-liquid ratio GLR, and total mass flow rate on the different levels of structure of SEs and DEs has been discussed. The effect of the disperse to continuous viscosity ratio A on the dispersion of emulsions in spray processing has been extensively explored, and a new dimensionless gas Weber number, Weg oropM related to the secondary emulsion drop diameter was defined. The resistance of the secondary emulsion droplets in two-phase nozzle spray processing (air assist) was given up to a critical value (Weg,DropA)c-... 

Fig. 4.12. Atomic-beam diffraction. A nearly monochromatic beam of helium, generated by a nozzle, falls on the solid surface with an angle of incidence. The diffracted beam is collected at an outgoing angle. The angular distribution of the diffracted helium beam contains the information about the topography and structure of the...

Figures 21-173 and 21-174 illustrate typical process and the stages of spray atomization, spray-air contacting and evaporation, and final product collection. A range of particle structures may be obtained, depending on the tower temperature in comparison to the boiling point and rheological properties of the feed (Fig. 21-175). Particles sizes ranging from 3 to 200 jam are possible with two-fluid atomizers producing the finest material, followed by rotary wheel and pressure nozzles.

ACC-4 still has about 3-4% voids and fissures, which are detrimental to the performance of the material. In its use as a missile nose cone or rocket nozzle, the extremely hot gas environment can result in rapid degradation of the part because the chemically reactive gases can rapidly permeate the structure via the interconnecting fissures and voids and attack the carbon fibers. Furthermore, in the bow shock wave of a missile nose cone that reenters the ionosphere, the atomic oxygen that is formed can similarly permeate and attack the fibers. Further densification of ACC-4 by another PIC cycle (to reduce the voids to below the 3% level) is virtually impossible because the resin or pitch cannot be forced into the microcracks and pores of the composite even under extremely high hydrostatic pressure of 700-1,500 bar, because of viscosity and surface tension considerations. 

The morphology of the resulting solid material depends both on the material structure (crystalline or amorphous, composite or pure, etc.) and on the RESS parameters (temperature, pressure drop, distance of impact of the jet against the surface, dimensions of the atomization vessel, nozzle geometry, etc.)[ l It is to be noticed that the initial investigations consisted of pure substrate atomization in order to obtain very line particles (typically of 0.5-20 m diameter) with narrow diameter distribution however, the most recent publications are related to mixture processing in order to obtain microcapsules or microspheres of an active ingredient inside a carrier. 

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