Spray droplet size

FIG. 14-126 Predicted spray-tower cut diameter as a function of sprayed length and spray droplet size for (a) vertical-countercurrent towers and (b) horizontal-cross-flow towers per Calvert [ J. Air Polliit. Control Assoc., 24, 929 (1974)]. Curve 1 is for 200-pm spray droplets, curve 2 for 500-pm spray, and curve 3 for 1000-pm spray. QHQc is the volumetric hqiiid-to-gas ratio, L liqiiid/nri gas, andt/cis the siiperBcial gas velocity in the tower. To convert liters per ciihic meter to cubic feet per cubic foot, multiply by 10 . ... 

Spray nozzle type plays an important role in the success of agrochemical application. For broadcast applications to soil, flat fan nozzles should be used. Newer spray tips such as the DG TeeJet, XR TeeJet, Turbo TeeJet and similar nozzles supplied by Lechler and Hardy have provided acceptable results in a number of studies. For a given nozzle type, the lower the application pressure, the larger is the spray droplet size and the less potential for spray drift. Similarly, the closer the boom is positioned to the soil surface, the less is the potential for spray drift." Most applications are made with spray tips having 80° or 110° spray angles and boom heights of about 50 cm above the soil surface. 

Spray droplet size distribution, 23 185-186 Spray drop size, 23 174-175 Spray-dry encapsulation processes, 16 447- 457... 

Binder spray Droplet size is affected by liquid flow rate, binder 17,54,71,... 

A comparison between the measured data and the results calculated by Eq. (5.6), with the values obtained by the regression for the parameters involved, is illustrated in Fig. 5.4. The standard deviation of the calculation is SD=21.06 pm. If the intrinsic difficulties in the measurement of the spray droplet sizes mentioned above are taken into account, then the results shown in Fig. 5.4 indicate that Eq. (5.6) is acceptable for fitting experimental data. 

Figure 4. Relationship between spray droplet size and the thoroughness of fusion...

The formation of cake around nozzle tip can significantly change the spray droplet size and spray pattern, which can lead to the formation of large agglomerates. In addition to considering proper nozzle location, spray properties, and reducing... 

The spray droplet size distribution has a major influence on the amount of oropharyngeal deposition and the amount of drug delivered to the lungs and the regions of lung deposition. Methods for spray droplet particle sizing from MDIs " have been reviewed. 

Spray droplet size Spraying surface and Process lime ... 

As indicated above, the atomizer wheel speed is the important parameter influencing the spray droplet size ancfthus the particle size of the final product. The atomizer machine will normally have the capability to operate the wheel at the required speed. More important for the atomization process is the selection of a wheel capable of handling a specific liquid feed with characteristic properties such as abrasiveness, high viscosity, nonnewtonian behavior, or tendency to coagulate. 

The F800 atomizer is the largest rotary atomizer offered to industry today. It has the capability of handling up to 200 t/h in one single atomizer. The capacity limit of an atomizer is normally its maximum power rating. As indicated above, the atomizer wheel speed is the important parameter influencing the spray droplet size. The wheel speed also determines the power consumption of the atomizer. It can be shown that the atomizer power consumption exclusive mechanical losses amount to... 

During the evaporation stage the atomized spray droplet size distribution may undergo changes as the droplets shrink, expand, collapse, fracture, or agglomerate. 

This technique was shown to have significantly less effect on spray droplet size and spray pattern than is typical of pressure-control systems. Response time was as fast as that achieved with standard on/off solenoid valves as described above, but the maximum flow-rate range that could be achieved was limited by the switching time of the valve. Experimental results showed that a range of 3 1 could typically be achieved. 

A word of caution is appropriate at this stage - the spray droplet size cannot be increased indefinitely, as ultimately overly coarse droplets will reduce spray droplet retention (Schaefer, and Allsop, 1983). 

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