Atomizing air volume

Product moisture content during spraying (dependent variable) Atomizing air volume/pressure Batch size Outlet filter shake (pulse) interval/time... 

Figure 18 Atomizing air volume and nozzle type for laboratory, pilot, and production...

Atomizing air volume dilutes particle mass in the up-bed, which promotes air and particle feed from the down-bed to the up-bed. 

Atomization air volume and pressure Liquid is atomized by the compressed air. This mass-to-liquid ratio must be kept constant to control the droplet size and hence the granule size. Higher liquid flow rate will produce larger droplet and larger granule and the reverse will produce smaller granules. At a given pressure an increase in orifice size will increase droplet size (39,59,87,94)... 

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). 

The most important sensors for control of the drying process are inlet-and exhaust-air temperature and sensors for airflow measurement, located in the air-transport system. Other sensors for the spray agglomeration process are, atomization air pressure and volume, pressure drops (across the inlet... 

Binder spray rate Droplet size is affected by liquid flow rate, binder viscosity, and atomizing air pressure and volume. The finer the droplet, the smaller the resulting average granules. 57, 74, 75, 95... 

Nozzle port size is selected to accomodate spray liquid viscosity and delivery rate and may influence droplet size because it affects the velocity of liquid at a given spray rate. At low atomizing air pressures and volumes, a low liquid velocity allows more complete atomization of liquid. Using a smaller nozzle port at the same spray rate generally results in a larger mean droplet size due to the higher liquid delivery velocity. At high atomization air pressures and volumes, this effect is minimized. 

In instrument neutron activation analysis (INAA) a small fraction of the stable atomic nuclei present in the sample are made radioactive by irradiation with neutrons or other particles. By measuring the resulting radioactivity, the original elements present can be determined. Reactor or thermal neutrons are usually used. The method does not work well for certain key elements of environmental interest including silicon, sulfur, and lead. Table 6.2 shows INAA detection limits for various elements and typical concentrations of these elemenis in urban air. In atmospheric samples, the fiiiiii of detectability for a particular clement depends on the quantities of the other elements in the filter matrix. The table is based on a total air sample of 17 actually used in the measurements. The tabulated results show that all elements listed could be detected in this air volume with the exception... 

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