has abstract
| - Rotary atomizers use a high speed rotating disk, cup or wheel to discharge liquid at high speed to the perimeter, forming a hollow cone spray. The rotational speed controls the drop size. Spray drying and spray painting are the most important and common uses of this technology. Many industries use processes like evaporative cooling, meteorology, printing, medical applications, spray combustion, coating, and drying, which need to convert a large mass of liquid into a dispersion of smaller droplets of a size range of microns. Various spray devices for the above-mentioned conversion have been developed over time, such as atomizers, sprayers, nozzles, and applicators. The spray generated by these devices can be viewed as liquid droplets submerged in a continuous phase of gases. This spray can be generated in a variety of methods. Generally, it is done by producing a high speed between the phase of gases and the submerged liquid to be atomized. These devices achieve this atomization by releasing the liquid at very high speed into the unagitated air. This same principle is used in a Rotary Atomizer. The rotating cup or disc forces the liquid to come out at a very high speed through its rim. The liquid can also be atomized by using a reverse process, instead of accelerating the liquid, gas can be accelerated to achieve a relatively higher speed than the liquid. The devices using this method to achieve atomization are called as airblast, air-assist, or popularly twin-fluid atomizers. The Rotary, Pressure-swirl or Twin-fluid Atomizers are used in general. Still, for special applications, alternative atomizer types are there such as the 'electrostatic' atomizer in which electrical pressure is used to drive the atomization, and the 'ultrasonic' atomizing device in which the liquid is passed through a transducer vibrating at ultrasonic frequencies to generate shorter wavelengths which convert the fluid into smaller droplets. Since the flow rate of liquid is low in both of these devices, their applications are limited. (en)
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