Definition - What does Spray Atomization mean?
Spray atomization is the transformation of a liquid into a spray of fine particles in a vacuum or a surrounding gas.
The breakdown of the liquid into small particles is achieved when compressed air mixes with the liquid. A spray nozzle is used to generate the atomized spray, which passes through an orifice at high pressure and in a controlled manner.
This process is widely utilized when distributing material over a cross-section area or generating a liquid surface area over an object.
Corrosionpedia explains Spray Atomization
Spray atomization involves creating a condition of high relative velocity between the liquid to be atomized and the surrounding air or gas. Typical atomizer types include:
- Impinging jet
- Twin fluid
Twin-fluid atomizers include all nozzle types, and may involve one of the processes below:
- Internal Mix - The gas and liquid are mixed within the body of the nozzle. It forms the finest atomization, which exits through one orifice. There is a direct relationship between the liquid and the air; any change in the air pressure affects the liquid flow. This method is suitable for liquids not exceeding 200 centipoises. The full cone, hollow cone and flat spray patterns can be achieved using the internal mix method.
- External Mix - The gas and liquid are mixed externally; this offers better control since there is no connection between the gas and liquid inlet lines. Viscous liquids of over 200 centipoises can be sprayed; however, the atomization is not as fine as in the internal mix. Both full cone and flat spray patterns are achievable.
The choice of the method and nozzle type depends on:
- Fluid to be atomized
- Flow rate
- Available pressure
- Spray pattern
The air pressure/volume, liquid pressure/volume and viscosity of the liquid determine the results of the spray. An increase in pressure results in smaller droplets and a finer spray.
The spray atomization process is utilized in a wide range of industries and typical applications including:
- Odor control
- Dust control
- Automatic control of hydraulic spray tips