August 26, 2019
Bigger is not always better for water droplets
The water droplet size matters for spray nozzle
Sometimes in order to spray water, a hole is drilled in a pipe or a hose. However, with this technique, there is no control over the water droplet size, and it will always wet even with a small hole and lower water pressure.
Spray nozzles exist in a wide range of category. They can handle a large scale of droplet size from under 10 µm (fog) up to 1.0 mm, (like rain).
How big should the water droplet be for which type of application?
Depending on the application, the size of the droplet is crucial
Spray nozzles are becoming increasingly important elements of the foundation for manufacturing.
Thousands of them are used in a factory for cleaning, spraying, coating, moisture control, polishing, etching, degreasing, descaling, foam breaking, rinsing, trimming, etc.
That is why it is important to be able to control the size of the water droplet for each application.
Some application need a strong spray impact with small water drops of 140 µm for an efficient cleaning.
While for wet FGD solution in pollution control for example, a larger mean droplet diameter of 1,800 up to 3,800 µm is common.
Here are 2 specific example: cooling and humidification.
Cooling without wetting
Even if it feels good to get cooled down by water during heat waves, getting soaked wet is not a nice feeling. Getting cooled down without being wet is where our expertise in water drops becomes handy.
For example, we can cool down animals in the livestock industry without stressing them. This is because the animals will not feel the small water drops. The water (with a mean droplet diameter of 35 to 65 µm for example) evaporates in the air before reaching the animals. This way, the barn stays nicely humid and cooled down without any water puddles.
In addition, the productivity will increase due to the reduction of the stress in the animals.
Humidifying without wetting
An example of an application where the size of the water droplets is important: humidifying in a clean room where equipment cannot be wet.
We are able to spray a Dry Fog with water droplets of an average of 7.5 µm (for AKIMist®”E” 03C). This will not wet the environment, nor the machines or the operators.
Therefore, clean rooms, electronics SMT companies, and other industries that need Dry Fog, can maintain a relative humidity at the level they require without the fear of wetting and damaging their production.
For additional information about the measurement of the droplet size, you can read “Droplet size: what to understand about the measuring methods“.