It’s now my opportunity to contribute to the around the world in 80 particles blog, and as we’re getting towards winter it’s time to start thinking about my favorite pastimes, skiing and snowboarding or in fact any way of sliding down snowy mountains 😊
As you’ll have come to realize over the course of these blogs, there really is particle sizing in everything! And where my favorite hobby and my job coincided was measuring the droplets produced by snow cannons to create artificial snow.
Most ski areas will rely on artificial snow to supplement natural snowfall and ensure consistent coverage. Artificial snow is produced by atomizing water in the right atmospheric conditions so that it freezes and falls as snow. Atomization is achieved by forcing high-pressure water through nozzles, and some systems also use high-pressure air. Atomization produces droplets of water with a high surface area to volume ratio enabling the droplets to freeze quickly. Proteins are also added to the water to act as nucleating particles which encourage crystallization and the formation of snowflakes. These droplets are either produced high enough that they fall to the ground as snow, in snow lances, or blowing the droplets with a big fan to ensure they have enough air time to freeze before landing, in snow cannons.
Depending on the temperature the droplet size may be adjusted by changing the water pressure, the warmer the temperature the smaller the droplets so that they freeze more quickly. And it’s in the generation of droplets and the characterization of droplet size using the Spraytec where I got involved. The Spraytec is a laser diffraction instrument specifically designed for the measurements of spray systems, and these can be anything from benchtop tests on nasal sprays and domestic aerosols, to larger-scale spray systems like agrochemicals, fire suppressions systems and even snow cannons. The researchers that I met were looking at ways to reduce the energy required to produce the required droplet sizes and enabling artificial snow to be produced more efficiently.
I hope this has highlighted another area where particle size is important that maybe you hadn’t thought about before. If you’d like more information please follow some of the links below: