These are devices used in various environments, such as concerts, clubs and other forms of entertaining environments. They emit dense vapors which look visually appealing in certain situations, and similar to smoke or fog. Although entertainment purposes are more common, they are sometimes used for personal reasons using smaller devices. They can also be used within training, industrial, or in certain military situations. Although there are various types of methods used, the basic concept operates by vaporizing glycol-based fluids and water.
Depending on the use, mineral oils may be used. The machine vaporizes the water or glycerin-based fluids, while atomizing mineral oils. After this process, it hits the cool air outside the machine and condenses, which is what creates the thick, dense fog.
There are two main processes used, heated or chilled. Below is a brief explanation of each.
These types of devices commonly use an electric pump or an inert gas pump for propelling the fluids inside, pushing it through the heat exchanger to vaporize the mixture. A pump machine is among the most commonly used heated forms.
There are basic forms available, which simply have a reservoir for fluid, and the pump for moving fluid through the heat exchange, releasing the vapor. Want something more complex? Some models have timer modules, fog output control, remote elements, and other features.
This approach creates thick clouds that remain closer to the ground, dissipating as they float upward. Usually they use liquid nitrogen, dry ice or in recent years, a product called liquid air.
When using dry ice, the effect is created as water heats up to near boiling and a piece of dry ice is dropped in. Due to the pressure and temperatures, the dry ice (carbon dioxide) instantly creates gasses, which condenses the water vapor and develops thick white fog. To direct the fog, a fan on top of the container is used.
When a lower laying fog is wanted, but do not want to use dry ice then Liquid Nitrogen is an option. Water is brought to a boil, creating steam which increases humidity within a closed space. As liquid nitrogen is applied, it quickly condenses the moisture, producing the thick white cloud.
This is also used for producing a low laying cloud effect, which is created from a ratio of 21% oxygen and 79% nitrogen. This ratio is that of atmospheric air, thus the name. It can directly replace liquid nitrogen in use of chilled machines, without the asphyxiation hazards presented by liquid nitrogen. However, one disadvantage of liquid air is that it will support combustion, while combustion in inhibited by liquid nitrogen.
Adverse Health Effects
Keep in mind, while entertaining it is possible that some people have adverse reactions to the chemicals used in these devices. Additionally, they can result in breathing hazards and asphyxiation due to the nitrogen and carbon dioxide elements.