What is Fog?

Fog over the River Dee at Chester

Foggy Scene over the River Dee at Chester.

Fog is seen when a cloud is formed near ground level. Moisture hangs in the air, because the air molecules can only support water droplets if they are very small.

Fog Defined: The Met Office defines fog or mist by visibility - by quantifying the distance that you can see through it:

  • Fog: Visibility less than 1km,
  • Mist: Visibility greater than 1km and less than 2km
  • Haze: Visibility more than 2km

The Renby MicronFog™ system recreates this phenomenon on demand from pure drinking water - there are no additives. We can produce anything from a Highland haze to a pea-souper!

How is Fog Generated Naturally?

Water Droplet

Water Droplet

Nature has developed a very effective way to produce fogs and mists naturally, by localised changes in temperature. This results in air becoming saturated and the surplus moisture appearing as a mist.

For an industrial process, fog is required upon demand, so a controlled approach is required that can be switched on or off at will.

How is fog generated artificially?

Micron-sized droplets can be generated in several ways. The two main methods used are:

  1. High Water pressure at 70 Bar / 1000 psi or more is fed through lengths of tubing to a network of nozzles and forced through a tiny orifice in the nozzle to produce a plume of fog. The quality of the orifice is essential to producing an even, fine spray of fog. Find out more about the high-quality, laser-drilled misting nozzles we use.
  2. Inject compressed air into the water stream and force it to hit a target to atomise the water. Whilst effective, the large amount of compressed air needed makes this expensive to run.

MicronFog™ uses the first technique, with laser drilled ruby misting nozzles, giving the lowest running costs whilst producing high-quality fog.

How does MicronFog™ Work?

Laser Drilled Ruby Nozzle

Laser Drilled Ruby Nozzle

MicronFog™ works by spraying water into the air under pressure to create minute droplets. To achieve a dust suppression effect without wetting, the droplets have a diameter of around 10 to 20 microns.

With this size of droplet, whilst airborne, dust attaches to the fog droplets and simply falls from the air. The MicronFog™ system is assembled with nozzles, narrow gauge, easily disguised tubing and push fit fittings.

These can be placed at precise locations to achieve the maximum effect required. Whether fogging to reduce dust or to create a visual effect, the system is extremely flexible and versatile.

Trust MicronFog™ Fogging Systems

Redknee Tarantula Fog Chester Zoo

Fog Effects at Chester Zoo

Some systems claim to produce fog or mist, using mains water pressure in the region of 6 Bar or even 20 Bar. This is not possible. These systems are really sprinklers and will generally wet an area rather than fog it. Droplet sizes are often in excess of 100 microns and are more like drizzly rain than a true fog system.

Beware of misting systems which are not specified with a water cleansing section. Renby insist on UV water disinfection to protect from legionella and other waterborne diseases.

Contact Renby

Call us on +44(0)1829 740913 or complete our contact form to find out how we can save money for you. Renby Ltd also Supply Fogging system spare parts, Tube Chain Conveyors, Moving Floors, Neutrapak Odour Control and Hydratech Toploaders.

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