Water Mist Technology

Water mist technology is the most dynamic area of fire protection growth in recent years. New system designs and concepts have been tested and listed, standards written and international debate on applications has taken place. The reason for this concentrated focus has been the expectation that water mist will deliver a safe, environmentally friendly fire protection solution.

The currently heralded applications for water mist as a replacement for halons and marine fire protection have been surpassed, with new applications being introduced even in the domestic, residential, industrial and commercial environments. The industry excitement is based on the impressive performance of mist systems in their rapid control and suppression of a fire as opposed to traditional fire test standards.

Our LP 2000 water mist system, with its small water droplets (typically 70-100 microns), is very efficient in absorbing a tremendous amount of heat as the droplets are converted to steam. This conversion to a vapour causes an expansion of over 1,600 times its original volume, thereby displacing oxygen and disrupting the combustion process. The small droplets affect heat transfer and tend to wet and cool combustibles much like a typical sprinkler system. The ability of small droplets to absorb heat and create steam at the fire source is key to the effectiveness of fine mist systems in controlling and extinguishing fires. This process makes water mist systems more effective than a typical automatic sprinkler system.

In addition the Water Mist System has a reactive surface area of water will be in the range of 2,000/6000m²/litre compared to 2m²/litre for conventional sprinkler systems. Thus being a far more sustainable and effective use of water.

In Summary:

• Gas phase cooling of the flame reaction zone below the limiting flame
  temperature,
• Oxygen depletion by steam expansion, and
• Radiant heat obstruction by wetting of fuel surfaces.

The Benefits:

• The efficient use of water as the extinguishing agent - for most applications fires are controlled at a nominal 4 – 11 lpm discharge rate dependent on system type,
• Reduced damage - as most of the discharged water is used for actual
  extinguishment thereby minimising runoff and consequential water damage,
• Non– toxic and pose little or no environmental problems,
• Potentially superior to sprinklers - For the following reasons:
  • they can suppress flammable liquid pool and spray fires:
  • they utilise water quantities a tenth or lower than sprinklers and, hence, little or no collateral damage:
  • functional performance in certain applications such as total flooding, inerting or explosion suppression: and
  • they may be non–electrically conductive.
• The system draws less power to supply the water mist nozzles and due to it using less water the storage requirements are greatly reduced.

The currently commercialised mist systems fall into several types, drop size and operation pressure. While certain systems types may perform more efficiently for some risks the general use of a single mist system across all types of risks has not previously been available. Until now the selection of a mist system for a specific risk has been necessary and conditions of listing vital in the design of the system.

Aqua-Mist Low Pressure LP 2000 water mist technology has progressed to an extent whereby the reliability and performance of a system can be effectively evaluated, and has been against a series of test criteria identified by the International Maritime Organisation (IMO) equivalent to sprinkler as the only system of its kind in the UK to have achieved and passed these stringent tests.