Thursday, 6 November 2014

Abcs Of Fire Sprinkler Hydraulic Calculations

By Young Lindsay


Water-sprinkler systems appeared during the end of XIX century. Favorable results of protection forced inventors to pay serious attention to this kind of firefighting. Before the revolution of liability insurance, companies recognized the impact of fire sprinkler hydraulic calculations in factories to reduce losses.

Automatic sprinklers have an outlet for releasing water, a firing mechanism and a deflector to convert the output stream in a spray of water in area where there is fire. The trigger sprayer can be done by two mechanisms: a thermo-sensitive element or a flame detector. In this type of sprayer, the jet has a stopper that prevents the leakage of water and a stopper device releasing the trigger mechanism in this case is a device for releasing the plug.

It consists of a thermo-sensitive element that is designed to destroy at predetermined temperatures, automatically causing the release of plug and the outlet of a water spray, which should extinguish the flame right in area where it has started. This device can be of two types: side of a disassembled sprayer without bulb or fuse Vista.

Hence the name sprayed, which varies depending on the application that you want to give the system sprinkler. The most common use of these sprinkler-systems is the cooling of walls of a storage tank of flammable liquids because they are easier and less costly to maintain than a system of sprinklers, which moreover do not correspond to a pattern of dispersal water required by such facilities.

Thermo-sensitive bulb. The most common sprinkler glass bulb holds the cap in place and containing therein a liquid that does not fill the bulb, leaving a gap. When heat from a fire acts on bulb, the liquid boils and vapor pressure breaks the glass stopper and then releases the pressurized water contained pipe network, download and poured over the baffle forming a jet sprayed water mist.

The response time of these systems shall not exceed 300 seconds for low-temperature sprinklers (57 and 68 degrees C) and 600 seconds for the highest-temperature sprinklers. In 1806, an automatic fire extinguishing installation was patented by Englishman John Carey. He proposed to build in the protected area network of pipelines from the water head tank, and on the network to install sprinklers with small holes.

In protected space stretching combustible cord, which when blown open locks that hold the valve, the valve is released and the water flowed to a sprinkler. The device consisted of a cylindrical sealed tanks of about 95 tys.litrov system and 10-inch (250 mm) of the distribution of the aqueduct, covering all parts of the theater. Series of pipes of smaller diameter departed from the distribution pipes and were imbued with a number of half an inch (13 mm) holes through which poured water in case of fire. But the system was not automatic.

First installation started in late XIX century, after the Englishman Stuart Harrison in 1864, has developed a sprinklers. Further development of sprinkler systems associated with the names of Americans Henry Parmelee and Frederick Grinnell. By 1882 in the United States for 200 enterprises was established about 200 thousand. Sprinkler-design Parmelee. During the same year in England the first such installation was witnessed.




About the Author:



No comments:

Post a Comment