Detonation flame arrestors is different from deflagration flame arrestors as it is supersonic and propagates through shock. Detonation involves a supersonic. Deflagration and Detonation Flame Arresters. Author(s). Stanley S. Grossel. First published August Print ISBN |Online. An overview of deflagration and detonation prevention and protection practices; An overview of combustion and flame propagation and how DDAs halt.
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As a recipient of only two of these awards made by Eastman Chemical Company in the UK, based on performance inAssentech are rightly proud of their achievements. Actual device performance is verified in the Elmac Technologies state-of-the-art in-house test facility. Similar chemical groupings have been developed by the International Electrotechnical Commission.
Heat is transferred detonatjon the element until combustion cannot be maintained.
Flame and Detonation Arrestors
This arrester is suitable for stopping a confined deflagration that has propagated through a pipe for some specified maximum distance. The size of the openings and their length of passage can vary, depending on the arrester style.
The communication regarding the manufacturing process was first class allowing us to easily plan our works and prepare the site. Installed at the top of an atmospheric vent line or storage tank to prevent flame propagation. Arrester elements are available in a number of different configurations parallel rectangular metal plate, wound crimped metal, parallel round metal plate.
Unlike other subcontractors I have experienced on this project, Assentech had a very positive attitude to producing the level of documentation required for a project of this scale. My experience with Assentech from pre-contract through to assembly has been very positive. A vapor cloud ignited in the open atmosphere is usually an example of an unconfined deflagration.
Upper Explosive Limit – UEL – The highest volumetric concentration expressed as a percentage of flammable vapor in air that is capable of sustaining and transmitting a flame throughout the vapor mixture, at a specified temperature and pressure. Assentech- pilot operated pressure relief valves service and calibration. Also “Stable Detonation” A flame front propagating through a flammable gas or vapor at a velocity equal to the speed of sound in that gas or vapor.
The classification of the chemical in the flammable vapor is a significant parameter in the choice of a flame arresting device. We were extremely pleased with the level of service and professionalism demonstrated by Assentechright from our initial enquiry, through delivery and post installation.
Detonations are observed in both conventional solid and liquid explosives as well as in reactive gases.
End-of-Line Arrester – A flame arrester that is mounted at the end of a pipe flanged or threaded inlet connection and which vents directly to the atmosphere.
Flashpoint – The minimum temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture with air near the surface of the liquid.
End-of-Line flame arresters are mounted on outlet flanges and they vent directly to atmosphere. In long or complicated multiple bends pipe runs the flame accelerates until it transitions through an overdriven detonation state into a stable detonation.
Overdriven Detonation – An unstable flame front that propagates through a flammable gas or vapor at a speed in excess of the stable detonation velocity.
Flame arrester – deflagration and detonation – Elmac
The materials of construction of a flame arrester or detonation arrester must be selected to insure compatibility with the process vapors being handled. Flame arresters and detonation arresters are passive mechanical devices that are mounted to threaded f,ame flanged connections on a tank or in a process piping system.
Assentech has an enviable reputation for delivering quality at a competitive price. Should the process conditions be changed it can then be easily identified if the flame arrester fitted remains suitable for the new conditions. In this section, an explanation of how flame fronts develop will be provided.
An unconfined deflagration results in relatively low flame speeds and virtually no pressure increase. As the flame front propagates in the pipe, its speed and associated arrezters increase. The material must be compatible with the service conditions. Flame arresters and detonation arresters that are designed and tested to withstand and stop these various categories of flame fronts are available.
The initial pressure and temperature of the vapors in the system being protected are also significant factors that must be reviewed. A flame traveling within a pipe may be a confined deflagration. Caused by ignition of a flammable gas mixture within a pipe. Mixtures below the Deflagrahion are considered to be too “lean” deflzgration burn.
It is essential that flame arresters are well maintained. The arrester element is mounted in the arrester housing. After conducting a Third Party Witness Inspection, I was most impressed with Ewart and his team, their professionalism, and product knowledge I found to be excellent.
Deflagration and Detonation Flame Arresters
When it comes to safety, there is no room for compromise or margin for error. We have been granted acceptance of our arresters by Underwriters Laboratories, Inc. They should be covered by a program of regular inspection and maintenance so they continue to be effective.