{"id":2296,"date":"2018-06-13T11:38:12","date_gmt":"2018-06-13T10:38:12","guid":{"rendered":"https:\/\/elmactechnologies.com\/?p=2296"},"modified":"2021-01-05T10:07:10","modified_gmt":"2021-01-05T10:07:10","slug":"flame-arresters-deflagration-detonation","status":"publish","type":"post","link":"https:\/\/elmactechnologies.com\/pt-br\/flame-arresters-deflagration-detonation\/","title":{"rendered":"Deflagration & Detonation Flame Arrestors"},"content":{"rendered":"

Elmac Technologies, the leading manufacturer of F<\/strong>lame Arrester<\/strong> technology is providing you with this useful guide to deflagration<\/strong> and detonation<\/strong> pipeline explosions.<\/p>\n

When the gas is ignited the flame begins to accelerate. This acceleration results in the build-up of a pressure wave ahead of the flame. Given enough run up distance, this pressure wave can build into a shock wave as the flame speed reaches sonic velocity. This first phase is known as a deflagration<\/strong>.<\/p>\n

Once the shock wave reaches a pressure to auto-ignite the gas through which it is travelling the flame front and shock wave couple together forming an unstable detonation<\/strong>.<\/p>\n

This deflagration to detonation transition (DDT)<\/strong> is the most severe phase of a pipeline explosion, which can generate flame speeds of >3000m\/s and high pressures, over 100bar in some cases.<\/p>\n

In short, the deflagration Flame Arrester<\/a> is designed to stop the initial phase of the explosion and is shorter and lighter than the unstable detonation arrestor, but the Deflagration Flame Arrester has restrictions on its placement within the pipework regarding distance from the source of ignition.<\/p>\n

Explosion characteristics<\/strong><\/p>\n

If you\u2019re unsure about Deflagration and Detonation Flame Arresters<\/a>, this brief guide to explosion characteristics is designed to help. Of course, for further advice or clarification in any way, please get in touch with one of our experts.<\/p>\n\n\n\n\n\t\n\n\t\n\t\n\t
Explosion Description<\/th>Explosion Type<\/th>Flame Arrester Required<\/th>Notes<\/th>\n<\/tr>\n<\/thead>\n
Caused by ignition of a flammable vapour cloud.<\/td>Unconfined deflagration<\/td>End of line deflagration arrester<\/td>Here, there is no physical restriction on the associated expansion of volume - the flame front travels below the speed of sound due to the quick dissipation of the heat and pressure into atmosphere.
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\n<\/td>\n<\/tr>\n
Caused by ignition of a flammable gas mixture within a pipe.<\/td>Confined deflagration<\/td>In line deflagration arrester<\/td>Here, gas is compressed resulting in higher pressure, accelerating the flame front. The initial stages are sub sonic.<\/td>\n<\/tr>\n
Caused by acceleration of a deflagration flame front and transition of pressure wave to shock wave within a pipe.<\/td>Confined detonation<\/td>Unstable detonation arrester<\/td>With Deflagration to Detonation Transition (DDT), flame speed reaches sonic velocity resulting in auto ignition of the gas at overdriven detonation stage. Here we see flame speeds of >3000m\/s and high pressures, over 100bar in some cases.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

Flame Arresters \u2013 what can go wrong?<\/strong><\/p>\n

A flame Arrester may not function correctly if:<\/p>\n