Flame Arresters & The Deflagration To Detonation Transition (DDT) Explained

00:02:48
https://www.youtube.com/watch?v=QZ7fIsUrkeE

الملخص

TLDRThe video explains the phases of ignition that lead to explosions when flammable gases mix with air. It details the transition from deflagration to detonation, highlighting important characteristics like flame speeds and pressure changes. Deflagration can escalate into unstable detonation under certain conditions, which is highly dangerous. The video advocates for using unstable detonation arrestors to ensure safety in systems where explosions might occur, providing maximum protection against both deflagrations and stable detonations.

الوجبات الجاهزة

  • 🔥 Ignition of flammable gases can lead to explosions.
  • 💨 Phase one involves the initial flame propagation.
  • 📈 Phase two is characterized by rapidly increasing pressure and turbulence.
  • ⚡ Phase three sees a transition to dangerous supersonic speeds.
  • 🛑 Phase four involves stable detonations that can still result in unpredictability.
  • 🔒 Unstable detonation arrestors are crucial for safety.
  • 🌪️ Galloping detonations are unpredictable and destructive.
  • 💪 Operators are urged to fit unstable detonation arrestors for maximum protection.

الجدول الزمني

  • 00:00:00 - 00:02:48

    The video discusses the phases of gas explosion and the importance of flame arresters in preventing potential catastrophes. It begins with phase one, ignition, where a flammable gas mixed with air can lead to an explosion. This is followed by phase two, deflagration, which is marked by a rapid increase in temperature and pressure in confined spaces, leading to subsonic flame speeds and pressure waves. Phase three explores the unstable detonation that can occur if deflagration continues unchecked, resulting in a dramatic transition characterized by supersonic flame speeds and significant pressure surges. Finally, phase four outlines stable detonation, which results after an unstable detonation; however, unpredictable detonation transitions may still occur. The video emphasizes the inadequacy of stable detonation arrestors alone in preventing detonations in early phases and recommends the use of L Mac Technologies' unstable detonation arrestors for comprehensive protection against various explosive scenarios.

الخريطة الذهنية

فيديو أسئلة وأجوبة

  • What are flame arresters?

    Flame arresters are devices that prevent the propagation of flames in pipelines and vessels containing flammable gases or vapors.

  • What is deflagration?

    Deflagration is the rapid combustion of a flammable mixture characterized by subsonic flame speeds.

  • What does DDT stand for?

    DDT stands for Deflagration to Detonation Transition.

  • What is the significance of unstable detonation arrestors?

    Unstable detonation arrestors are crucial for preventing detonation during the DDT phase and offer protection against stable detonations and deflagrations.

  • What can trigger a deflagration?

    The accidental ignition of a flammable gas or vapor mixture can trigger a deflagration.

  • What are peak pressures during deflagration?

    Peak pressures during deflagration can reach up to 10 bar.

  • What speeds can a detonation reach?

    Detonations can achieve flame speeds in the range of 1600 to 3000 meters per second.

  • Why is it important to have stable detonation arrestors?

    Stable detonation arrestors help mitigate the risks associated with detonations and ensure safety in systems handling flammable materials.

  • What is a galloping detonation?

    A galloping detonation refers to unpredictable detonation events that can occur due to changing gas mixtures and pipeline geometries.

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الترجمات
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التمرير التلقائي:
  • 00:00:02
    [Music]
  • 00:00:04
    flame arresters for the deflagration to
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    detonation transition
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    phase one ignition
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    whenever a flammable gas or vapor is
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    mixed with air there is the potential
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    for an explosion
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    accidental ignition of the flammable
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    mixture will initiate a flame which when
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    confined in a pipe or vessel will
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    accelerate through the unburned mixture
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    driving the flame front forwards
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    phase two deflagration
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    the rapid increase in the temperature
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    and volume of the burning mixture
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    together with conditions that increase
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    turbulence in the system such as changes
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    in size roughness or bends in the pipe
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    etcetera results in a pressure wave that
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    travels ahead of the flame
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    this phase is typically characterized by
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    subsonic flame speeds of several hundred
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    meters a second with peak pressures in
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    the range of 10 bar the flame can
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    accelerate from a slow to a fast
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    deflagration
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    phase 3 unstable detonation if the flame
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    continues unchecked and if there is a
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    sufficient pipe length then due to flame
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    front instabilities it will undergo a
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    sudden and rapid transition from
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    deflagration to detonation
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    this deflagration to detonation
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    transition often referred to as a ddt is
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    characterized by supersonic flame speeds
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    in the range of 1600 to 3000 meters a
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    second and a shock wave that is now
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    coupled to the flame front and creating
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    enormous peak pressures often well in
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    excess of a hundred bar
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    phase four stable detonation
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    following a ddt an unstable detonation
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    will degrade to a less severe stable
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    detonation
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    however due to the gas mixture and
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    changes in the pipeline geometry further
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    unpredictable ddts may occur resulting
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    in what is known as a galloping
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    detonation
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    the location of the incredibly
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    destructive forces of an unstable
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    detonation cannot be predicted with any
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    certainty
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    it follows therefore that the use of a
  • 00:02:05
    stable detonation arrestor in isolation
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    is not suitable as it would not stop a
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    detonation in the ddt phase
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    accordingly and in order to ensure
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    maximum protection from worst case
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    scenario explosions
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    l mac technologies strongly recommends
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    that one of its patent-protected
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    unstable detonation arrestors be fitted
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    in all systems where a detonation could
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    occur these unstable detonation
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    arrestors also provide protection
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    against stable detonations and
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    deflagrations thus providing the
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    operator with ultimate protection and
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    complete peace of mind
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    [Music]
الوسوم
  • flame arresters
  • explosive safety
  • deflagration
  • detonation
  • DDT
  • gas mixtures
  • pressure waves
  • pipeline safety
  • explosion prevention
  • L Mac Technologies