自民國92年5月起,您是第 位訪客
 赤足英雄・挑戰搜救認證最高殿堂(108/11/8)  車禍救援競技期突破 消防義消國外齊爭鋒 (108/11/1)  災情蒐報添利器!內政部再獲贈災情勘查車(108/11/1)
 
  焦點新聞
  活動花絮
  救災實錄
  案例宣導
  人物介紹
  法規命令
  政風宣導
  消防二三事
  衛生保健
  消防英文
  笑話天地
  服務連結
  各期消防電子報
  訂閱RSS
 
 
消防電子報資料庫首頁 :: 消防英文
 
What is backdraft?
-- 何謂爆燃?
文/曾郁青

A backdraft is a smoke explosion that can occur when additional air is introduced into a smoldering fire and heated gases enter their flammable range and ignite with explosive force.(爆燃是一種煙霧爆炸,發生於額外的空氣被引入悶燒中的火場且加熱的氣體混合濃度位在燃燒範圍內,引燃後伴隨爆炸力量。)

A backdraft is an “air-driven event,” unlike a flashover, which is temperature driven.(爆燃是一種「空氣驅使事件」,與溫度驅使的閃燃不同。)

The fact that most fires are air regulated and not fuel regulated makes the understanding of backdrafts so important.(事實上,大多數火災都是空氣控制燃燒而不是燃料控制燃燒,因此對爆燃的了解非常重要。)

A fire has begun and grown, it may or may not have the thermal radiation feedback to flashover, but it has consumed the contents of the room and is now “burning itself out” by using all the available oxygen in the room.(火勢已經開始成長,它可能會也可能不會有熱輻射回饋導致閃燃,但它消耗了房間的可燃物並透過使用房間裡所有可用的氧氣「自行燃燒」。)

The normal oxygen level in air is approximately 21 percent. Below 14 percent, visible flame is reduced.(空氣中的正常氧氣濃度約為21%,若低於14%,有焰燃燒將會減少。)

The room’s contents are at their ignition temperature and will erupt in flames when oxygen is introduced, and the hot gases will ignite with explosive force. This is a backdraft.(房間內可燃物處於其著火溫度,當引入氧氣時會瞬間引燃火焰,並且使加熱的可燃性氣體點燃伴隨爆炸力量,這就是爆燃。)

The explosive force at which the backdraft occurs is a result of the amount of superheated gas in the space and the amount of oxygen introduced.(爆燃產生的爆炸力是空間中大量過熱氣體和大量引入的氧氣造成的結果。)

The explosive force can break windows, knock down walls, and injure firefighters.(爆炸力可以打破窗戶、推倒牆壁並傷害消防員。)

Backdrafts can occur anytime during the decay stage of fire development, anytime before the gases have cooled below their ignition temperature.(在火災成長曲線中衰退期的任何時間及可燃性氣體尚未冷卻至低於著火溫度時,隨時都有可能發生爆燃。)

If the room was left and the gases cooled before any oxygen was introduced, no backdraft would occur, but the room would have been consumed by fire.(如果房間被靜置且在引入任何氧氣之前內部可燃性氣體已經冷卻,則不會發生爆燃,但房間仍會被火燒掉。)

If backdraft conditions are suspected, proper ventilation will prevent the explosion.(如果懷疑有爆燃發生之條件,適當的通風排煙可以防止爆炸。)

Openings must be made above the fire to allow the superheated gases to escape before oxygen is introduced at lower levels-the lower levels where firefighters would be entering.(排煙口必須開啟在火焰上方,讓過熱的可燃性氣體在氧氣通過消防員進入的較低開口引入火場之前逸出。)







註:本文相關內容來自https://www.usfa.fema.gov/(本專欄內容可能與我國消防現況有所出入,僅供學習消防英文參考使用。)


(108年6月28日 )
 
便 利 工 具
友善列印
轉寄好友
意見反映