Watching fires is not a fun

http://www.dailystar.co.uk/news/latest-news/502597/petrol-station-explode-blast-Russia-Dagestan-multiple-dead-natural-gas-firefighters-police

In the video, it is seen, persons walking aside, not knowing the dangers of such fires. Fragments from explosion can travel great distances and can kill the persons. Thermal radiation from fireball also will be felt at longer distances, the overpressure in the form of pressure waves can lift the equipment/persons off the ground, making them to hit other objects and thus get injured/killed.

Refinery explosion - sound heard 25 miles away

In an explosion in a gas refinery at Texas, the sound was heard 25 miles away. Residents within 10 miles were evacuated. Two persons were injured in the incident. A person near the explosion says that his vehicle got shaken after the explosion.

Watch the report and the video.

http://www.dailymail.co.uk/news/article-3348269/Hundreds-oil-workers-run-lives-massive-explosion-rocks-gas-refinery-Texas.html


As per another report, there were already two small fires with intermittent sirens causing locals to evacuate. Soon after followed an explosion with a big fireball.

http://www.firehouse.com/news/12145837/early-warning-spared-injuries-in-massive-orla-texas-gas-plant-fire

Fire in an eatery kills 8 - Times of India's report

As per the reports in Times of India, 8 persons died due to fire from possible short circuit and subsequent fireball from leaking gas in an eatery.

During fire, the stairs leading to eatery in upper floor gave way, trapping the persons in it.

It is found that this eatery does not have any permission for that floor from municipal and also NOC is not obtained from fire authorities.

The manager is charged with culpable homicide not amounting murder. If proven, maximum punishment of life term is possible.

http://indianexpress.com/article/cities/mumbai/fire-in-restraurant-7-from-kurla-college-among-8-dead/

Fire & Explosion Prevention Strategy in Refineries

Please see the LINK on the above article with download link. The download PDF document lists hazards in LPG bullet area, fireball radius, thermal radiation, probability lethalities, etc

BLEVE Training Video - Safety Engineering Network (SAFTENG)

A video on BLEVE (boiling liquid expanding vapour explosion) is available at the link below.
BLEVE Training Video Part 1 - EXCELLENT Info - Safety Engineering Network (SAFTENG)
BLEVE Training Video Part 2 - EXCELLENT info - Safety Engineering Network (SAFTENG)

http://www.safteng.net/index.php?option=com_content&view=article&id=1038&Itemid=178 (Part 1)
http://www.safteng.net/index.php?option=com_content&view=article&id=1037%3Ableve-tests-results-1-excellent-info-&catid=52%3Aemergency-response&Itemid=178 (Part 2)
LINK

The video explains about the phenomena of BLEVE, the fire ball radii, the safe distance for emergency responders. We will understand that the safe distance for emergency responders is FOUR times the fireball radius with minimum distance at 90 m. For a 400 lit capacity tank, the fireball radius can be 18 m. We also learn that as the capacity of the flammable storage tank increases by a factor of 10, the fire ball radius doubles. The evacuation distances can be taken as 20 times the fireball radius.

However, these distances are not exact as there are instances of explosion fragments travelling more than 20 times fireball radius. During the incident at New Mexico in 1984, a fragment weighing about 20 T travelled 1200 m.

The water required to cool the exposed hot surfaces 10 lpm/sq.m. It may be noted that inspite of all efforts, if there is whistle/jet engine sound from valves, it is indication of over pressurization inside and all emergency responders should stop their activities and move to safe distances.

Some people assume that BLEVE is possible only with flammable substances. But, as the video explains, BLEVE is possible with any substance that leads to vaporization and pressure rise during external heating/impact and the container rupture leads to BLEVE. Fireball is the result if the substance inside is flammable.

Note: Literature gives following equations:

Fireball radius, R (meters) = 29 M^1/3  where M is mass of flammable in the fireball in tonnes
Fireball duration, t (seconds) = 4.5 M^1/3

Most likely distance for 3^rd degree burns = 80 M^0.42 meters

Maximum distance for 3^rd degree burns = 130 M^0.42 meters

Most likely distance for 2^nd degree burns = 150 M^0.42 meters

Maximum distance for 2^nd degree burns = 240 M^0.42 meters

The heat radiation intensity from the fireball can cause damage to human beings and property. From the literature, it can be seen that 12.5 kw/sq.m heat intensity can be fatal, 8.5 kw/sq.m can cause 1^st degree burns whereas solar radiation gives 0.6 kw/sq.m

Explosion and fireball incidents at Canberra and Oklahoma

There were reports of chemical factory fire and explosions in Australia in leading  about 200 m fireball, temperature of 1000 deg.C. As the fire could not be controlled, the firefighters were asked to move back by 300 m distance. It took 22 hours to control the fires involving combustible chemicals.

http://www.canberratimes.com.au/news/local/news/general/biggest-fireball-ive-ever-seen-superintendent/2295464.aspx
http://www.dailytelegraph.com.au/news/massive-chemical-fire-after-series-of-explosions-rock-canberra/story-e6freuy9-1226138503397
http://www.skynews.com.au/national/article.aspx?id=662748&vId=
http://news.google.com/news/story?ncl=http://www.canberratimes.com.au/news/local/news/general/biggest-fireball-ive-ever-seen-superintendent/2295464.aspx&hl=en&geo=us


In another incident of gas rig fire and explosion at Oklahoma, more than 100 ft high flames were seen, lighting an area of about 60 mile distance. People in 2 mile radius were evacuated. No injuries were reported.

http://www.washingtonpost.com/business/sheriff-warnings-helped-workers-reach-safety-before-okla-gas-rig-blast-homes-evacuated/2011/09/20/gIQAFo2DiK_story.html
http://today.msnbc.msn.com/id/44589618/ns/us_news-life/
http://news.google.com/news/story?ncl=http://www.washingtonpost.com/business/sheriff-warnings-helped-workers-reach-safety-before-okla-gas-rig-blast-homes-evacuated/2011/09/20/gIQAFo2DiK_story.html&hl=en&geo=us

BLEVE explanation with video

The following link gives explanation for BLEVE (Boiling Liquid Expanding Vapor Explosion). The explanatory text below states that BLEVE is possible even with nonflammable liquids which should be noted. Many experts differ with this statement and they talk firmly that BLEVE is possible only with flammable substances. Though, the phenomena is same whether it is with flammable or non-flammable substances, I do not understand why some experts in the field differ about BLEVE with non-flammables. If the substance is flammable, then BLEVE is followed with a fireball, else no fireball. Thermal radiation from fireball can trigger secondary fires (domino) if flammables are present nearby.

http://my.firefighternation.com/video/bleve-explanation