Helium to replace Halon 1301
 

Any ideas about this Prospective Development?

The aviation industry has another challenge in fire
protection. This challenge deals with replacement of
Halon 1301 from the existing airplanes and designing
non-halon systems for_ future airplanes like the A380
and the 7E7. Production of Halons has ceased woldwide and it
is recognized as a hazardous material in several
industrial nations. In the US_ a tax is levied on halon inventory.

My Patent that has been published by US Patent Office. It is in Public domain and can be accessed by going to
http//:www.uspto.gov
search for Application 20040020665

My Patent application deals with the use of Helium for
fire protection.

Helium is an inert gas like nitrogen or carbon dioxide.
Its molecular weight is 4 compared to 28 for nitrogen
and 44 for carbon dioxide._ Thus to reduce the oxygen
content of a compartment one requires Helium 1/7th the
weight of Nitrogen or 1/11th the weight of carbon
dioxide._ This makes Helium competitive with Halon 1301
on weight basis._ My estimates indicate one would
require lesser amount of Helium for fire suppression in a compartment than Halon 1301._
On a system basis there may or may not be a weight advantage as helium cylinders may be heavier.
In addition, Helium is a clean agent (leaves no residue),
safe for humans and animals, easily available world
wide at a reasonable cost, and non-conducting. All
these properties are highly desireable for a fire
suppression agent for use in aviation.

If the above interests you then I suggest you download
the Application from the uspto web page.

The Abstract is as follows.

United States Patent Application_ _____ 20040020665
Kind Code _____ A1
Date:_ February 5, 2004

Helium gas total flood fire suppression system
Abstract
The invention provides systems and methods adaptable to all gaseous agents including Helium to suppress fire in at least one enclosed space. Suppressants are delivered by a dedicated subsystem connected to cargo compartments or to engine nacelles, or by an integrated system connected to cargo compartments and engine nacelles. For example, at least a first reservoir stores fire suppressant composition for knocking down a fire in an enclosed space. Piping delivers the composition from the at least first reservoir to the enclosed space. A pressure sensor senses pressure of the composition in the piping, and a controllable purging device permits air to exit the enclosed space
responsive to sensed pressure in the piping of the composition.

Hmmm, seeing how the Bush ranch is on top of most of the world's supply, I smell a conspiracy!:(

Shadow;

Very interesting; have you tested this yet?

It would not work for a cargo compartment, it's a communication issue. It would leak into the command bunker, and you lot would sound like Chip and Dale.
Brgds
Doc

Helium is not a fire supressant. It may smother the fire in the same way as CO2, but I don't believe it interupts the chemical reaction in the way that Halon does. To smother the fire would require in excess of 35% by volume of the space to be protected as opposed to 7% for Halon. Even then it is unlikely to be as effective. When the concentration drops and the O2 level increases to 15% plus, the fire is likely to re-ignite!

one other problem is that the helium would rise to the top of the compartment rather than settle to the base and source of the fire.

Simple. Use Radon. Nice and heavy and you'll be able to see it working at night.

Hey I like it! And no worries about sounding like a duck with helium!!!:ok:

Actually, a new product called Halotron is in the final stages of testing to replace Halon as the fire suppression gas of choice.

Wouldn't Nitrogen be just as effective, and far cheaper? Halon is the mandated standard for airliners and is perfect for the application. If people are really concerned about greenhouse gas/ozone layer depletion they should train cows to stop farting.

Actually, I think I read about an injection that claims to cut this in sheep by a significant percentage. I wouldn't mind volunteering some humans of my aquaintance for these tests..... :ooh:

Ripline

Ah, yes, it's here: http://www.newscientist.com/news/news.jsp?id=ns99996431

Ripline

I started a thread on same subject (NOT helium) in JetBlast this morning
We actually had the same idea about some human beings ;)
Throuble is the vaccine does not affect gas production, it merely reduces its methane contents (and methane is odourless)

About nitrogen : big warehouses are now using reduced-oxygen-partial-pressure (or increase nitrogen if you put it the other way around) for fire prevention. Take a look here especially at the video, quite impressive (just for information - I'm not affiliated with them)

Bre901

Ah, so I see. My apologies, I usually start from JB, but not this morning. I really don't see the industry changing the halon systems anytime soon - I believe it is a legal requirement across the world. If you've ever seen a demonstration of a halon extinguisher dealing with a fire it's quite awsomely effective. Avalanch inhibition effect, I was told once. CO2 is effective, but you can't breath it without choking. Halon is all right for this, although obviously it doesn't support life, but it buys you valuable time to escape. Causes liver damage on prolonged exposure.

Flying balloons for pleasure, it has always mystified me why powder extinguishers are recommended for dealing with propane fires. I use mine as ballast and carry the green one to do any actual firefighting. Extracting powder from wickerwork isn't my idea of fun......

Ripline

During my days as a ship's engineer, I saw a few systems for fire suppression. It was, if my memory serves me correctly, a requirement to have a fixed sytem to protect the machinery spaces on board.

Older ships had a steam smothering system which would I suppose be quite effective in putting out the flames, but hardly a good environment to move around in.

Slightly more up to date was the CO2 smothering systems. This consisted of a room with row upon row of large CO2 bottles. Opening the activation box would sound a warning siren to make sure the machinery space was evacuated. More modern systems would have a refrigerated tank to hold the CO2 which was a smaller neater installation.

The most modern ships I worked on (at least 20 yrs old now) had a Halon system. As stated above, it is possible to survive in a Halon atmosphere sufficiently dense to extinguish the fire. Lord knows what the release of several cubic metres of Halon does to the ozone layer.

There were also fixed foam systems, Hi expansion foam systems and Aqueous Film Forming Foam systems.

I believe now they have gone back to CO2 and Halon substitutes such as HFC-227ea

As a matter of interest, does anybody know why fire extinguishers have gone from being nicely colour coded so that the type of extinguishant was patently bleeding obvious, to making them all red?

Doubtless some sort of EU ruling?

Yep Bally Heck, EU ruling, you are allowed to put a band around in the previous colour though

I was always under the impression that aircraft fire supression systems used Halon 1211, and not 1301. Was there any particular reason for the change?

Cheers
ExO