Thoughts on partial pressure blending......

[NeilB]

I was blowing 3 tanks of EAN32 the other day and the the thought occured to me - what happens if my burst disk decided to blow now?

Like most (I assume) I empty my cylinders to make the most of my O2. I then put 27 bar or 37 bar of pure O2 in (depending on if I want EAN32 or EAN36), then top off with air.
If I had 36 bar of O2 and my burst disk blew all that oxygen is very rapidly going to exit through a small home that may well be not clean. What's the chance of it all getting hot and bothered?
Or will 'expansion causes cooling' keep it below combustion temp?

Thoughts appreciated......

[nigelH]

Originally Posted by NeilB

If I had 36 bar of O2 and my burst disk blew all that oxygen is very rapidly going to exit through a small home that may well be not clean. What's the chance of it all getting hot and bothered?

Never did think burst disks were a good idea. I'm glad we don't use them in Yorkshire.

No major problem. Oxygen escaping is relatively safe oxygen. Contained oxygen fires are bad news. Dirt isn't the problem, fuel is. You don't work with naked lights when you're oxygen filing.

[Simon A]

Niel,
the odds of you burst disk going at 36 bar are astronomicaly small, after all it probably had 50 bar in it before you emptied it? You're much more likely to get the burst disk blow as you get towards working presure as you top it up with air.

Simon A

[NeilB]

Originally Posted by Simon A

Niel,
the odds of you burst disk going at 36 bar are astronomicaly small, after all it probably had 50 bar in it before you emptied it? You're much more likely to get the burst disk blow as you get towards working presure as you top it up with air.

Simon A

Very true but a million to one shot happens 50% of the time (who used to say that?).

It was just a thought. I was not overly worried as, as Nigel says, the O2 is escaping into the air so there should be no sources of ignition. Just the idle musing of the, well, idle......

[The Duck]

Originally Posted by NeilB

Very true but a million to one shot happens 50% of the time (who used to say that?).

IIRC

Terry Pratchet (can't remeber the particular book) - "A million to one shot comes up nine times out of ten"