[TheForge] [OT] Pyro-boom (Re: Thanks for the info...)

Sun Jun 1 03:30:01 2003

Paul;
A while back we had a discussion about cutting open old propane tanks 
and several of us had fairly elaborate precautions we took first.
Clearly you are the expert here...
The text below infers that you just jerk the valves and plugs and cut 
them open straight off...is that right?........Pete

Paul Hewitt wrote:

>While O/A has an awesome power to exceed the sound barrier making small
>sonic booms, I am failed to be impressed by the percussive powers.  For a
>small experiment about 8 years ago, we made a "blast container"   I own a
>propane tank disposal buisness, so we are always coming by 1000 gallon tanks
>that are damaged or out of service that must be burned down.  We cut one to
>about 8 feet long, and buried the bottom 4' in the ground.  We then set up a
>20# (5 US GAL) propane tank with a 3/4 plug instead of a valve, and a
>detonator mounted in the plug.  We filed the tank with a perfect mixture
>then plugged it and placed it in the bottom of the tank, and set it off.
>Much to our dismay it went PING, and then proceeded to suck air back into
>the container as the burnt O/A takes up less space creating a vacuum and
>sucking the small wire back into the container from the detonator through
>the epoxy.   We devalve about 500 to 1000 tanks a day, and typically then
>cut holes in them.  The guys with torches usually pride themselves on the
>tanks that become "jet engines"  when a tank sits open long enough they get
>a perfect mixture and then will burn inside the tanks emitting the hot
>exhaust gasses out the hole that's been cut.  After about a 2 to 3 second
>interval they burn out, but do not explode the tank.
>
>After the first dismal failure at turning a tank into shrap inside the blast
>container, we decided to see exactly what it would take.  and open top tank
>was filled with O/A and touched off without a plug, still no shrap, just a
>ping and a whoosh as the air returned into the vacuum of the container.
>The guys finally settled on black powder.  Lets just say at about 500 grams
>they finally succeeded in splitting a tank at the weld line.
>
>Aceyt will not burn back into the tank the regulator is a one way out valve
>even high back pressure will result in nothing more than the regulator will
>back bleed the pressure due to the set imbalance of the spring.  This can
>result in a fire.  Because Aceyt will rapidly decompose without oxygen, it
>is possible to create a section of hose that will explode, although its not
>nearly as spectacular as if it has an good oxygen mixture.  Forcing O2 back
>into the hose will not mix the gas correctly, but will result in a high
>pressure forcing the Aceyt to "mechanically decompose"  the Aceyt chemical
>structure is really quite unstable as we already know and will split into
>smaller less flammable chains of hydrocarbons.
>
>As for some jokes with a sack full in the back of the truck that's a damn
>good way to get a head full of glass, I can just imagine tempered window
>squares flying at 24000
>FPS...................................................
>
>I heave read article in the paper where some idiots where carrying about 30
>balloons inside a minivan, rolling around on the carpet, of course one going
>off will set them all off, the windows were all blown out of the van, and
>both idiots lost their hearing... Geeze I wonder why?
>
>They had been stuffing them in mail boxes, with pull type firecrackers
>attached.  Luckily no one opened any of the mailboxes before authorities got
>to them.  By the time the van exploded they had placed 70 some balloons in
>mailboxes.  Can anyone imagine a Ford Aerostar full of O/A balloons going
>up????  At least a hundred?  I mean I know what 50 can
>do.......................
>
>
>
>
>
>
>----- Original Message -----
>From: "Blacksmith" <[email protected]>
>To: <[email protected]>
>Sent: Saturday, May 31, 2003 6:42 AM
>Subject: Re: [TheForge] [OT] Pyro-boom (Re: Thanks for the info...)
>
>
>  
>
>>    A couple of years ago 2 guys in Toledo were going somewhere with a
>>garbage bag
>>of oxy/act in the back of the pickup truck. I don't think their
>>intententions were ever
>>discovered. In any event they never made it to wherever they were going
>>before the
>>bag exploded. Darn near destroyed the truck. They escaped with their lives
>>fortunately.
>>
>>Bob Willman
>>The Eagle's Anvil
>>Bowling Green, Ohio
>>WB8NQW
>>
>>----- Original Message -----
>>From: "Mike Spencer" <[email protected]>
>>To: <[email protected]>
>>Sent: Friday, May 30, 2003 23:46
>>Subject: [TheForge] [OT] Pyro-boom (Re: Thanks for the info...)
>>
>>
>>    
>>
>>>Pyro Boy quoth:
>>>
>>>      
>>>
>>>>Imagine a 150' long piece of 5 mil anitstatic plastic bag roll (we
>>>>make smaller bags from the large roll of tube with a heat sealer) Then
>>>>imagine some idiot and all his buddies, and 3 full 235 CF sets of
>>>>oxy/acet tanks, and a mixing valve preset to the perfect
>>>>mix...........
>>>>        
>>>>
>>>Um, have you *done* this?  Why didn' I hear?
>>>
>>>"Antistatic plastic", eh?
>>>
>>>I once touched off a small party balloon full of no particular ratio
>>>of oxy/acet with a 4' piece of rod heated one end.  Exceeded
>>>expectations by an order of magnitude.  Rattled distant
>>>windows. Deafened me for awhile.  Before trying a second one, I got to
>>>thinking about static electricity.  Hmm....  I have 9.8 fingers,
>>>decided to keep it that way.
>>>
>>>Is there a way to guarantee that a party baloon will remain
>>>static-free for a predictable period of time?
>>>
>>>I've also thought, in my more irritated moments, that a clear trash
>>>bag, filled with oxy/acet, with a peeled flash bulb inside, hung high
>>>in the old apple tree by the road and connected to the house with some
>>>lamp cord would offer a remarkable surprise to the deer jackers who,
>>>in the dark of an autumn night, check the tree for deer nibbling the
>>>drops.  And then I thought, "Do I need deaf, blind, frightened, armed
>>>drunks staggering around in my pasture?"
>>>
>>>- Mike
>>>
>>>--
>>>Michael Spencer                  Nova Scotia, Canada
>>>
>>>[email protected]
>>>http://home.tallships.ca/mspencer/
>>>
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>>>
>>>      
>>>
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>>
>>    
>>
>
>_______________________________________________
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>theforge mail list group photo site is
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>
>  
>

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