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Hi Shawn.
What a marvelous idea you have. Use the existing
autoclave and make it the hulls outer layer while cooking under pressure laid
down cf to reinforce and increase the autoclave's
thickness from the inside. Sounds great except for
one thing. As mentioned with propane tanks here in the past and recently as
well, these pressure vessels are made to hold pressure
from the inside not the outside. Remember it is
hard to blow up the beer can but easy to crush it. However, it would be
interesting to compute what the autoclave's external crush pressure would
be
and then compute what that increased crush depth
would be if reinforced with cf like you suggest. The addition of the cf on the
inside of the hull might overcome any shortcomings of the original
autoclave's
unreinforced hull and make it so it would withstand
greater pressures afterall. Very interesting! If I was you and going to do this,
before I spent any money I would find out everything about the tensile
strength
and makeup of the autoclave's metalic hull, its
thickness and how much pressure it could hold from the inside without blowing
up. Then I would have someone compute those figures into what its external
pressure holding
force would be. Then compute the tensile strength
of the autoclave's hull reinforced with cf. You never know, you just may have
something here. But I would do it all on paper and computing first before
spending
a dime. Just one question though. How do you
propose worker access to lay down the cf from inside the autoclave and then
pressurize it?
Bill
----- Original Message -----
Sent: Tuesday, November 08, 2005 12:16
PM
Subject: Re: [PSUBS-MAILIST] Composite
Huls - self annealing?
I just came up with another interesting
idea. We all know the basis behind the autoclave right? An
autoclave is basically a huge PRESSURE VESSEL with a heating element
inside. So, why re-invent the wheel? Simply reverse the
thinking:
Prefab D.O.T. pressure vessels usually have the
stringers on the outside, this is good. They also come with
endcaps. Simply have one made that can handle internal pressures with
temps 250F+. (most chemical storage tanks meet this I presume).
Next, we install a compressor at one
endcap. Then, a power supply with a heating element on the other, that
runs the length of the cylinder. Or better yet, if you can, install them
both on the same side.
The CF is then laid on the INSIDE of the tube,
closed up, and pressure cooked. The autoclave itself is the outside
shell of the sub.
Once you've laid as much CF as you want, you
remove the compressor and the heating element and voila - strongest personal
sub. in the world. You could also have the heat source on the OUTSIDE,
but this doesnt guarantee uniform temp. dispersal.
This technique makes simple sense
to me, because the high internal pressures are pushing the CF to the
shell while curing, as well as eliminating the voids WITHIN the CF and between
it and the shell.
Only other thing I could think of is maybe using
the shell to lay some kind of thermoplastic, probably on the outside.
The shell could be heated to accomodate it and then cooled to solidify
it. Thermoplastics are actually going to put autoclaves out of
business eventually, so they say.
Shawn
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