The WiZard is In
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Glass Containers Shatter During Experiments with Volatile Materials
I was looking for something (not yet found) in my files and
came upon this from the US DOE —
Glass Containers Shatter During Experiments with Volatile Materials
Safety Shields/Forceps/Remote Handling Can Help Prevent Injuries
http://www.hss.energy.gov/publications/safety_health_note/ns...
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quicksilver
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This is an interesting subject as an inverse proportional effect is in place with heat resistant / tempered type glass (Pyrex, quartz, etc). As we
find stronger designs or thicker existing ones the projectiles from an explosion increasingly dangerous. I don't think there are simple answer to the
issue as shielding has always been a hindrance to direct manipulation. Many working environments with automation make excellent use of shielding but
in a lab environment, the better protection would possibly be individual. Israeli gas masks cover the eyes and face with fairly heavy protection
(& shield from fumes) but the hands have always been a serious trade off between moderate protection and the unhindered ability to maintain
skilled movement, etc.
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albqbrian
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Why not shield???
When Mr. Murphy makes an unwanted appearance we move from the land of Avogadro to that of Newton. The latter is pretty straight forward. I've created
plenty of shrapnel, both intended and unintended. A nice thing? It's one of the few things in the real world that behaves linearly. This fact would
seem to make having shield a prudent addition for any work with energetic materials.
Look at your reaction vessel. Picture it as a light bulb radiating straight out from all surfaces. That's how it's shrapnel will fly. Take a stick and
move it around the vessel. Anywhere that stick points at you, you need shrapnel protection. Luckily while the pieces may be of high velocity; they're
pretty light. Distance from the vessel and minimal shielding will take care of most problems.
Just tossing some ideas off the top of my head. A junked car window should work; plus you can see through it. Or a sheet of plywood or thin metal.
Heck, I'd bet a decent thickness of cardboard would work. Of course now you'd need to set up some remote viewing system.
Then how about a basic "stick structure" to remove your hand from the immediate connection with the reaction vessel? That is certainly one of the
greatest areas of risk if a project goes wrong.
This also brings up the idea of having a second person present. A lot of pros and cons here. The biggest pro is that if you suffer a serious,
debilitating injury; that other person can perform immediate first aid and call 911 possibly saving your life. Also a 2nd pair of eyes may notice
something important you're missing. The cons. You put a 2nd person at risk. You also have to find someone willing and able to acquire the necessary
skills. Then there's the legal part. If what you're doing is illegal; and in the US I'd bet almost anything I've seen discussed here will run afoul
some federal, state, local, CPSC law or laws. We'll you've now added conspiracy charges to that mess. Prosecutors love to pile on charges until you
cop a plea rather than risk a huge jail sentence at a trial. Plus the cops can now get one of you to rat out the other. Ugly no doubt.
So two people is murky. But a shield seems to be a pretty simple addition if you work in a world where "Glass Breaks"
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The WiZard is In
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Quote: Originally posted by albqbrian  | | When Mr. Murphy makes an unwanted appearance we move from the land of Avogadro to that of Newton. The latter is pretty straight forward. I've created
plenty of shrapnel, both intended and unintended. A nice thing? It's one of the few things in the real world that behaves linearly. This fact would
seem to make having shield a prudent addition for any work with energetic materials. [snip] |
Extracted from:
Journal of Hazardous Materials, 5 (1982) 359-371 Elsevier
Scientific Publishing Company, Amsterdam - Printed in The
Netherlands
REMOTE HANDLING - BLENDING OF ENERGETIC MATERIALS
R. L. PARKS
Monsanto Research Corporation, Mound Facility,* Miamisburg,
Ohio
In 1974 to meet a need for a less sensitive, but still energetic,
explosives initiator other than the commonly used primary
explosives, such as lead azide, Monsanto Research Corporation
started the development and production of a series of high energy
pyrotechnics. It soon became apparent that these high energy
pyrotechnics were not simple mixtures, easily handled, or subject
to deflagration only. There was more to it. The safety literature
and technical data on pyrotechnics did not deal fully with the
materials under study. In-house work on small quantities, less than
a gram, indicated that these metal/oxidizer blends were truly
high energy mixtures.
Important production safety questions quickly surfaced. How large
a batch could be blended safely? Was there a "critical mass” for
detonation? How important was container shape and size? If these
pyrotechnics detonated, what would be their TNT equivalency On
deflagration, what would be the size of the “fireball”?
[0.5 kg (1.1) lb 10 feet] 260 ms duration.]
The objective of the test series was to determine the output energy
of the titanium powder and potassium perchlorate mixture in a
mechanical blender configuration representative of that used at
Mound Facility. This was accomplished by measuring: (1) the free
field air blast output equivalency as compared to an equal weight
of TNT at the same scaled distances;,(2) fireball diameter and
duration; and (3) static pressure in a closed chamber.
The composition tested consisted of one-third by weight of 2-
micron particle size dry titanium powder and two-thirds by weight
laboratory grade KCl04. The number of tests and the quantities of
ingredients for each test conducted are tabulated in Table 1. Five
of the nine tests were conducted in a simulated blender
configuration to determine free air equivalency, and the remaining
four tests were conducted in closed chambers to measure static
pressure.
The Ti/KCl04 mixture exhibited characteristics of a detonation
when thermally ignited in a light, metal container. For the 500-g
(1.10 lb) charge, the TNT equivalent value was 53% at a scaled
distance of 1.07 m/kg sup 1/3 (2.22 ft/lb sup 1/3) and
approximately 75% equivalency at a scaled distance of 3.24 m/kg
sup 1/3 (8.16 ft/lb sup 1/3). Equivalent values for the 250-g
(0.55-1b) charge weight were 68% equivalency at the 1.07-m/kg
sup 1/3 . Because of the limited number of tests, it cannot be
determined whether the apparent difference at the smaller
distance is significant. The 125-g (0.28-1b) quantity failed to
detonate. This was probably due in part to the volume of the
container and the resultant depth of material.
A fragment analysis was made on the assumption that a detonation
of the pyrotechnic would occur in the hopper of the aluminum
aliquot vessel. It was also assumed that the detonation would
equal 1 lb. of TNT, and that all available material would detonate,
the worst case. The 0.5-in. Thick Steel walls will not stop a
primary fragment, 1/8 X 1 X 1 In. aluminum, striking it at right
angles.
[How thick is your skin?!?!]
For most of us a little polycarbonate (Lexan©) with some
angle iron could work wonders.
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albqbrian
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So you're agreeing with me...
Yes 
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The WiZard is In
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You can never be too —
Rich (However, money can't buy poverty.)
Good looking
Safe
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