On Jan 27, 2006, at 12:32 PM, Jed Rothwell wrote:
See:
http://lenr-canr.org/acrobat/MizunoTanomalouse.pdf
This includes the PowerPoint slides, which are interesting.
- Jed
Note the plexaglass front door of the 1L-6 incubator appears to still
be intact in
http://www.lenr-canr.org/images/MizunoAccident.JPG
This is an indication the door was opened by the blast prior to the
glass shards hitting it. The shards came through with enough energy
to cause widespread injuries. This is only consistent with the
primary energy of the blast being in the 1L-6 incubator, not the flask.
I think Mizuno had it right when he said: "The effluent hydrogen and
oxygen were mixed in the cell headspace. There 2 ~ 3 cc of hydrogen
at the time, although this is an open cell so only minimal amounts of
gas remain in the headspace. It is possible that the tungsten cathode
may have been exposed to the gas in the headspace." (See accident
report appended below.)
The accident report states: "The event occurred in the early stage of
the experiment before a plasma normally forms." However the Chart in
Fig. 6 in:
http://lenr-canr.org/acrobat/MizunoTanomalouse.pdf
shows a run time of over 10,000 seconds before the explosion. That's
almost 3 hours.
The beaker cap used in the explosion was black and both thin and
thinly tapered compared to the white cap shown in the "before"
photos. It is possible there was a leak in the cap or other leak in
the system, or that hydrogen had accumulated in the 1L-6 incubator
during prior runs.
On Jan 27, 2005, at 9:25 AM, Jed Rothwell wrote:
Mizuno reports that the inverted glass funnel was not in use in the
latest series of experiments, so there was a stoichiometric mix of
hydrogen and oxygen in the headspace of the cell. After further
investigation, he concluded that the explosion was probably
triggered by the platinum mesh anode. I will revise the accident
report to include his latest comments, and I will upload a version
of it in a few days.
The outlet tube leading to the mass spectrometer was definitely not
blocked or impeded, so the gas in the headspace was at 1 atm.
One of the glass shards struck Mizuno's neck next to the carotid
artery and penetrated about 1 cm. I'll bet that put the fear of God
in him! He has been rather slack about safety up to now, in my
opinion.
There is a great deal of opposition to cold fusion in Japan and at
the university, so I feared that the university might step in and
tell him he can no longer perform these experiments. But
apparently, he is already back at work starting the experiments
again, despite the trauma. Mizuno has guts. All cold fusion
researchers have guts. They are an ornery bunch, but you have to
admire them.
- Jed
On Jan 31, 2005, at 12:40 AM, Horace Heffner wrote:
It appears the explosion may well have been ignited in the flask,
but the
main energy from the explosion came from the top interior of the
Yamato
1L-6 incubator. It looks like the explosive force was primarily
downward,
and the overpressure on the conical cap on the flask blew the flask
apart
in radial directions, leaving the base cracked but in leaving it
place. It
looks like the base of the flask may be stuck (by prior heating) to
the
polypropylene insulation underneath it.
Assuming the plastic door was not blown to pieces, the overpressure
was
clearly enough to blow open the plastic door before the glass
shards went
through the open door. This indicates the overpressure hit the
door before
the flask pieces. The source of the blast pressure that opened the
plastic
door was therefore not inside the flask, but rather probably coming
from
the top of the 1L-6 downward.
One has to wonder if there was a long run at a somewhat earlier
time, but
not more than a few days prior to starting the demonstration for the
visitor. From the pdf experiment description it appears the
hydrogen from
the flask is ultimately dumped into the interior of the 1L-6, even
if/when
the generated gas volume is being measured. There are clearly various
spaces in the 1L-6 that could trap an H2-O2 mixture, even if the
door were
opened for a while for access to the experiment. Upon closing the
plastic
door and leaving the experiment sit, any residual H2 in semi-confined
spaces (e.g. cloth, instrument boxes, etc.) in the 1L-6 would
eventually
tend to diffuse toward the top of the 1L-6.
Regards,
Horace Heffner
http://lenr-canr.org/acrobat/MizunoTgeneration.pdf
On Jan 26, 2005, at 5:22 AM, Jed Rothwell wrote:
[I will upload an Acrobat version of this report that includes
photographs.]
Accident Report
Tadahiko Mizuno
Division of Quantum Energy Engineering,
Research group of Nuclear System Engineering
Hokkaido University
E-mail: [EMAIL PROTECTED]
On January 24, 2005 at around 4:00 p.m. an explosion occurred
during a plasma electrolysis experiment being performed by Mizuno
in the Quantum Energy Engineering Section.
The cell was a 1000 cc Pyrex glass vessel which has been in use for
about 5 years. It contained 700 cc of 0.2M K2CO3 electrolyte; a
platinum mesh anode; and a tungsten cathode wire 1.5 mm in
diameter, 29 cm long, with 3 cm exposed to the electrolyte.
Electrolyte temperature was 20 deg C. The cell was placed inside a
constant temperature air-cooled incubator (Yamato 1L-6) with the
outer door open, and the inner Plexiglas safety door closed. The
experimental setup is described in Ref. 1. The event occurred in
the early stage of the experiment before a plasma normally forms.
Soon after ordinary electrolysis began, voltage was increased to 20
V and current to 1.5 A. 5 or 6 seconds later, a bright white flash
was seen on the lower portion of the cathode. The light expanded
and at the same instant the cell exploded.
The explosion blew open the Plexiglas safety door and spread shards
of Pyrex glass and electrolyte up to 5 ~ 6 m into the surrounding
area.
When the explosion occurred, Mizuno and a guest visiting the
laboratory (who wishes to remain anonymous) were observing the cell
about 1 m from the incubator. They were wounded in the face, neck,
arms and chest by shards of glass 1 ~ 5 cm long. Fortunately, there
were no injuries to their eyes. The injuries are light, and they
are expected to recover in a week. However, the explosion made such
a tremendous noise both victims were temporarily rendered
completely deaf. It is not known whether this will have any after-
effects.
Possible Causes
The vessel was old and may have had a scratch on the inner surface.
The effluent hydrogen and oxygen were mixed in the cell headspace.
There 2 ~ 3 cc of hydrogen at the time, although this is an open
cell so only minimal amounts of gas remain in the headspace.
It is possible that the tungsten cathode may have been exposed to
the gas in the headspace.
Recommendations
Researchers performing similar glow discharge experiments are
advised to make an experimental setup that can undergo an explosion
without endangering personnel. Care should be taken not only to
protect against shards and fragments, but also to avoid exposure to
the extreme noise of an explosion.
Voltage, current and electrolyte temperature were below the levels
needed to form a glow discharge, so it is unclear what might have
caused the explosion.
Countermeasures
Here are some basic protective steps that should be taken in all
experiments of this nature:
Perform experiments under remote control, with power supplies and
meters placed a safe distance from the cell.
Use an explosion-proof cell vessel and equipment chamber.
Do not use glass cells. (We are now investigating alternative
materials.)
All glass and plastic vessels should be wrapped with filament tape
to prevent fragmentation.
Prevent mixing and recombination of effluent hydrogen and oxygen.
However, it would be impossible to prevent mixing during the glow
discharge phase when both gasses are generated at the cathode.
Use nontoxic or reduced toxicity electrolyte solutions.
Always use safety glasses, helmets, faceguards and an acrylic blast
screen.
While we have not concluded this incident was caused by a cold
fusion reaction, be aware that cold fusion is still poorly
understood and difficult to control.
Be aware that in normal operation these systems often produce
intense ultra-violet rays that can damage unprotected eyes; and
they can produce intense magnetic fields and possibly x-rays and
neutrons. Take steps to protect yourself from these as well.
References
1. Mizuno, T., T. Ohmori, and T. Akimoto. Generation of Heat and
Products During Plasma Electrolysis. in Tenth International
Conference on Cold Fusion. 2003. Cambridge, MA: LENR-CANR.org.
http://lenr-canr.org/acrobat/MizunoTgeneration.pdf
