Re: hydrogen gaps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dr. Duncan Cadd by way of Terry Fritz <twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>

Subject: hydrogen gaps


Hi Mike!

Oooohhh.  There's some jolly spiffing posts appeared on this list of late!  My
word this is good stuff :-)


>Original poster: "Mike Novak by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<acmnovak-at-email.msn-dot-com>
>
>Hi All,
>
>Has anyone on the list had any experience with Hydrogen gaps?

<snip>

No experience, but many a plan which so far have come to little other than
library work.

The Danish inventor Valdemar Poulsen, who patented an arc rf generator in 1903
(and which incidentally was very popular, especially it would seem with the US
Navy - forget using those arc welders as ballast and hook 'em up as rf power
sources!) operated the arc in either illuminating gas or hydrogen.  The US Navy
used alcohol vapour.  One of the effects of this was that it prevented the arc
electrodes from oxidising.  My gap is forever accumulating black oxidised gunk
on the electrode surfaces.  A hydrogen gap would prevent this (as would helium,
carbon dioxide, argon and a few other things) so point one is - your gap stays
clean.

"Teslina" who inhabits this list has used a small arc for some interesting
experiments - his site (via Tesla webring) is well worth a look.

Point two, as you say, is that there are no other reactions going on.

Point three is that ionisation and deionisation times will be very short.  The
ionic mobility of hydrogen ions is very high (the highest of all ions) and for
this reason is used in hydrogen thyratrons for pulsed radar service.  I would
expect the quenching to be very quick and efficient.

However, the setting of the spark gap distances and the breakdown voltage is
something else.  From the Electronic Engineer's Reference Book, editor L.E.C.
Hughes, 2nd edn, Heywood & Co, London 1959, the minimum spark breakdown voltage
is 327V for air, 137V for argon, 273V for hydrogen, 156V for helium and
420V for
carbon dioxide.

Whilst I would expect the quenching in hydrogen to be so quick as to give a
significant improvement in performance, the breakdown volts per gap will be
lower than with air.  You might need to stretch the gap length to maintain the
breakdown volts for your setup.

Given the high breakdown volts for CO2, that might also be worth a try.
The gap
in this case may need shrinking.  Obviously there's no fire/explosion hazard
when using CO2 and small bottles are cheap and readily available in many
supermarkets (soda syphons etc) and welding supply houses.

>engineering tasks as well. For instance, the container in which the gap is
>housed... It must be able to handle not only heat, but pressure (vacuum),
>acoustic vibrations, outgassing, rigidity, and other unforseen factors. If
>anyone would attempt such a project, they would be at it for some time.


Exactly why I didn't get any further than plans - I would need to machine a new
gap which could be gas filled and I haven't the time right now (or money, truth
be known.)  Yikes, it took me a month or more to build my existing multi-plate
gap and the raw materials cost over £100!  (Looks good though.)

Outgassing and back-filling are not necessarily problems, the gas can simply
flow steadily through the gap, as it did with Poulsen's arcs, and if it is
flammable you can have a 'gas jet' on the outlet and burn the waste as it comes
out, so long as you don't want to run pressurised.  Actually, if you do want to
run pressurised, just restrict the size of the outlet hole (and stand well
clear
of the lonnnnnnggggggggg flame ;-)

>Any other thoughts on the subject?
>
>-Mike


Hope you get further with it than I did!

Dunckx