Plasma? - Page 3

 On Fri, 23 Jan 2009 17:45:06 -0600, "William Wixon"



Cutting speed ratings paint the clearest picture, although they can be
hard to find sometimes. Mine is rated to sever 3/4, but at an
impractically slow rate. Still useful occasionally on such thickness
for short cuts of material that won't fit in the chop saw. Anyway, the
ratings assume that the consumables are in good shape, which tends to
make the ratings overly optimistic. With even somewhat worn
consumables, mine will breeze through 1/8" and cut 1/4" acceptably,
but gets sluggish at 3/8", particularly when starting at awkward
angles. On thick stuff I usually start with new consumables and try to
get through any difficult areas early. I keep the worn consumables for
lighter material, or for when clean cuts aren't important. One other
note about my machine - I find that unshielded consumables yield a
narrower kerf and therefore are more effective on thick material. I
only use the shielded parts when I'm using a template, since the
square edge of the shielded cap makes that easier.

Wayne

  Winston wrote:

http://www.trackg.com/R4CleanEnergy/Presentation-slides/Tuesday-tech-Ben%20Taube/Lou%20Circeo-Plasma%20Arc%20Gasification%20of%20Solid%20Waste.ppt  

The principle probably makes sense, but I think it is a bit
oversimplifying and optimistic to describe the output as "inert".  For
example the granules will contain whatever heavy metals were in the
original waste, eg cadmium, which will eventually leach into water
courses if they are used for landfill or construction.  As they are
produced in a reducing atmosphere, the metal residues will likely be
rather more reactive than in oxidised basic slag.

While high temperature processing simplifies most organics etc to
manageable gases, some hazardous gaseous residues such as dioxins will
remain in the syngas and so in its eventual combustion products released
to the atmosphere.  Not all the gaseous product will have passed through
the plasma, some will distil earlier and bypass it, so an amount of more
complex and even biological compounds will remain in the gases too.


Tim Jackson

 Tim Jackson wrote:

http://www.trackg.com/R4CleanEnergy/Presentation-slides/Tuesday-tech-Ben%20Taube/Lou%20Circeo-Plasma%20Arc%20Gasification%20of%20Solid%20Waste.ppt  

Thanks, Tim.

--Winston