lvjrf
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Reactor
Hi all
Anyone tell me how made reactor with pressure control ?
thanks
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lvjrf
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Like as Autoclave
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not_important
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Try
http://www.sciencemadness.org/library/books/autoclaves_and_h...
for starters. Old, but has the basic concepts.
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Quince
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I want to know the opposite: how to make a vacuum furnace that can sustain vacuum at temperature where Pyrex would melt, so I can't just seal the item
in a Pyrex tube and bake that.
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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not_important
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| Quote: | Originally posted by Quince
I want to know the opposite: how to make a vacuum furnace that can sustain vacuum at temperature where Pyrex would melt, so I can't just seal the item
in a Pyrex tube and bake that. |
Use fused silica, Vycor, alumina, sapphire , or mullite tubing. Or metal, with a sapphire window or windows if you need to see in.
Another possibility is to use pyrex, with a heating method that directly heats the load. The pyrex can only be heated by radiation through the vacuum,
a air blast on the outside of the pyrex will keep it cool enough.
http://www.sentrotech.com/index.php
http://www.rayotek.com/index1.htm
http://www.graphitestore.com/items_list.asp/action/prod/prd_...
and many more
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matei
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| Quote: | Originally posted by Quince
I want to know the opposite: how to make a vacuum furnace that can sustain vacuum at temperature where Pyrex would melt, so I can't just seal the item
in a Pyrex tube and bake that. |
You can seal a pyrex tube with a methane/oxygen torch and than place it in an oven.
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Quince
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| Quote: | Originally posted by matei
| Quote: | Originally posted by Quince
I want to know the opposite: how to make a vacuum furnace that can sustain vacuum at temperature where Pyrex would melt, so I can't just seal the item
in a Pyrex tube and bake that. |
You can seal a pyrex tube with a methane/oxygen torch and than place it in an oven. |
matei, I said where it is too hot for Pyrex and that would melt. I could use a quartz tube, but I can't develop the heat to seal that (I don't have
oxy-acetylene, just propane).
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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not_important
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Get some quartz heaters, like these http://www.infraredheaters.com/quartz3.htm
Get a big pyrex tube
Trace out an ellipse that will have one of the heater tubes at one focus, and the center of the pyrex tube at the other.
Rotate the ellipse N times arround the focus at the center of the pyrex tube, erasing any part of an ellipse that falls within another ellipse so that
you end up with a sort of N-point start except the star's points are ends of ellipse.
Make that star shape out of shiny aluminum or stainless steel sheet, long enough that it will extend to the end of a quartz heater. This is your
reflector.
Mount the reflector with the pyrex tube a the center, and a quartz heater at the focus in each arm of the star. mounting clips and electrical
connections for the lamps, end connections for the pyrex tube so you can pull vac and insert/support a holder for the sample.
Get a hunking big fan/blower. Make a end plate for the reflector that allows the HBF to blow air in that end, with the air flowing around the outsides
of the heaters and pyrex tube.
Devise a support for the sample, an alumina rod or tube. The section that will be well within the pyrex tube, exposed to the glare of the lamps, can
be stained near-black with mixed Fe/Co/Ni/Mn oxides.
Put your sample in its container - boat or crucible, that onto/into the support, that into the pyrex tube. Pump the tube down, turn on the HBF, then
the quartz heaters.
The region at the image focus of the heaters can be raised to nearly the temperature of the heaters' filaments, depending on heat losses. As the
radiative loss is mostly 'seeing' the filaments, conduction losses and absorbtion by the pyrex tube will likely be the controlling element.
The pyrex will be absorbing the longer IR. The larger the tube, the less heating per unit area of the pyrex tube there is. The air blast needs to
carry away that absorbed heat.
Or you could just use what I suggested earlier for the containg, Mo heating elements in the container, or maybe induction.
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Texium
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Thread Moved
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