| Pages:
1
2 |
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
My buddy in the Bay Area who is in the bead business tells me that a Kg of 4mm OD 4mm long glass beads is $150 there, but that if I go root around at
the Chatuchak weekend market I can find same for about $15. (Here = Bangkok).
I think I will wait till his next visit and let him go to the Market, as it is a hot crowded maze which I detest. I'd rather pay $150 than have to
spend an hour or two there.
Sic gorgeamus a los subjectatus nunc.
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
Two minutes of Google searching = $38.25 kilo (OK, 8 kg volume discount, firemountaingems.com). Include Matsuno with the other two Japanese companies
that I named. The point is that with searching comes better things.
Someone is making nice ceramic ones in 3mm and 4x6 (getting close to the pony bead range), though I'm not sure if these are glazed well enough for this use. They are sold as "Greek".
|
|
|
shadow
Hazard to Self
Posts: 52
Registered: 17-10-2007
Member Is Offline
Mood: No Mood
|
|
Is glass wool too dense to be used in a condenser?
|
|
|
MagicJigPipe
International Hazard
Posts: 1554
Registered: 19-9-2007
Location: USA
Member Is Offline
Mood: Suspicious
|
|
I've seen glass wool used to support packing material in tubes/condensers that weren't designed to be columns (ie no supports/indentations).
I'm not sure exactly how it would affect performance, though.
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
The cheap Indian-made glass beads sold here for about $15 a Kg are definitely glass, and available in clear colorless form.
So there is no issue of glazed vs unglazed as there is with ceramic beads.
I noticed also that Aldrich sells PTFE Raschig rings as small as 3 mm x 3mm x 1 mm in a pack of 500. In (borosilicate glass they just resell Ace's
product and smallest is 5 x 5 x 1 mm.
I shudder to think of Aldrich's pricing however.
Sic gorgeamus a los subjectatus nunc.
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
We looked into clear glass beads at the Chatuchak weekend market and came up empty. They had plenty of colored glass beads, but I wanted clear, and
for that all they had was crystal (quartz) for about $300 a Kg.
So no dice.
Meanwhile I found a local source for PTFE tubing, wall thicknesses of 0.5 and 1 mm, ODs from 2 mm to 22 mm. They also have other fluoropolyner tubing
and they do custom fabrication so I am asking for a quote for the following:
3 x 3 x 0.5 mm, qty 5000 pcs
4 x 4 x 0.5 mm, same qty
5 x 5 x 0.5 mm qty 3000 pcs
6 x 6 x 0.5 mm qty 3000 pcs
I already know what Aldrich sells the 3 mm and 6 mm PTFE raschig rings for in packs of 500 and 300 respectively.
The little rings are great for smaller columns up to 19mm ID and the larger for columns up to 30mm ID.
Hopefully the low local labor content will allow some economy because Aldrich is just too damned expensive.
For glass tubing, a small benchtop diamond cutoff saw, say 4" blade, selling for $100 or so in USA, from jewelers supplies is ideal for fast and easy
parting of small diameter glass tubing. A stop can be added for repetitive parting to predetermined length. Feeding of stock is by hand and cooling is
by water (a little messy.) This is another option if you don't mind spending some tedious hours making your own raschig rings.
Sic gorgeamus a los subjectatus nunc.
|
|
|
kalacrow
Harmless
Posts: 38
Registered: 23-5-2008
Member Is Offline
Mood: No Mood
|
|
One more alternative is, assuming you have the equipment, to make packing from lengths of flint glass tubing. You will need a cutoff wheel, and these
can be gotten from lapidary supply as "trim saws". There are various designs.. some are more suited to this than others.
Yes, its expensive, but the equipment will pay for itself, long term I think. Especially if you are fabbing your own glassware and cutting short
lengths of tubing a lot.
Plus, you will have a way to cut up small rocks and crystals 
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
The following pretty much renders DIY moot, at least for me.
Chemglass sells 6mm berl saddler for $25/200 cc abd slightly more than $100 a liter.
The piece count is approx 250 to 200 cc and 1250 to the liter.
That is pretty damned cheap and the ceramic saddles are better packing than raschig tings.
The catalog number is CG-1284.
[Edited on 12-6-2008 by Sauron]
Sic gorgeamus a los subjectatus nunc.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
