Panache - 26-2-2008 at 14:32
Does anyone have any experience with using alternatives to the QVF branded ones (which are a little overpriced to say the least). Or better still has
anyone cut their own? The standard QVF spiel is all about failure after heat cycles for non-QVF products and given what a time consuming (albeit fun,
mechano for chemists!!!) task putting this stuff together is i'd rather not have to do it weekly.
Finally does anyone have experience with using a torque wrench on the bolts as opposed to using the QVF tension springs? Any advice?
As an aside if anyone has a box of 1.5", 3'' and 4" inserts and flanges sitting around yelling 'sell me' i'd be happy to take them off your hands.
chemrox - 26-2-2008 at 14:51
YPB! (you poor bastard). What machine? Quick answer re the torque wench idea. Not a good plan. Those springs work together to create balanced
tension at a pressure well below what a torque wrench would deliver to accomplish a similar balance. I.e., the glass would break first. Torquing
with a wrench is controlled deformation. The only thing being deformed in the QVF springs is the springs. Remove them and you'd have to deform the
glass to get a balanced tension. Back to my first question, is there any way to replace the damned flanges with a coiled springs arrangement like
Buchi uses? Your first question: Have you tried any automotive materials? There are "mold your own gasket" types and cut your own gaskets...They
are temperature and pressure tolerant and must be able to withstand chemical attack from hydrocarbons... Good luck. YPB!!
Panache - 26-2-2008 at 15:37
I bought what was essentially a 100L continuous water stil and i'm turning it into a ethanol stil (vacuum though) so there are several modifications,
including the cutting of 40L of raschig rings for the column.
I received it assembled supported on a 'handi-angle' framework it covered two pallets and was 8' high however the condenser was positioned for
downward distillation i assume because the room it was housed in wasn't high enough to cover a different configuration.
I intend to pull the vacuum from the top of the condenser above the boiling vessel and column and use a reflux head to cut the fractions, meaning it
will end up 10' tall
None of the flanges were springed which is why i assumed they had been torqued, but i guess repeating this technique is inviting disaster given it's
second hand already. Its funny although i have only one intended use for it you still are inclined to view it as a piece of lab glass and as such want
to make it as multi-functional as possible, even though it just isn't.