Funkerman23
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vessel shape opinions needed
First let me ask forgiveness if this is a spoon feed request. My intent is not to be lazy; I just don't know how I would search for the answers to the
following questions or where to look.
I have been trying to find a good reaction vessel for some time. But given the cost this looks like I'll be able to buy one good one and that's it(
for a few years it seems). With that limitation in mind and knowing that this will be used for a lot of preparatory work: would you. if in the same
scenario, buy a spherical shaped or a cylindrical shaped reaction kettle? Again assuming you only can buy one and you will use this later on for many
preparations.
Opinions, and advice are very much appreciated and needed here.Comments and feedback are needed and welcomed as well. Thank you for your time and I
wish you the best.
" the Modern Chemist is inundated with literature"-Unknown
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confused
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what exactly will you be using it for?
that would determine the shape/type of the reaction vessel
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Dr.Bob
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It is hard to clean a real cylinder, so if you can find a cylinder with a nice round bottom, that it the best option, otherwise, I would just go
spherical. What size and type are you looking for, if you post what you most desire, someone might turn out to know where to find it, or have one
available. I have had weirder things happen.
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Muffn Man
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Opinion
If/when you figure out what you want, check out Dr.Bob's "Glassware Inventory.xls" list on page http://www.sciencemadness.org/talk/viewthread.php?tid=15667&...
Many have ordered from the good Doctor, including myself and all of us have given rave reviews following excellent
transactions/service/price/selection/communication.
I am not a puppet animated by Dr.Bob...
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DJF90
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I suppose the key question is what size do you have in mind, and is the vessel jacketed (and do you have a heater/cooler system suitable). Both types
of vessel have advantages and disadvanges, and share many common features.
"Cylindical" vessels typically come with a conical or round bottom, and may or may not be baffled. They will generally have a BRO (bottom run-off)
valve to empty the vessel/perform phase separations/transfer slurries to filter. Get one which is jacketed as heating and cooling will be a real pain
in the arse otherwise. You need to use mechanical stirring with a cylindrical vessel, but this is not a bad thing. Cleaning will typically be done by
charging sequential portions of solvent and "boiling out" the vessel (to dissolve residues) and emptying, very similar to pilot plant operations.
"Spherical" reaction vessels are typically the "smaller scale" rbf. Heating can be performed with heating mantles, oil baths, air baths etc and
cooling can be done with a bucket/bowl of ice/dry ice-acetone. Larger reaction flasks usually (advantageously) come with a flange neck for easy
filling, emptying and washing, and a variety of different lids allow for different equipment/ancillary glassware arrangement. Stirring can be magnetic
(especially on small scale) but mechanical stirring is also accomodated. I've done reactions using 20L flange pots before. Transfers are done using
vacuum lines, and phase separations are perfomed in stationary 10L sep funnels. Mixing of the phases is done in the reaction pot. Filtration of solids
is a very manual job requiring the chemist to lift and pour but is good exercise. Approx. 1 kg of material can be processed per batch on this scale
(as a rough indicator)
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Funkerman23
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Right now I am limited in size. if I want to use my mantles 2 liters is the max I can go without buying a new one and a suitable variac. My biggest
concern is if I go with a larger size, it will have to be cylindrical, to be used on a hotplate but if I ever need to put it under a vacuum I dunno
how well that will work and for how long. Long winded dreck was edited out, Dr bob makes a good pint though: a big part of buying this thing is to
make difficult to clean reactions less of a nuisance.
[Edited on 13-2-2014 by Funkerman23]
" the Modern Chemist is inundated with literature"-Unknown
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