Sciencemadness Discussion Board

Heating mantle

AlChemicalLife - 17-7-2017 at 16:38

Does anyone have any experience with these heating mantles ? I was thinking on buying this in addition to my hotplate stirrer but wanted to know if this was a good buy or if there is a better company / model .
http://m.ebay.com/itm?itemId=252821869760

~Steven



[Edited on 7-18-2017 by AlChemicalLife]

PirateDocBrown - 17-7-2017 at 18:11

Just ordered one just like that, except 1000mL. I expect delivery any day now. All my mantle experience, both professional and academic, has been with the glass hemispheres. So this is something new.

I notice the same design wears many nameplates, so I assume it's made by one factory, and sold through many distributors.

AlChemicalLife - 17-7-2017 at 19:15

i think im gonna bite the bullet and buy it this pay check and see if its worth it . because my hotplate stirrer doesn't seem to heat well( havent really used it much though ) and i need to stir things while distilling and refluxing, so im really liking that mantle and its cheaper than the other hotplate stirrer by corning i was gonna buy for $150 .
that saves me a few dollars to buy the sohxlet extractor i want and a few other things

Dr.Bob - 18-7-2017 at 06:18

Looks like a decent item, not sure how long it will last. I prefer the simple plain heating only ones, along with a stir plate, as then you can use multiple sizes with only one stir plate. But that requires a separate stir plate and method of controlling the temperature, so this may be a good alternative for home use. Maybe both of you can post a review once you have use them to help others decide.

MrHomeScientist - 18-7-2017 at 07:38

If I want to heat, say, a 100mL flask in that, could I just add in some filler like copper BBs? Or is that a bad idea? Seems like a good deal, but I don't want to be limited to one size flask.

speculation

Sulaiman - 18-7-2017 at 10:44

I have only been using a (diy) heating mantle for a short time, only a little experience,
not 100% certain but I think that most of the heat transfer is infra red radiation,
not as I previously imagined, by conduction.

If you could see in infra red, water is almost deep black, https://www.youtube.com/watch?v=lAM-sLYCoXs
thermal ir is absorbed by the glass and in the first few mm of water.
I have been using my mantle with a small (c5mm) gap between the glass and the mantle for even heating.
If you use a smaller flask it will still heat up in about the same time
as you will have to reduce the power
because instead of being absorbed, the heat/ir now heats up the rest of the mantle,
technically, look at Stefan-Boltzman Law https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
T14 - T24 etc.
where T2 is either the liquid temperature, ot mantle temperature depending upon whether or not the flask is there.
/speculative/

JJay - 18-7-2017 at 11:01

BBs have a steel core, so they would probably interfere with the magnetic stirring, but other than that, I don't see why they couldn't be used to fill empty space in a heating mantle.


Sulaiman - 18-7-2017 at 11:46

except that a few sneaky ones will end up rattling around in your heating mantle :P

BILLBUILDS - 20-7-2017 at 12:47

ive had one that blew the power every time i turned it on. i may have spilt some liquid (solvent or water ) on it the first time i used it but other mantles have always worked after drying out so im not sure. i got a refund when i asked for a reship which pissed me off but trying other types now