Odyssèus
Hazard to Self
Posts: 50
Registered: 7-3-2006
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Mechanical stirrer
I am having trouble finding any suppliers of mechanical stirrers. I need one that will fit to a ground glass joint. I dont know what size yet because
I havent bought the flask yet.
I am trying to put together a distillation apperatus, this is what I'm looking at buying:
2-neck RB flask 500ml
500ml heating mantle
RB flask 250ml
200mm Liebig condenser
Vacuum adapter
3 way adapter
Thermometer adapter
0 - 400 C thermometer
Mechanical stirrer
I am leaning towards going with 14/20 joints. I would rather have a 1-neck flask and a heating mantle with a built in magnetic stirrer but I cant find
that either.
This is frustraiting... I'm alredy going to have to order this stuff from 4 different suppliers just to get everything.
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Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
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Mood: Chemistry: the subtle science.
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Since this is a fairly sizeable and longterm investment you are contemplating, I would try to make it as generally useful as possible.
14/20, in my opinion, is pretty small for a general setup. I recommend 19/22 or 24/40 joints. Also, getting a shafted stirrer that will fit down a
14 mm hole might be tough.
I have never really required a mechnical stirrer on a shaft. I use a magnetic stirrer driven by a stirrer-hotplate. I can even use this for stirring
by resting a heating mantle on the hoplate and leaving the hotplate off.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Odyssèus
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Registered: 7-3-2006
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Hmmm, so even if the hotplate is a couple inches away from the stirbar it still works? I wouldve thought the range would be much shorter.
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Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
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Mood: Chemistry: the subtle science.
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Yes. I just made a test using a 1" stir-bar, a 500mL mantle, a 250mL flask, and a Corning PC-320 stirrer-hotplate. The bar was spinning fast (in
air) up to a distance of about 2 inches between the hotplate and the bar. But in practice you don't need it anywhere near that far away.
The single most important condition for a successful synthesis is good mixing - Nicodem
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bio2
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...... if the hotplate is a couple inches away from the stirbar it still works? ........
Yep, except the torque and speed control suffer the farther
away it is.
My 12' stirrer/hotplate will spin a magnet 4-5 inches away
but the torque is pretty useless at that point.
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armo
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Registered: 23-8-2005
Location: Brasil
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Mood: Cool....
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Hi bio2, sometime ago I made a small mechanical stirrer by using the electric motor inside the credit card machines. I found several on a surplus
store. If you find one, you will need just a variable 12 V power supply. Changing volotae changes speed and torque. As they are bilt with a small
reduction gears you have a fair amout of torque.
armo
| Quote: | Originally posted by Odyssèus
I am having trouble finding any suppliers of mechanical stirrers. I need one that will fit to a ground glass joint. I dont know what size yet because
I havent bought the flask yet.
I am trying to put together a distillation apperatus, this is what I'm looking at buying:
2-neck RB flask 500ml
500ml heating mantle
RB flask 250ml
200mm Liebig condenser
Vacuum adapter
3 way adapter
Thermometer adapter
0 - 400 C thermometer
Mechanical stirrer
I am leaning towards going with 14/20 joints. I would rather have a 1-neck flask and a heating mantle with a built in magnetic stirrer but I cant find
that either.
This is frustraiting... I'm alredy going to have to order this stuff from 4 different suppliers just to get everything. |
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