Leben - 13-9-2014 at 06:35
Can anyone suggest a good one that can handle superchilled (-80 degree) solvents? Most of the sites I encountered were in chinese, or featured
superexpensive total coolers/circulators. I am looking for something like an aquarium pump, except one that can pump low temperature solvents.
Something big enough for small-medium sized lab cooling applications.
Seems I will need a magnet pump, but in the US I can only find ones that tolerate 0 degrees up to high temperatures, and none for low temperatures, so
far in the search.
[Edited on 13-9-2014 by Leben]
Dr.Bob - 14-9-2014 at 15:26
I know that someone makes a peristaltic pump that deals with low temps, but not sure of who, just saw demo years ago. They use either silicone or
Chemflex (Gore) tubing. I would goodle low temp peristaltic pump to find more.
ziqquratu - 14-9-2014 at 16:06
You could look in to a centrifugal pump. I think they tend to be reasonably cheap, or can be made yourself fairly easily. Designed right, the motor is
attached to the pump head by a shaft (as long as you need), and the moving parts are very simple (an impeller in a housing) and are as resistant to
the temperature and solvent as the material they're made from.
Just Google "centrifugal pump DIY" (without quotes) and there's a bunch of examples that should give you some ideas!
In my old lab, we had a recirculating chiller that used a stainless steel centrifugal pump, and it was more than capable of pumping ethylene
glycol-water through two rotavap condensers at around -10*C. I also built one myself in an afternoon for stirring a bath of MeOH at about -90*C
(cooled with liquid nitrogen) from a piece of aluminium can for the impeller, the lid of a 50mL centrifuge tube for the housing and a steel shaft and
DC motor for a model car. Worked well enough for my needs, although a lot of tweaking would have been needed to make it a "good" pump!
Leben - 14-9-2014 at 17:31
I'm not too up to date on pump terminology. Magnetic Drive pumps are considered a type of centrifugal pump. Is that what you are referring to? All of
the reasonably priced magnetic drive pumps, that they use for brewing ($150ish) are not self priming, which poses an operational problem, a solveable
one, but manual priming is something I would like to avoid.
I have a good source of temperature resistant silicon tubing, I just need to find a pump that doesn't require manual priming that can handle
temperatures -80 -> 150 degrees.
ziqquratu - 15-9-2014 at 04:11
The pumps I'm referring to are most definitely self priming. The housing has a hole in the top (or bottom) that lets fluid in, and it's primed. The
impeller forces the fluid out another hole in the side.
The search terms I suggested should get you some good examples of homemade ones, which also show how they work, such as:
http://www.instructables.com/id/DIY-Centrifugal-Water-Pump/
https://www.youtube.com/watch?v=nWVZzcvjDfY
https://www.youtube.com/watch?v=AyTSeFKXouw
These are not complicated devices, and assuming you choose suitable materials should be perfectly suited to your purpose. As I said, I have used a
professional one at -10*C 12h a day, 7 days a week for 3-4 years, and used a homemade one at -90*C for hours at a time too.