Sciencemadness Discussion Board - Best Lightweight Portable Mini Vacuum Pump ?

Best Lightweight Portable Mini Vacuum Pump ?

LuckyWinner - 2-4-2020 at 08:18

Hello everyone,

I need to vacuum distill an oil with a boiling point of 295 C.
the pump should pull a strong enough vacuum to lower this to 140 C max.

https://www.sigmaaldrich.com/chemistry/solvents/learning-cen...
5.45 mmhg or 7.26 mbar of vacuum is needed, according to this calculator.

my flask has 250ml/500ml of volume.

My prerequisites :

-Relatively quiet
-LIGHTWEIGHT not 12kg,6kg if possible under 2kg max
-vacuum gauge
-Pulls a steady vacuum (not keen on fluctuations)
-Ability to run continuous for several hours
-Chemical resistance
-pumping speed does not matter
-NO WATER ASPIRATOR
-NO chinese fridge AC rotary vane pumps, they break are loud and heavy
-price under 2000 USD

[Edited on 2-4-2020 by LuckyWinner]

[Edited on 2-4-2020 by LuckyWinner]

Sulaiman - 2-4-2020 at 16:39

https://www.youtube.com/watch?v=gGtYlS1ihbE&t=70s

dicyanin - 2-4-2020 at 17:24

Quote: Originally posted by Sulaiman

https://www.youtube.com/watch?v=gGtYlS1ihbE&t=70s

neat, but I doubt it will pull 5mmHg ?

What about this? Yes it's cheap Chinese but it'll do the job.

LuckyWinner - 3-4-2020 at 07:24

Quote: Originally posted by Sulaiman

https://www.youtube.com/watch?v=gGtYlS1ihbE&t=70s

looks good on video but...
i googled some scienmadness threads about these type of pumps and came up with this

http://www.sciencemadness.org/talk/viewthread.php?tid=9782

' Peristaltic pumps are designed for pumping liquids, they suck at vacuum production. Well, they don't suck well enough. '
...

did you successfully reproduce what is seen in the video?

SWIM - 3-4-2020 at 10:06

It his video.
Why would he bother to reproduce it???

It is now time to edit your post so you look like you were paying attention.

LuckyWinner - 3-4-2020 at 11:29

Quote: Originally posted by SWIM

It his video.
Why would he bother to reproduce it???

It is now time to edit your post so you look like you were paying attention.

to check if its valid and actually working as seen in the video for a longer period of time...
and not just for a couple seconds...

obvious...

Lion850 - 3-4-2020 at 13:41

Quote: Originally posted by dicyanin

Quote: Originally posted by Sulaiman

https://www.youtube.com/watch?v=gGtYlS1ihbE&t=70s

neat, but I doubt it will pull 5mmHg ?

What about this? Yes it's cheap Chinese but it'll do the job.

Hi Dicyanin I use a Value vacuum pump, maybe a bigger model than shown in your picture. These are made for air conditioning service personnel. They pull a great vacuum, mine often boils solutions at 45 ambient temp. But they don’t seem to be chemically resistant as mine show signs of internal corrosion after a few months. And the pump side gets very hot when running more than 15 minutes or so.

monolithic - 4-4-2020 at 07:21

Search eBay for PTFE diaphragm pumps and check the spec sheets for your vacuum requirements. It's going to be really hard to find something that fits your needs, period. Chemically resistant means a diaphragm pump and the ones that can pull <5 mm Hg are multi-head models cost $4-6k new. Examples include Labconco 7393000, Welch 1191B series, Buchi V300, Welch 2000 series "high capacity" diaphragm pumps, etc.

It would be far cheaper to just buy a Chinese HVAC pump for $50-100 that can pull <5 mm Hg without any trouble, plus another $10 on oil to flush the pump after use. Use a weaker vacuum source (aspirator) to strip any solvents that might hold your oil and then switch to the HVAC pump to vacuum distill the oil.

BromicAcid - 4-4-2020 at 15:02

Quote: Originally posted by monolithic

Chemically resistant means a diaphragm pump and the ones that can pull <5 mm Hg are multi-head models cost $4-6k new.

We use the Welch rotary vane pumps at work. Pull HCl, phosgene, HBr, amines, everything in the world through them. As long as you change the oil after the fact they hold up for years and years. Unless you put them on a cart though they are certainly not portable - super heavy.

monolithic - 5-4-2020 at 18:07

Quote: Originally posted by BromicAcid

Quote: Originally posted by monolithic

Chemically resistant means a diaphragm pump and the ones that can pull <5 mm Hg are multi-head models cost $4-6k new.

Yes, I have an old Welch-style pump that I've torn down to bare components and rebuilt. They seem practically indestructible as long as you're not trying to vacuum pump HCl fume and then letting the oil sit. Might not be the case with the cheaper HVAC pumps, however. And yes, they are definitely not portable! I think mine is close to 65 pounds.

[Edited on 4-6-2020 by monolithic]