Sciencemadness Discussion Board

Air mattress pump for vacuum filtration?

NiK - 18-11-2013 at 10:33

Been starting off with some super basic experiments that demonstrate simple concepts like differential solubility (sand and sugar)...anyways the filtering is not working out for me at all. I have an air mattress pump that I could probably use as a vacuum pump; does anyone know if this would be an appropriate pump for that purpose, i.e., if it's too strong or weak? Assuming I could get it properly set up with an air-tight apparatus.

Thanks!

DraconicAcid - 18-11-2013 at 10:34

Try it and let us know!

BobD1001 - 18-11-2013 at 12:52

I think it should work. Give it a try, with some pictures of your setup and post your results.

subsecret - 20-11-2013 at 18:34

I, personally, think it'll be too weak to complete the filtration. Give it a shot!!

A water aspirator is the best way to go IMO, based on functionality and price. I got mine for about 20 USD.

bfesser - 20-11-2013 at 18:52

Those pumps are glorified fans in tubes&mdash;in effect, a shitty <a href="http://en.wikipedia.org/wiki/Gas_compressor#Axial-flow_compressors" target="_blank">axial-flow compressor</a> <img src="../scipics/_wiki.png" />. Operated in reverse, it <em>will</em> reduce the pressure in a container, but I doubt you'll achieve a significant vacuum with only a single stage. At near atmospheric pressures, I don't think the principles employed in a <a href="http://en.wikipedia.org/wiki/Turbomolecular_pump" target="_blank">turbomolecular pump</a> <img src="../scipics/_wiki.png" /> (chiefly momentum transfer) apply. As <strong>Awesomeness</strong> pointed out, a water aspirator would be simpler; possibly cheaper.

[edit] Unless I'm mistaken, a <a href="http://en.wikipedia.org/wiki/Mechanical_fan" target="_blank">fan</a> <img src="../scipics/_wiki.png" /> operates by <a href="http://en.wikipedia.org/wiki/Bernoulli's_principle" target="_blank">Bernoulli's principle</a> <img src="../scipics/_wiki.png" />, with <a href="http://en.wikipedia.org/wiki/Airfoil" target="_blank">airfoils</a> <img src="../scipics/_wiki.png" /> rotating around a central shaft to achieve axial flow.

[2nd edit] After a quick Google image search for "mattress pump," I see mostly <a href="http://en.wikipedia.org/wiki/Centrifugal_pump" target="_blank">centrifugal</a> <img src="../scipics/_wiki.png" /> and manual <a href="http://en.wikipedia.org/wiki/Piston_pump" target="_blank">piston pumps</a> <img src="../scipics/_wiki.png" />. Go figure. After spending the time to write this...

[Edited on 21.11.13 by bfesser]

NiK - 22-11-2013 at 18:28

Well guys, I gave it a shot and it seems to work alright; of course, I have yet to try it with sediment to filter out but there was a significant increase in just filtering water haha.

Here is a 15 second video of it:

Attachment: IMG_2639.MOV (1.5MB)
This file has been downloaded 660 times


NiK - 22-11-2013 at 18:39

Hmm, looks like you have to download it...well I promise it's not a virus so if you're so inclined to watch it then go for it; otherwise, here is a picture of my set up.

The tube came from here

The flask came from here

The funnel from here

And finally, the stopper from here and used a drill for the hole (had wrong size bit so the hole is sloppy, but it's also a little small which gives me a seal when I squeeze the funnel in.

As you can see, it's a pretty cheap set up except for the mattress pump which I have for my inflatable mattress; of course, the source of vacuum is the expensive part anyways but I hope this is at least interesting/helpful to someone!




FilterFlask.png - 1.1MB

bfesser - 23-11-2013 at 16:17

I look forward to hearing how this works when the paper is loaded with solids. Glad to see a pen and notebook, though! Keep up the good work, and <em>welcome to ScienceMadness!</em> :)

NiK - 25-11-2013 at 07:23

Quote: Originally posted by bfesser  
I look forward to hearing how this works when the paper is loaded with solids. Glad to see a pen and notebook, though! Keep up the good work, and <em>welcome to ScienceMadness!</em> :)


It actually does make a little bit of a difference! I'm not sure what difference a legitimate one would make (I'm sure it's much better) but this definitely spend up the processes of filtering my CuCl2 solution.

However, it's very loud and can only run for 5-8 minutes at a time because it gets very hot. I haven't reached the point where it makes any weird noises or starts to smoke or anything but I was hot to the touch after about 5-8...

Any good ideas on how I could have a little home-use water aspirator? Do they make some type of thing that hooks up to your kitchen sink? Haha..maybe I should start a new thread for that.

bfesser - 25-11-2013 at 08:51

Oh, no need to start a new thread on that topic! It's been discussed <em>ad nauseam</em>. Try out the search function, or try searching Google with "site:sciencemadness.org" at the end of your search terms. In the mean time, I'll see if I can dig up a couple useful topics/links for you. One of the easiest ways to go about it, if you're not familiar with plumbing, is to take your vacuum aspirator along with the aerator off your faucet to a hardware store and ask for advice. Be warned, though. If they try to sell you more than two parts, they either have no clue or are just trying to rip you off&mdash;I've never encountered an aspirator/faucet pair that couldn't be matched with two fittings or less. Of course, there's always the option of two hose barbs, a piece of flexible tubing (thin-wall latex tubing is inadvisable as it inflates like a balloon), and a couple of hose clamps.

P.S. Filtering a CuCl<sub>2</sub> solution? If you're filtering to clarify the solution, use gravity filtration. Vacuum filtration is typically reserved for isolating solids.