Sciencemadness Discussion Board

How to emulate lab taps with home equipment?

weeksie98 - 10-11-2013 at 12:40

Hi,

Of late, I have been investigating the possibility of getting a Buchner flask, funnel and aspirator to use for vacuum filtration. All of the aspirators do, however, require rubber hosing from the tap to the aspirator. Are there any adapters or tricks that will allow me to attach the hose to a normal, and slightly old, kitchen tap, or will I need to get a lab tap fitted?

Thanks!

elementcollector1 - 10-11-2013 at 12:47

Given that the average garden hose does not produce anything more than 10 gallons per minute in practicality, and the average kitchen sink will be significantly less, it is presumably not worth it to try. What would be a better solution is to find an aquarium pump that produces upwards of 90 gallons per minute (usually what an aspirator needs to produce significant vacuum). I've seen some models on Amazon for $30 that do 130 gph.

weeksie98 - 10-11-2013 at 12:57

Thanks much, I'll have a look. So I'd just hook it up to the aspirator somehow, and hey presto?

By gallons per minute, I presume you mean gallons per hour? :D

[Edited on 10-11-2013 by weeksie98]

elementcollector1 - 10-11-2013 at 13:03

Quote: Originally posted by weeksie98  
Thanks much, I'll have a look. So I'd just hook it up to the aspirator somehow, and hey presto?

By gallons per minute, I presume you mean gallons per hour? :D

[Edited on 10-11-2013 by weeksie98]


My mistake, it was gallons per minute. Think 60 GPH, then.
http://www.amazon.com/gp/product/B006K31WLC/ref=ox_sc_act_ti...
Definitely somewhere to start, if the rating is to be trusted.

You would presumably hook it up to the aspirator via some thick PVC tubing, or some other thing that could hold up to the water pressure.

Magpie - 10-11-2013 at 13:10

I kindly suggest that you do a little searching on this forum. This question comes up like clockwork about every 6 months.

Oscilllator - 10-11-2013 at 15:19

I hook my aspirator up to my garden hose. Its perfectly capable of pulling enough vacuum for filtration, and also performed well for a HNO3 distillation.

Metacelsus - 10-11-2013 at 16:51

Relevant thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=8352

Next time, search before posting, either in the forum search engine, or Google.



[Edited on 11-11-2013 by Cheddite Cheese]

The_Davster - 10-11-2013 at 17:04

Quote: Originally posted by Oscilllator  
I hook my aspirator up to my garden hose. Its perfectly capable of pulling enough vacuum for filtration, and also performed well for a HNO3 distillation.


Yup. My ex-lab's sink produced more than enough flow to run an aspirator for filtration and mild-vacuum distillations.

testimento - 10-11-2013 at 17:13

Are you really serious? 90 gallons, like 350 liters per minute? Whoaa, I've seen a ballast pump yielding that numbers, but nowhere like 21 tons per hour for any aspirator.

It's not about the flow rate, but the pressure. For a small ejector, you can easily drive with only few liters a minute to produce 16-32mbar pressures, if the line pressure is high enough, over 4 bars. I've driven a small aspirator with one liter per minute with 12bar high pressure pump.

Filtration doesn't need that much vacuum anyways, it's the high boiling point stuff that requires it. Any hose-ejector can do a buchner filtering.

chemrox - 10-11-2013 at 19:44

I have glass aspirator that works better than the Nalgene one which in turn is superior to any of the metal one I've tried. Since the glass one has no threaded end I had to work around the standard lab fixture. I did this with clear tubing and hose clamps. The tubing bulges a bit but holds under the city water pressure (I forgot what I measured). I get < 10 mm according to the manometers.

MichiganMadScientist - 13-11-2013 at 11:12

If all you need vacuum for is for simple buchner-funnel-filter-flask style vacuum filtration, a simple hand-operated brake-bleeder (usually sold as a $40 kit at a local auto parts store). It will produce more than enough vaccum for filtration using a buchner funnel.

[Edited on 13-11-2013 by MichiganMadScientist]