Sciencemadness Discussion Board

condenser pumps

Crucible - 14-6-2009 at 17:58

I'm using a Leibig condenser, and looking for a water pump. I'm not really sure which type would be suitable, and don't want to spend a lot of money on trial and error. I'm sure there must be many types of water circulators used in fish ponds, etc, but haven't a clue which kind I should be looking for. I'll either need it to fit my .25" latex tubing or be able to find an adapter of some sort. Even better if it uses sparkless motors as I work with flammable solvents at times. Any suggestions on what kind of water flow (gallons/min) I should be looking for?

I've considered simply hooking up the sink faucet or garden spigot to the tubing but again haven't any idea about what kind of adapter would be needed.

UnintentionalChaos - 14-6-2009 at 18:08

I use a 120gph sumbergible fountain pump. It cost me about $25 at the hardware store and it came with an adapter so I could connect it directly to 1/4" latex tubing. It is plenty sufficient to cool a 500mm liebig condenser for anything I've come across so far. I just drop it in an insulated icebath and turn it on.

These pumps come with some sort of tubing adapter. If it doesn't have a 1/4" adapter, you can construct a step-down with various barbs from the plumbing department.

On the below suggestion: if they don't have a flow-rate control of some sort, you will blow the rubber tubes off the condenser, should the pump be too strong. Perhaps the only stupid thing I did in organic lab was to turn the water on full blast through a small 19/22 liebig. After a few seconds, the inlet tube blew off and sprayed water everywhere.



[Edited on 6-15-09 by UnintentionalChaos]

1281371269 - 14-6-2009 at 18:11

I would suggest checking on Ebay (as I always do :D)
There will be quite a few old pumps that used to be used for central heating and so on, they will be very heavy duty and should only cost a few £ / $.

Crucible - 14-6-2009 at 19:21

Fountain pump, beautiful! Here I am looking at $85 sump pumps, thinking I only spent $30 on the condenser and am in no mood to pay 3x as much for a pump. Any idea whether a fountain pump is likely to use brushless motor, ie sparkless? If I can't find a sparkless pump, then I suppose I just have to use extra tubing to keep it well away from the apparatus and any potentially flammable fumes.

UnintentionalChaos - 14-6-2009 at 19:36

Quote: Originally posted by Crucible  
Fountain pump, beautiful! Here I am looking at $85 sump pumps, thinking I only spent $30 on the condenser and am in no mood to pay 3x as much for a pump. Any idea whether a fountain pump is likely to use brushless motor, ie sparkless? If I can't find a sparkless pump, then I suppose I just have to use extra tubing to keep it well away from the apparatus and any potentially flammable fumes.


The pump I use sits completely underwater, meaning the motor is encased in plastic. Fumes are of absolutely no concern in this situation, I believe. It is listed as a "wet rotor" type if that helps at all. Also, pumping rate drops the higher the water has to travel and cuts out completely if you try to make it pump too far. My ice bath sits on the benchtop next to the distillation setup. At max, the water travel upward about a foot.

Why spend more than $30 on a condenser? A good sized liebig can be snared off ebay for that much (like mine, for example), which is sufficient for many tasks. $40 is probably a more reasonable spending goal. By a stroke of luck, I have also acquired a excellent reflux condenser for next to nothing.

I am looking at a more powerful pump to drive an aspirator though. Not only should it be able to exceed the capabilities of running tap water in flow rate, I will be able to use ice water (and not run up the water bill).

[Edited on 6-15-09 by UnintentionalChaos]

Magpie - 14-6-2009 at 21:46

You should be able to find a small submersible pond pump locally for around $25. Install a tee at the pump discharge to lower the pressure to the condenser hose, if necessary.

[Edited on 16-6-2009 by Magpie]

submersible pump.bmp - 706kB

kclo4 - 14-6-2009 at 22:31

Quote:
I've considered simply hooking up the sink faucet or garden spigot to the tubing but again haven't any idea about what kind of adapter would be needed.


I shove a 1 hole stopper in my sink and make sure it is on there well, the hole of course fits the tubing which takes it to the condenser.

This was originally just until I found something better, but since I've done that I haven't worried much about it since it seems to work pretty well.

Crucible - 15-6-2009 at 09:06

Ah, I see I missed the key words "fully submerged" the first time. The sump pumps I had been looking at were only partially submersible. It will be rather difficult for a fire to start a foot underwater. This neatly solves both my problems. Thanks!

As for my $30 Leibig condenser. Wilmad labglass is having a sale. Nearly everything is 60% off, so ebay prices on new glassware.

entropy51 - 15-6-2009 at 15:09

Crucible, here's one that looks like mine, for $8.99 :D

http://www.amazon.com/Submersible-Aquarium-Light-Water-Fount...

Mine is Homedics PT-808L 1S

It doesn't produce enough pressure to pump water uphill more than a foot or so, so the bucket with the pump must be on the table with the condenser, not on the floor. To start the water flowing, turn on the pump and raise the bucket containing the pump above the condenser outlet and the outlet hose will fill with water. Once the hoses are filled and the air bubbles are out you can put the bucket down on the table again and the flow will continue. Takes a few times to get the hang of purging all the air, but after that it's quick and painless.

anotheronebitesthedust - 29-6-2009 at 18:04

I use this:
http://cgi.ebay.com/977gph-AQUARIUM-FOUNTAIN-POND-PUMP-Via-A...

Just drop it in a pail with ice and plug it in and you're ready to go.

Although this one is over twice as powerful and twice as expensive:
http://cgi.ebay.com/2219gph-Submersible-or-in-line-Pond-Pump...

querjek - 30-6-2009 at 02:46

I believe I paid $10 for my eBay condenser pump. It was the cheapest at the time and works well with ice--I bought a $4 plastic box from CVS and carved a set of holes through the lid to create a decent recirculating station.

Contrabasso - 30-6-2009 at 12:01

Bilge pumps for small boats will be 12 or 24vDC and will likely be suitable for submerged running. One of the bigger ones should suit driving an aspirator pump!

AlChemicalLife - 10-2-2012 at 19:51

i need help finding a pump for my condenser . im gettign a 200mm and 300mm condensers. i cant find 1 with a flow rate control. please help me this is my kit im getting http://www.ebay.com/itm/New-Organic-Lab-Glassware-Kit-Joint-... please help i need a pump. what should the gph be on it ? if u can find me 1 that would be grate. my price is around 25$.

AlChemicalLife - 10-2-2012 at 20:21

will this pump work for a 200mm and 300mm condensers. please get back asap

AlChemicalLife - 10-2-2012 at 20:22

will this work http://www.northerntool.com/shop/tools/product_200420883_200...

cal - 10-2-2012 at 22:57

Quote: Originally posted by Crucible  
Ah, I see I missed the key words "fully submerged" the first time. The sump pumps I had been looking at were only partially submersible. It will be rather difficult for a fire to start a foot underwater. This neatly solves both my problems. Thanks!

As for my $30 Leibig condenser. Wilmad labglass is having a sale. Nearly everything is 60% off, so ebay prices on new glassware.

Wait till the water bill comes after doing alot of chemistry work. The fountain pump as stated, is used in many college labs for ice baths and so forth.

cal - 10-2-2012 at 23:00

Quote: Originally posted by AlChemicalLife  
will this pump work for a 200mm and 300mm condensers. please get back asap

Flow rate can be controlled with a simple PCV handle on and off from Home Depot. Just turn it till the desired flow is set. Put a t on the pump as shown in the diagram.

Organikum - 11-2-2012 at 00:03

Just use the smallest fountain pump which is rated for 50cm up-pumping. Get a bucket of 15l or more fill it two thirds and depending on your setup place it on the table or on a chair under the table or so. Run the pumping tube to the cold side inlet of the condensor, the lower and fix a tube at the outlet awhich is long enough to go almost to the bottom of the bucket, start the pump and for it will not have the power to push the water through suck on the outlet tube to help. Once the water is through stuck the tube to the bckets bottom and gravity and the closed loop will do what the pump couldnt do. The flow of water may seem tiny but it suffices for about everything. If running a Friedrichs or high-power condensor put the bucket higher, on the table.

The most expensive pump I ever bought was still <10€ in the cheapest Baumarkt and this was one of the few things in my setups which nerver made a real problem.

If you have glass-olives on your condensor then it is a good idea to leave the tubes fixed by cable-straps and instead improvise a tube to tube connector by a piece of glass or hard-plastic tube which does not much restrict the inner diameter. Costs nothing and removing the often baked rubbe/plastic from the olives says sooner or later breaking them.

/ORG

garage chemist - 11-2-2012 at 02:09

I also use a tiny submersible fountain pump for my condensers, with a maximum pumping height of only about 60cm, and I do it like Organikum and fill all the hoses and condenser full of water in order to overcome the lack of pumping height before putting the bucket with the pump on the floor again with the condenser up to 2 meters above the pump.

There's a safety advantage with such a setup: the water in the condenser is under negative pressure, and if one of the hoses comes loose, only air will be drawn into the coolant loop and no water gets out. A big plus if there's an extremely hot oil bath below the condenser!

Hexavalent - 11-2-2012 at 05:14

This works a treat for my 60cm liebig;

http://www.ebay.co.uk/itm/HYDROPONICS-MICRO-JET-MC320Lph-SUB...

smaerd - 11-2-2012 at 08:27

I put my pump into a relatively small rubber-made tub. I drilled two holes in the lid one for the in-let and one for the outlet to prevent dust and things from getting into the water.

AlChemicalLife - 11-2-2012 at 18:50

ok i found this 1 its 70gph - 130gph will it work. http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDi... i think it will. i just dont want to blow the hose off the thing and have water go everywere. i hope it can work. what would be the max GPH i can put through my condenser? if u didnt read the post up top im gettign a 200mm (20cm) and 300mm (30cm) condenser. if u want to know what kit im getting i can post the link.

Hexavalent - 12-2-2012 at 08:13

That seems like it should work. To avoid the hose coming off the condenser barbs, I both use a very tight hose and attach some Jubilee clips to the connections. Works a treat!:)

I once knew somebody who attached a liebig to his outdoor hose, with securing Jubilee clips in place. The force of the water actually bust the water jacket of the condenser!

AlChemicalLife - 12-2-2012 at 22:54

ok another update im also getting 14/20 glass and my condenser is vary small its anoly 10cm (100mm) smaller then my hand. what gph should i get for it.i think it should be around 40 GPH . just wondering i love to have a diferent selection off sizes in the lab so now im going to own a 24/40 and 14/20 kits. thank u for all the help

AlChemicalLife - 16-2-2012 at 20:04

awsome :) getting my kit soon. cant wait.