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Ubya
International Hazard
Posts: 1232
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
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18thTimeLucky? i'm from italy and i never use ebay.it, it doesn't show listings from everywhere and most of the times shipping costs are excessive, i
shop from ebay.com (and sometimes from ebay.co.uk), there are more and cheaper listings from china with free shipping (most of the time) so i think
it's better. anyway i bought that pump for about 10$ (i don't remember exactly) and free shipping to italy, so i can recommend to buy that pump from
ebay, shipping time is about 1 month so if you are impatient order it from your technitian, if you don't mind the waiting go for it, i never had any
problems (i bought stuff on ebay from chinese sellers many many times)
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feel free to correct my grammar, or any mistakes i make
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18thTimeLucky
Hazard to Self
Posts: 51
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline
Mood: 0 Kelvin and still won't crystallise from solution
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Thanks for quickly reply Ubya. I will have to keep that in mind when looking at eBay. I don't mind waiting a month - I have plenty of time but not
much money - so if I still can, I will cancel my order with my college science technicians tomorrow and buy a similar water aspirator pump to you
(they are 3x cheaper!).
Yep, I have a chemistry blog!
18thtimelucky.wordpress.com
"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't
clean up after themselves, but you love them anyway" - a dear friend |
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DavidJR
National Hazard
Posts: 908
Registered: 1-1-2018
Location: Scotland
Member Is Offline
Mood: Tired
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Try deschem on aliexpress. I got my aspirator from them along with a lot of glassware. Very fast shipping.
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18thTimeLucky
Hazard to Self
Posts: 51
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline
Mood: 0 Kelvin and still won't crystallise from solution
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I managed to cancel buying the water aspirator pump from the list of equipment I asked them. I wish I could order chemicals through my college, would
be so convenient...
I think I might try deschem then if you recommend them DavidJR.
It seems many people go for a similar 100Psi 12V DC water pump to couple with their water aspirator pump (I am guess this is because Nurd Rage
recommended that design). Ubya, or anybody else, you seem to use a water pump like this, how do you power yours? (Nurd Rage does not mention how he
does in his video) Do you just use a AC/DC 12V phone charger or similar? I have one laying around but it gives out 1.5A and I don't know if this would
be enough if the water pump is 60W, I am not particularly brilliant at electronics.
This is a water pump I am interested in for reference: https://www.ebay.co.uk/itm/Hot-DC-12V-115Psi-High-Pressure-D...
Thanks in advance.
EDIT: Link was not working.
EDIT: A smily emoji keeps ruining my link! I will give a different link.
[Edited on 20-3-2018 by 18thTimeLucky?]
[Edited on 20-3-2018 by 18thTimeLucky?]
Yep, I have a chemistry blog!
18thtimelucky.wordpress.com
"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't
clean up after themselves, but you love them anyway" - a dear friend |
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DavidJR
National Hazard
Posts: 908
Registered: 1-1-2018
Location: Scotland
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Mood: Tired
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That's the exact listing I bought.
P=IV
=> 60W=I * 12V
=> I = 60/12 A
=> I = 5 A
So you'll need a supply capable of at least 5 amps. These pumps will run at lower current but the results will be less than satisfying...
Here's a link to the aspirator from deschem: https://www.aliexpress.com/store/product/Laboratory-Aspirato...
They also have a copper version for a slightly increased price.
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18thTimeLucky
Hazard to Self
Posts: 51
Registered: 19-8-2017
Location: The one-and-only tea and crumpet land (UK)
Member Is Offline
Mood: 0 Kelvin and still won't crystallise from solution
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Thank you, I apoligise for the spoonfeeding, making you do such a simple calculation - I expected it to be way more complicated than that. Thanks for
the link, although deschem's eBay account seems to be selling atleast the stainless steel one cheaper for some reason so I think I will get it from
eBay.
Seems like I now have a shopping list of:
https://www.ebay.com/itm/Stainless-Steel-Aspirator-Pump-Humb...
https://www.ebay.co.uk/itm/Hot-DC-12V-115Psi-High-Pressure-D...
https://www.ebay.co.uk/itm/AC-Converter-Adapter-DC-12V-5A-Im...
Hopefully this will pull a decent vacuum.
Again, thanks for the help Ubya and DavidJR, much appreciated.
Yep, I have a chemistry blog!
18thtimelucky.wordpress.com
"Amateur chemistry does seem like being in a relationship with someone very beautiful and seductive but has expensive taste, farts a lot and doesn't
clean up after themselves, but you love them anyway" - a dear friend |
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Ubya
International Hazard
Posts: 1232
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
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Quote: Originally posted by 18thTimeLucky?  |
It seems many people go for a similar 100Psi 12V DC water pump to couple with their water aspirator pump (I am guess this is because Nurd Rage
recommended that design). Ubya, or anybody else, you seem to use a water pump like this, how do you power yours? (Nurd Rage does not mention how he
does in his video) Do you just use a AC/DC 12V phone charger or similar? I have one laying around but it gives out 1.5A and I don't know if this would
be enough if the water pump is 60W, I am not particularly brilliant at electronics.
This is a water pump I am interested in for reference: https://www.ebay.co.uk/itm/Hot-DC-12V-115Psi-High-Pressure-D... |
i use a 15v 60w laptop charger to power the pump, but soon i want to upgrade it to a 120W 12V LED power supply i found one on ebay for cheap , i could use the extra 60w for other things i might need in my DIY fumehood
[Edited on 21-3-2018 by Ubya]
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feel free to correct my grammar, or any mistakes i make
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NeonPulse
Hazard to Others
Posts: 417
Registered: 29-6-2013
Location: The other end of the internet.
Member Is Offline
Mood: Isolated from Reality! For Real this time....
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Just finished my new vacuum pump yesterday and testing it this morning. It is powerful. Maybe the pressure pump is a bit of overkill but in
combination with the tap I can easily control the pressure delivery. I’m yet to test it with a water distillation to get a gauge of what vacuum it
can attain but I’m sure it will reach the optimum vacuum that the aspirator can reach. I found the small caravan water pumps do work but the
diaphragm shits out after a few hours run time. This pump is also quieter. The pump I have now cost me 30$ second hand and the plumbing fittings all
up cost me 10$ since I had some of them already the aspirator was 15$ from Deschem so it’s well under 100$ to make it and it will prove to be very
useful for some distillations where I don’t want to subject my rotary vane pump to like acidic and solvent laden solutions. The reservoir is
sufficient enough to ass ice bricks and such to keep it cool too.
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Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
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| Quote: Originally posted by NeonPulse | | Maybe the pressure pump is a bit of overkill but in combination with the tap I can easily control the pressure delivery. |
Thats like saying by building a blast wall we are controlling the explosion, you'd be far better off controlling the pumps motor as soon enough the
back pressure is going to affect your mechanical seal, or worse your motor.
But technically i guess you're correct and if works and only see's intermittent use then fine and its looks kind of sculptural with that bend in the
hose...
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wg48
National Hazard
Posts: 821
Registered: 21-11-2015
Member Is Offline
Mood: No Mood
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| Quote: Originally posted by Panache | | Quote: Originally posted by NeonPulse | | Maybe the pressure pump is a bit of overkill but in combination with the tap I can easily control the pressure delivery. |
Thats like saying by building a blast wall we are controlling the explosion, you'd be far better off controlling the pumps motor as soon enough the
back pressure is going to affect your mechanical seal, or worse your motor.
But technically i guess you're correct and if works and only see's intermittent use then fine and its looks kind of sculptural with that bend in the
hose... |
The motor looks like an induction type so it will not be easy to control it.
A bypass would be simpler i.e. put the tap between the output and input.
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Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
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| Quote: Originally posted by wg48 | | Quote: Originally posted by Panache | | Quote: Originally posted by NeonPulse | | Maybe the pressure pump is a bit of overkill but in combination with the tap I can easily control the pressure delivery. |
Thats like saying by building a blast wall we are controlling the explosion, you'd be far better off controlling the pumps motor as soon enough the
back pressure is going to affect your mechanical seal, or worse your motor.
But technically i guess you're correct and if works and only see's intermittent use then fine and its looks kind of sculptural with that bend in the
hose... |
The motor looks like an induction type so it will not be easy to control it.
A bypass would be simpler i.e. put the tap between the output and input.
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i concur, i wasn't really thinking about what i was saying at that point i just wanted to use that blast screen to control the explosion bit.....
[Edited on 13-5-2018 by Panache]
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Sulaiman
International Hazard
Posts: 3555
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
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What is the attraction to re-circulating vacuum pumps ?
So far I have been using a cheap small 12 Vdc motor vacuum pump like this https://www.ebay.co.uk/itm/DC-12V-24V-80Kpa-Micro-Piston-Vac...
for 'vacuum' filtration and reduced pressure distillation.
Admittedly over four years of use/abuse it's performance has dropped a little, but it works just fine.
What is the benefit of a recirculating water pump driven vacuum aspirator ?
Surely the water needs de-gassing and cooling ?
Why is all the extra effort and cost beneficial ?
P.S. I have a dual-stage rotary but it never gets used for chemistry,
mainly due to fear of damaging it.
(and the vacuum would boil most common liquids at room temperature)
CAUTION : Hobby Chemist, not Professional or even Amateur
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XeonTheMGPony
International Hazard
Posts: 1636
Registered: 5-1-2016
Member Is Offline
Mood: No Mood
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| Quote: Originally posted by Sulaiman | So far I have been using a cheap small 12 Vdc motor vacuum pump like this https://www.ebay.co.uk/itm/DC-12V-24V-80Kpa-Micro-Piston-Vac...
for 'vacuum' filtration and reduced pressure distillation.
Admittedly over four years of use/abuse it's performance has dropped a little, but it works just fine.
What is the benefit of a recirculating water pump driven vacuum aspirator ?
Surely the water needs de-gassing and cooling ?
Why is all the extra effort and cost beneficial ?
P.S. I have a dual-stage rotary but it never gets used for chemistry,
mainly due to fear of damaging it.
(and the vacuum would boil most common liquids at room temperature)
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- Allot of places you are charged for the water per gallon, So think about the amount of water needed for a long distillation! It adds up fast.
- Compounds absorbed by the water my render it illegal to discharge down the drain (re circulation nullifies this issue)
- City water pressure can fluctuate heavily unless you have a hydro static booster pump (Most good labs and medical buildings will have this
equipment) House tend not to have these so your vacuum can fluctuate unpredictable.
- Water condition, some places have crap loads of salts dissolved in water (Like my place) that will corrode or plug aspirator, my water will do both,
re circulation eliminates this issue by being able to use distilled, which further offers better predictable vacuum
just a few off the top of my caffeine deprived brain.
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Sulaiman
International Hazard
Posts: 3555
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
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| Quote: Originally posted by XeonTheMGPony | | Quote: Originally posted by Sulaiman | So far I have been using a cheap small 12 Vdc motor vacuum pump like this https://www.ebay.co.uk/itm/DC-12V-24V-80Kpa-Micro-Piston-Vac...
for 'vacuum' filtration and reduced pressure distillation.
Admittedly over four years of use/abuse it's performance has dropped a little, but it works just fine.
What is the benefit of a recirculating water pump driven vacuum aspirator ?
Surely the water needs de-gassing and cooling ?
Why is all the extra effort and cost beneficial ?
P.S. I have a dual-stage rotary but it never gets used for chemistry,
mainly due to fear of damaging it.
(and the vacuum would boil most common liquids at room temperature)
|
- Allot of places you are charged for the water per gallon, So think about the amount of water needed for a long distillation! It adds up fast.
- Compounds absorbed by the water my render it illegal to discharge down the drain (re circulation nullifies this issue)
- City water pressure can fluctuate heavily unless you have a hydro static booster pump (Most good labs and medical buildings will have this
equipment) House tend not to have these so your vacuum can fluctuate unpredictable.
- Water condition, some places have crap loads of salts dissolved in water (Like my place) that will corrode or plug aspirator, my water will do both,
re circulation eliminates this issue by being able to use distilled, which further offers better predictable vacuum
just a few off the top of my caffeine deprived brain. |
Those all seem to be reasons to not use an aspirator ?
CAUTION : Hobby Chemist, not Professional or even Amateur
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XeonTheMGPony
International Hazard
Posts: 1636
Registered: 5-1-2016
Member Is Offline
Mood: No Mood
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No, just to use a self contained system, Aspirators can with stand things that will destroy a rotary van pump, and a cryotrap for a rotary van pump is
allot more costly then a simple aspirator set up.
I've been working on a multistage PELT set up for a cryo trap, trying to figure out some different topolagies and geometries for both vacuum freeze
drying and for vacuum trap. you need -80 to ensure most substances are properly scrubbed from damaging the pump.
The system must be able to run for 24h as well so it is no small task! most use autocascade systems.
So either you invest a couple grand for that, or less then a hundred for aspirator in a self contained system.
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monolithic
Hazard to Others
Posts: 435
Registered: 5-3-2018
Member Is Offline
Mood: No Mood
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| Quote: Originally posted by NeonPulse | | Just finished my new vacuum pump yesterday and testing it this morning. It is powerful. Maybe the pressure pump is a bit of overkill but in
combination with the tap I can easily control the pressure delivery. I’m yet to test it with a water distillation to get a gauge of what vacuum it
can attain but I’m sure it will reach the optimum vacuum that the aspirator can reach. I found the small caravan water pumps do work but the
diaphragm shits out after a few hours run time. This pump is also quieter. The pump I have now cost me 30$ second hand and the plumbing fittings all
up cost me 10$ since I had some of them already the aspirator was 15$ from Deschem so it’s well under 100$ to make it and it will prove to be very
useful for some distillations where I don’t want to subject my rotary vane pump to like acidic and solvent laden solutions. The reservoir is
sufficient enough to ass ice bricks and such to keep it cool too. |
Did you get a chance to test your new recirculating aspirator? How much vacuum did it draw (mm Hg, boiling point of water, etc.)? Also, what are the
specs of your pump?
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Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
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I have a $90 US General vacuum pump from Harbor Freight that I bought several years ago.When I needed it a few days ago it wouldn't run. Today I
pulled off the oil reservoir and the pump head. The reservoir contained a fair amount of black goo, and, what I first thought were metal shavings.
The metal was mercury droplets, a tiny amount. These came in from my manometer. I cleaned the reservoir, reassembled the pump, and added new oil.
Works like a champ now. Just 2 Allen wrenches and an hour of labor is all it took. It pulls 29"Hg vacuum.
The single most important condition for a successful synthesis is good mixing - Nicodem
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monolithic
Hazard to Others
Posts: 435
Registered: 5-3-2018
Member Is Offline
Mood: No Mood
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| Quote: Originally posted by Magpie | | I have a $90 US General vacuum pump from Harbor Freight that I bought several years ago.When I needed it a few days ago it wouldn't run. Today I
pulled off the oil reservoir and the pump head. The reservoir contained a fair amount of black goo, and, what I first thought were metal shavings.
The metal was mercury droplets, a tiny amount. These came in from my manometer. I cleaned the reservoir, reassembled the pump, and added new oil.
Works like a champ now. Just 2 Allen wrenches and an hour of labor is all it took. It pulls 29"Hg vacuum. |
Magpie, I've also looked at the Harbor Freight vacuum pumps because they are cheap and, from what I hear, durable. Have you used it for distilling
flammable solvents -- is it safe?
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Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
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Yes, I have used it often with flammable solvents.
The single most important condition for a successful synthesis is good mixing - Nicodem
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zed
International Hazard
Posts: 2277
Registered: 6-9-2008
Location: Great State of Jefferson, City of Portland
Member Is Offline
Mood: Semi-repentant Sith Lord
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Those 30+ Dollar, U.S. models, have a different type of threaded connector.
You can screw them right onto an outdoor type U.S. faucet, or onto a faucet adapter.
Very convenient, if you have an endless supply of free, or very inexpensive water.
The Deschem aspirator, utilizes hose/tubing fittings, which are more or less universal.
Push the tubing on, tighten the clamp.
A bigger hassle to install, requiring the hook-up of multiple adapters, but more suitable for the portable vacuum unit actually being built here.
I have a hardware incompatibility problem myself. I'm going to tap the entry end of my aspirator pump, and screw in a smaller hose nipple.
The tubing exiting the electric pump, is of too small a diameter to attach directly to the aspirator pump. No fitting, I have tried to date, will
screw directly unto the aspirator without modification.
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