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Db33
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[*] posted on 25-11-2016 at 19:57
aspirator vacuum question



Reduction-in-a-Vacuum-no-notes1.jpg - 616kB


i want to do vacuum distillations, but ive been told a rotary vane type pump wouldnt work because of solvent vapors would corrode and ruin it. So that leaves aspirtator. I dont have a running faucet to connect to so i need to make one myself.

Now my question is, can i just buy something like this? this looks like it would work for vacuum distillations if i keep it stocked with ice cold water, right? or is this not what i need? thanks.
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elementcollector1
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[*] posted on 25-11-2016 at 20:25


Get a vacuum pump, they're probably much cheaper.

https://www.amazon.com/gp/product/B012CFTYX4/ref=oh_aui_deta...

^The one I bought. More than enough for most amateur uses.




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Db33
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[*] posted on 26-11-2016 at 08:04


thats what i wanted, a simply vacuum pump. But wouldnt distilling oils and solvents ruin it? What if i change the oil every distillation? would that keep the pump good enough? Also, should i get a 1/3hp, 1/2hp, or 1hp power vacuum pump?
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Dwarvensilver
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[*] posted on 26-11-2016 at 09:59


NurdRage has a great video on YouTube about aspirator vacuum
https://www.YouTube.com/watch?v=tYLlkTDstmo
check it out it may well answer some of your questions :)

Cheers,




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Db33
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[*] posted on 26-11-2016 at 11:17


Quote: Originally posted by Dwarvensilver  
NurdRage has a great video on YouTube about aspirator vacuum
https://www.YouTube.com/watch?v=tYLlkTDstmo
check it out it may well answer some of your questions :)

Cheers,


ive actually seen that video and really loved it but i didnt understand what the red and black wires did. Do you see the diahpram pump? it has 2 wires, a red and black one. What do i do with those? He never explains. Here is a photo, what do you do with the red and black wires?

mbzdXIt_t42nRxH9EBQI6KQ.jpg - 8kB
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Chlorine
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[*] posted on 26-11-2016 at 14:00


I assume the pump is a DC diaphragm pump, if so that means the red is typically positive and the black is typically negative. Then go to the users manual and acquire the correct voltage to run the pump.
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Db33
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[*] posted on 26-11-2016 at 14:06


it IS a DC diaphragm pump, but what do i connect the wires too? its DC12V
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Chlorine
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[*] posted on 26-11-2016 at 14:15


You can either use a 12V battery, veriac or buy a cheap power supply adapter:
https://www.amazon.com/Adapter-100-240V-Transformers-Switchi...
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Db33
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[*] posted on 26-11-2016 at 14:45


Quote: Originally posted by Chlorine  
You can either use a 12V battery, veriac or buy a cheap power supply adapter:
https://www.amazon.com/Adapter-100-240V-Transformers-Switchi...


that shows connecting red and blue wires but i assume red and black is the same? Thanks i really appreciate thats exactly what i was looking for.

Now my other question, does anyone know a good link for a good place that sells GOOD VACUUM hosing to use for the aspirator and for strong vacuum distillations/filtrations?
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[*] posted on 27-11-2016 at 01:36


Quote: Originally posted by Db33  
Quote: Originally posted by Chlorine  
You can either use a 12V battery, veriac or buy a cheap power supply adapter:
https://www.amazon.com/Adapter-100-240V-Transformers-Switchi...


that shows connecting red and blue wires but i assume red and black is the same? Thanks i really appreciate thats exactly what i was looking for.

Now my other question, does anyone know a good link for a good place that sells GOOD VACUUM hosing to use for the aspirator and for strong vacuum distillations/filtrations?


Red is positive and blue would be negative. Buy a 12v power supply with the same amperage (amps/A) as your pump. Strip the wires of the power supply connector and solder them to the 2 wires from the power supply, that's all. Check out the power supply pic.

You can get the "vacuum" hose at almost any hardware store or Home Depot/Lowes, go to the tubing/hose section and get a reinforced hose like in the picture below.

hose.jpeg - 5kB

[Edited on 27-11-2016 by beerwiz]

power supply.jpeg - 5kB
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Dwarvensilver
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[*] posted on 27-11-2016 at 09:11


Greets,

I agree with beerwiz, with the caveat that it would not hurt to have the power supply a couple hundred mA more than your requirement.

For the reinforced hose you might want to go with might be something like
pvc_suction_hose_2.jpg - 47kB

https://www.amazon.com/HydroMaxx%C2%AE-Flexible-Suction-Disc...

The reinforced hose as beerwiz has pictured above, (speaking from experience) will work but may collapse with vacuum for a longer period or if your temperature is elevated as this type of reinforcement is for pressure inside to the out and as it gets warm it may collapse. The ribs in the hose pictured here are meant for pressure outside to inside support to prevent collapse up to the rating of the hose.

Cheers,

Dwarvin




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Db33
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[*] posted on 27-11-2016 at 09:53



sku_119375_1.jpg - 27kB


thats the pump i got, can anyone show me a link to where i can buy the correct ampage power supply your talking about? it says DC 12V 60W, i thought all i needed for this was something what the guy poster above, but if anyone has a link to something better please let me know.

i also dont know how to solder so i was hoping i could just get some kind of adapter where i put the red and black plugs in but really any info would help.

[Edited on 27-11-2016 by Db33]


this is an old dell laptop adapter i have, if i stripped this and connected the wires would this work??





[Edited on 27-11-2016 by Db33]
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[*] posted on 27-11-2016 at 10:07


When I bought one of these for an aspirator a while back, I rigged a laptop battery charger to power it. Provides 12V at 5A (60W, just as needed), so it works out great.

Unfortunately, the pump itself was too weak to sustain a good vacuum when hooked up to the aspirator. You're going to want something like a pump rated for 400 GPH, because the faster the water goes through the pump, the more chance you'll have of drawing a vacuum.




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Db33
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[*] posted on 27-11-2016 at 10:23


Quote: Originally posted by elementcollector1  
When I bought one of these for an aspirator a while back, I rigged a laptop battery charger to power it. Provides 12V at 5A (60W, just as needed), so it works out great.

Unfortunately, the pump itself was too weak to sustain a good vacuum when hooked up to the aspirator. You're going to want something like a pump rated for 400 GPH, because the faster the water goes through the pump, the more chance you'll have of drawing a vacuum.


any link to something u would recommend? this is so complicated maybe i should just a vacuum pump and just change the oil every time, then i wouldnt have to worry about this. but yeah, i already bought the aspirator and now i dunno what to do.
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[*] posted on 29-11-2016 at 12:11


That adapter is no good! You need one that is 12V x 5A (amps). You can twist the wires together and cover them with black electrical tape instead of soldering but the connection will be flimsier.
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[*] posted on 29-11-2016 at 13:07


Quote: Originally posted by beerwiz  
That adapter is no good! You need one that is 12V x 5A (amps). You can twist the wires together and cover them with black electrical tape instead of soldering but the connection will be flimsier.


what does 5A mean, and how do i know thats what the diaphragm requires?


http://www.ebay.com/itm/12V-5A-60W-AC-to-DC-Adapter-Power-Supply-for-5050-Flexible-LED-Light-Strip-3528-/371241294072?hash=item566fb498f8:g:vPQAAOSw2s 1UwKpI

this one says its 60W and 5A , the diaphragm says its also 60W so is this the correct adapter? and i just strip the wire and connect the black and red wires and then use electrical tape?

[Edited on 29-11-2016 by Db33]
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[*] posted on 29-11-2016 at 17:17


Watts = Volts Times Amps

Think of the volts like water pressure, and amps is like the flow! You need the pressure to push the volume through the device.

12V * 5A = 60W, Good design is all ways going to an adapter that can supply more, ie you need 5A aim for a 7Amp adapter n such.
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[*] posted on 29-11-2016 at 20:20


I have seen the Savant Gel Pump recommended on this site also.

It is an oil-less, Teflon coated pump designed to handle acid vapors. They show up on eBay for $100-150 with shipping. They pull 7mm, which is better than the ~30mm of an aspirator, and have a pump rate of about 1.4 CFM.




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Db33
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[*] posted on 29-11-2016 at 20:49


Quote: Originally posted by careysub  
I have seen the Savant Gel Pump recommended on this site also.

It is an oil-less, Teflon coated pump designed to handle acid vapors. They show up on eBay for $100-150 with shipping. They pull 7mm, which is better than the ~30mm of an aspirator, and have a pump rate of about 1.4 CFM.


you got a link? also what is a good CFM for a vacuum pump? alot of pumps ive seen have between 3-7 what is the best?
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[*] posted on 29-11-2016 at 22:35


Actually you can use dell's adapter, but put 12V (car taillight ~20W) light bulb in series, this will ghetto step-down the voltage. It will also lower wattage a bit, to around 45W.
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[*] posted on 30-11-2016 at 07:00


Quote: Originally posted by Db33  
Quote: Originally posted by careysub  
I have seen the Savant Gel Pump recommended on this site also.

It is an oil-less, Teflon coated pump designed to handle acid vapors. They show up on eBay for $100-150 with shipping. They pull 7mm, which is better than the ~30mm of an aspirator, and have a pump rate of about 1.4 CFM.


you got a link? also what is a good CFM for a vacuum pump? alot of pumps ive seen have between 3-7 what is the best?


Best volume depends on how much of a wet substance you want to boil with the vacuum alone! to fast and you freeze it to little you wait for ever. For most lab scale things 2L pump is plenty, my little pos 1.2L one does every thing I need it to do.

For the vacuum desiccation/drier system I am building I will aim for a 6Lpm pump as the faster pull down will be required

So what is best? That depends on you! if it doesn't matter just get the most common one at the cheapest quality price.

EDIT: If there are any HVAC/ refrigeration repair places near you, Ask if they have an old fridge compressor or buy one from them that still works.

Fill it with a quality mineral oil for an air compressor, On the outlet bend the pipe down into a can packed with Stainless steel scrubbies (Oil trap)

This will make a fairly good vacuum pump for most purposes most will do apx 25Inches of mercury no prob and are fairly quiet, you will need some sort of chem trap and a cold trap to protect it, but the same is true for any vacuum pump other then a diaphragm type or aspirator

[Edited on 30-11-2016 by XeonTheMGPony]
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[*] posted on 30-11-2016 at 17:30


A decent car battery charger should be an adequate power supply. A five to ten dollar, garage sale item. Most of mine, have two settings. 2 Amps or 6 Amps, at 12 volts. Now, this is a mite puny, for actually starting a car directly...But, it should be plenty for powering the small motor on that water pump. Love you very long time.


Next....Learn how to solder. Solder those leads to longer wires. Then slid shrink tubing over your soldered wires, and shrink it. Then, seal over that tubing , to make it water-proof. Rosin core solder, and a cheapo soldering gun, will work fine for small jobs.

http://www.harborfreight.com/180-watt-industrial-soldering-g...

Looks like this model comes with solder and flux. Surprisingly, sometimes these dirt cheap units work well and last a long time.

[Edited on 1-12-2016 by zed]
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Db33
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[*] posted on 30-11-2016 at 19:00


i think im just gonna say fuck all this and just get a regular vacuum pump and just change the oil after every vacuum distillation. Its too much work trying to find the right adapters and make an aspirator unit. I just want a vacuum i can switch on and off and let it go. Now i just have to decide on whether to get a single or double stage pump, and figure out what CFM is best, 3, 3.5, or the higher 5-7 yellow jackets.
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[*] posted on 30-11-2016 at 19:20


A typical aspirator pulls 0.4 CFM (11 L/min), and its max vacuum is about 10mm with ice cold water.*

Virtually any mechanical vacuum pump will beat it handily in both capacity and max vacuum.

*Water's vapor pressure is 4.65mm at 0 C, but the water goes through the pump, gets squeezed through a nozzle, and it is in the throat where it mixes with air where the temperature matters and it will be significantly warmer than in the tank.




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[*] posted on 30-11-2016 at 20:07


Quote: Originally posted by Db33  
i think im just gonna say fuck all this and just get a regular vacuum pump and just change the oil after every vacuum distillation. Its too much work trying to find the right adapters and make an aspirator unit. I just want a vacuum i can switch on and off and let it go. Now i just have to decide on whether to get a single or double stage pump, and figure out what CFM is best, 3, 3.5, or the higher 5-7 yellow jackets.


Depending on what your doing that simply will not help it.

Go with a single stage at 3cfm, cheapest to replace and more then enough.

Make sure to buy a cold trap and allot of air duster! (Fill a thermose with the air duster liquid and put the cold trap in it!)

To start with use a fridge compressor, as it will be free to stupid cheap, and you'll learn how fast you'll cook it from fumes.

[Edited on 1-12-2016 by XeonTheMGPony]
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