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Shingoshi
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A different purpose...
Quote: Originally posted by not_important  | Is your goal to purify the water, or to recover the butane/ammonia?
For simply removing the gas, bubbling air through the water might do the job, use a packed column with counterflow of air and water.
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The system is a completely closed-loop. I'm looking for a way to drop the temperature of the liquid by causing it, or a gas in solution with it, to
boil. I want to know can I use a venturi to produce the vacuum to make a mixture vaporize, instead of using heat as is commonly done in absorption
refrigeration systems.
Shingoshi
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not_important
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Vacuum coiling of water is used industrially, high pressure steam driven venturi devices can freeze water by removing heat through vapour. Check the
vapour pressure vs temperature tables for water.
I think you need to run the maths on the concept, I have doubts it could be run as a closed system, recovering the 2nd substance from the exhaust
water stream is also going to be a problem.
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Shingoshi
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Absorptive Refrigerators are closed systems. So why would it be a problem here, when it's not for the refrigerator? I'm trying to remove the need for
a heat source, and replace it with the injector for creating the vacuum. Why doesn't that make sense?
Shingoshi
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not_important
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Add heat adds no matter to the system, the low boiler is removed in a relatively pure state; it can be cooled and either condensed or absorbed back
into the higher boiling fluid. Using an injector mixes the low boiler with the injector working fluid, there's no simple method of recovering it from
the vapour or injector working fluid. Plus what is the ratio of cooled water to injector exhaust stream?
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Shingoshi
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not_important,
Here's the link to the project in question. I guess anyone else can look at it now too!
http://www.xtremesystems.org/forums/showthread.php?t=229936
What would stop me from stacking two venturis in series? How many venturis would I need to get and maintain the vacuum I need?
Shingoshi
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not_important
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First, are you sure the case you picked will stand the negative pressure? Firgure out how much force will be on it under vacuum.
Second, yes you can stack Venturis in series with the 'downstream' one being larger than the upstream one as it has to handle the full flow of the
upstream.
Beffore going any further, you should analyse the requirements. Don't think about the liquid you will use, you will calculate what it's properties
need to be.
How much heat is being generate, and what is the target temperature. How do you plan to dump the heat; remember that pumps will add heat to the
system, and dry heat exchanges can not cool below ambient temperature.
So you end up with a heat source of X watts that you want to keep at temperature Y while rejecting that heat into a sink of temperature Y. This lets
you calculate the thermal impedance, and the size of the heat sink if you are rejecting heat into the ambient air - heat sink vendors should show you
how to calculate that.
Venturis using liquids will give you no lower vacuum than the vapour pressure of the liquid at its working temperature.
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Shingoshi
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Moving this topic to the correct location...
| Quote: Originally posted by not_important | First, are you sure the case you picked will stand the negative pressure? Firgure out how much force will be on it under vacuum.
This case is nothing more than a miniature clean-room, in which the components will operate. The coolant-loop is completely closed. If there
were any leaks into the cavity of the case, the process would stop. And, if the vacuum system isn't strong enough to boil water, how would it have
enough power to impact the structure of the case?
Second, yes you can stack Venturis in series with the 'downstream' one being larger than the upstream one as it has to handle the full flow of the
upstream.
I almost didn't understand you here. But now I realize by upstream, you mean the pump. And by downstream, you mean the outlet of the injector.
This is precisely how the design is configured
Before going any further, you should analyse the requirements. Don't think about the liquid you will use, you will calculate what it's properties need
to be.
How much heat is being generate, and what is the target temperature. How do you plan to dump the heat; remember that pumps will add heat to the
system, and dry heat exchanges can not cool below ambient temperature.
This system will have a maximum cpu count of 12 in the present configuration. Given 75 Watts per processor, the load will greater than 900
Watts when the cooling system is included. The cooling system will produce some heat. Though I'm not sure yet how much. I intend to simply provide the
largest cooling system to handle any possible load.
So you end up with a heat source of X watts that you want to keep at temperature Y while rejecting that heat into a sink of temperature Y. This lets
you calculate the thermal impedance, and the size of the heat sink if you are rejecting heat into the ambient air - heat sink vendors should show you
how to calculate that.
Venturis using liquids will give you no lower vacuum than the vapour pressure of the liquid at its working temperature.
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I will copy this post to the main thread for this project, as this will end up being off-topic (if not already). I would encourage you or anyone else
to join in the discussion there:
http://www.xtremesystems.org/forums/showthread.php?p=3917399...
Shingoshi
[Edited on 2009.7.21 by Shingoshi]
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darel
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aspirator
I have been using a vacuum pump with an absorbtion train to catch as much of the corrosive fumes from entering pump with some success. But I would
like to use an aspirator because I have to change the oil after 2 disillations of HNO3. I am looking to reuse the water to save money. I have heard of
using bilge pumps. I don't think these will work because there is not a lot of pressure behind them. I am thinking of using an electric pressure
washer and rigging it up in a way so as to have it in a five gallon pail circulating.
I also found this on ebay
http://cgi.ebay.com/Buchi-B-169-Aspirator-Pump_W0QQitemZ3801...
would this be worth investing in?
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entropy51
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darel, $195 will buy an awful lot of H2O where I live, and H2O is not cheap here either.
IMO the pump on ebay might be worth it if (1) it was in excellent condition, and it probably isn't and (2) you do one heckuva lot of vacuum
distillations, or maybe use well water and have to pay for pumping it.
I think the trick with aspirators is to get a good one. Some use much less H2O than others. I have found the more pricey glass aspirators to be much
better than the cheap plastic ones. I don't have to run my glass aspirator with a full open tap to get an excellent vacuum, if the system is
leak-free.
DIY aspirator pumps work very well, but the pump head and flow characteristics have to be matched to those of the aspirator which can require some
trial and error.
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Shingoshi
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I don't know if this actually applies or not...
| Quote: Originally posted by darel | I have been using a vacuum pump with an absorbtion train to catch as much of the corrosive fumes from entering pump with some success. But I would
like to use an aspirator because I have to change the oil after 2 disillations of HNO3. I am looking to reuse the water to save money. I have heard of
using bilge pumps. I don't think these will work because there is not a lot of pressure behind them. I am thinking of using an electric pressure
washer and rigging it up in a way so as to have it in a five gallon pail circulating.
I also found this on ebay
http://cgi.ebay.com/Buchi-B-169-Aspirator-Pump_W0QQitemZ3801...
would this be worth investing in? |
I found this link while searching for something else. Here's the link (Read the part about the collection of oil):
http://www.wondermagnet.com/diamagh2o.html
At least, it should be interesting or intriguing.
Shingoshi
[Edited on 2009.7.21 by Shingoshi]
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darel
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I do have a well that I pump from. Does anyone have any plans for a DIY Aspirator pump.
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uchiacon
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Hey guys, I plan on constructing an aspirator with a water pump I got from a $1 reserve auction for $100, normally sold for $274.
Its a jet waterpump, 460W, 30PSI and able to suck water from 7M down. It pumps 46L/min and has a max head of 35M. Also says its suitable for use in
pools etc.
So I'm just wondering if this will work for an aspirator, is it just right? I'm guessing it should provide quite a crazy vacuum right?
Because there is such a lack of any real instructions on this on the internets, I'm kinda fumbling round in the dark here.
Heres the article I'm going off.
designer-drugs.com/pte/12.162.180.114/dcd/chemistry/equipment/aspirator.html
Can somebody please post any useful information on making an aspirator, I've got no idea of what the smaller pipe ratio should be to the large to make
the vacuum etc.
Cheers.
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JohnWW
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I bought a similar pump at a local auction here for $50 earlier this year. It also has a pressure chamber on its top. I bought it partly for
irrigation purposes, and partly to add extra delivery pressure to a fire-fighting hose.
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uchiacon
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MM so is it too powerful then? I want as much vacuum as water can offer. Planning on distilling nitric.
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Shingoshi
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The one I love...
I found this pump a while ago. I was impressed with it's construction. It's made by a company called Shertech.
I've wanted to use it to drive this injector by Mazzei. The 1585X
Shingoshi
[Edited on 2009.8.17 by Shingoshi]
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darel
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I am looking for an electric pressure washer. I was going to take the motor out of that. yea it's a huge overkill. I haven't found plans but it seems
pretty straight forward.
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Shingoshi
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We think alike!
| Quote: Originally posted by darel | | I am looking for an electric pressure washer. I was going to take the motor out of that. yea it's a huge overkill. I haven't found plans but it seems
pretty straight forward. |
Harbor Freight Tools has some pretty cheap pressure washers. And I thought why not do the same thing as you've suggested here. I may still do that.
Because in my case, I really do need the high pressure.
Shingoshi
[Edited on 2009.8.17 by Shingoshi]
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uchiacon
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Could you post those plans? Any info on making aspirators or anything would be great.
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uchiacon
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I've just been looking through the aspirator threads on the forum, and if anything, it's just made me even more confused. I don't like the idea of
those cheap looking plastic aspirators(I have no idea how they can get away with selling them for $30US), and they probably wouldn't be able to handle
the pressure and flow rate of my pump.
So could anybody just post some pics of their OTC constructed aspirator or something? Don't have the necessary tools(lathe etc) to make it properly,
and I'm pretty sure one could be constructed from OTC brass fittings from a plumbing store. Normally I don't have any trouble making things, but for
the lack of tutorials(and frogfot's site being removed) I'm left high and dry.
I really want to make my white nitric before I'm 15(and various nitrations) and the only thing standing in my way is the obstacle of constructing a
hydroaspirator...
Any help will be appreciated.
Cheers
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watson.fawkes
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| Quote: Originally posted by uchiacon | | So I'm just wondering if this will work for an aspirator, is it just right? I'm guessing it should provide quite a crazy vacuum right?
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"Crazy vacuum"?-no. Regular water aspirators are limited by vapor pressure. There are higher pressure
ejector pumps that run on steam that get down lower than the vapor pressure of their working fluid, but they use very fast exit streams to do it. What
you might get is higher gas pumping rates than an ordinary faucet-tap aspirator. If you want even higher suction rates, build two aspirators and gang
them in sequence, with a common manifold feeding both nozzles.
The only two parts of an aspirator that aren't off the shelf are the penetration of the water pipe into the air flow and the nozzle. You should be
able to build the bulk of the device out of PVC pipe. Drill a hole in an end cap and glue in a pipe section to get your penetration. As for a nozzle,
use a brass end cap and drill a hole in the end. You'll need to use a drill press for that, if you don't want to be breaking drill bits. You'll find
the whole system easier to assemble if you break the air pipe into two sections with a union. Locate the union in a place were the water nozzle sticks
out.
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uchiacon
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Could I look at some pictures of your home made aspirator? I'm a bit unfamiliar with some of the terms you are using.
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watson.fawkes
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| Quote: Originally posted by uchiacon | | Could I look at some pictures of your home made aspirator? I'm a bit unfamiliar with some of the terms you are using. |
I don't have a PVC one myself. Perhaps I should make one as a demo.
If you have questions about vocabulary, just ask.
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uchiacon
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One of these aspirators should definately be able to pump out enough air for vacuum nitric distillation right?
People have been saying the vacuum provided by one of these aspirators should be able to create a 20-30torr vacuum so that the nitric boils below
decomp point.
Seems like a lot of threads here go on huge tangents, or only briefly cover some parts of a process... i.e the nitric acid thread only having about
4-5 posts on the vacuum aspects...
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watson.fawkes
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| Quote: Originally posted by uchiacon | | One of these aspirators should definately be able to pump out enough air for vacuum nitric distillation right? |
How big is the distillation and how big is the pump? | Quote: | | People have been saying the vacuum provided by one of these aspirators should be able to create a 20-30torr vacuum so that the nitric boils below
decomp point. |
Go look up the vapor pressure of water at two ordinary operating temperatures: 40° C
for room temperature, 5° C for ice water. This is the lower limit of pressure for a regular water aspirator.
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uchiacon
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I've got a 1L boiling flask, a 500ml boiling flask as a receiver, a condenser with a 20cm long jacket... and the attachments to make it all fit.
If you have a larger aspirator it's going to suck more air than a smaller one correct? Down to the vapour pressure of water I'd presume?
I'm struggling to see what I'd need to build this aspirator, and I can always get my dad to pay for one off the internet, but if I chose to build one
I would have to do it with my own money. However, My pump is a 46L/min job with 30 PSI, and I'm quite certain the bought aspirator could not take that
much pressure. And the pump might fail too. Without a pressure tank, it is harder to get a higher pressure correct?
Will you have a problem of bumping between 20-30torr? So if you concentrating your nitric will you have to get a magnetic stirrer with your hotplate?
Also... I found this with a google images search for metallic aspirators...
designer-drug.com/pte/12.162.180.114/dcd/chemistry/meth.louisfreeh.html#7.2
Thats got some interesting stuff in it, including a guide to making 70% nitric and some information on an aspirator pump.
Least those meth makers have helped me in some way!
[Edited on 04-07-09 by uchiacon]
[Edited on 04-07-09 by uchiacon]
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