How to Draw a 5,000 Cubic Meter Vacuum

Tornado, what is this telling you about the vacuum concept?

"If the temperature in a system remains constant (an isothermal system), vapor at saturation pressure and temperature will begin to condense into its liquid phase as the system pressure is increased. Similarly, a liquid at saturation pressure and temperature will tend to flash into its vapor phase as system pressure is decreased" link

To me it says the compressor is removing air and flash vapor = "steam".

What can you hope to condense in the vacuum end due to 'adiabatic' T drop? - zero (unless you additionally refrigerate).

Therefore, in any event, you're going to have to put a condenser and air/water separator on the output of the screw compressor to catch the moisture in extracted air.

What then is the point of a vacuum at the intake?

Vaporize more compressor lubricant?

Add impressive junk?

More stuff to run?

I already agree, but I'm trying to give the OP's concept the best shake possible. If the thermodynamics don't kill it, maybe the economics will. The posts on refrigerated systems made that approach look more attractive, but I didn't see any HP/GPH figures. I don't know much at all about desiccant wheels as a third appoach.

You don't need to know all about desiccant wheels to grasp the concept. A desiccant such as silica or 4A molecular sieves will absorb a great deal of water without a change in ambient pressure or temperature. This saves the considerable energy that must be expended to deal with large volumes of air. The bad news is that once the water has been absorbed, energy must be expended to extract it from the desiccant; however, this is considerably less than the energy required to change the temperature or pressure of large volumes of air.

Hi welderman, I've seen talk of desiccant atmospheric water collectors, but no specifics of how they then recover the water from the desiccant. Is there a 'cheaper way' than 'boiling it off' - (about the same energy as distillation)? Can you crush it out mechanically, or some such?

Not to distract from the above curiosity; ref; "the energy required to change the temperature or pressure of large volumes of air." - Having said the same, and now having considered the harvesting options/processes; I'd like to add;

Which ever way I look at this - when it comes down to what the process/apparatus must be to actually get water in hand - the OP concept ends up utilizing an additional apparatus/method that will work better in 'dense air' (worse in a vacuum) - so the why of the OP approach totally eludes me (twice).

No, it would not be economical to extract the water from the desiccant by crushing it. That would be like destroying a sponge when it gets saturated with water. The beauty of desiccants is that they are reusable, plus they provide a means for not having to pressurize or cool large volumes of air, in order to extract the water. Like a sieve, they have small holes in them that allow only water vapor to enter and condense. Oxygen and nitrogen molecules can not fit into the small holes and are excluded. Desiccant wheels work this way, but usually include an oven section to dry the desiccant after use. I have seen the air in entire buildings (larger than 50m³) dried with the use of desiccant wheels.

It would be nice if someone could offer a silver bullet to solve this problem, but failing that, we may have to rely on physics. In my book, the use of desiccants offers more promise than other methods because of its selective action on water vapor.

Kyzine,

You may be interested in checking out http://www.sciperio.com/watertech/water-from-air.asp. These people are attempting to extract water from air by use of liquid desiccants.

Thanks - thoroughly spooky.

"it is only the latent heat of vaporization for condensed/extracted water that must be managed"

"a heat pump which is used to heat liquid desiccant in the evaporator stage and cool water vapor in the condenser stage"

It's like posts coming back to haunt!

Sorry for dropping off into domestic life for the past few days. As I have stated I am not here to convert the non believers, but rather to look for good innovative ideas. I think that this thread has gone through many good ideas and come around to a consensus that it would be easier for us to place large cisterns around the globe and collect the rain. Though I would love to debate many statements that have been put forth as statements of immutable facts I will invest my time in pushing through the prototype development.

I feel that I do owe some of you a slightly clearer picture as to what we are working on. Our device is much smaller than 5,000 cubic M's. We are working on a scale that a consumer would consider, and at a scale that the military would consider. As for some of the people that have claimed the energy required to run an adiabatic decompression is greater than isothermal compression. Here are some numbers for you to check your math against. Assume ambient air temp 50F, pressure 1000 mb, RH 64%: adiabatic decompression needed to condense 95% of the water in the air mass - drop the pressure by 653 mb; Isothermal compression required to condense 95% of the water in the same air mass it would take an increase of 30,209 mb. Assume the process ends when 95% of the water is condensed and removed, and then the final mixing ratio is .25 gms H2O per Kgm Air. So you need to process a lot of air to get meaningful amounts of water.

If you need water to quench a large group of people that are regularly on the move and with out easily accessible surface water then your options grow limited. You can transport water through logistics and it will cost you between $20-50/gallon per soldier. The passive systems that have been suggested here are great if you are stationary and don't care how long it takes to create the water. We are focused on creating a minimum amount of water in a finite amount of time with only a given amount of energy input and most importantly assuming that the people are constantly on the move.

I don't remember who put forward the idea of orifice design and expansion chambers and centrifugal separation, but here is a very interesting site that will open your eyes. Go to "http://twisterbv.com/products-services/twister-supersonic-separator/how-it-works/".

Thanks again for everyones input. As the new year begins I have a lot on my plate and won't be able to slavishly watch this posting. If anyone has an interesting idea or comment for me and would like quicker response please send me a note directly through the email function of this site. Happy New year to all and I wish everyone great success in their 2010 endeavors.

"I feel that I do owe some of you a slightly clearer picture as to what we are working on"

Oh?

Why didn't you state your actual requirements at the outset?!? Like, the requirement for mobility changes everything. A 5000-cubic-meter-chamber does not - repeat: not - suggest mobility, AE. Does it to you?

You might have had some pretty good ideas waiting on your doorstep right about now if you'd posted the actual problem for which you'd like potential solutions. When you call for a cab, do you tell the driver, "No thanks. I'll walk." No?

Well, you just did.

It's been fun, AE, but I have to now.

You beat me to it, but I was thinking along the same lines. That 5000 m³ thing, with all its necessary structural complexity, was sure a wild-goose chase. I wonder if this thread would constitute a time stamp for any of the ideas in it, such as where priority of invention might lie.

Well, let's hope he comes back when he has less time.

I found it un-surprising.

I found the last comments most illuminating, but not for your reasons (T & Eu)

I'm reminded of Boing v.s. General and wannabees and JSF.

Reinterpret the locations mentioned and think of strategic parallels.

This thinking on 'information' is how this happens;

Okay, I'm open to additional reasons.

Hi Tornado,

If I understand you correctly,..............

Good manners, etiquette, common sense etc is the reasons I had in mind. However the OP lets such thoughts glide straight over his head!

Please forgive me if I misunderstood your question, and wrote erroneously OK?

Take care and good luck.

Hi europium,

I think I have only ever seen one or two posts light that from AE!

What an ass. He just proved if not exactly said that he thinks he knows more than the combined forces of CR4? And what about the original definition? It bore no relation in the slightest to the ideas in his last post!

A total waste of space for sure. Need we vote on this, I hardly think so. As you say, I look forward to seeing a post from him when he has 'LESS' time! ROTFL!

I wonder if he realises how many hours and days have just gone down the drain? The one good thing is: I am not in partnership with this idiot!

Sorry for the sour flavour of this post but it seems you have been left with that sour taste in your mouth, as has Tornado perhaps?

I have talked of peoples arrogance before and been told off for it, but this time it fits the OP to a T!

It is a shame the OP knows nothing of the knowledge in depth of the true Members of this site. An honest description of his ideas rather than the nonsensical 5000 M³, which had most scratching their heads and wondering, would have been a good start?

Take care and have a brilliant new year.PS. I know this is badly written but it is honest!

Would this cover that BB?

Hi Kyzine,

I appreciate your efforts, but...............................

It comes close but, I cannot put into words how angry I am!

The world would be a better please without this kind of person for sure.

So he thinks he knows more than the combined knowledge of the honest and true Members of CR4? I ........... Don't..........Think..........SO!

I sent him the same post as I put on open forum about three or four from the end.

Take care and thanks for the chance of letter of a little steam! And where is my bloody GA? !!! LOL! Only joking on that of course!

BB, do not get so upset it is not good for your health. The AE behavior is the one of an "inventor" we already had some examples with discoverers of the black energy and perpetual movement. There 2 kinds of inventors those who believe they are right but open eyes and ears to comments in order to learn and see if the idea can or cannot be made to work and the second which does not take into consideration any negative comment or even any constructive critical comment. It is not worth of any other comment. Anyway I doubt that the way he works very superficial that he will ever have any success. To use your words : take care and do not get angry and a healthy and happy new year!

Hi nick name,

I really appreciate your very kind and thoughtful post, I thank you sincerely.

I am cooling a little now your kind words and others jokes I think have helped each other to chill, you know?

I agree to some extent with your words on 'Inventors', but Inventors are people, and most people run with the crowd and this should have been the case this time as he came to this great site CR4 to ask for help. No one told him to do so, and even when he was trying to apologise to someone on this thread there was disdain, ignorance and was it seemed to me contemptuous of almost everyone on the site. Others on the site will naturally not like every other Member, but they/I/we give respect to our fellow Members. There was none of that companionship from the OP. As far as I could see or tell he 'helped' no one.

I am chilling as I say but this has hit me hard. There is also about half a dozen others whom have been hit as hard or harder. My wishes are with them. To me it is not 'only a game', he has wasted peoples time and there efforts to try and help were pushed to one side by the deliberately in-correct definition on his first post of the thread. We were working on a dream that was never achievable. Had it been on the perhaps more possible transportable version, it may have been a different outcome?

I am trying to forget this now.

I am sincerely thankful to you for your kindness!

Hi Kyzine,

Thanks for sending that pic of the man shouting at his computer.

On second thought and reading the typed message under it, this would seem to suit me perfectly!

Take care.

bb, my friend

More important than AE having no success with sucking us dry (I still have all the knowledge he might really need), is that you have shown your true spirit and dedication to this forum. The condensation he could have gotten out of this is possibly as negligible as the water he will be able to retrieve economically from this imaginary concept. Although your comments have never "nailed it" they were fertilizer and encouragement for others in many ways and have not only been taken up by the OP but by all of us. I thank you for that.

It has crystallized that there is a military application that is driving all this. That is the disappointing and bitter kernel that upsets me. It is not some newly fashioned way of corresponding with fellow experimenters that can be upsetting (like using a mobile phone in a restaurant), but the trivial results that will be the out come. Nothing will ever come out of this unless information is dealt with in a constructive and less speculative fashion, way. They should put me in charge of their work shop, only then will they get to know how unbearably chaos can hurt and keep hurting, unless a solution to a/the problem is found. Mobile phones are to be left at the reception, no escaping, no mercy. Breathing would be the only automatic action allowed.

Such behavior is to be expected in this hit and run world. Standard procedure really. Compared to the ignorance of some government bodies, which deal with inventions in just the same way and worse, AE has done no "damage", but to him self.

I will still find your dedicated posts in other threads and shall be watching. Painting sheep black is not one of my favorite past times but AE has now a kind of gray tinge. A pity I can't put my 'self pressurizing, double sphere, rotating pneumatic valve' idea here. It would jeopardize other activities/projects that I am concerned with. The truth is out there bb, don't you lose a second of sleep over it.

I hope that this is something Mama-bear would have said in such a situation. You see, I have not even lost one molecule of my humor. Then again, Australians are known for their sheep sheering skills, never mind the tinge of the beast.

Now get a grip on your self and get the gloves up, you lazy bastard, Ky.

Yo, mate!

And right now the RH in Afghanistan is 60% (one of AE's assumptions from somewhere). What's the RH in the next place we go? Excuse the pun, but this VaporWare^TM scheme won't have much added value in monsoon country, for instance. (I dibs that potential trademark, too.)

If AE says we are giving him unusable info, we should track to see if he actually uses any of it.

I'm amused that we haven't heard anything from his silent atmospheric Ph.D. partner...

GA for the portable crack. (yep that too)

I'm outta here. You, too, BB?

Hi europium,

Yes outa hear! I just wrote you a PM and it disappeared as I was editing it! Have you got it by chance?

Take care

Hi AE,

I have seen a couple of posts like your last one, where the writer thinks they are 'to busy' or to important to follow a thread they put a lot of work, and dare I say nonsense down as fact when asking the question.

Your rudeness astounds me! This site does not have "an email function". It has a PM but you will still need to visit the site to read your post.

Tell me why did you lie on your original post in this thread? First you state you want a 17.1 m³ (5000 cubic Metres) now you say you want it to be transportable? The specs for a 'transportable' method would be totally different to your original request.

The 'regular' Members on CR4 do not 'kid' each other, and are up front and honest with each other, even when a Patent is involved. We understand Patents and the consequences of saying something before they are lawful, despite your disdain and insolent ways. You talk as if we have little or no knowledge in this matter or at all?

Your last post showed your ignorance of the knowledge in depth there is on this site, by your rudeness and, by continuing to try and converse with us while you say you are too busy to return and read any posts.

I would be interested in your Patent Number please to allow me, as one of the many whom have tried to suggest ideas to help you achieve your aim.

BTW, have you any idea of the number of Patents which are filed and they do not work so they are not heard of again? I just wondered?

I doubt I will here from you again but perhaps you could work with some fact rather than "assuming" definitions and so "assuming" a design for a machine that will not work.

Tell me 'where on earth' you will find the definitive you mention please, outlined here in bold Italic.

Take care and I hope you are successful, though how you would "develop a prototype" that can be transported I would be interested to see.

----------------------------------------------------------------------------------

Here are some numbers for you to check your math against. Assume ambient air temp 50F, pressure 1000 mb, RH 64%: adiabatic decompression needed to condense 95% of the water in the air mass - drop the pressure by 653 mb; Isothermal compression required to condense 95% of the water in the same air mass it would take an increase of 30,209 mb.

You wrote:

Sorry for dropping off into domestic life for the past few days. As I have stated I am not here to convert the non believers, but rather to look for good innovative ideas. I think that this thread has gone through many good ideas and come around to a consensus that it would be easier for us to place large cisterns around the globe and collect the rain. Though I would love to debate many statements that have been put forth as statements of immutable facts I will invest my time in pushing through the prototype development.

I feel that I do owe some of you a slightly clearer picture as to what we are working on. Our device is much smaller than 5,000 cubic M's. We are working on a scale that a consumer would consider, and at a scale that the military would consider. As for some of the people that have claimed the energy required to run an adiabatic decompression is greater than isothermal compression. Here are some numbers for you to check your math against. Assume ambient air temp 50F, pressure 1000 mb, RH 64%: adiabatic decompression needed to condense 95% of the water in the air mass - drop the pressure by 653 mb; Isothermal compression required to condense 95% of the water in the same air mass it would take an increase of 30,209 mb. Assume the process ends when 95% of the water is condensed and removed, and then the final mixing ratio is .25 gms H2O per Kgm Air. So you need to process a lot of air to get meaningful amounts of water.

If you need water to quench a large group of people that are regularly on the move and with out easily accessible surface water then your options grow limited. You can transport water through logistics and it will cost you between $20-50/gallon per soldier. The passive systems that have been suggested here are great if you are stationary and don't care how long it takes to create the water. We are focused on creating a minimum amount of water in a finite amount of time with only a given amount of energy input and most importantly assuming that the people are constantly on the move.

I don't remember who put forward the idea of orifice design and expansion chambers and centrifugal separation, but here is a very interesting site that will open your eyes. Go to "http://twisterbv.com/products-services/twister-supersonic-separator/how-it-works/".

Thanks again for everyones input. As the new year begins I have a lot on my plate and won't be able to slavishly watch this posting. If anyone has an interesting idea or comment for me and would like quicker response please send me a note directly through the email function of this site. Happy New year to all and I wish everyone great success in their 2010 endeavors.

Not only is this the Silly Season, but also the season of "Leaping to Conclusions". I have not misrepresented myself in writing this post!!!!!!!!!!! I asked if anyone knew how to create a large scale adiabatic decompression. Seems like a pretty provocative question and posting. I asked this question because I am struggling with how to scale up my technology which is currently mobile focused. My question was legitimate and considering all the contributions to the thread it sparked some curiosity among the broader audience. What I was trying to accomplish in my last posting was to let everyone know that I was not some joker with a crazy idea. It seemed like a number of the guru's were overtly hinting that I hadn't any clue as to what I was asking the group. You will also see that many people on the thread have suggested to start SMALL and work up. All I did in my last posting was confirm that I have taken that approach. Many people who make postings keep confidential data secret from their postings. I, like everyone else using this site, want to gain knowledge and insight from a broad audience, but we don't want to create new competitors by oversharing.

The burning question why did I ask for a solution based upon 5,000 cubic meters? There is a reason for that number and I am not looking to create competitors as to why that number is important. I don't see why the large scale is a mystery, it has been clearly stated on many postings that there are scant grams of water held in a killogram of air regardless of the ambient conditions. Anyone looking to create water from air in a short period of time needs to process a lot of air. You either do this via many smaller machines placed in series or create a bigger machine. Why do I need to spell this out? Did I over estimated some of the contributor's abilities to put 2 and 2 together without me spelling everything out. I have found that when dealing with smart people they often get offended if you over explain, so I did not over explain to this audience.

Why is it so unbelievable that I started small. I think that Baby Bear has read way too much into my last posting. All I did was share an additional data point, and hopefully convince some of the participants that there has been a significant amount of scientific and business thought put into this concept. I am sorry if some of the people in this audience are incapable of reading a posting and not leaping to conclusions. I didn't think that I needed to over explain my points.

BABY BEAR, I don't know what to make of you. You are smart, experienced, and clearly well thought of in this community. Wise men seek to understand before they disparage and JUMP to conclusions. I think that you need to cool that trigger finger of yours. I was big enough to apologize earlier when I erred I wonder what you will do?

I did not mean to hurt anyones feelings by saying that I was not going to respond to this posting everyday. I was acknowledging that it seems like most of the contributors had come to a consensus that I was "off in the weeds" and that the task was soooooo insurmountable that it would be like sending someone to the MOON. OH, sorry bad example we did that 40 years ago. I will continue to monitor the posting, but it would be much more helpful if people started off with the premise that it could be done instead of assuming it can't and then working to support that assumption.

Happy New year.

Your scheme is most ingenious. Speak effusively of sharing, pick lots of brains, give back misleading or little information. If you can get the informational check valves all flowing in the right direction, you can be a big winner. Inherit the wind.

Hi ky and all,

For your caring and kind posts

I am writing this to 'all' as I am not able to see to type, for reasons I have explained to most if not all my friends here, so I cannot at the moment type several posts, OK? But my sincerely thanks to you all as I say for your kind posts.

It is amazing what a good strong drink (Coffee!!!) and a good nights sleep can do for one? I am OK, but it does seem our other Member, (take that as you wish!) fails to see or notice oftentimes what he is writing, and how that can effect the people whom were prepared to put their time aside to help him even though he himself seemed to be asking 'for a bet'. (I bet they will not be able to tell you how to accomplish your magic machine?)

But forgetting me for a second. I wonder if AE would, has ever become a business man? The reason I say this is because he seems incapable of having a straight talk with us, who are/were trying to help him, and with his with his last posting, again excluding me from his mentioning, he tried to apologise and yet again ended up insulting us all. Hence my wondering whether he is at all capable of of making friends let alone keeping them through sensible conversation.

I also note there is no Patent application number mentioned.

Take care and good luck to all.

AE is just a lurker, he's been around since 06 without actually becoming part of the community

He took his shot to wind us up & then act butthurt when we didn't appreciate his tactics or motives... Being worried about competition, is understandable but pointless. If he really is dealing with the military, he should be much more concerned about halliburton or rockwell, then the likes of us

doesn't matter the thread took on a life of it's own.

Original Posters are not moderators, no matter what they might think.

AE could explain the seeming contradiction of wanting to pull a vacuum which would cause more water to vaporize, not the opposite?

Hi ky,

I found a part of CR4 where it looks like they explain different rules and laws. I have to try and remember where I saves it now! Will send you the address.

Not sure it is what you need but here is the address:

http://www.globalspec.com/TechLib

Take care

Hi europium,

Are, now I understand the translation of that, thanks! Frustrating to realise we actually pay them to be windbags though?

Hey, this should have been in my previous post, but, what temp is it where you are europium? And does it get very much colder at sundown?

Take care

AE, I am severely tempted to rewrite your original question to reflect what you actually want/need - that the forum might then provide considered and relevant input.

PM me if you would like to avail yourself of this service - for which I (severely) charge.

Hi Kyzine,

I want at least 10%!

Take care

"... and then working to support that assumption."

Well, then, consider this novel idea: Hows about you work on your project and we check in occasionally to see how your assumptions pan out?

Who knows, there might even be a few patents in it for us!

Hi europium,

I thank you for writing that. And I wonder if that will get through to our non friend just how disrespectful he has been to us all?............. Mind you, I doubt it!

Never the less it does put down in black and white just what he was asking us to do, because he was tooooooooooo bloody busy, well big deal, he aint the only one who is busy, but some of us also have some pretty decent manners as well.

The expedient use of a couple of these 'emoticons' may have eased the hurt, which is kind of what they are there for.

IE, or should that be 'AE': to take the edge of a criticism or remark that could be taken wrongly and misconstrued?

Take care

Two words: Remedial Thermodynamics.

Hi europium,

I like what you say but am having trouble saying it, merideil thrembotics? The nearest I can get.

I know with reference to your words remedialsd things, we will need that knowledge to stay warm here as the temp is about -0/-1 °C and we are in for the snow China has just had by the end of the week! BBbbbrrreee.

It is big news in China, I wonder if the same 30 cm (~1 foot) we got here last week was big news in China then? Mmmmm

Take care

"... am having trouble saying it, merideil thrembotics? The nearest I can get."

Don't sweat it, BB. Here's a bottle of J.D. Take it. It won't help your pronunciation much, but after a couple of shots neither will you care (much less notice).

I'm puzzled. How can you be "in for the snow China has just had?" I've always been under the impression that once snow fell, it didn't fall again somewhere else.

Hi europium,

Like your post a lot! And was waiting for someone to pick me up on my 'fact' that China had a foot of snow etc.................. If I could speak Chinese I would give you the answer from their sperspective..............

Whats dat word......... pis/prunenciaation??? Sorry the JD is getting to me and do you know what, I do not give a damn! Oh soõd it Ive dropped the bottle............. Come ere to devil..........

Hey BB: 7893

AE wrote:

"You either do this via many smaller machines placed in series or create a bigger machine."

I suspect you are overlooking an obvious option. Why don't you consider placing many smaller machines in parallel?

welderman you are not alone in that reading WTF!

Hi Kyzine, and welderman,

Can I just echo my agreement here!?

Take care

Possibly, but I just haven't seen any numbers on it yet. I guess the relevant figure of merit might be units of money or energy input divided by units of water output, considering also the temperature of the water. Some of this data is difficult to come by, or even estimate.

I was going with coalescing-element separation rather than centrifuging, but this Twister separator is intriguing. Their example operates at high pressure rather than in partial vacuum, though. But with my user name, I would have to be intrigued, wouldn't I?

If the orifice-chamber-screw compressor idea were to prove useful, it would be scalable to your portable size with virtually off-the-shelf components.