Dean Kamen's Water Purifier

[Olowkow]

Just saw Dean Kamen (inventor of the Segway) on the Colbert Report demonstrating his water purifier. He claims that it will remove "any impurities" from water and produce 1000 liters per day of "distilled" water.

http://www.treehugger.com/files/2006...kamen_sequ.php

There are many references to this on the web, incuding apparently a claim that he can use a stirling engine, using cow dung as fuel, that would generate power for the device. He has a patent according to wiki:
http://en.wikipedia.org/wiki/Dean_Kamen

The patent mentions a "vapor compression distillation unit". I am wondering how one patents a distillation device, and how it could be powered efficiently with a stirling engine. The demo unit was running producing cold water in quite copius amounts, no steam was visible. Colbert dumped a whole bag of his favorite corn chips into the supply tank.

Anyone have the low down on this device?

[Graham Jackman]

Originally Posted by Olowkow

Just saw Dean Kamen (inventor of the Segway) on the Colbert Report demonstrating his water purifier. He claims that it will remove "any impurities" from water and produce 1000 liters per day of "distilled" water.

http://www.treehugger.com/files/2006...kamen_sequ.php

There are many references to this on the web, incuding apparently a claim that he can use a stirling engine, using cow dung as fuel, that would generate power for the device. He has a patent according to wiki:
http://en.wikipedia.org/wiki/Dean_Kamen

The patent mentions a "vapor compression distillation unit". I am wondering how one patents a distillation device, and how it could be powered efficiently with a stirling engine. The demo unit was running producing cold water in quite copius amounts, no steam was visible. Colbert dumped a whole bag of his favorite corn chips into the supply tank.

Anyone have the low down on this device?

I would have thought that any device that uses a form of distillation, is up against the latent heat of vaporisation of water. Certainly, a typical still working at atmospheric pressure would require kilowatts to produce 100 l/day. There would also be the problem of removing suspended solids, which would eventually clog the device. It would seem more sensible to have a simple filter followed by UV irradiation to destroy organic contaminants. if inorganic contaminants are a problem then maybe include an ion-exchange unit.

[Olowkow]

Originally Posted by Graham Jackman

I would have thought that any device that uses a form of distillation, is up against the latent heat of vaporisation of water. Certainly, a typical still working at atmospheric pressure would require kilowatts to produce 100 l/day.

I would certainly think so, but there was no mention of how much power it required, or any detail on its workings, just claims of saving the world and almost a "magical" process of water purification. That's why my radar went up. Of course, Colbert didn't ask the right questions.

[davefoc]

I saw the story on the Colbert Report also.

I thought there would be technical details on the web about it, but I didn't find anything except for some short summaries of what is claimed.

[e-sabbath]

Kamen does have a background as an inventor. He has pushed out usable product before. His claims were wildly exaggerated, but only socially, not technologically. (Eg, the Segway does what it does, just not world transformingly)
The Stirling engine could be used to purify water as it produces energy: eg, the steam produced would be purified. It's real efficient, and very reliable. Kamen has experience in compressed air devices, which are related, as well as a history of messing with steam.

Probably, it'll work. I can imagine, given the named parts, it will be cheap. (There is a patent) I dunno how effective or useful it'll be.

[EGarrett]

Originally Posted by e-sabbath

Kamen does have a background as an inventor. He has pushed out usable product before. His claims were wildly exaggerated, but only socially, not technologically. (Eg, the Segway does what it does, just not world transformingly)
The Stirling engine could be used to purify water as it produces energy: eg, the steam produced would be purified. It's real efficient, and very reliable. Kamen has experience in compressed air devices, which are related, as well as a history of messing with steam.

Probably, it'll work. I can imagine, given the named parts, it will be cheap. (There is a patent) I dunno how effective or useful it'll be.

Absolutely. Kamen seems to be dead-on when he says what his machines CAN do...but not so much with what they WILL do for society.

[Graham Jackman]

Originally Posted by e-sabbath

Kamen does have a background as an inventor. He has pushed out usable product before. His claims were wildly exaggerated, but only socially, not technologically. (Eg, the Segway does what it does, just not world transformingly)
The Stirling engine could be used to purify water as it produces energy: eg, the steam produced would be purified. It's real efficient, and very reliable. Kamen has experience in compressed air devices, which are related, as well as a history of messing with steam.

Probably, it'll work. I can imagine, given the named parts, it will be cheap. (There is a patent) I dunno how effective or useful it'll be.

You still need to find energy to produce steam. of course you can usefully recover some of that by a final stage condensation cycle, which is what made steam engines practical. I just suspect that in that case, the production of water is a minor aspect of the energy production.

[casebro]

Vacuum distillation perhaps? And/or freeze drying.

Results would be instant crystals of crud.

Stirlings made mechanical energy, good for making vacuum. Not heat energy for making steam.

[DRBUZZ0]

Ah yes, the Segway. An amazing amount of engineering to produce a scooter that you can stand up on and only has two wheels. Both of these had been possible before, but never at the same time. Now we have a scooter that is both stand-up and two-wheeled.

And the world is basically the same. Who woulda thunk?

[Dr Adequate]

I was recently impressed by this.

A bottle, a pump, and a really really fine filter. What could be simpler.

Unfortunately, the filter eventually needs replacing, so you can't just give one to everyone in the Third World and say "there, problem solved". However, it should work as intended in disaster areas, and the military interest should bring about a gratifying reduction in the price.

[Graham Jackman]

Originally Posted by casebro

Vacuum distillation perhaps? And/or freeze drying.

Results would be instant crystals of crud.

Stirlings made mechanical energy, good for making vacuum. Not heat energy for making steam.

Unless you provide the heat of vaporisation, both vacuum distillation and freeze drying only benefit from a reduction in atmospheric pressure - for which you have to provide the energy. One reason freeze drying works is that the heat of vaporisation comes from the sample being dried, which keeps it frozen (if you maintain a good enough vacuum!). Without heat, both processes tend to be slow.

[robinson]

His device recycles the heat used to distill water, making it very efficient.

[Graham Jackman]

Originally Posted by robinson

His device recycles the heat used to distill water, making it very efficient.

I can see that helping to some extent but without some form of heat pump, I still think it's going to be energy intensive

[robinson]

I saw the Colbert report last night that had him as a guest. This thing is pretty amazing. On house current it can make a thousand liters a day of pure distilled water. From almost any source.

I don't know what the amperage is, but that is damn impressive. His statistics about water and health worldwide were sobering. If true, and they probably are, using these devices would be the most efficient way to improve the health of people on the planet.

Us being rich spoiled people, with fresh water always there, it is hard to imagine 1.2 billion people sick and thirsty, every day. Because they have dirty water. And not much of it.

[robinson]

He also made the point about how much energy it takes to bottle and transport all those 5 gallon jugs of water to offices and homes every day. One of these nifty distillers would be far cheaper to have onsight, and you have guaranteed quality. Of course he didn't say how much it will cost, but considering how much people spend on bottled water, unless the thing was over the top expensive, it would be a bargain.

[kallsop]

I met Dean a couple of weekends ago at the FIRST Robotics competition in Hartford, CT. My daughters team made it to the finals and finished second, not too shabby. Dean is the real deal and made his fortune in medical autosyringe and insulin pumps. You should find and watch a video of his iBOT wheelchair going up flights of stairs, it's really incredible.

Don't know much about this water thingy but if Dean says it works, it works. He's not a flimflam scammer.

[robinson]

I agree. I see them Segways everywhere now. They have changed foot patrols forever.

[Graham Jackman]

Originally Posted by robinson

I saw the Colbert report last night that had him as a guest. This thing is pretty amazing. On house current it can make a thousand liters a day of pure distilled water. From almost any source.

I don't know what the amperage is, but that is damn impressive. His statistics about water and health worldwide were sobering. If true, and they probably are, using these devices would be the most efficient way to improve the health of people on the planet.

Us being rich spoiled people, with fresh water always there, it is hard to imagine 1.2 billion people sick and thirsty, every day. Because they have dirty water. And not much of it.

Sadly, those people with no water tend not to have electric power either. How about a pedal powered version? Similarly, those people who can afford bottled water usually have a ready mains water supply that is as good, if not better, than bottled water.

[robinson]

I imagine it can be run in solar power. A device like this would be a life saver in disaster/crisis situations, (thinking Katrina type), Especially if it could use a solar panel to work, or bicycle power, something.

Not having fresh water can kill you in a matter of days, depending on the temperature.

The bottled water thing is so bizarre. This huge infrastructure to get drinkable water to people, and they reject it as drinking water because it has fluoride and chlorine in it. (and other stuff). Because it taste bad.

Or something. Now I understand that, because I drink distilled water if I can. But buying water in little bottles is insane. Even 5 gallon bottles is a pain. Running your own distiller costs less, but it takes forever. Like 8 hours for a gallon.

Anything that uses house current and can make a 1000 liters a day of distilled water has my vote. I wonder how much it costs.

[roger]

This device was covered in more detail in a broadcast of the show Iconoclasts, which airs on the sundance channel. I wasn't paying strict attention to the science-y parts, though.

[Skeptic Ginger]

Here's the article the treehugger blog got the story from. It has a few more details and a diagram.

Segway Creator Unveils His Next Act

[Skeptic Ginger]

And from someone's post on the sciforum's discussion of the device,

Vapor-compression evaporation^WP is the mechanism involved and is explained in this Wiki entry.

Post #2 on that forum has a detailed diagram that describes the process.

[Skeptic Ginger]

Kamen discusses it further in this interview, though the interview is not just about the purifier.

Quote:

[Question] On that note, one of your current projects is using a small Stirling engine to produce electricity and purify water. Engineers have long been mesmerized by the Stirling's theoretical efficiency, but frustrated by their failure to realize that efficiency while managing issues of size, control, and cost. What are DEKA's plans for the Stirling?

[Answer] I have had a life-long fascination with Stirling engines and with thermodynamics generally. But as you say, the Stirling has been fascinating scientists and engineers for well over 100 years, yet it has never been a competitive solution to most problems versus other kinds of heat engines out there, like steam engines, internal combustion engines, and gas turbines. Stirling engines are big relative to their energy density, expensive, hard to manufacture, etc. In short, they cannot compete with the power generators that are already a part of the infrastructure in the U.S. and other industrialized countries. However, there are a lot of places in the developing world that are waiting, and will continue to wait, for a top-down approach to provide power. But there is no infrastructure in place, and it will probably take 20 years, 30 years, 50 years, or longer before centralized power and electricity will be available in these places--if it ever happens--for reasons that have nothing to do with engineering or technology. The obstacles are social, financial, and political, but they are not technological. Our goal is to use a bottom-up approach to instantly get people on to the ladder of technology, beginning with getting them electricity in their homes and villages. This enables them to take care of their basic needs, attain a better quality of life, and start creating wealth. We defined the problem: they need a generator that runs on any fuel, is very reliable and essentially maintenance free, is able to generate sufficient power for a small village, and is small enough so that a couple of people can carry it around. If we had an engine that could do all that, it would be a big deal. We realized that in developing world environments, the Stirling, despite a number of problems that had to be solved with it, could really be the core of a bottom-up way to build distributed point-of-use power generation throughout the world. It was as much an insight into the practical realities of the situation as it was about the second law of thermodynamics....

What generally comes first, the solution or the problem? That is, do you typically start with a solution and then try to find a problem, or start with a problem and then try to find a solution?

The answer is "yes." We are surrounded by important problems that need solving. For example, we live in a world that continues to sink into this "have and have not" dilemma. The environment is under assault in a variety of ways. More than a billion people are without access to electricity or drinkable water. You mix your judgment and experience and imagination with awareness of these types of problems, and you get a kind of serendipitous soup from which problems are matched to solutions. This does not occur in a linear way, where you say, "aha, here is the problem...aha, here is the solution." You start with a vague understanding of a problem and a vague understanding of a technology. You think about it, talk about it, try some things, build a prototype or two, and get smarter. Occasionally, things coalesce into a match. If the match turns out to be a prince and a princess, the world is a better place.

[Olowkow]

I don't think the sciforum discussion adds anything. Kamen specifically said there are no filters, just distillation. To vaporize 1000 liters of water and condense it is going to require a lot of power. Wouldn't you have to have some refrigeration to condense as well? If it were not for Kamen's reputation, I'd think it was more woo.

Quote:

The bottled water thing is so bizarre. This huge infrastructure to get drinkable water to people, and they reject it as drinking water because it has fluoride and chlorine in it.

Fluoride is the greatest thing since chlorine. I have not had a cavity since I was a kid.

[Skeptic Ginger]

Just an FYI, I only cited sciforum to credit them for the links. I did note the one diagram in the sciforum post but I have no clue how this thing works and am reading what I can to find out.

[Prometheus]

As I understand it, Kamen's device runs off of the waste heat produced by a multi-fuel electric generator (something also needed in the places he is targeting). It is able to produce a lot of clean water off of a comparatively small amount of otherwise wasted heat by using an extremely efficient condensation/recapture process.

[casebro]

Or even cheaper, just put bottles of water in the sun. The UV will kill the germs in a couple hours. No moving parts required.

[Skeptic Ginger]

That doesn't work cb unless the water is already highly filtered, but even if it did, it wouldn't remove toxins or make sea water drinkable.