Slashdot Mirror


Segway Inventor Turns To Environment

MBCook writes "CNN has an article in which they talk about Dean Kamen's latest inventions designed to provide water to rural villages. His goal is also to provide electricity and opportunities for entrepreneurship. From the article: 'Eighty percent of all the diseases you could name would be wiped out if you just gave people clean water,' says Kamen. 'The water purifier makes 1,000 liters of clean water a day, and we don't care what goes into it. And the power generator makes a kilowatt off of anything that burns.'"

6 of 439 comments (clear)

  1. don't blame him, and he has done much more by johnpaul191 · · Score: 4, Informative

    his company was not responsible for all the hype building up to Segway's release. they have made a ton of incredibly useful inventions and i would think anyone with any interest in technology or engineering would know about his work long before the Segway. inventing a portable insulin pump seems like a pretty valid invention, right? a wheelchair that can climb stairs?

    http://en.wikipedia.org/wiki/Dean_Kamen/
    or
    http://www.dekaresearch.com/

  2. Make fun of him all you want for the Segway by mdarksbane · · Score: 4, Informative

    But these sorts of projects are what the guy actually cares about.

    After he made his initial fortune (in medical devices) he started up an organization called FIRST, designed to get more smart kids interested in engineering, and to help our culture value problem solving more than drama. Since then the organization has grown to include thousands of teams, tens of thousands of high schoolers in countries all around the world.

    I've been working with one of those teams for three years, and every year Kamen stands up and gives a speech, not about how much fun we're going to have building robots, but about his vision for what we can do to solve these sort of engineering problems, to bring clean water to those who need it, etc. He's done a lot of good work, aside from his kind of whacky human transport device, and for all that his speeches are about as depressing and boring as you can get, it's very clear that this is where his heart is. He's put a ton of money and effort into getting people into engineering so that some day if he can't solve these sorts of problem someone will.

    And for as bored as I am every time I have to sit through him talking about it, I can admire that. This is about things a lot more important than a goofy looking scooter.

  3. Re:I was thinking about this the other day by tinkerghost · · Score: 5, Informative

    Nice idea but boiling water (100C/212F) won't kill most bacteria in 5 minutes.
    Steralizing is usually done via steam at 2atm( 250-275F IIRC) for 15 minutes. Plus it doesn't remove contaminants. Mud + heat = dryer mud.
    Most of the water purification systems use either an evaporation/condensation cycle or reverse osmosis through a semi-permiable membrane.
    Of the 2, evap/cond is both more reliable and more scaleable. As a bonus, you can literally do it with 2 coconuts and a banana leaf.

  4. Re:Rumors by DavidTC · · Score: 5, Informative
    Anyone making fun of his Segway does need to realize that, and yeah, his wheelchair was fucking brilliant. If you haven't seen it, it's a upright wheel-'chair'.

    People in it are the same height as people who can walk (Thus, he says, elimating a lot of prejudice.) and can go over bumps and up and down stairs. It doesn't take up any more horizontal space than a fat person.

    Think of it as a segway made into a wheeled mech suit for the lower half of your body. And I read somewhere that he planned to slim it down once it caught on, so it would be basically leg braces with wheels at the end. People might come up to you, and you wouldn't even notice their legs aren't moving.

    And this isn't some pipe dream, these things actually work, balancing the same way as the segway, with two wheels on each side, so they can flip forward and move you up or down stairs. They're just too expensive right now. He was hoping to use the same parts as the segway to cut the cost down,but that didn't work out, obviously.

    --
    If corporations are people, aren't stockholders guilty of slavery?
  5. basic water filtering info here by drwho · · Score: 4, Informative

    It's been fifteen years since I was in the water treatment business, but I doubt any of the fundamentals have changed.

    Here's how it works: You mix a chemical called a 'flocculant' in with the water, which has been roughly filtered and perhaps let sit for a while to let any silt settle. This water is then mixed with air under high pressure, and pumped into tanks, entering halfway between the bottom and top of the tank with as little turbulence as possible. Because of the decrease in pressure, air bubbled form, and the flocculants cause small particles (bacteria, shit, uranium) to stick to them. The bubbles then gradually float to the surface, where the 'suds' or 'scum' is skimmed off, again with a minimal amount of turbulence. After enough of this happens, the water is then called clean and sucked out and wasted on fertilizing laws.

    Generally, this is done on a continuous basis, and the equipment is a big, round vat. The ones I knew were from 5 to 23 meters in diameter. There's some real issues that make this process a bit more tricky than the description above would make it seem:

    1) raw water is not produced, nor clean water consumed, at uniform rates. However, the filtering equipment works correctly at a very small flow/pressure. Holding tanks on either side are neccessary.

    2) Flocculant is a consumable, and it takes a certain amount to clean a given volume of water to a certain improvement. Costs money.

    3) water is not uniformly dirty.

    4) generally, the larger units can let water stay and bubbles float (and grit sink to the bottom) longer, so less flocculant is needed. But these take up more space...LOTS more.

    5) How clean does water really need to be? If there's some nasty outbreak (Cholera, Giardia) maybe it needs to be much cleaner. Maybe not so much at other times. Who makes that decision? My thoughts are that tap water should only be cleaned to a certain percent, which can be used for lawns / car-washes / firefighting / pools, cleaned a bit further for household uses (laundry, bathing) by an in-home filter, and cleaned further for drinking by a tap-based carbon filter (Brita, etc). But this is a lot of equipment. Real serious policy issues here. I doubt that such a poor and corrupt country as Bangladesh can handle these problems correctly. But hey, I guess eomthing is worth a try.

  6. Back to the topic of cheap Sterling engines- info by Savantissimo · · Score: 4, Informative
    From the CNN article: "Kamen's goal is to produce machines that cost $1,000 to $2,000 each. That's a far cry from the $100,000 that each hand-machined prototype cost to build."

    This has always been the trouble with Stirling engines. They seem simple until you actually try to make one that outputs a usable amount of power at some reasonable efficiency that doesn't cost a fortune. Many people have tried over the centuries, but so far it's always been a matter of picking which two of the three goals you want to fulfill. Dean Kamen has a nontrivial challenge ahead in trying for the Sterling hat-trick.

    Don Lancaster's Blatant Opportunist #32

    One way to avoid bad engineering is to stay away from energy sinks into which bunches of time and money have previously been dumped with no visible effect. I like to call these engineering ratholes. Let's look at a few of the more popular examples coming over my voice helpline...

    Stirling engines- Every few years somebody rediscovers the Stirling engine. They build a few prototypes which just barely fail to work, and then just barely go bankrupt. The promise here sure is enticing. A low delta-T engine which accepts anything from oily rags to sunlight. But there's two fundamental gotchas here. First, any engine designed for a low DT temperature differential is inherently inefficient. Carnot and all. More crucially, there is a key component to a Stirling engine that nobody - but nobody - has figured out how to build yet. It is called a regenerator. Any regenerator has to be long and thin and short and fat. Not to mention being an excellent insulator and a superb conductor.

    [Also see Hardware Hacker May, 1993 http://www.tinaja.com/glib/hack64.pdf for everything you ever forgot about heat engines and thermodynamics.]

    Wikipedia - Problems with Stirling Engines:

    Stirling engines require both input and output heat exchangers which must contain the pressure of the working fluid, and which must resist any corrosive effects due to the heat source. These increase the cost of the engine especially when they are designed to the high level of "effectiveness" (heat exchanger efficiency) needed for optimizing fuel economy.
    Stirling engines, especially the type that run on small temperature differentials, are quite large for the amount of power that they produce, due to the heat exchangers. ...
    Power output of a Stirling is constant and hard to change rapidly from one level to another. Typically, changes in output are achieved by varying the displacement of the engine (often through use of a swashplate crankshaft arrangement) or by changing the mass of entrained working fluid (generally helium or hydrogen). This property is less of a drawback in hybrid electric propulsion or base load utility generation.
    Hydrogen's lowest molecular weight makes it the best working gas to use in a Stirling engine, but as a tiny molecule, it is very hard to keep it inside the engine and auxiliary systems need to be typically added to maintain the proper quantity of working fluid. These systems can be as simple as a gas storage bottle or more complicated such as a gas generator. In any event, they add weight, increase cost, and introduce some undesirable complications.

    U.S. Patents:

    6,862,883 Kamen, et al. Regenerator for a Stirling engine

    A regenerator for a thermal cycle engine and methods for its manufacture. The regenerator has a random network of fibers formed to fill a specified volume and a material for cross-linking the fibers at points of close contact between fibers of the network. A method for manufacturing a regenerator has steps of providing a length

    --
    "Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry