Slashdot Mirror
High-Tech Electro-Defroster
DahBaker writes to mention a News.com story about an ingenious way to de-ice a surface. From the article: "Dartmouth College engineering professor Victor Petrenko, not to be confused with one of the Champions on Ice, has devised a way to use a burst of electricity to remove ice caked on walls or windows. For surfaces coated with a special film, the jolt gets rid of ice in less than a second, far less time than it takes to hack at it with an ice scraper. While drivers might find easy-cleaning windshields convenient, the technology--called thin-film pulse electrothermal de-icing, or PETD--could have significant economic impact if widely deployed. It could, for example, cut the costs of repairing power lines downed by ice storms and keep plane windshields frost-free, decreasing fuel consumption."
Or is slashdot not working?.. I don't see any comments for the last five hours.. that just doesn't happen ever, heh.
Assuming the material is durable enough it would be great on the flying surfaces too preventing icing which adds considerable weight and changes the aerodynamics of the plane. This would probably be far lighter then current solutions for this.
10 bucks says it's not. now to go RTFA because this sounds incredibly appealing, as I am lazy and dislike scraping my windshield. If only they could make this work with all the snow around my car, too..
... still waiting for this free-as-in-beer free beer I keep hearing about.
from the article:
"We built a solar cell made of ice," he recalled. "While it is not as efficient as a silicon solar cell, it costs a penny a square mile."
Solar panel that uses ice! This could be very cool for people in colder climates.
In Soviet Russia, articles before post read *you*!
I think this invention would be something for Canada and the northern states in the U.S. to consider. We've seen some really nasty freezing rain over the years. Covering core infrastructure with this defroster could save us quite a bundle of cash, even if the initial cost is expensive.
It could be more useful on the wings. Keeping a plane in the air might be important too.
I have nothing to say.
This being
ID: the nose did not occur naturally, how would we wear glasses otherwise? (apologies to Voltaire)
Did anyone else read this as "High-Tech Electro-Disaster"?
Has anyone seen the video demonstrating the technology? Yeah, they can remove a very thick layer of ice or snow, but I'm pretty sure it would be much harder with a very thin layer, on a surface that isn't oriented at 90 degrees.
Hehe. It's nice to know I'm not the only one waiting till the last minute (April 17)*
*Although "/." did pick a bad time to do DB.
BTW Which Unreal engine is better? 2.0 or 2.5?
No more defrosting refrigerators! It would beat putting naked orphans with ice picks into my freezer, too. Er, not that I do that. The human remains in my garbage can were from some other pervert, officer...Not me.
If you de-ice the wings of an aircraft flying at, say, 900 km/h, you are sending said ice toward the tail of the plane at same speed, repeating a recipe that caused, err, a major malfunction not so long ago at the occasion of a shuttle launch, aren't you? And that was not even ice, but just foam. Granted, the place will not have to suffer the penalty of a reintry into the atmosphere, but it is now understood that light debris flying fast can cause serious damage.
Depending on the efficiency, this might work on Mars. Particurly, if it is easy to construct.
I prefer the "u" in honour as it seems to be missing these days.
I'd love to see the car version chargable by cranking the charger inside. Same energy efficiency, same exercise program, but much more comfortable.
--
make install -not war
The technology essentially takes advantages of the inherent properties of ice. Ice, it turns out, is a semiconductor, meaning that it conducts an electrical charge under certain circumstances.
This appears okay so far, but as in any popular writing about a technical or scientific subject, use of such words as "under certain circumstances" is excessively vague. One can only hope that a later sentence clears this up. But that doesn't happen here.
Unlike silicon, which conducts negatively charged electrons, ice conducts protons, the core of hydrogen atoms that are part of the water molecules.
So the article is that the proton is the charge carrier in ice conduction?
In a "P type" semiconductor doped for positive carrier conduction, it's the 'holes' that move and carry the charge, though their movement is correlated with electrons moving the opposite direction. I know of positively charged particles moving in a plasma (such as an electrical spark), but not in a solid.
Does the author (or the person who tried to explain it to him) mean that ice uses holes as the charge carrier just like P-type semiconductor, and he just messed it up/reinterpreted it as protons?
What's so frustrating about these watered-down "popular science" type articles is it's impossible to know if I'm reading something that is truly new to me, or (as I always suspect and too often find) it turns out I already know more than the writer ever will.
Can someone post a REAL article on this topic?
Tag lost or not installed.
So the article is that the proton is the charge carrier in ice conduction?
should read:
So the article is saying that the proton is the charge carrier in ice conduction?
Tag lost or not installed.
I must be missing something... Maybe the article is just light on details, but I can't see how this is any more advanced than the rear window defroster standard in every car made in the past couple decades.
Electricity turns to heat, and melts the ice. Yippie. In this instance it sounds like electricity is being applied directly to the ice, possibly making this slightly quicker and more effecient, but I don't see anything revolutionary here. I also can't see how this is any less obtrusive...
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
The foam was several inches think, waterlogged and frozen solid. The vehicle was traveling at great speed. The heavy, solid, ice-laden foam had a relatively long distance to decelerate before the leading edge of the wing hit it. And the damage was to the heat resistant tile; it was the failure of the tile that brought the aircraft to its end.
In atmosphere - bound aircraft, the systems that shed ice are designed to shed it in small pieces at intervals that preclude it from building up too thick. Also, the speeds and distances are a lot smaller.
In short, they do think of these things.
What's fun is to be sitting in the seat that is in line with the propeller on a turboprop plane when the prop sheds its ice.
I never sit in the seat that's in line with the prop on those planes.
--97T--
You can't use the ice for making electricity - I need it for my drink!
This issue is a bit more complicated than you think.
One of the biggest problems with frost free freezers are that they have to warm up above freezing, on a regular schedule, so that they don't frost up.
The problem is that outside/edges of frozen items also thaw a bit creating all sorts of problems. (ice crystals on your popcicles for example!)
That's why a deepfreeze(non-frost free) freezers are recommended
for longer term storage.
A quick thaw of the surfaces where ice builds up
would keep the feezer ice free and the food frozen.
The BS detector is ringing -- fact free news article, company website with no information, and no products to buy. Sounds like a stock swindle, to be blatantly impolite about it. A few questions that come to mind, that aren't addressed anywhere; 1) As mentioned, proton conduction, instead of electrons? Huh? Is there some electrolysis going on? If so, why is it not mentioned? 2) This talk of ice being a semiconductor -- OK perhaps, but then if you put a film on a surface, then cover it with ice, then 'pulse' it, how exactly to you get current flow through the ice which is supposed to conduct current through its protons? In other words, you need something to complete a circuit. I could postulate that it is electrostatics, but shouldn't the claimant explain this? (Ice doesn't fly off transmitting antennae.) 3) It is mentioned that you need to bring the surface to very close to freezing temperature for it to work. This implies heating of the surface with these pulses, not heating of the ice. So obviously the energy density required will depend on a lot of external factors. This rather sounds like a method for rapidly heating the surface, rather than something to do with ice being a semiconductor. 4) A solar cell that costs pennies per square mile? And we are not getting free electricity from it because ? ......
5) Any conductor that is pulsed with high enough current jumps because of the magnetic field. If it is coated with ice at a temperature near freezing, it seems likely that it could shed the ice. How much is really new here?
The BS detector is on high alert. Real information, products with price tags will be required to silence it.
--97T--
Victor Petrenko, not to be confused with one of the Champions on Ice - If you put those two into the same room, hilarity and confusion are bound to ensue, since they seem to be the Ice Champion and the Anti Ice Champion, the Ying and the Yang. We must keep them as far away from each other as possible, or there could be an anti-matter equivalent explosion.
You can't handle the truth.
Why not use it on roads for deicing? It gets rediculous in some parts of the country.
IMAGE VERIFICATION IS EVIL!
The last sentence interest me - 1c for a square mile of solar panel. Just think - all the electricity need generate in north pole
Could they use something like this on the outer tanks of the shuttle instead of foam?
Breaking and removing this ice before it becomes a huge iceball could be double plus good.
liqbase
I don't either -- but not because of ice. If I'm anywhere near the "prop row", during the entire flight my mind keeps replaying a picture I saw years ago showing what happened when a prop blade got loose and entered the cabin. My mind doesn't seem to understand that the event happened on the ground (IIRC, because a vehicle and plane tried to occupy the same space at the same time while the plane's engines were spun up).
So I suspect that to commercialise this a lot of research will be needed. Changes to windshield composition and design. Changes to wiper design. Uprated batteries. It might actually be cheaper to fit one of those nice Kenlowe or Eberspacher heaters with mobile phone control so you can simply start the car heating ten minutes before you leave the house or the office. After all, no matter how well the pulse technology works, at the end of it you are sitting in a freezing cold car, even if you can now see through the windshield.
Pining for the fjords
My exceptionally boring (yet I love it to bits) Ford Focus (3 years old) has loads of tiny heating elements built into the front windscreen. I press a button on the dashboard an in about 15 seconds it's melted whatever happened to be stuck to the windscreen. Well actually it's more like what described here, it melts the layer between the ice/snow and the glass, so as you drive or use the wipers it all just comes off in chunks.
The only advantage I can see with this method is that it's a bit faster and I assume cheaper to make (I got the windscreen bundled in my package, the cost of replacing it is astronomical seemingly).
"And the damage was to the heat resistant tile; it was the failure of the tile that brought the aircraft to its end."
I thought that, according to the findings of the review board, the damage was to one of the curved carbon-carbon panels that covered the leading edge of the wing, and not to the heat resistant tiles the cover the underside? Carbon-carbon composite is not the same thing as heat resistant ceramic tile.
Any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so.
Similar articles have been posted on slashdot about his work over the years.
2 7/226221
Here's one from 2002.
http://science.slashdot.org/article.pl?sid=02/12/
There was another one from I believe 03 or 04. Talking about slip/grip tires and using pulses to defrost electrical lines.
Cool stuff if it works.
-William Shatner can be neither created nor destroyed.
They all seem to say how hard it would be and how much power it would take. Do you know how much power is generated on an airplane? I don't, but I assume it is more than is generated by my car, and the car has do do this for the entire windshield, and possibly side windows and the rear-window. I'm pretty sure that the area to be defrosted on a plane's wings compared with the area of windows in a car is less than the ratio of power produced on a plane compared to that of a car. It looks like the de-icing only takes a second or two, so capacitors or batteries could be used to store the charge for the de-icing. If you are going to complain about how "hard" it would be for a plane, complain about a car first.
Every winter, as I survey the masses of snow that have just thwumped down on our grounds and exterior stairs, I remember my implicit assumption that the phaser was initially developed as an ice and snow clearance tool---hit the right resonances all at once, and the stuff sublimes away, or maybe goes directly to a plasma.....
Preface: I was a grad student at the Thayer School of Engineering, where Petrenko does this research. During a power electronics class, we learned about the workings of some of this technology, and some classmates of mine designed some of the HF electronics that are behind this.
Electrically heated windshields, propellers, etc... have been around for 70+ years. Yes, but those devices have heating elements that conduct heat into the bulk ice. You don't want to spend all the energy needed to melt all of the ice, or even a sizeable portion of it, but rather melt just the ice that's adhered to the windshield or airfoil. This technology does that. It creates HF eddy currents in the ice at the ice-windshield interface, liquifying that thin layer almost instantly. The liquification happens quickly enough that very little heat is conducted away into the bulk, which means that you aren't wasting or losing much energy. What's more, the heat is applied directly to the ice - no heater elements needed. Instead of pumping XX watts of power into heater elements and waiting for enough ice to melt to easily be removed, you pump (let's say) 10 times the power for 1/1000 the time into just the ice that matters, then let gravity, airflow, and wiper blades take care of the rest. It is a far more efficient way to remove ice.
Jet planes spend 95% of their flying time way above or below the icing levels. Unfortunately, the place where icing is most likely is also the place where it is most dangerous: during takeoff and landing. Just because it is not a continuous threat during the flight doesn't mean that it isn't still extremely dangerous.
Jet turbines have a virtually free and unlimited amount of hot air availbale for deicing. The hot gasses need to be hot if they are to produce thrust. Were the gasses diverted through some complicated heat exchanger to melt ice from the airfoils of aircraft, the exit gasses wouldn't produce nearly as much thrust. Once again, this technology works only on the ice that is adhered to the surface, and so works very efficiently. Using hot gasses, like heater elements, inevitably has most of its heat conducted into the bulk, where it does little good.
It's not affordable to load down a plane with 100's of pounds of extra generators, batteries, and/or capacitors that are only needed in very rare and usally avoidable circumstances. This is not additional equipment for an airplane, it is meant to replace the de-icing equipment that some already have. Consider the cost of applying thousands of gallons of chemical de-icing to aircraft wings on the ground, or the electrical equipment needed to generate the huge amount of electrical power that goes into heating elements. If anything, this technology would have less equipment associated with it than other methods, because it uses far less energy. The amount of energy that it takes to use this equipment, even over the entire leading edge of an aircraft's wing, it relatively small compared to the power needed to run everything else, or the tremendous power output of the engines. It makes use of high-frequency power electronics, which are much more compact and efficient than traditional power electronics. True, it isn't need all the time, but there is tons (literally, tons) of equipment in an airplane that is only used occassionally. They all serve a specific purpose. I will admit that it will be expensive technology at the beginning, especially for retrofits, but most new technology is. Airbags were initially only seen in high-end luxury cars, but eventually trickled down to lower models.
The planes that would need this the most, little prop planes that can't climb above icing, are also the ones that can least afford the weight penalty of this deicing system. Adding even 150 pounds to a small plane can make it a non-viable flying machine. Once again, this is not additional equipment, it is meant to replace existing de-icing equipment on a plane.