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Solar Metal Smelter
- g0ran 4y agoAnd here it is in use: https://www.youtube.com/watch?v=DoixjuGNxPY https://www.youtube.com/watch?v=DoixjuGNxPY
- newphonecartel 4y agoDid he just touch the crucible with his hand there at the end??
- jessaustin 4y agoHe was wearing gloves; a momentary contact like that wouldn't harm anything.
- newphonecartel 4y agoStill, that's like 1200°F! Is this guy in undergrad???
- rkagerer 4y agoIs there one of him removing the cast part from the mold?
- qikInNdOutReply 4y agoIn an old game of mine, there was a monastry driving on wheels through the dessert. The monks spend there days collecting sunlight, smelting sand into "glasstrees", which would then use daylight to collect water (silica gel), pump it up at night (using optic fibres for transport, salt water for storing heat, glass wool for isolation and distills to re-capture the nightly water vapors).. creating a ecosystem in its shade. Nearly all of it made from glas. While the premise might be idiotic scifantasy, the idea to terraform in situ with what you got, is quite neat. https://imgur.com/gallery/yPU871e https://imgur.com/gallery/yPU871e https://www.youtube.com/watch?v=ptUj8JRAYu8 https://www.youtube.com/watch?v=ptUj8JRAYu8 Solar Sintering by Markus Kayser Just imagine this driving around on mars, with huge halftransparent balloons over it, which like a parabolic mirror pre-collects the light, printing structures for future ecology with the little light that world offers from the material at hand.
- AlbertoGP 4y agoI’m not an expert on this, and I might be missing something because to me this sounds like a spectacularly useful idea. Compared to something I would have thought of, like the trivial idea of raised solar panels that left enough space below for animals and plants to grow, those glass trees have wide manufacturing tolerances and work independently of each other. Thinking now about their degradation process, they might produce a blanket of fine glass shards which would make animal life impossible. I wonder whether there would be ways of mitigating that.
- Retric 4y agoThere’s another name for Blanket of very fine glass shards, it’s sand. Which suggests the mitigation process might be to insure degradation doesn’t stop in an unpleasant middle ground. Not that glass trees are a good idea…
- kragen 4y agoSand is not normally made of glass, but there are obsidian beaches in, for example, Hawai‘i that are.
- actionfromafar 4y agoI think it's not much of a problem, but even so it can probably be mitigated. There are types of glass (tempered safety glass) which break into tiny little cubes instead of shards.
- samatman 4y agoThis wouldn't so much be glass, as sintered sand. Energy spent rendering the sand fully amorphous would be wasted. There are analogous igneous rocks, they aren't good for knapping into blades, leading me to think that broken glass trees wouldn't be especially dangerous either. Frits used in chemistry are sintered glass, and they don't break into sharp edges either.
- throwaway4aday 4y agoI think you could redesign this to be 100% glass with no optic fibers or silica gel. Heat transport can be accomplished heating the water until it becomes steam and then condensing it again at the bottom. Even if there isn't enough heat to produce steam you can still induce flow by exploiting the fact that hot water rises to the top of colder water. Water collection could be accomplished using a fog fence made from glass. https://en.wikipedia.org/wiki/Fog_collection https://en.wikipedia.org/wiki/Fog_collection
- Tade0 4y agoAccording to the description under a video showing it in use on a good day it melts aluminium - that means 660°C is achieved. I wonder how much embedded energy is there in that giant fresnel lens. These things are notoriously expensive. In any case this is a great example of just how much solar power we're given on a daily basis free of charge. Would be a shame to not tap into at least a small part of it in ways other than via agriculture.
- Cthulhu_ 4y agoIt's squared off, which I suspect might be an optimization for production. In theory, could you mass produce a fresnel lens like that? Either from glass or plastic. I can imagine that in this case, you can get away with imperfections or suboptimal focusing by just sizing it up a bit to compensate. edit: just had to google to remind me what a fresnel lens is; it's already cheaper (and flatter) than a conventional lens that would have the same power.
- wiredfool 4y agoI've got a letter-paper sized fresnel that was like $1 at American Science and Surplus. Making a big glass one might be expensive, but plastic ones (which, admittedly, are going to be a bit bad in terms of oil) shouldn't be that much worse than any other formed plastic sheet. Now, the glass ones for lighthouses, those are expensive.
- Tade0 4y ago
- wingi 4y agoSee more on the solar sinter project back in 2011 https://www.dezeen.com/2011/06/28/the-solar-sinter-by-markus-kayser/ https://www.dezeen.com/2011/06/28/the-solar-sinter-by-markus...
- mnw21cam 4y agoVery neat. Youtube version: https://www.youtube.com/watch?v=L2dvwdbQshQ https://www.youtube.com/watch?v=L2dvwdbQshQ
- newyankee 4y agoI wish there was a project which with minimal materials would convert sand to solar panels using solar heat energy, but somehow without the metal framework of aluminium needed today. So , in theory we could have a source of energy with minimal materials, no fossil fuels and something that can be used over many decades. As I understand making polysilicon today is a very energy intensive process. So is making aluminium but like 75% of the global aluminium resources are recycled
- ben_w 4y agoAFAICT, aluminium isn't required, merely cheap and plentiful, but if you had a solar economy you can make it cheaply anyway so it doesn't matter. PV quality silicon, however, I know nothing significant about. If I was trying to rebuild from mud and sticks upwards, in the style of the Primitive Technology YouTube channel, I'd probably go for thermoelectric heated first by fire and later by a focusing mirror — bronze (copper and tin) is, after all, a bronze age tech.
- pfdietz 4y agoSilicon is made by reduction of silicon dioxide with carbon in an arc furnace. One heat that furnace with concentrated light instead, I guess, but it requires very high temperature. There is also a process using aluminum as the reducing agent. Very pure silicon for PV is produced by converting silicon to SiHCl3 by reaction with HCl, followed by distillation and thermal conversion back to silicon. Recycled silicon could be treated the same way for purification; it's going to be less contaminated than the raw silicon coming from silica reduction. I think you'd probably go a thin film route to make PV yourself; much less semiconductor would be needed. Maybe copper oxide?
- jokowueu 4y agoInteresting. The website isn't but going to the main website it https
- tiku 4y agoI'm still wondering if the old builders used this to melt stone, through parabolic mirrors etc.
- kragen 4y agoThere's speculation that the Inka used that approach to melt stone for construction, but as far as I know not much evidence. It doesn't seem to have been used anywhere else before the last couple of centuries.
- gigaflop 4y agoThis is interesting, and supports some sci-fi-fantasy I have: I'm convinced that this process could be done in zero-G, and could be a way to start processing raw resources in space. How else can we expect to build megaships?
- noxer 4y agoIn case anyone wants to build this but cheap. You can use an old satellite dish and either very reflective tinfoil or many small pieces from a (broken) mirror.
- cestith 4y agoWould a mylar sheet work with the dish to shape it?
- noxer 4y agoAnything reflective should work but it has to reflect short wavelength. Anything polymer could have a transparent layer on top which could (partially) filters the UV an other short wavelength and heats up the dish instead. You can also remove the paint and mirror polish the dish itself but that requires tools and it likely will not stay shiny for long.
- kragen 4y agoMost of the energy of sunlight is visible and near infrared; UV is only a very small part of it.
- noxer 4y agoBut UV is what destroys the polymer if it does not reflect it. Beside that if something is "glossy" and reflects UV like tinfoil (Al) it will almost certainly reflect most of the visible light waves and part of the IR too and that is what you want. In contrast anything transparent like a clear coating on a polished dish, is very likely only partially transparent to visible light.
- cestith 4y agoIt turns out after some reading that a reflective BO-PET should be reflective enough initially but will yellow and become brittle within fewer than 1000 hours of sun exposure. So as a very short-term use in an emergency if it's what's available to build a solar still, oven, or forge it could do the trick if it's the only thing available. Some metal foil should be far more durable though.
- njarboe 4y agoThis is a cool project but I was hoping to see a solar powered machine that turned ore into metal. That is what a smelter is. This is a solar metal melter or what is generally called a furnace, not a smelter. Too bad.
- robotsteve2 4y agoMight not be much of a production line. Very big, very slow, sensitive to weather conditions. What do you do about all the scattered light? The guy in the picture is wearing goggles, but people in the building who see the crucible (while looking out the window) won't be.
- timmaxw 4y ago> What do you do about all the scattered light? I think it's actually fine. Quick back-of-the-envelope calculation: - The lens collects about 1 m^2 of sunlight. - At the focal point, the concentration is way higher than sunlight. - But when the light is scattered away from the focal point, it's distributed over an area of ~4 pi R^2. - So from the point of view of a person looking out the window, R^2 would be much greater than 1 m^2, so the crucible would be less bright than the outdoor sun. - The outdoor sun doesn't blind people unless they look directly at it, and humans are good at avoiding that. So I think the crucible would appear as an annoying glare that people would instinctively look away from, but it probably wouldn't accidentally blind people.
- kragen 4y agoSolar-powered smelting would be great but this is not it. This is melting metal, not smelting it, which means reducing non-metallic ores to metal and is the crucial technology that allows people to use metals in the first place (other than copper). See https://en.wikipedia.org/wiki/Smelting https://en.wikipedia.org/wiki/Smelting: > Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. Likely the most effective way to reduce iron or copper from ore with solar power at a human scale would be electrolytic metal reduction: hydrometallurgy or electrometallurgy rather than pyrometallurgy. Pyrometallurgical processes at human scale are painfully inefficient; see Christopher Roy's documentary "From iron ore to iron hoe: smelting iron in Africa" or John Plant's more recent experiment "Primitive Technology: Iron knife made from bacteria", both available on YouTube for the time being. These are both charcoal-powered rather than sun-powered, but I think the higher temperatures attainable by solar power will only increase the process's efficiency modestly. The false claim is original to Jelle Seegers (see https://archive.fo/qk3dZ https://archive.fo/qk3dZ), not introduced by Kris De Decker, but you can be sure that De Decker will not correct the error. He is consistently enthusiastic about continuing to promulgate his false claims even after they are pointed out.
- tinco 4y agoNot sure if it's a false claim per se, as "smelten" is Dutch (Jelle being Dutch also) for melting. A device that melts things in Dutch would be called a "smelter". Of course, in his description he does use the English word melting correctly, but he also describes what it does correctly, so maybe he's just being artistic about it.
- kragen 4y agoMaybe it's just an error due to a false friend? I didn't know "smelten" in Dutch meant "melting". Etymonline says English actually got the word from Dutch: > smelt (v.) mid-15c. (implied in smelter), from Dutch or Low German smelten, from Proto-Germanic *smelt- (source also of Old High German smelzan, German schmelzen "to melt"), from PIE *smeld-, variant of PIE root *mel- (1) "soft." Thus the word is related to melt (v.). Related: Smelted; smelting. As usual, once the word was adopted into English, it started rapidly changing in meaning.
- kabanossen 4y agoThe trick to doing this cheaply is by using two parabolas and mirror the light into a point. https://youtu.be/qKcVwmkJbQM https://youtu.be/qKcVwmkJbQM https://www.youtube.com/watch?v=Td_c8fIiu4M https://www.youtube.com/watch?v=Td_c8fIiu4M