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Most industries that deal in refining or other heat-intensive processes are nearly hard to impossible to pause or stop. My understanding is that glassmaking pla
by johncalvinyoung 3y ago
Most industries that deal in refining or other heat-intensive processes are nearly hard to impossible to pause or stop. My understanding is that glassmaking plants, for instance, will literally solidify if they ever stop operation--making it an extremely rare occurrence. I wouldn't be surprised if aluminum refining is the same way--fighting entropy keeping things hot is a losing battle, so not very dispatchable.
- speed_spread 3y agoI confirm that an aluminium refinery is not something you stop lightly. I remember something about taking two weeks to restart? Maybe more. Source, had family working at a large northern plant.
- Filligree 3y agoBeing able to restart it at all makes it better than a lot of industries. Many of these liquid-metal affairs depend on convection and inertia to keep the metal molten, and if it solidifies inside a pipe—well, then you don't have a pipe anymore; you have a bimetal pole. Or ceramic cladding for an iron pole, depending. Either way it's a rebuild, not a restart.
- iancmceachern 3y agoTotally, like magnetic induction pumps that pump molten iron, once the iron solidifies its a composite tube.
- Arrath 3y ago> well, then you don't have a pipe anymore; you have a bimetal pole. I love that way of describing it.
- iancmceachern 3y agoThat is true about float glass plants but for a different, very interesting reason. Float glass plants work by literally floating a thin sheet of molten glass on top of a giant tank of liquid tin. They have a swimming pool of liquid tin, float molten glass on top, and then push it along the tank length wise. The glass and tin is then gradually cooled until the glass is solidified. It's then cut into pieces, cooled and stacked. If the thing suddenly stops, or there is a hiccup of some kind, the thermal expansion of the glass, along with its extreme hardness (lack if strength) it will just shatter the whole mile long sheet of glass. My understanding is that it takes the better part of a year to recover from something like this. In aluminum, its basically electroplating. They basically electroplate the aluminum out of the ore onto the ingots. My understanding is that takes a few weeks to a month to recover from a similar incident.
- eru 3y agoIf I remember right, you can stop the electricity to an aluminum smelting plant. But only for a while.
- pfdietz 3y agoRight. The wall has to continue to be cooled -- if it reaches the temperature of the melt, it's ruined -- so there's always some heat loss. And if the electrolyte freezes you're also in trouble.
- jskrablin 3y agoGlass melting furnace never stops after it's started. If it cools down it's basically destroyed so yeah, they run uninterrupted for years. Any maintenance or fixes need to account for that.
- Mistletoe 3y agoHow do they account for power outages? Huge generators? Or is it gas fired?
- iancmceachern 3y agoFrom what I've read its gas
- pfdietz 3y agoThere are electrically heated glass furnaces. They work by immersing electrodes in the molten glass, which is electrically conductive, if somewhat resistive. I imagine they could use gas for startup though. The use I saw for this was in making fiberglass from recycled glass cullet.