A 37-second video of snaping and crackling while humming during a heat
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| Dustin Gregory commented on the video post EAF#3 Attica indiana Dennis DeBruler: Dustin Gregory I presume this is in Harrison Steel Castings. This is one of the best EAF overview shots that I have seen. It clearly shows how the lid swings to the side and the size of the electric cables that attach to the feeds on the side of the building. |
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| Dustin Gregory commented on Dennis' comment Yes sir, Harrison steel castings This is the twin sister right next to it. |
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| Jon Wolfe posted Geoff Palfrey: It’s an old Krupp design, fixed roof lifting and slew cylinder, the bushings of which wear, the hot electrode arms are modern but there’s no chemical energy source, and it’s spouted not EBT. Phil Petrowski: How many volts/amps are needed to run an EAF? Jon Wolfe: Phil Petrowski A mid-sized modern steelmaking furnace would have a transformer rated about 60,000,000 volt-amperes (60 MVA), with a secondary voltage between 400 and 900 volts and a secondary current in excess of 44,000 amperes. Lee Bradshaw: Phil Petrowski one of ours is 132 MVA, 1200 volts 66000 amps |
Ken Biddle posted three photos with the comment: "Gunning the breast on the EAF Vallourec in Youngstown"
[Judging from the comments, "gunning" means throwing aluminum ingots into the melt. The electrodes are 24".]
Brian Stahl: Looks like they are over drafting the furnace from looking at the electrodes. They are penciling bad.
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| Screenshot @ 0:05, the charging bucket is being moved into place. (source, there are quite a few informative comments.) |
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| Screenshot @ 0:53, the charge started dropping at 0:45, but this is the flare up. I saved the 0:05 screenshot so that you can see the charging bucket since it becomes hidden by the flames. |
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| Screenshot @ 1:39, the lid is hidden by the flames so I had to capture it after it was almost closed |
A nice view of the electrodes.
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| Steven Ray posted A minor water leak we had on C phase. Minor because you can see it and know it there. [According to the comments they use water to cool stuff. But I don't understand the comments well enough to understand what is being cooled.] |
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| Ro Hair posted An electric arc furnace’s power cables to the electrodes. Nick LeBlanc: A truck tire around the cables as a cable tie? Linus Tech Tips needs bigger cables ties Steve Croft: Nick LeBlanc that big tire is a CT or current transformer. It is used to read the current in the arc furnace. 30 million watts 600 volts 50 thousand amps. The arc furnaces may be different nowadays but this one looks like the type I’ve worked on. This looks to be a three phase AC furnace. After looking closer at the picture the lower one looks to actually be a tire with tread. The upper one on the center phase is a CT. Max Stehmeier: Steve Croft 50K amps!? Do you have a notify ComEd when you're about to turn that thing on so they can give you extra power? Then notifying when you turn it back off so you don't fry the grid. Erick Huntsman: They jump when they're turned on because of how high the current is flowing through them. The entry to the furnace from the front is all of maybe 2 1/2"x 5 feet. The exterior walls are a water coolant system of all things. Above that is various sands usually imported from turkey I can recall what sand, grade, or otherwise it's been years. Next is dolomite bricks which are laid by hand to the contours of the furnace. The furnace has to be rebricked every 4-6 weeks depending on usage and when rebricking happens the sand beneath the brick is still glowing hot in some areas. The furnace may reach upward of 4-500* f without the aid of large shop fans. This jobs is often handled by a crew of 5-15 men typically 5-10 inside with a crane operator outside using a few spotters. Remember how I said the sand is still glowing orange? I've watched a man's boots melt to the deck because he stood still too long. He went to take a step and the soles melted to the deck. His next steps were one big ass leap for that tiny entrance which again is got damn hot to the touch. When they flip the arc you hear this loud crack and ZZZZZZZZZTTTTTTTT it's the loudest buzzing you've ever heard. There's a lot of blue/white light, smoke and aerosolized solids like lime dust and crystaline silica that floats the areas snowing down upon everything. One thing I learned about the arc that I thought was wild is that it's okay for water to get on the molten steal in the furnace should it have a catastrophic cooling system failure but should the same water get underneath the steal it could cause a large eruption of molten steel within the confined space around itself. Thanks for coming to my Ted talk. Next we'll discuss how to get the probie to ask everyone where the electrode stretcher is. Sébastien Zanelli: Erick Huntsman I worked at an aluminium mill a few years ago, I was rerouting electric cables just under the ceiling and I saw a lot of metal splatters on it, confused, I asked the guy I was working with what happened, he told me that there was a melter incident in 2001, a smartass had thrown his beverage can into a scrap bin that was ready for melting, the load got dumped into the melter and the rest is history... a huge explosion and melted Al flying everywhere, thankfully no one got hurt but the guy in the protected loading machine had the fear of his life... and the ceiling was something like 40 or 50m high. Ray Schloss shared That’s a lotta juice ⚡️. Fun to watch ‘em jump around. Mark Pozzuto: Wow not water cooled , that will make your watch jump a few hrs. Gary Poulakis: I remember when those cables were wrapped in asbestos cloth other people should remember that back in 1966 anyway. Nate Ausmus: What an out dated nightmare that is lol [According to some other comments, they now use water cooled cables.] Phil Shimko: I’ve changed quite a few EAF conductors,but ours had water jackets. These would be a motor inspectors nightmare to change. I keep looking at this setup and keep shaking my head. We had 7 furnaces with 4 conductors per phase, 12 total for each furnace. Output was 480volts with peak nominal amps of 120,000 average 90,000A. They sure could dance when running. |
I didn't realize that such major maintenance has to be done rather frequently. Although, according to some comments, the frequency varies quite a bit.
Ryan L Stone posted three photos with the comment: "EAF bottom changes happened about once every 90 days at our meltshop in Perth Amboy. Pulling the roof and the cage was a fact of life for a bottom change. Everyone in the Maintenance Dept. was on 16 hour shifts during turnaround. It made for interesting paychecks...and lots of OT."
Chris Dudley: We’re you changing it because you had another one ready to go?
Ryan L Stone: Yup. We had a Refractory Dept that did nothing but line bottoms and ladles. Two bottoms and six ladles in rotation.
RicknDebbie Nichols: I worked there almost 20 year. At one point the meltshop superintendent had that bottom being changed every 2 weeks.
Lloyd Hanning: RicknDebbie Nichols Hey Rick: what was the reason for replacing the bottom that often? I’ve worked in meltshops all my life and never heard of something like that. I’d be embarrassed to be a superintendent in a shop like that! Crazy.
RicknDebbie Nichols: Lloyd Hanning we burned through a couple of times and the super was paranoid it would happen again. I was at the caster and we could see when they knocked the brick out that they were like new. We all thought it was nuts.
John Shaw: We just dig it out then re brick and ram refractory every 6 weeks. No dismantling required. Bezle ring and roof stay on. 12 hr turn around.
Adam Keye: At our meltshop they try to go 120 days before a reline.......lol
Roy Scragg: When Irish Steel was operational we would have a weekly maintenance shutdown day every Thursday which involved changing out the shell of the 120t EAF.
Pretty awesome seeing that happen with all the heavy machinery involved and some great work done by very experienced people.
Ed Skuchas: And they have to remove the shell for Relining?
Andy Watkins: I remember when our company bought that mill along with the one at Sayerville. We split the shell and replace bottom once a year at our mill.
Michael Harley: John Braun we do our every 8 years.
Michael Boley: How many tons can that furnace hold. Anyone know?
Ryan L Stone: Michael Boley 300T.
Brandon Klinedinst: 90 days doesn’t seem too bad, how many heats is the question. Luckily we have a big enough crane to not have to split the shell we just swap the whole furnace with our spare. Cool stuff though.
Keith Wilburn: Hell once a year.
Caleb Gilmore: Yep now we do shel/hearth every 8 weeks.
[The land now has a Home Depot.]
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| Peter Skelton commented on John's comment |
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| Ryan L Stone commented on Ed's comment The cage had to be removed to pull the bottom out. Bottom had no panels. |
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| Peter Kelton commented on the post. We just rebricked the one I worked with. |
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| Richard Byers posted New EAF bottom and rebuild of scrap bucket. Kevin Regan: Well that’s interesting. The scrap bucket is the type used to charge scrap into a BOF Converter. EAF scrap buckets are usually Clam-Shell type. Unless this EAF shop may be a ConSteel process?? Richard Byers: 2 different Mills. We build new and refurbish.. clam buckets,ladles,bottle cars,J hooks and bails. |
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| safe_image for 5:32 YouTube video [They should have got a thumbnail from their video rather than this forging operation.] |
A 2:16 video of a furnace operating The electricity is turned on at 0:45. I presume from the comments this is more "action" than normal because there was some water in the scrap metal that charged the furnace.
A 1:00 video of a charge being dropped A comment has a 0:20 video of a wet charge being dropped.
Peter Skelton: First bucket, low and slow, second bucket, high and hard 😉
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