Little bit of lathe work

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Got a new notebook for my birthday, and in transferring photos across, found this one...
0427091130-00.jpg


That was when I replaced the L-0 (last row LP) blades. 33.5" long, the change in blade design was worth around 10,000 shaft horsepower, or nearly a 1% reduction in coal consumption.

This is the final machining of the blade tips.
 
Years ago I took a CNC class and the instructor showed us a picture of him riding the cutter on a huge lathe. It must have been close to 100' long.
 
Originally Posted By: turtlevette
You showed some up close Picts before I think. Or was that a repair? I'd like to hear more.


Those other pics were of a series of L-2 failures on an old Parsons 500MW machine. They were originally a GEC design (the Eriths), that ended up being sold by Parsons. There were a few in the world, and the two that I looked after gave me a lifetime's worth of engineering in a decade.

My first day as turbine engineer was after a round of redundancies, including the turbine engineer...I got marched out to the hall, with one of the machines in pieces, full strip pedestal to exciter, and told that I had 4 weeks to get it back together.

I think I had the last ones to close down in the world.

Here's from the last day both ran together....
WW7%20turbine%202.jpg


RIP old girls...
 
Originally Posted By: tom slick
That's big! Is it in your plant?


Yep, the one still operating...Toshiba 660MW units (GE licenced, but have diverged from G.E. technology over the decades) bumped up to 700MW...actually pulled up just shy of 1M horsepower when I did the upgrades.

Here's the blades going on.
0416091207-00.jpg
 
Originally Posted By: Garak
You said little, and then I saw it, nope.
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3 feet of blade, and they skimmed 1mm or thereabouts...little bit of lathe work.
 
Originally Posted By: tom slick
Each of those blades are longer than the diameter of the turbines I worked on. As always, thank you for the pictures.


tom slick, here's the other thread that turtlevette mentioned, on fixing some broken blades without taking the rotors out.

http://www.bobistheoilguy.com/forums/ubb......#Post3842393

Couple of other bits from the past...

I built this in the mid '90s...A 35,000 tonne circular stacker reclaimer (Schade) and associated 900-1,200 tonne per hour coal handling plant....the "Jupiter 2" is 330 feet diameter, and you can watch eagles riding the thermals that come off it.
P1171049.jpg


Here's another interesting one that not many get to see...



It's technically what hades should look like...that's molten sulfur burning in air, inside a reaction chamber. Forms SO2, which then goes over a vanadium pentoxide catalyst to make SO3. SO3, injected into the power station flue gasses decreases the resistivity of the fly ash (ours was highly resistive, being mostly alumina and silica), improving the ability of the electrostatic precipitators to capture it.

Adding Sulfurous oxides to the flu gas actually decreased our sulfur emissions.

Built that plant in the 90s as well.

Then moved from "construction" to operations at the end of the '90s, and managed the coal, ash, dust and whatnot until I got turbines in around 2001.
 
Originally Posted By: Garak
Originally Posted By: Shannow
3 feet of blade, and they skimmed 1mm or thereabouts...little bit of lathe work.

Okay, a little it of work on a mighty big lathe.
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One of the jobs that was done on that lathe was one of the other companies had a big crash.

Ran down their machine without oil, and amongst other things, a rotor of similar size to that one spun through the white metal of the bearings, and sunk 5-6mm into the cast iron bearing shell.

Aeriously heat damaged (hardened) the bearing surface on the shaft, making it unsafe to run through crack sensitivity...also bent the shaft slightly, and 30 tonnes of rotor running off centre would never get up to speed, let alone synchrinised.

So that company calculated the minimum shaft diameter that could be tolerated, and the amount that it had to be offset to rebalance the egg beater...then set it up, and machined the hard layer off, while getting the centre off mass back on journal centreline.

They've got some really clever cookies.
 
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