My trip through the power plant

[Inspector507]

A very good friend of mine works in a Midwestern power plant. Probably not a good idea to mention where this is, I took a camera in there /forums/images/graemlins/grin.gif Probably not a smart thing on my part due to security concerns.
Anyway, we went to visit them last month. He works in the coal yard at the plant and I wanted to see the equipment he runs daily. He regularly runs two different models of Cat D9's, a D10, three different Cat scrapers. I got more pictures of the plant than I did of the Cat's because it got dark on us. One of the things I did not photograph was the dumping operation. Darn it /forums/images/graemlins/crazy.gif that was neat.

He also gets to run the train anywhere from 6-15 miles, depending on where they dropped the coal cars. Here is the engine. Fully computerized, carrying 5000 gals of diesel in the tanks.

 

[Inspector507]

Once the train gets back to the yard, the engine is pulled into the dumping building, it is then disconnected, leaving cars that are full and stretch a mile or so outside. The first car is lined up by the engine at the indexer. The indexer has 2 arms that come down between 2 cars and then it pulls them into the dumper. The dumper has 2 arms that come down on top of the car and then the whole car is turned upside down while it's still connected to the ones in front and rear. The indexer then moves the next car in to be dumped.

 

[Inspector507]

This is the coal yard. You can see the mile long train of cars. Also the equipment needed to maintain the yard in the lower left. Inside each tower of coal is 3 feeder tubes that take the coal into the plant underground via belts and augers.
You can also see the reserve pile of coal in the background. They stock some of the "crap coal" back there to mix in occasionally with the good stuff.

 

[Inspector507]

I didn't get a good shot of the equipment, but they are out in the yard waiting on the guys to get to work /forums/images/graemlins/grin.gif
Several D9's a D10 and several Cat scrapers.

You also see the empties running down the track.

 

[Inspector507]

This is the blade on the D10.....11' high and 16' across....WOW.

I got to sit in it but didn't get to run it. Swing shift hadn't started to work in the yard yet or I may have been able to beg my way in.

 

[Inspector507]

It got dark on us but this a part of that mile long train. These have already been dumped.

 

[Inspector507]

Once th coal is fed underground into the plant, it gets sent up 16 stories to the top level. There the coal is moved by feeder belts to be dumped into the feeders, which feed the coal to any of 3 boilers.

 

[Inspector507]

The coal is dropped down into the feeders and then fed into the boilers. The pipe with the coal in it is the rusty colored one, I think.

 

[Inspector507]

The coal is injected into the boiler here. I asked how it was injected, but he didn't really know.

 

[Inspector507]

The boilers heat water to make steam which in turn runs the tubines on the generator. But first you have to get water from somewhere to accomplish that.
This a 2,000 acre man-made lake that is filled from a local river. The water used to cool the boilers and used to make the steam comes from here.

 

[Inspector507]

Once the water has turned to steam it travels to the turbines. There are 3 of them in this plant, this is just one set. One turbine/generator is capable of producing about 580 MW of electric at 360,000 volts. The total for the plant could be as high as 1,760 MW (thats MEGA watts)

 

[Inspector507]

When the water is used for cooling and when the steam is recovered, it goes back into the lake to cool and is re-used. A lot is lost in the process of course.

 

[Inspector507]

This is the switch yard......lots of power flows through this yard.
Thats the last pic. I think I did good to get the ones I did. We did have to take a few detours inside the building to dodge the managers /forums/images/graemlins/grin.gif
I got to see the control room, but kept the camera discreetly hidden in my pocket.

 

[RobS]

Fascinating Inspector, thanks for the field trip. I got to tour a nuke plant under construction years ago courtesy of a friend of mine who worked there. It too was quite impressive.

My office is right along a high traffic rail line where those mile long coal trains go through quite often. Interesting how they dump. Do they have to unhook the cars to turn them over?

Thanks again /forums/images/graemlins/smile.gif

 

[MossRoad]

Hey Rob. That reminds me... a few weeks ago I had to cross the tracks by the Amtrak station and we had to wait for two trains. The eastbound was full of coal and the west bound was full of coal. I think they send high sulfer coal in one direction and low sulfer in the other, but to me, it looked like the same coal in each. The cars on both trains were identical shiney newer cars and they were both being hauled by Norfolk. They even looked to be loaded exactly the same. ... real efficient system, hmmm? /forums/images/graemlins/tongue.gif

Inspector,
Thanks for the pics. Very interesting. /forums/images/graemlins/laugh.gif

 

[Inspector507]

Rob,
<font color="blue"> Do they have to unhook the cars to turn them over? </font>

No, that was the fascinating part. All of the cars are painted or identified on one end with a Yellow stripe/paint/decal, whatever. If they are all connected properly, the yellow end is facing the dumping operator. In this orientation, they can be turned upside down, these went approx. 150-160° upside down. If one of the cars are connected backwards, it could flip the car in front or behind it. The couplers have a rotating sleeve to go one direction more than the other.
The dumper can be all automatic or operator controlled. My Buddy prefers to do it manually, otherwise it's too boring to just sit and watch the computer do it all.

 

[gsganzer]

I've done some work at a number of coal plants around the country. The coal trains and coal yards are always amazing. When you see all that coal (typically 30 day supply) you realize that there's a giant hole in the ground somewhere. A lot of the coal is PRB (powder river basin) from Wyoming and Montana, this is typically low sulfur. When you see all that's involved in a coal boiler, you wonder how they can even make money. As you saw on your tour, the dozers push the coal to a belt where it's conveyed to silo's. From the silo, it goes to a pulverizer where it's ground into a fine powder. It's then conveyed through piping to the fuel guns. The piping is often ceramic lined to prevent erosion from the coal. Because it's a fine powder, it burns much like a gas as it shoots out of the fuel nozzles.

Then the plants need to deal with all of the ash generated, another labor intensive operation and the maintenance on the boiler and steam turbine. Boiler feedwater chemistry, baghouses and electrostatic precipitators for particulate removal, scrubbers and selective catalytic reduction systems for NOx/SOx reduction etc. etc.

It's always an amazing process that leaves me wondering about the economics.

 

[jwstewar]

Hey, that was pretty cool. I've always wanted to be a train engineer. That would be the ideal way, drive the train, but yet not be away from home for days/weeks upon end. Neat how they dump them.

This was a neat set of photos of something that most of us probably won't ever see. Thank you. /forums/images/graemlins/laugh.gif

Pretty interesting seeing power from the "other side," huh?

 

[Inspector507]

Yes it was Jim, especially seeing the control room. They can control almost any electrical/mechanical function in the plant. One thing they can't control are the humans /forums/images/graemlins/grin.gif

 

[slowzuki]

To answer a few Q's you had: THe coal is pulverized in ball mills, these are big drums full of iron balls that rotate. The coal dust is then blown into the boiler.

The river water is used for cooling the condensor but the water inside the turbine is in a closed loop. The water goes from the boiler feedwater pump to the boiler to the turbine to the condensor then back to the bfwp.

The reason they do this is the boiler would become scaled and clogged too quickly. The water in the loop is demineralized and treated with anti-corrosion chemicals to make the boiler tubes last longer.

Neat photos! Here they mostly use trucks or boats to deliver coal.