Coal Mines, Steam Engine, Electric Motor, Coal-Fired Power Plants, Water Pumps, Ventilation Fans, Strip Mining, Draglines and Coal Washing

Posted by PITHOCRATES - September 12th, 2012

Technology 101

The Steam Engine pumped Water from Mines allowing them to go Deeper as they followed Veins of Coal

Petroleum is the lifeblood of advanced economies.  It propels our airplanes, ships, trains, trucks, ambulances, air ambulances, fire trucks, cars, etc.  It moves everything.  Our sick and injured.  Our families.  Our food.  Our goods.  The raw materials that build the world we live in.  You would not recognize the world if we removed petroleum from it.  There would be no aviation.  No emergency vehicles that could respond in minutes.  No family car.  But we could still have ships and trains.  Because before petroleum there was coal.

Before the Industrial Revolution we used animals to move people and things.  We were using fuels for other things.  But not to move people and goods.  Until there was a problem getting that fuel.  The British were mining coal near the coast.  But there was a problem.  As the coal veins they mined moved under the sea they filled with water.  Limiting how far they could follow those veins.  They had a pump.  Driven by a crude steam engine.  But it just didn’t do the job very well.  Until a man came along and improved it.  James Watt.  Who improved that crude steam engine.  And changed the world.

The steam engine pumped water from coal mines allowing them to go deeper as they followed veins of coal.  But the steam engine had other uses.  They could power a drive shaft in a factory.  Allowing us to build factories anywhere.  Not just by moving water that drove a waterwheel.  And using a steam engine to move a train allowed us to connect these factories with other factories.  And to the stores in the cites that bought the things they built.  Steam-powered tractors replaced the horse and plow on the farm.  While steam locomotives brought coal from distant coal mines to our homes we burned for heat.  Coal was everywhere.  We had a coal-based economy.  And a coal-based life.  The more we used the more we had to mine.  Thanks to the coal-fired steam engine we could mine a lot of it.  And did.  It powered the Industrial Revolution.  And powers our modern economy today.  Because coal even powers the engines that replaced the steam engines in our factories.

The two largest Electrical Loads in a Coal Mine are the Water Pumps and the Ventilation Fans

We’ve replaced the steam engines in our factories with the electric motor.  Instead of having a main drive shaft through the factory and a system of belts and pulleys we put an electric motor at each workstation.  And connected it to the electric grid.  Greatly increasing our productivity.  And the electric power to drive these electric motors came predominantly from coal-fired power plants.  Coal has never been more important in the modern economy.  It provides about half of all electric power.  Followed by natural gas and nuclear power at about 20% each (though natural gas is on the rise).  Hydroelectric dams provide less than 10% of our electric power.  And everything else provides less than 5%.

Just as the steam engine made mining more efficient so did electric power.  Mines can go deeper because electric pumps can more efficiently pump water out of the mines.  And large fans can circulate the air underground so miners can breathe.  As well as disperse any buildups of methane gas or coal dust.  Before they can explode.  Which is one of the hazards of mining a flammable and, at times, explosive material.  The hazard is so real that you will not find ventilation fans inside the mine.  You’ll find water pumps deep in the mines.  But not the ventilation fans.  Because if there is a fire or an explosion underground they’ll need to protect those fans from damage so they will still be able to ventilate the mine.  For if the mine fills with smoke surviving a fire or an explosion will matter little if you cannot breathe.

The two largest electrical loads in a coal mine are the water pumps and the ventilation fans.  Mines consume enormous amounts of electric power.  And most of it goes to fighting the water seepage that will fill up a mine if not pumped out.  And making the mines habitable.  Electric power also runs the hoists that haul the coal to the surface.  Transports miners to and from the mines.  And runs the mining equipment in a confined space without any hazardous fumes.  As critical as this electric power is to survive working in such an unfriendly environment more times than not the power they use comes from a coal-fired power plant.  A plant they feed with the very coal they mine.  Because it’s dependable.  That electric power will always be there.

Coal will always let you Charge your Electric Car Overnight and Surf the Web in the Morning

But we just don’t mine coal underground.  We also dig it up from the surface.  With strip mining.  Most of the coal we use today comes from great strip mines out West.  Where they use mammoth machines called draglines to scrape away soil to get to the coal.  And then they scrape out the coal.  These machines are as big as ships and actually have crew quarters inside them.  They even name them like ships.  They operate kind of like a fishing rod with a few minor differences.  Instead of a rod there is a boom.  Instead of nylon fishing line there is a steel cable up to two inches in diameter.  And instead of a hook there is a bucket big enough to hold a 2-car garage.  The operator ‘throws’ the bucket out by running it out along the boom.  Then drops it in the dirt.  Then drags the bucket back.  The massive scale of the dragline requires an enormous amount of power.  And the power of choice?  Electric power.  Often produced by the very coal they mine.  Some of these machines have electric cables even bigger around than the cables that drag their buckets.  At voltages of 10,000 to 25,000 volts.  Drawing up to 2,000 amps.

These draglines can mine a lot of coal.  But it’s a lower-quality coal than some of our eastern coal.  Which has a higher energy content.  But eastern coal also has a higher sulfur content.  Which requires more costs to make it burn cleaner.  In fact, before any coal ships today we wash it to remove slate as well as other waste rock from the coal.  And it is in this waste rock where we find much of the sulfur.  So the washing makes the coal burn cleaner.  As well as raise the energy content for a given quantity of coal by removing the waste that doesn’t burn.  There are a few ways they do this.  But they all involve water.  Therefore, at the end of the process they have to dry the coal by spinning it in a large cylindrical centrifuge.  So a lot happens to coal between digging it out of the ground and loading it on a unit train (a train carrying only one type of cargo) bound to some power plant.  And chances are that it will go to a power plant.  For our coal-fired power plants buy about 80% or so of all coal mined.  So if you see a coal train it is probably en route to a coal-fired power plant.

Coal created the modern world.  And it powers it to this day.  From the first steam engines that dewatered mines to the coal-fired power plants that power the massive server farms that hold the content of the World Wide Web.  Yes, coal even powers the Internet.  As well as our electric cars.  For only coal will be able to meet the electric demand when everyone starts plugging their car into the electric grid overnight.  Because solar power doesn’t work at night.  And wind power is even less reliable.  For if it’s a still night you’ll have no charge to drive to work in the morning.  But if you plugged into coal you’ll always be able to charge your electric car overnight.  And surf the web in the morning.


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