How steam engines work

The basis of a steam powered engine is as follows. A substantial amount of
liquid, "water", is collected into a boiler. The boiler is simply a tub that
contains the liquid, and; at it's top is a tube where steam rises into. Some
boilers may have tubes where heat rises directly into the boiler, or a heat
source such as wood or coal may be placed underneath the boiler.

Either way, the heat brings the liquid in the boiler to a "boil". As when any
liquid is heated, it gives off steam as it's chemical properties become gas. The
steam rises to the top of the boiler, where it is released into another chamber,
the "cylinder". The cylinder is merely an oblong shaped tube where pressure is
released into one end and emptied in the other end.

This works via the use of a piston. The piston is an object sealed inside the
cylinder that works like a rubber band. As steam enters through the front of the
cylinder, the piston is forced towards the back of the cylinder. When the piston
reaches the back of the cylinder, it trips a pressure relief valve. When the
pressure release valve is tripped, all steam is emptied into the outside areas
sending the piston slamming back into it's original position, much like snapping
a rubber band.

As long as the boiler is kept at the appropriate temperature, it will
continually pump steam into the cylinder, so each time the piston is "slammed"
backwards, the pressure propels it forwards again.

The piston also has a crankshaft or turning mechanism connected to it. This can
be anything as simple as a long tube that sticks out the end of the cylinder.
When the piston goes forward, the tube goes outwards from the cylinder, and when
the piston goes backwards, the tube is forced backwards as well. This "pumping"
motion is connected to whatever the steam engine is designed to operate.

And that, my friends, is how a steam engine opererates.

Learn more about this author, Wes Laurie.
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