Embedded Files
Though not formally developed hand in hand, the rich history of the creation and innovation of steam power is quite amazing. From achieving the impossible to small events that turned out to be huge thresholds, this is the story of steam power.
History
History
Steam has been in use for thousands of years, mainly for cooking and brewing. The first boiler predecessors were made in England, the first being for the Newcomen engine. Basically a large brewers kettle, and the steam powering the engine pumping water from the mines.
Types of Boilers
Types of Boilers
Boilers have indeed come a long way since the early days of the Rocket and early steam power. While sometimes not the most efficient, they're definitely massive improvements over their ancestors. The reuse of exhaust heat reduces the need for more fuel intake, and different types of coal can produce more heat, or burn longer, as needed.
Fancy Toy?
Fancy Toy?
The first ever realization of steam power was by the ancient Romans. A gadget called Aeolipile, was a cauldron of water with a lid, and the mechanism on top of it. When set over a fire, the steam created would fill the ball, and the steam exiting the elbows on the ball would make it spin.
The History of Steam Engines
The History of Steam Engines
Newcomen Atmospheric Engine
Newcomen Atmospheric Engine
Thomas Newcomen invented and built his atmospheric engine to pump water out of Englands coal mines, as water was a huge problem. It turned out to be extremely successful, and was extremely useful.
The Newcomen atmospheric engine was first used in Cornwall in the very early 1700s. It works in an atmospheric design, because after steam moved the cylinder to its farthest position, some water was sprayed into the cylinder, causing the steam to condense, creating a vacuum.
Its use spread all throughout northern England, and Wales. There were a few sprinkled around Europe, and there’s even evidence of one in Midlothian, VA, USA.
These engines typically saw use for over 50 years, and inspired many to improve upon its design, and even use it for other applications.
Watt Beam Engine
Watt Beam Engine
Between 1763 and 1775, James Watt, who realized steam power's use when harnessed correctly, began designing his own improved steam engine. He looked at the Newcomen design, and saw that when water was introduced into the cylinder, it cooled off to the point where it wouldn't operate.
The steam would condense as soon as it entered the cylinder, and a significant amount of heat had to be used to heat it up again. Watt instead added a second cylinder filled with water, so the steam could first exit the cylinder and condense in the second one, leaving the main cylinder warm enough for continued operation.
The piston rod was connected to a beam, which was hinged in the middle, driving a flywheel on the opposite end. The flywheel creates inertia that is used to help push the exhaust steam from the cylinder, and was used to power a pulley system. For many industrial businesses in England, this became their first engine, and revolutionized their output, which was a huge step towards mass production.
The Watt beam engine was introduced commercially in 1776, the first being sold to Carron Ironworks, of Scotland. It was the first practical steam engine, and was efficient. It had the same power as the Newcomen engine, but used half as much fuel.
It paved the way for England's industrial revolution, and once the patent expired in 1800, other manufacturers copied the engine. Ever since the invention of the Watt engine, most steam power applications used similar designs until the 1900's.
First Steam Powered Vehicles.
First Steam Powered Vehicles.
In 1765, a french army captain, Nicolas-Joseph Cugnot, began experimenting with working models of steam powered vehicles for the French Army, intended for transporting cannons. In 1769, he built a model of a three-wheeled fardier à vapeur, or steam powered cannon cart. By 1770, he built a full size version, specified to carry 4 tons, at a rate of 4.8 miles in an hour, though it probably never did.
It wasn't well balanced, due to the location of the boiler, directly over the central front wheel. The boilers performance was very poor, the fire had to be relit every hour and steam built up, reducing its speed and distance. Despite this, it still had an impact and proved the possibility of using steam power.
In the 1770’s, John Blakey designed a horizontal type boiler, and an american, Oliver Evans, recognized that it's design was the best. In a vertical boiler, almost all heat goes straight up and out the top. In a horizontal boiler, the heat takes more time to get out, therefore more heat transferred.
He proposed that lots of work could be done if this type of boiler was used correctly. He designed his own boiler, a single flue one pass boiler. This was the predecessor of many an Englishman’s multiple fire tube design, to be used in mining and early locomotives. One man who did so was George Stephenson, who helped his son designed and built the Rocket.
Robert Stephenson, of Robert Stephenson and Co. designed and built the rocket with the help of his father George Stephenson for the Rainhill trials in Lancashire, in 1829. It's unclear where the multiple firetube idea came from, but the increased heating area made it the most successful locomotive at the trials.
The firebox is the hottest part of any locomotive, and the Stephensons knew this. They designed the copper firebox to have a water jacket around it, and Rocket made steam very effectively. Most other engines had 4 driving wheels and connecting rods between them, but Rocket only had 2, and the cylinders were connected directly to them.
At the trials, each locomotive pulled 3 times its weight, and Rocket did this perfectly, as half the engines weight was on the pair of drivers. The last innovation rocket made use of was a blastpipe, which exhausted the steam up the chimney, increasing draft, and heat.
This locomotive was the most successful of the Rainhill trials, and the Robert Stephenson and Co. continued building locomotives for years. The rocket served the Liverpool and Manchester Railway until roughly 1836. It's been modified several times, but it is now preserved at the National Railroad Museum in York.
The Rocket
The Rocket
Scotch Marine Firetube Boiler
Scotch Marine Firetube Boiler
For heating or some manufacturing applications, more traditional fire tube boilers are used. This means the heat from the firebox, where the fuel is combusted, travels through tubes surrounded by a body of water. They use fuel like gas, or coal, among others. Coal is stored in a hopper, and when needed, either an auger or belt moves it out the bottom.
These boilers usually have a moving chain grate, and the fuel slowly makes its way through the firebox. The chain grate moves slowly enough for the fuel to burn thoroughly, by the time it reaches the end, where the remains and ashes are removed from the bottom of the firebox.
These are known as automatic stokers. Scotch marine boilers are laid out horizontally, like a locomotive boiler.
They’re usually gas fired, with one or multiple burners, sending a massive jet through the firebox. They can also have automatic stokers. Some Scotch marine boilers are a three pass fire tube flue system.
The flue gas travels from the firebox towards the front of the boiler. It rises and returns through the boiler a second time.
It reverses again in a smokebox just over the firebox door, and passes to the front and out a separate exhausting smokebox. The more passes in a boiler, the more heat extraction rate, or efficiency. Basically, this means less heat goes out the stack.
Google Sites
Report abuse