In 1757, when Watt was 21 years old, he worked as a maintenance worker at the University of Glasgow, responsible for repairing teaching instruments. This is the great opportunity of his life. In school, he met Blake, a chemist, and Robinson, who later became a physicist, and the three became good friends. Watt learned a lot of scientific knowledge from them and became very interested in steam engines.
At that time, the British had already begun to use steam-powered machines. In 1698, the Englishman Seville built the first steam pump (bènɡ), which used steam to press water to high places and drive the machine to rotate. Later, in 1705, a blacksmith named Newcomen built the first steam engine on this basis, which was quickly adopted by the industrial sector and spread to various European countries. However, this kind of steam engine consumes a lot of fuel, has low power, and is inconvenient to use.
Since the Department of Astronomy was recently established at the University of Glasgow, the instrument Jamie repaired was still a rarity in the school.
Therefore, professors often come to Watt with experimental instruments and ask: "I'm sorry, Mr. Watt, please take a look at it for me."
Watt's self-confidence is getting stronger and stronger. Stronger.
Afterwards, he went home to discuss with his father and opened a teaching equipment store near the school.
This incident had a significant impact on Watt's life path, allowing him, an ordinary worker, to enter the university.
Watt’s store is located in the corner of the university, but it is right on the street, so orders from outside the campus can be freely entered and exited.
Every morning, before the school opened, Watt had already opened the store door and worked hard.
Unconsciously, this place has become a club for professors and students. They all like to interact with this simple, optimistic, frank, and insightful young man. And, in Watt's store, they can easily see various equipment models.
On this day, Robinson came to Watt and said to Watt:
"Mr. Watt, I have a special business I want to talk to you about!"
< p>"Oh? What special business!" Watt asked curiously.Robinson said: "You know, in ancient times, when humans were not yet highly intelligent, they only knew how to do things with their own strength. As humans gradually became smarter, they thought of using the power of animals. .
“For example (pì) when it comes to carrying things, humans initially carried things on their shoulders. By the time they understood how to put things on a cart and use horses to pull them, human strength had evolved. It has increased several times, even dozens of times.
"But this is not enough. In addition to animals, we must come up with other stronger power to move the car. Is there such a power?"
After that, Robinson waited for Watt's reply, but when he saw that Watt was silent, Robinson continued.
"Yes, I think there is, and that is the power of steam. I think a car driven by steam will definitely be invented."
Watt raised his eyes She opened her eyes wide and looked at his face, but Robinson became more and more energetic as he spoke and continued.
"Although the idea of ??using steam to propel a car is surprising, it is by no means a dream! The steam pump (bènɡ) invented by Newcomen has been widely used by people. The power used to pump water is the same as the power used to propel a car! "
"What you said makes sense." Watt listened with relish: the description is interesting; interesting... ...In fact, I only learned about the Newcomen steam engine today. Although I already have some understanding of its principles and structure, this understanding is of no use. If you want to produce something new from it, you must have extraordinary imagination and inventive ability.
"Mr. Watt, as long as the two of us are willing to cooperate, there is nothing we can't do? Do you want to try the invention of steam-propelled cars?"
"Of course! "Watt took a keen interest in this new goal.
The next day, he immediately ran to the library of Glasgow University, found books about steam machinery, and then started experiments based on the principles.
He managed to find a cooker (the original prototype of the current pressure cooker) and used it as a device to generate steam. He connected a small water injector equipped with a sealed piston block to the cooker. And install a valve between the boiler and the water injector. This valve can rotate in both directions, up and down. According to the rotation direction of the valve (fá) door, steam can enter the cylinder (ɡānɡ) (i.e. the small water injector). ), it can also be discharged entirely.
Watt twisted the valve, steam entered the cylinder, and the small piston was pushed upward by the steam. This force could actually lift something weighing 7 kilograms.
"Ah, it's moving! It's moving!" Neither Watt nor Robinson could control their surprise.
Just when they were about to work together to make a big difference, Robinson graduated. He was going to serve in the navy and left the University of Glasgow. Watt had no choice but to continue his research on steam machinery alone.
After understanding the history of steam machinery, what Watt was eager to see was Newcomen's machinery.
Just at this time, Watt heard that there was a model of Newcomen's machinery in the herbarium of the University of Glasgow.
Watt took the model back to the shop. This was the first time he saw a model of the Newcomen machine.
Watt immediately dismantled the model machinery one by one, which was his usual practice. It was not until he understood its structure and operation that Watt completely repaired the damaged areas and reassembled it properly.
Watt couldn't wait to light a fire, put it under the boiler, and wanted to turn the model to see.
As soon as the water was boiled, a lot of steam came out. When the valve was turned, the steam entered the small steam cylinder and started to rotate.
"Ah! It's moving! It's moving!" But the strange thing is that the piston only moved three or four times before stopping.
"Hey! What's going on?" Watt tried again, but the result was still the same.
Three times, four times, five times... I did it several times, but the piston still stopped halfway.
"Strange! What's the reason for this?" Watt was thinking.
He immediately went to the library to look through the books to see if there was any problem, but he could not get any results. There is no other way to figure this out than to experiment again.
Watt re-examined all parts of the model machinery, and after several similar tests, he finally discovered the problem. The steam cylinder is made of brass, which makes heating and cooling slower. Steam cylinders made of iron should be used.
In addition, a more important point is: the reason why the machine cannot rotate smoothly is the temperature problem of the steam cylinder. Steam condenses immediately when it encounters cold. Therefore, when the steam is initially transported from the boiler to the steam cylinder, in order to prevent the steam from condensing needlessly, the steam cylinder must be kept above 100 degrees Celsius.
But if you want to condense the steam in the full steam cylinder and turn it into a vacuum, you have to lower the temperature of the steam cylinder to normal temperature, which is below 15 degrees Celsius.
The purpose of spraying cold water into the steam cylinder is to cause the temperature to drop rapidly and make the steam condense earlier. That is, the steam cylinder must be constantly heated and cooled.
But the problem is: once the temperature of the steam cylinder is cooled, a large amount of steam must be consumed to raise it to the boiling point.
Newcomen’s invention could no longer continue at this point.
Watt was a true inventor with both knowledge and technology. He has always been rigorous and cautious about the structure and function of the Newcomen machine. He studied it with an attitude and found its shortcomings.
For several days, he always sat in front of the workbench, not even bothering to do experiments. Sometimes I would sit in front of the stopped machine and meditate quietly, then stand up and walk around the room muttering.
In the past few days, whether he was sleeping, eating or working, he kept thinking about this issue. On this day, he went out for a walk. From the streets and alleys, from the square to the main road, Watt walked for almost an hour.
Watt inadvertently raised his head, and what he saw was a piece of green grass.
“Extremely beautiful!”
Watt relaxed and sat down on a bench, closed his eyes, held his chin and rested quietly.
At this time, the problem of "heat and condensation" quietly disappeared in Watt's mind, making Watt feel extremely comfortable.
"Alas! Go home!"
Watt stood up and stretched, then slowly and leisurely: describing the movement slowly and unhurriedly. I walked home, but I couldn't help but think of his problem again.
Just after walking through the laundry and arriving at the hut where the shepherd lived, another thought flew into his mind.
“Since steam is an elastic object, it penetrates everywhere where there is a vacuum. If a channel is added between the cylinder and the steam chamber, the steam will enter and condense. In this way, there is no need to cool the cylinder, and the problem of the Newcomen machine is easily solved: if the main problem is solved, other related problems can be easily solved."
Isn't it unexpected? The idea that came out of his mind completely solved the problem that he had been thinking about for a year.
Because steam has propulsive force, it can rush into the vacuum container. If a vacuum container is attached to the steam cylinder, the steam will definitely enter that container after passing through the steam cylinder. Then, the steam can condense in that container instead of condensing in the steam cylinder.
In other words, in order to condense the steam, just make another condenser and connect it to the steam cylinder. In this way, the steam will condense there without cooling the steam cylinder, and the steam cylinder will always be It's a vacuum.
Various functions are carried out in different containers. The steam cylinder can always maintain heat, and the condenser will always cool it down. In this way, not even a trace of steam will be wasted. .
Watt’s brain was spinning like a windmill.
However, if this condenser adopts the Newcomen machine method and sprays cold water to condense the steam, how will the sprayed water, condensed water, and leaked air escape?
This problem was bothering Watt again. After repeated thinking, he came up with a way.
Set a drain port below to squeeze water out of the pipe. When steam rushes in, the air can also be squeezed out.
Watt’s idea is getting closer to the edge of success step by step (yuán). Thinking of this, he had already walked two streets. At this point, he had come to the conclusion that he would build another condenser next to the steam cylinder.
How simple this is! In an afternoon, cozy and cozy (qiè): satisfied; gratifying; comfortable. During a walk, I came up with this invention.
As Watt concentrated on inventions, the business in his shop was also slow. All the money he earned from teaching equipment was used up. In addition, he borrowed 1,000 pounds from Dr. Dick, but Watt The new steam machinery has not yet been completely successful. In order to experiment with the new device, a huge amount of money has to be spent. Who will pay for this money?
Robotock was the founder of a company called Galen Iron Works and had strong capital. At that time, he was engaged in the coal mining business, so he was very concerned about the drainage problem in the coal pit.
What a rare opportunity this is!
Due to the introduction of his friend Dr. Dick, Robock established a cooperative relationship with Watt.
Watt was so happy that he immediately started experimenting with the new model until the new model was successfully tested.
"There must be no problem, let's apply for a patent immediately!"
Watt went to London to apply for a patent in August of that year.
Later, in early 1769, Watt's steam engine patent was approved.
Watt was already 33 years old at that time. It took nearly 10 long years from the beginning of the experiment. During these 10 years, Watt endured financial pressure and hardship in life. Encountered many difficulties and setbacks. Frustration (cuò): failure; failure. , but he was not discouraged, because he knew deeply that this new machine would be a great and useful invention.
He decided to improve and manufacture the new machine in a large house in Robock. The house was located on a small river in a valley, with easy access to water and unnoticed.
In September 1769, it took six months to complete the first machine.
But Watt's first steam engine was not successful.
The condenser did not work very well, and the steam cylinder made by Galen Iron Works was also poorly cast and could not be used at all. The biggest difficulty was to keep the piston tight. Watt used cork, oilcloth, linen, old hats, and kraft paper to wrap the piston, but the steam still leaked out, and those methods were of no use at all.
Watt was very discouraged.
His friend Robinson wrote to encourage him: "The fault of this failure is not your invention. It is entirely due to the poor manufacturing technology of the factory. As long as there are reliable workers, It will definitely succeed." Watt then plucked up the courage and planned to start over.
At this time, Robock, who supported him, lost money in business and could no longer support him. The inventor was in real trouble. He had to work as a surveyor and engineer to support his family's livelihood. But at this time, his wife also passed away due to illness. Watt fell to the lowest point in his life. But he was still enthusiastically engaged in the research of steam engines, because this was his life goal.
The hard work paid off, and Watt’s hard work finally attracted the attention of a big businessman. He was Robock's friend Bolton. He took over Robock's position and cooperated with Watt, so that Watt finally had the opportunity to build his steam engine again.
The Newcomen engine in the past was not so much a steam engine as a pneumatic machine, because it rotated with the help of atmospheric pressure and could not avoid the disadvantage of air leakage.
The machine invented by Watt fully utilized the expansion force of steam and could be described as a veritable steam engine.
The test was very successful. Watt and Balton were very satisfied, so they set up a steam engine manufacturing workshop in the Seho Manufacturing Factory and prepared to officially engage in the manufacture of steam engines.