gnovel Chapter 34 The Institute of Natural History is still useful
Chapter 34 The Institute of Natural History is still useful
After listening to Wang Lai's report on the steamship, Liu Yulong directly instructed him:
"The steam engine is like the steel mill; it continues to be upgraded, improved, and iterated, while production is rapidly expanded."
"All shipyards should build steamships as much as possible, and only continue to build traditional sailing ships when the supply of steam engines is insufficient."
This matter involves a wide range of people, and several secretaries from the Institute of Physics agreed to it together:
"Your Majesty, we will keep this in mind."
Wang Lai went on to report on a situation and also asked a question:
"Your Majesty, after the steel mill was able to mass-produce high-quality steel, the Machinery Department resumed the research on steam turbines in accordance with Your Majesty's previous decree."
"A six-bladed steam turbine has been built, and its maximum output is comparable to that of a reciprocating steam engine."
"Moreover, given the characteristics of steam turbines, it is clear that they can be further expanded to obtain greater power."
"By His Majesty's decree, steam turbines may be used on large ships."
"However, the speed of a steam turbine is much higher than that of a reciprocating steam engine; it can only achieve relatively high efficiency after exceeding three thousand revolutions per minute."
"In theory, the speed can be changed by using a reduction gear to drive the paddle wheel."
"However, the paddle wheel cannot rotate too fast, usually around 30 to 60 revolutions per minute. If the speed is too fast, it will be easily damaged."
"The reduction gear is extremely difficult to design and manufacture, as it is reduced from thousands of revolutions per minute to tens of revolutions per minute."
"The craftsman wishes to consult Your Majesty if there is a better solution to this matter."
Liu Yulong has officially decided on the name of the steam turbine, and the craftsmen are no longer allowed to call it a disc steam engine. The European-style steam engine will also be renamed a reciprocating steam engine.
Liu Yulong also specifically requested that, after the application of reciprocating steam engines, the development of steam turbines should continue.
After the converter steelmaking technology was basically perfected, the smelting cost of refined steel dropped sharply, and the research on steam turbines was subsequently expanded.
After building a larger steam turbine and testing its performance, it was prepared for use in ship conversion experiments.
But the craftsmen encountered a complex problem that was difficult to solve.
The most natural way to propel a ship with a machine is to use a waterwheel-like "paddlewheel" to build a steam paddlewheel ship.
Reciprocating steam engines are heavy and rely on crankshaft and piston transmission, so they are suitable for very low speeds, usually in the range of tens to hundreds of revolutions per minute.
Paddle wheels need to continuously slap the water surface, and the appropriate rotation speed is also very low, usually tens of revolutions per minute.
To drive a paddlewheel with a reciprocating steam engine, usually only one reduction gear is needed, or even no reduction gear is required, and the steam engine can be used to drive the paddlewheel directly.
Therefore, the technology of paddle steamers with reciprocating steam engines was extremely easy, which is why they were quickly adopted after the invention of the steam engine. They can be considered a derivative technology of the reciprocating steam engine.
However, steam turbines are different. Normally, they start at 3,000 revolutions per minute, and once they are fully developed, they can reach 10,000 revolutions per minute.
The propulsion wheel requires a hundredfold reduction gear set, which is very difficult to manufacture.
If we could mass-produce this, we could directly produce internal combustion engines and automobiles, without having to bother with reciprocating steam engines.
As for how to solve the problem, Liu Yulong naturally thought of the propeller.
However, this wasn't a strange idea; Liu Yulong felt that others had probably thought of it before.
"Since the craftsmen have already made steam engine fans, and fans can blow air, they can also blow water."
"With so many craftsmen in the Gewu Academy, surely someone must have considered this design?"
"However, the fan needs to be changed in shape, with the long, straight blades replaced by short, round blades like a palm leaf fan, arranged in a spiral at the end of the main shaft."
"Submerge it in the water, rotate it to push the water backward, and in turn, make the ship move forward."
"This device can be called a propeller."
"The propeller will not continuously slap the water surface, so the rotation speed can be greatly increased, which should be around 300 revolutions per minute."
"For such a high-powered turbine, a reduction gear of at most twenty times is sufficient."
"Small-powered turbines can even be directly driven."
Wang Lai thought for a moment and immediately nodded, saying:
"Your Majesty is wise; indeed, craftsmen have tested this propeller design."
"The rotational speed can indeed be increased significantly, which greatly reduces the design pressure on the reduction gears."
"Even using a low-speed steam turbine to directly drive the propeller will not cause damage, but the performance will be significantly reduced."
"But this creates two other difficulties."
"If the steam turbine is placed above the water, it needs to be turned twice by a 90-degree gear to drive the propeller."
"This structure is very easy to be damaged under high-speed rotation."
"If the steam turbine is placed below the water surface and the drive shaft passes directly through the hull, the sealing problem will be difficult to solve."
"Because the spindle needs to rotate at high speed continuously, it cannot be directly sealed."
"The craftsmen proposed using oily wood, brass, and asbestos rope for sealing, while also using a separate watertight compartment at the stern and a pump to continuously drain water."
"However, these sealing materials wear out quickly, and more importantly, the leaky stern compartments are also prone to damage..."
Steam turbines are a better match for propellers, but getting propellers onto ships presents new and more complicated problems than with reciprocating steam engines.
This series of new problems requires special attention and is likely a negative consequence of leapfrog research and development.
When Wang Lai explained the situation, the surrounding scholars focused their attention, wanting to hear what good ideas Liu Yulong had.
Liu Yulong recalled how modern ship propeller drive shafts are sealed.
Like many men, Liu Yulong was curious about this kind of thing, so he talked about it with the engineers while working at the shipyard.
Liu Yulong then directly presented the explanation the engineer had given him to the craftsmen before him:
The issue of waterproofing the propeller drive shaft falls under the category of "dynamic sealing".
"Once the transmission structure starts moving, there will definitely be leakage; it is physically impossible to achieve a 100% seal."
"Therefore, we should abandon the idea of 'sealing' and instead use the approach of 'preventing water leakage' to solve the problem."
"The goal of sealing is to prevent water leakage, but sealing is not the only way to prevent water leakage."
"We can blow water, oil, or even air from the inside out."
"As long as the pressure from the inside out exceeds the water pressure from the outside in, then water will naturally not be able to enter the cabin."
"It's like offensive defense. As long as we can kill all the enemies, we naturally won't need to defend ourselves anymore."
The scholars all suddenly realized what was happening and couldn't help but praise it unanimously:
"I see, we can solve it from a different perspective."
"So that's how it can be done."
"Your Majesty is wise."
"With this method, there will be no more obstacles to putting steam turbines on ships."
After venting their emotions, Liu Yulong and the other scholars continued to give instructions on specific methods and details that they had overheard:
"Change the bushing of the drive shaft from one to an extended cylinder."
"Several semi-independent cavities are left inside the long tube, one of which is used as the original bearing bushing."
"The other two use oil pumps to pump in oil, and the other two use air pumps to continuously blow in air."
"The oil first supplies oil to the bearing, while blocking air penetration to prevent air from being blown into the bearing and creating cavitation bubbles."
"Air is continuously blown outwards, reducing oil penetration and waste."
"This requires air pumps and oil pumps. The manufacturing logic is similar to that of water pumps, but the processing difficulty is closer to that of steam turbines."
"At the same time, the gaps between the semi-independent cavities in the bushing should be as narrow as possible."
"To prevent the oil, air, and seawater from gradually mixing together and losing their effectiveness."
"Add two layers of shrink-fit sealing rubber gaskets on the outside, which open when the drive shaft rotates, without hindering the movement of the drive shaft."
"When the machine stops, it contracts to form a static seal to prevent air leakage, water seepage, and oil seepage."
This is the waterproofing method used for the main shaft of modern large ships, which typically has a total of seven layers.
According to the shipyard engineers, it can be made watertight for life, at most damaging one or two layers of the structure.
The scholars quickly praised it and carefully recorded these things, which saved them a lot of brain cells.
After Liu Yulong and the others took notes on the spot, he continued to talk about other issues he was concerned about:
"Research on various processing tools driven by steam engines should not be relaxed either."
Steam blowers, water pumps, sawing machines, coin-making machines, forging machines, rolling mills, etc.
"Then there is the research on materials, the research on the properties of various alloys, which must also continue."
"For example, what kind of material can be added to pure iron, and what kind of effect can be obtained?"
"What kind of processing method should be used, and what kind of results can be obtained?"
"These are all long-term tasks for the future, and we can never stop."
Even if there are no results in the short term, the support in terms of manpower and resources cannot be reduced.
"Discovering a new material could solve a long-standing problem."
"Make tools with higher precision, produce machines with higher levels of sophistication, smelt materials with higher performance, and then make new tools."
"Production and processing capabilities are constantly upgraded in this cycle."
"By the way, have there been any new discoveries in this area recently?"
"Whether it seems useful or not is not the point for now. Let me make the judgment. Let's talk about the particularly special findings first."
The secretaries exchanged glances, and Li Rui, somewhat uncertainly, stated a situation:
"A recent report mentioned something."
"A craftsman is exploring machining methods for large drive shafts. In his experiment, he tried to roll steel columns longitudinally using a rolling mill."
"However, after rolling, the strength of the steel column not only did not increase, but actually decreased."
"After further testing, he discovered that the strength of the rolled steel column decreased continuously from the outside to the inside, with the core of the steel column being the softest."
"It will become pitted and uneven when tapped lightly, like dough."
"This was exactly the opposite of what he expected, and the other craftsmen in the Metallurgical Department also found it very strange."
"Some craftsmen were unwilling to believe it, so they went to conduct separate tests, but eventually they all reproduced the result."
"Some craftsmen also realized that tree trunks were used to pave the ground to transport large stones, which also had this effect."
"When a tree trunk is crushed by boulders too many times, the middle part becomes extremely fragile and eventually collapses completely."
"Some craftsmen have noticed that this collapse is happening from the inside out."
After listening to these explanations, Liu Yulong was briefly puzzled, but then he suddenly realized what might be going on.
So, with a half-smile, he asked a seemingly unrelated question:
"Has anyone tried using a mandrel to press down on the center of a steel column to produce steel pipes?"
Li Rui immediately nodded in reply:
"Some craftsmen have tried this method for making copper pipes, but it failed when applied to steel pipe processing..."
"Wait—Your Majesty, do you mean to roll the steel column longitudinally first, and then apply pressure?"
Li Rui realized halfway through his sentence that if the inside of the steel column would become soft, it could be pierced by the core rod.
Liu Yulong smiled and said to Wang Lai:
"Set up a team as soon as possible to study this phenomenon and the processing method."
"The rolling mill rolls should not be parallel to the steel column. Instead, three rolls can be tilted at a certain angle to continuously roll the steel column."
"Use bearings to fix the position of the steel column, and let the steel column rotate under the pressure of the rollers."
"After continuous long-term rolling, will the steel column's center soften to its limit and tear?"
"Regardless of whether it will tear, prepare another mandrel and use it to press down on the core of the steel column while rolling."
"To confirm whether it is possible to produce steel pipes using this process with mandrel pressure."
Several scholars suddenly realized something, and Li Rui, who had been singled out by Liu Yulong, immediately agreed:
"I have noted it down. I will make the arrangements today!"
Liu Yulong knew this method would succeed because it was based on the technical principle of seamless steel pipes.
Seamless steel pipes are a very common pipe material in modern industry, and their research and development and production are not particularly difficult.
They had stable quality steel, a basically mature steam engine, and large rolling mills capable of rolling steel billets.
Those who possess these resources can also try various processing methods, which may lead to the development of this technology.
This is the advantage of having well-established research institutions, where a large number of engineers dedicate themselves to various experiments and constantly make new discoveries.
With Liu Yulong's foresight and guidance, useful technologies can mature quickly and take root, preventing important technologies from being buried.
Seamless steel pipes are mainly used to produce various pressure-bearing pipelines, thereby improving the performance of metallurgy, machinery, and boilers.
Modern standard gun and cannon barrels are actually made by drilling holes in forged steel columns, and are not usually made using seamless steel pipes.
Because forged parts have higher performance than rolled parts, the performance of a drilled steel barrel is higher than that of a rolled seamless steel pipe.
However, in the mid-19th century, gun barrels were still made of wrought iron and were hand-rolled by blacksmiths.
Seamless steel pipes have far superior performance and stability compared to wrought iron barrels, and their production speed is also significantly faster.
Even a skilled craftsman can only produce two rolled gun barrels a month.
However, once the seamless steel pipe technology matures, a single production line can produce thousands of gun barrels per day.
One production line can replace thousands of craftsmen.
Most of the Han militia still only have cold weapons, and their main tasks are to maintain public order and serve as reserve forces.
Only a regular army can ensure that every soldier has a rifle and a bayonet.
With seamless steel pipe technology, Liu Yulong was able to issue guns to the 20 million militiamen of Dahan.
In the future, overseas militias will naturally also be able to carry firearms.
The supply of firearms and ammunition in the industrial age could also be a means of restricting the army from acting alone, so this technology is very important now.