It took more than half an hour for the water in the tripod to cool down, the steam around it dissipated completely, and the fire below had already been extinguished. Qin Huan came forward and began to look at the unprecedented tripod carefully.

The big tripod is actually very similar to the Dan stove. The only difference is that it is higher. It is divided into three parts. At the bottom, there are also four columns supporting the whole tripod, but it is built with refractory bricks, which is similar to the stove hole for burning fire.

Qin Huan frowned when he saw this, because it was not close to the machine at all, but he reluctantly accepted the principle of boiler self-discipline.

But when I saw that there was a cover above the boiler, which was pasted later, my face twitched. When I found a fist sized wooden plug not far below the cover, I couldn't help it anymore.

"Is it difficult to pull out the cork when you want to add water, add water from here, and then plug it?"

"Yes, your majesty."

They didn't think there was anything wrong with it. Didn't they stop the steam with a wooden plug?

But if it is welded with copper and iron, how can it be pulled out and added water? Therefore, the best solution is to plug it with a wooden plug, which is both convenient and effective.

"You can't use a wooden plug. Now the steam pressure is small, so naturally there's no problem. But once the steam is large, the wood like this hard plug will be squeezed out, so you must use metal."

Qin Huan just said a word and didn't explain any more. Instead, he walked to the real machine on the side, because the boiler was really simple and rough and didn't look good.

To completely solve the problem of water injection nozzle, we must get out the thread and match it with rubber sealing ring to withstand the high pressure, and it is also convenient to remove and add water at any time.

If the boiler was only heavier and rough, Qin Yu's eggs would ache for this piston steam engine.

Because the whole machine was square. Except that the main frame was made of iron, all sides were made of wood. The iron pipe connected to it was used as the air inlet. Qin Huan didn't have to guess that the structure inside was almost the same as that of the waterwheel. It was driven by the impact of steam. If the power was big, it would be hell.

If the steam generated by the huge tripod was not enough, and the box was relatively sealed, there would be a gap around the iron root protruding from the inside, otherwise it would be absolutely immovable.

"Take it apart and I'll see how it's structured." Qin Huan turned around and pointed to the cabinet. He was speechless to the extreme.

These guys completely regard the steam engine as woodworking. If he hadn't repeatedly stressed that the steam engine is an iron machine, I'm afraid they would all use wood for convenience.

People do not know, Qin Yu heart in crazy Tucao, immediately rushed to make complaints about it, three, five, two, the steam engine will be demolished, and many places still use tenon and mortise joint, after demolition, all accessories without loss.

"If only you could turn all these parts into iron."

Qin Huan looked at the wooden parts on the ground and said with emotion. He also knew that there was a long way to go to build a practical steam engine.

Because these guys are completely opportunistic, wood can never withstand high temperature and vibration, so even if they can solve metal sealing and steam pressurization, these guys can't turn this cabinet into all metal.

Sure enough, as Qin Huan guessed, the structure inside was also very simple. The eight leaves were all wood, embedded on a wooden cylinder and worn by an iron column. Although they were made very finely, they were useless?

The only desirable thing is that the connection points on both sides are connected by bicycle wheels, which are stuffed with small iron beads, smeared with lard, and then sealed. Because these guys have excellent carpentry skills, the vibration range is very small, which has reached a practical level.

Because Qin Huan had already told these people about the principle of nuts and screws, it was not difficult for those old carpenters to carve threads on wood, and the accuracy was quite high, but they would be completely blind if they were replaced with metal.

When it is impossible to make bearings, this transmission structure connecting bicycle wheels is undoubtedly the best choice to reduce friction. Nowadays, most of all waterwheel windmills are of this structure, but some use metal beads and some use wood beads.

"Your Majesty, how can we increase the pressure of steam?"

People couldn't wait to see that Qin Huan didn't say a solution. After all, it was almost impossible for them. It was more incredible than the sealing of the metal joint.

"In fact, it's simple..." although he lacked interest, Qin Huan patiently explained the operating principle to them. In fact, he designed a load-bearing valve based on the concept of pressure cooker in previous generations. The steam can't come out before the pressure reaches a certain pressure. Only when the pressure reaches a certain pressure can he open the valve.

As for metal contact sealing, it is easier to use rubber gasket. Fortunately, in cooperation with Portugal, natural rubber has been hoarded, which was originally used to make wheels.

People heard that rubber could be used as gaskets, and they all clapped their foreheads directly, because there were rubber Tiangong academy, but they didn't expect this. As for the load-bearing valve, although they didn't understand, your majesty said yes, it was absolutely OK, so they all rubbed their hands and wanted to start immediately.

But Qin Huan poured cold water.

"For steam pressurization, several people can try it first. The focus of the next work should be on how to transform the boiler and steam engine."

"Ah!"

"Your Majesty, is there something wrong with the boiler? How to reform the steam engine? "

"Of course, there is a problem. First of all, it is too heavy, and it can't be poured with copper at one time. It's reckless. It should be made with the best refined iron. In addition to the bottom, the top can be spliced.

As for the steam engine, I think it's similar to calling a windmill, so it must be made of refined iron. Except that rubber can be used for sealing, no wood can appear in other parts. "

Qin Huan said with a black face.

"Your Majesty, it's... All made of metal. It's really difficult. It's not easy to carve threads on this metal, but it's very troublesome to drill holes."

All the craftsmen were stunned.

"Then connect directly with rivets without screws."

Qin Huan waved his hand and knew that it was unrealistic to make metal screws now. The key was that the accuracy could not be reached, so he had to use rivets.

Rivets can only be stronger than screws. I don't see that rivets were directly used when countries built armored warships in the 18th century.

After hearing the connection principle of rivets, everyone's eyes lit up, and then one of them frowned and said, "according to your majesty, if you use rivets to connect, once there are internal problems and want to repair, it is bound to be forcibly removed. In this way, the whole machine must be returned to the furnace for recasting!"

"Don't worry about these first. Let's get the steam engine out. He'll solve the problems one by one later."

Qin Huan waved his hand. He knew that even if he finally got the steam engine out, it would take many years for mass production to reach a practical level.

However, as long as we get out the real object and let everyone see the magic of the steam engine, it will one day be able to be mass produced and will also allow future generations to continue their research.

In fact, the steam engine they developed can not be regarded as a reciprocating piston steam engine, but should be called a runner steam engine. Its efficiency is very low. Even if it is pressurized again, its strength is limited, and finally it can not reach a practical level.

But it doesn't matter. First get the runner steam engine out, so as not to dampen their enthusiasm. After all, they made it all by themselves from beginning to end. Finally, it's great to be able to rotate. It's a big step.

As for the real reciprocating piston steam engine, they can wait until they improve the steam engine and develop it. At that time, people's confidence will burst and other research institutes will be inspired.

So although Qin Huan knew some general principles of reciprocating piston steam engine, he didn't tell them now. It was inevitable that they would be affected.

But I plan to tell them after they finish this one. At that time, I have accumulated some experience and technology. I believe it won't take long to make a real steam engine.