Zhang Baigui looked at the bowl in his hand, and said regretfully: "Mr. Lian, although there is this bowl mouth gun that can be referenced, but now the war bureau still can't imitate it!" ”

Liu Juntao rushed to the military battle bureau under construction, thinking that he could build firearms on a large scale, although it is not a sharp firearm like a bird gun and a thunderbolt, but it is also a good start, at least it can make the Yushan Guards transition from cold weapons to hot ~ weapons.

Unexpectedly, Liu Juntao was poured a basin of cold water on Zhang Baigui's head.

Liu Juntao frowned and said: "Master Zhang, it's okay to say that we couldn't build a fire gun before, after all, the masters of the War Bureau have never seen the real thing, and they don't know it very clearly just by looking at the drawings." But now that we have this bowl as a reference, we can clearly see the detailed structure of the firecracker, why can't it be imitated? ”

Liu Juntao was also anxious at this time, although Liu Juntao was very clear about the structure and manufacturing method of the gun and artillery, and had already drawn a detailed pattern for Zhang Baigui, but Zhang Baigui and other craftsmen had not actually done it, even if Liu Juntao stood aside to give instructions, everyone still had no idea where to start.

Moreover, there is another problem that Liu Juntao also ignores:

Zhang Baigui knocked on the barrel of the bowl and said, "Now our War Bureau can't refine qualified wrought iron!" ”

Speaking of this, Liu Juntao instantly understood.

At this time, the guns of the Da Ming Flame are basically rolled with a whole piece of wrought iron, and then tightened with iron hoops, basically there is no direct drilling of the guns on the iron rods in the late Ming Dynasty, because it is too time-consuming and laborious, and there is no suitable equipment available at this time.

At this time, only tempered high-quality wrought iron can withstand the huge impact generated when gunpowder is fired, and the ordinary pig iron refined before the War Bureau is completely enough to make cold weapons, but it is not good to use it to make firearms.

Liu Juntao frowned and looked at the bowl repeatedly, and said, "It seems that I am going to open the golden finger and make steel!" ”

"Goldfinger?"

When Zhang Baigui heard the word steel, he didn't have time to ask Liu Juntao what a golden finger was, so he asked in surprise: "Juntao, do you still know how to smelt wrought iron?" ”

"What's so hard about that!"

Liu Juntao said with a smile: "However, this time, we don't practice wrought iron, just make steel!" ”

In fact, it is not that Liu Juntao is boasting, although the iron-making technology of the Ming Dynasty at this time is very advanced compared with Europe at the same time, and the output of steel is the first in the world, but it is still backward compared with later generations.

The steelmaking method that Liu Juntao knows is also very simple, and it has been widely used in later generations when there was a large amount of iron and steel among the people.

As he spoke, Liu Juntao found a pen and paper and wrote down what he needed to make steel.

Zhang Baigui hurriedly looked at it, and kept chattering: "If you want bricks, iron fan blades, and artificial ......, these are all fine, we have them in the war bureau." Jun Tao, I'm going to gather people, prepare tools and things I need now, how to make steel, you give orders, all the craftsmen of our War Bureau will listen to you! ”

After speaking, Zhang Baigui trotted all the way to prepare.

In fact, what Liu Juntao has to do is very simple, that is, to add a regenerator to the iron-making furnace of the War Bureau.

At this time, the iron-smelting furnaces of Daming iron-making were all open, and the thermal efficiency of the fuel was very low. According to Liu Juntao's method, a regenerator was built with heat-resistant materials to improve the thermal efficiency of the fuel.

The greater role of this regenerator is actually to increase the furnace temperature, which can be used in steelmaking. The furnace temperature for smelting pig iron is less than 1,200 degrees at most, and 1,600 degrees is obtained by melting molten steel. It's just that there are no enough heat-resistant materials for furnaces, so Liu Juntao can only use the existing blast furnace to try, and then seize the time to develop and build refractory bricks for steelmaking furnaces.

At this time, Zhang Baigui was recruiting the manpower of the War Bureau to rebuild the iron-smelting furnace according to Liu Juntao's wishes. It just so happened that the masons who built the war bureau were there, and this happened to be done at the same time.

Through the transformation of the iron-smelting furnace, Liu Juntao became familiar with Tan Qing, the charcoal head of the War Bureau. This Tan Qing is about thirty years old, but the whole person looks like he is forty or fifty years old, and he has to lose his scum.

In the War Bureau, Tan Qing did the work of burning soil and firewood. In addition to burning charcoal, he also worked as a brick burner.

The design drawings of the new iron furnace are actually in Liu Juntao's mind, and throughout the day, the War Bureau is busy with the preparation work before steelmaking, and the craftsmen of the War Bureau are under the command of Zhang Baigui, burning bricks and preparing materials, and the carpenters also roll up their sleeves and start working, and the entire War Bureau is a busy scene.

That night, Liu Juntao saw that the preparations for steelmaking were not over, and it seemed that it was going to be tomorrow, so he went home to sleep first and came over the next morning.

And Zhang Baigui is still immersed in the joy of steelmaking, I don't know why, Zhang Baigui after listening to Liu Juntao's words, he firmly believes that according to Liu Juntao's method, steel will be smelted.

At this time, Zhang Baigui, who has been a blacksmith all his life, seemed very excited, rolled up his sleeves and kept shouting loudly to the blacksmiths and apprentices under his hands, making the final preparations for steelmaking.

"Everyone, work hard! We must be ready tonight, and every morning, we will make the first furnace of steel! ”

In fact, according to the transformation drawings given by Liu Juntao, the renovation project of the iron smelting furnace of the War Bureau is not complicated, and even the bricks do not have to be burned. Tan Tantou dismantled a charcoal kiln that had been abandoned before, and together with the furnace that had collapsed, it was enough to make up the refractory bricks that Liu Juntao needed.

All they had to do was prepare charcoal, iron, and everything within fifty paces of the new furnace.

According to Liu Juntao, this steelmaking is a test of the water, and for the sake of safety, the area around the iron-smelting furnace must be emptied to prevent the furnace from suddenly collapsing and catching fire during the steelmaking process.

Early the next morning, Zhang Baigui and a group of blacksmiths gathered around the Xinsmelting Iron Furnace after a busy night, and everyone's faces were full of joy and curiosity.

At this time, Liu Juntao also rushed over and took a closer look at the new iron-smelting furnace.

I saw that this new iron-smelting furnace was actually digging another pit directly on the top of the pit next to the original iron-smelting furnace to build a small brick house, and the brick house was a honeycomb-like refractory brick structure.

After that, the craftsmen dug another passage to the blast outlet of the furnace, which was also built with bricks. On the brick house, a passage is also built with bricks, close to the top of the furnace, a chimney is built in the middle of the passage, and a convex pipe structure is set up, and a fan made of iron sheets is installed behind the convex pipe, and it is shaken by manpower, so that the heavy smoke and dust can go out from the chimney, and the light hot air can be pumped to the regenerator by the fan in order to increase the temperature in the iron smelting furnace.

The rest of the work is all the work of the carpenter and the blacksmith.

I saw that Zhang Baigui led the carpenters and blacksmiths to transform the air vent so that it went straight to the heat storage chamber, and the air inlet was placed on the side of the heat storage room. These tasks were not difficult, and Zhang Baigui took a few carpenters and blacksmiths to complete the transformation in three or two clicks.

At this time, Liu Juntao deliberately looked up at the top of the furnace, if it is steel refining, the most ideal regenerator is of course to close the furnace top, but now because it is only a transformation, so I have to consider feeding from the top of the furnace.

Therefore, Liu Juntao's plan can only be to use iron sheets to make a large horn, which can cover the roof of the furnace after feeding. Above the bell is a curved iron pipe, the other end of which can be inserted into a brick passage.

In short, Liu Juntao's design is very simple, and I don't know how much worse it is than the steelmaking furnaces of later generations, but Zhang Baigui and others were still shocked by one of the details.

"Mr. Lian, why does the iron fan blade of this fan rotate so fast with a gentle shake?"

Zhang Baigui looked at the newly smelting iron furnace that was all ready, and asked curiously.

In fact, in other iron-smelting furnaces, the fan rotates very slowly, and no matter how hard the furnace worker tries, it is impossible to spin too fast.

The reason why the fan of this new iron furnace can spin so fast is that Liu Juntao specially designed a variable speed gear made of wood to drive the hand-cranked fan.

The idea of this gear-changing gear was inspired by the pulley set that Liu Juntao had taken out before seeing him on the construction site of the War Bureau yesterday.

"You have to learn a lot to understand this."