Chapter 871 Open-hearth and blast furnaces

Wait for ten years in Xining, after the transformation of the smelting furnace, the output has doubled, the average annual output of about 80,000 catties, and with the use of coking coal, the expansion of blast furnaces, the investment of various advanced technologies, as well as the discovery of the two forests in the south, ferry, Zhengzhou, Xuzhou, Yunzhou, and Wuzhou subway mines in the two Zhejiang roads, the production capacity of southern iron and steel has caught up with the north, and the three divisions estimate the first year of Yuanfeng, the national iron class, will reach about 13 million catties.

However, the quality of steel varies from place to place, and the best steel is in Erlinbu and Wuzhou, where the steel produced in these two places, in addition to being used to cast guns and weapons, is often used by other iron smelters to improve the quality of their own steel.

But Jiaozhi iron, because of the quality relationship between iron ore and coal mines, is better than the Erlin long knife of the Erlin Department and the Longquan Sword of Liangzhejiang Road, and the most important thing is that the sixth generation of blast furnace has made a qualitative leap after more than 20 years of accumulation in the first five generations!

Structurally speaking, this is already an iron-smelting blast furnace in the modern sense!

The Yezhou blast furnace, like later generations, uses steel plates as the furnace shell, and the shell is lined with refractory bricks. From top to bottom, the blast furnace body is divided into five parts: throat, body, waist, belly and cylinder, which are almost exactly the same as those of later generations.

In the production of blast furnaces, limestone, iron ore, coke, and limestone, a flux for slag making, is also loaded from the top of the furnace, and preheated air is blown from the tuyere located at the lower part of the furnace along the furnace perimeter.

The molten iron is discharged from the iron mouth, and the slag is discharged from the slag mouth.

The gas produced is discharged from the top of the furnace and used as fuel for hot blast stoves, heating furnaces, coke ovens and boilers after dust removal, and is also a raw material and fuel for the production of sulfuric acid and ammonia.

Blazing gas is also an important fuel for steelmaking furnaces.

And slag is the raw material for brick factories and cement plants.

The feeding and batching system of the blast furnace also adopts the volumetric batching method and the gravimetric batching method. Among them, iron ore and coking coal use bucket trucks with fixed volume, while limestone uses bucket trucks and spring platforms.

The refractory bricks inside the blast furnace shell are as thick as one meter at the bottom and 40 centimeters at the top, the bottom of the furnace is made of graphite bricks, and the upper part is made of high-alumina bricks fired from bauxite.

There is also a blowing system for supplemental combustion, and this blast furnace blows pulverized coal.

An iron water tank is hung outside the furnace as a cooling system to prevent the furnace shell from collapsing at high temperatures.

In addition, there are countless strict operating specifications, operating procedures, and protective measures, all of which are lessons learned in exchange for human lives.

Strictly speaking, this blast furnace can only be regarded as a small furnace, and a furnace can only produce 2,000 catties of molten iron, not to mention that compared with later generations, even the output of an ordinary iron smelting furnace in the Great Song Dynasty cannot be reached.

But it has a modern blast furnace characteristics, that is, once ignited, day and night, it can smelt four furnaces a day, and the daily output is 8,000 catties.

With three million catties a year, a blast furnace accounted for almost half of the Great Song Iron Class ten years ago! And there is no need to refine a furnace and destroy a furnace to build a furnace as before, a blast furnace can be used continuously for more than ten years!

This blast furnace is the result of the concerted efforts of the Royal Institute of Technology, Meishan Institute of Technology, Zhongshan Institute of Technology, Si Tianjian, Jiang Zuo Supervisor, Sansi Guan, Shangzhou Guan, Shijia, Sitong Firm, and Huangsong Bank.

The chief designer of the blast furnace is Shi Fu, and the deputy chief designers are Chen Zhaoming and Zhao Zongyou, who are responsible for research and development.

The chief supervisor is Su You, and the deputy supervisor is Shi Luan, who is responsible for coordinating funds, manpower, and material resources, and dispatching elites from all over the world to participate in the design, calculation, and discussion......

The plan has been taken out five years ago, and there have been repeated revisions in the middle, and key parts such as refractory bricks, blowing systems, slag mouths, iron mouths, and countless small design improvements have been experimented in iron smelting in various places.

Therefore, this blast furnace can be described as the crystallization of the common wisdom of the great Song Dynasty national science and engineering talents, skilled craftsmen, subway supervisors, and actual managers.

When all the designs, calculations, and experiments were finally done, the blast furnace got stuck on the ore.

Coal and iron ore specimens from all over the Great Song Dynasty, after the inspection of the Royal Institute of Technology, only the ferry port is barely qualified, and the rest of the sulfur content is too high, which will seriously affect the life of the blast furnace and the quality of iron.

However, after a lot of hard work, the ore obtained from the Qilian Mountains of Western Xia and the prairie of the Liao State passed the test.

After Zhao Ji received the report in the Fuwen Pavilion, he was so angry that he threw the jade shanzi on the desk on the spot.

Su You comforted Zhao Ji in the secret compromise, the progress of metallurgy is accumulated little by little, just like the knowledge of science and engineering, although the large blast furnace can not be built for a while, but the small measures used in iron smelting everywhere have also doubled the steel output of the Great Song Dynasty in ten years, which is already very good.

But in the hearts of the two, in fact, it is inevitable to regret it.

The conquest of Cochin and the discovery of high-grade coal and iron ore finally brought a comfortable pillow to Meimeng.

The production of steel was a long and complex preparatory process, and the construction of what is now the largest steel base in the Great Song Dynasty in Jiaozhi can be said to be completely self-made.

Exploration, mapping, road opening, bridge building, trial, grading and grading of railroad tracks, organization of manpower, handling of machinery, explosives, mining, construction of transit warehouses, construction of ports, organization of shipping......

After the first furnace of molten iron was refined, Su You had no excitement at all, just like Zhang Daochang who handed the dibutin glue in front of him, and in front of the great achievements, there was only a faint taste of pretending to be forced......

It's not that I want to pretend to be forced, it's really so tired, I don't even have the strength to pretend to be forced!

Blast furnaces can produce not only iron, but also ferromanganese, but the real useful applications are steel and manganese steel, as well as ductile iron.

Therefore, these must be refined in a steelmaking furnace.

The refining of the development of Da Song University of Science and Technology has always been the road of open hearth.

From the earliest graphite crucible with a lid and the strong blowing of hot air at the bottom of the coke to smelt, from small to large, step by step.

Later, glass was introduced, and the crosses began to smelt glass in crucible furnaces.

The open-hearth stove is essentially a huge crucible stove that looks a bit like a huge pan with a lid.

However, due to the influence of heating efficiency, the volume of the open-hearth furnace was destined to be large, and not much steel could be made in one pot.

Until Shi Fu turned his brain to the gas.

At that time, the gas did not have so many applications as it is today, and a lot of waste was wasted, and only after the ball valve and pressure gauge were available, Shi Fu introduced an additional inlet pipe on the side of the crucible furnace and added the stove head to use it to take the gas.

So in today's steelmaking open-hearth, the furnace is a molten pool with a regenerative chamber at the bottom that heats air and gas. The overall structure is composed of a melting chamber, a furnace head, a rising channel, a sediment chamber, a regenerative chamber, a reversing valve, a flue, a chimney, etc.

The melting chamber is the central part of the open-hearth furnace, with a charging furnace door in front and a taphole at the bottom at the back.

The melting chamber has a thick fire shield cover, and the melting process is carried out in a sealed environment, through the rotation of hot air and gas, combustion heating and reduction reactions.

In such an environment, the excess carbon is oxidized and taken away, and the carbon content of the molten iron gradually decreases and becomes molten steel.

Unlike converter steelmaking, the converter only needs to use the heat provided by the molten iron itself to complete the steelmaking process by blowing in hot air.

However, because of the large furnace body, the long smelting time, the heat loss of the furnace wall and the heat carried away by the high-temperature exhaust gas, the open-hearth furnace must be supplied with fuel from the outside and preheated air to maintain the heat and oxygen required for steelmaking.

It takes twenty-four hours for a furnace of steel to be smelted.

But compared with converters, open-hearth furnaces are also more advanced. This thing has a high temperature, can re-smelt scrap iron and scrap, can be precisely controlled and proportioned, can add the rest of the metal and non-metal additives to it, and adjust it into alloy steel or ductile iron.

Ductile iron is very high, that is, through spheroidization and inoculation treatment, the carbon in the iron can exist in the form of spheroidal graphite, which can effectively improve the mechanical properties of cast iron, especially improve plasticity and toughness, so as to obtain cast iron with carbon steel strength.

In order to fight against the sulfur present in large quantities of local steel and improve the performance of steel, the flower grower actually invented spherical graphite cast iron as early as the Han and Wei dynasties.

The addition of ferry-crossing iron makes the ductile iron process more perfect and convenient, because the iron there is rich in rare earths and magnesium, and the ferry-crossing iron is the "iron mother", which can greatly improve the performance of cast iron.

If you add manganese-rich slag or mirror iron to it, you get high manganese steel.