Chapter 871 Open Hearth and Blast Furnace

By the tenth year of Xining, the output of the transformed smelting furnace had doubled, with an average annual output of about 80,000 kilograms. With the use of coking coal, the expansion of blast furnaces, the investment of various advanced technologies, and the Southern Erlin Department,

With the discovery of iron ore mines in Dukou, Zhengzhou, Xuzhou, Yunzhou and Liangzhe Road and Wuzhou, the production capacity of Southern Steel has caught up with that of the North. The third company estimated in the first year of Yuanfeng that the national iron class will reach 1,300

About ten thousand kilograms.

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

"Iron Mother".

But Jiaozhi iron, because of the quality of the iron ore and coal mine, is even better than the Erlin Changdao of the Erlin Department and the Longquan Sword of Liangzhe Road. The most important thing is that the sixth generation blast furnace has experienced more than 20 years of experience in the previous five generations.

After years of accumulation, a qualitative leap has occurred!

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

Like later generations, the Yezhou blast furnace used steel plates as the furnace shell, and the shell was lined with refractory bricks. The blast furnace body was divided from top to bottom into five parts: the throat, the furnace body, the furnace waist, the furnace belly, and the hearth. It was almost the same as that of later generations.

Exactly the same.

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

The smelted molten iron is released from the taphole, and the slag is discharged from the slag port.

The generated gas is discharged from the top of the furnace. After dust removal, it is used as fuel for hot blast furnaces, heating furnaces, coke ovens, and boilers. It is also the raw material and fuel for the preparation of sulfuric acid and ammonia.

Hot gas is also an important fuel for steel-making furnaces.

Slag is also a raw material for brick factories and cement factories.

The loading and batching system of the blast furnace also adopts the volumetric batching method and the gravimetric batching method. Iron ore and coking coal use bucket trucks with fixed volumes, while limestone uses bucket trucks plus spring weighing platforms.

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

There is also a blowing system for supplementary combustion. 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 regulations, 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. One furnace can only produce two thousand kilograms of molten iron. Not to mention compared with later generations, even the output of one furnace of ordinary iron smelting in the Song Dynasty cannot be reached.

But it has a characteristic of modern blast furnaces, that is, once it is ignited, it can be smelted day and night, and can smelt four furnaces a day, with a daily output of eight thousand kilograms.

Three million kilograms a year, one blast furnace accounted for almost half of the iron work of the Song Dynasty ten years ago! And there is no need to make one furnace, destroy one furnace and build another furnace as before, a blast furnace can be used continuously for more than ten years!

This blast furnace is the result of the joint efforts of the Royal Institute of Technology, Meishan Institute of Technology, Zhongshan Institute of Technology, Si Tianjian, Jiang Zuojian, San Sizhou Case, Shangzhou Zhou Case, Shi Family, Sitong Company, and Huangsong Bank.

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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 Hao. They are responsible for coordinating funds, manpower, and material resources, and recruiting elites from all directions to participate in design, calculation, and discussion...

The plan was put out five years ago and has been revised repeatedly in the process. Key parts such as refractory bricks, blowing system, slag mouth, taphole, and countless small design improvements have been tested in iron smelting companies in various places.

Therefore, this blast furnace can be said to be the crystallization of the wisdom of all the scientific talents, skilled craftsmen, railway supervisors and practical managers in the Song Dynasty.

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

Coal and iron ore specimens from various places in the Song Dynasty were tested by the Royal Institute of Technology. Only the ones from Dukou barely passed the test. The sulfur content in the others was too high, which would seriously affect the life of the blast furnace and the quality of the iron materials.

On the other hand, Tingfeng Pavilion went through a lot of hard work to obtain mineral materials from the Qilian Mountains of Western Xia and the prairie of the Liao Kingdom, and passed the test.

After Zhao Xu received the report in Fuwen Pavilion, he was so angry that he threw the jade mountain on the desk.

Su You comforted Zhao Xu in the secret compromise. The progress of metallurgy is accumulated bit by bit, just like the knowledge of science and engineering. Although a large blast furnace cannot be built at once, the small measures and improvements used in iron smelting everywhere can be achieved.

Da Song's steel output doubled in ten years, which is already a very good result.

But in both of their hearts, regrets were unavoidable.

The conquest of Cochin and the discovery of high-grade coal and iron ore finally gave the dream a comfortable pillow.

The production of steel is a long and complicated preparation process. The construction of the largest steel base in the Song Dynasty in Jiaozhi can be said to be completely started from scratch.

Prospecting, mapping, opening roads, building bridges, testing, determining grade, building railroad tracks, organizing manpower, transporting machinery, blasting ores, mining, building transit warehouses, building ports, organizing shipping...

After the first furnace of molten iron was smelted, Su You had no sense of excitement at all. Just like Daozhang Zhang who handed the dibutanol in front of him, there was only a faint smell of pretentiousness in front of his great achievements...

I’m not trying to show off, I’m really too tired and I don’t even have the energy to show off!

Blast furnaces can not only produce iron, but also ferromanganese, but what are really useful in applications are steel, manganese steel, and ductile iron.

So these all need to be refined in steel-making furnaces.

The refinement of the development of science and technology in the Song Dynasty has always been the open-furnace approach.

Starting from the earliest graphite crucible with a lid and forced hot air blowing from the bottom of the coke for smelting, we have slowly progressed step by step from small to large.

Later, when glass became available, Sitong began to use crucible furnaces to smelt glass.

An open hearth furnace is essentially a super huge crucible furnace, which looks a bit like a huge pan with a lid.

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

Until Shi Fu turned his brain to gas.

At that time, gas was not used in as many applications as it is now, and a lot of it was wasted. After the ball valve and pressure gauge were installed, Shi Fu introduced an extra air inlet pipe to the side of the crucible furnace and added a burner to take out the gas.

Therefore, the current open-hearth steelmaking furnace has a furnace with a molten pool with a regenerator for heating air and gas at the bottom. The overall structure consists of a melting chamber, a furnace head, an ascending channel, a slag chamber, a regenerator, a reversing valve, and a flue.

, chimney, etc.

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

The smelting chamber has a thick fireproof cover, and the smelting process is carried out in a sealed environment. By injecting hot air and gas in turns, combustion, heating and reduction reactions are carried out.

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

The open-hearth smelting chamber is built with alkaline refractory materials, that is, bauxite bricks. Unlike converter steelmaking, the converter only needs to use the heat provided by the molten iron itself and can complete the steelmaking process by blowing in hot air.

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The open-hearth furnace has a large furnace body, long smelting time, large heat dissipation loss from the furnace wall and high-temperature exhaust gas. Therefore, fuel must be supplied from the outside and preheated air must be used to maintain the heat and oxygen required for steelmaking.

A furnace of steel takes twenty-four hours to refine.

But compared to the converter, the open-hearth furnace also has more advanced features. It has a high temperature and can remelt scrap iron and steel. It can accurately control and mix the ratio, and can add other metals and non-metallic additives to it to make alloys.

Steel or ductile iron.

Ductile cast iron sounds very fancy. Through spheroidization and inoculation treatment, the carbon in the iron is allowed to exist in the form of spherical graphite, which can effectively improve the mechanical properties of the cast iron, especially the plasticity and toughness, thereby obtaining carbon steel.

Strength of cast iron.

In order to combat the large amount of sulfur present in local steel and improve the performance of steel, flower growers actually invented spheroidal graphite cast iron as early as the Han and Wei dynasties.

The addition of ferry iron makes the ductile iron process more complete and convenient, because the iron material there is rich in rare earths and magnesium, and using ferry iron as the "iron mother" can greatly improve the performance of cast iron.
Chapter completed!