1635 Han style rises again

Chapter 101 Small Blast Furnace

The road from Jianye City to Heishan Valley was finally completed.

Qi Tian used the five carriages (musle carts) that had already been assembled to transport the refractory bricks prepared in advance to the vicinity of the Black Valley Iron Mine immediately.

A small fortress will be built near the Heishan Iron Mine, with a radius of about 400 meters. There will be two furnaces for ironmaking and steelmaking, as well as supporting steel and iron mold workshops, coke workshops, coal storage yards, and workers. Production and living facilities such as residences, canteens, and bathhouses.According to the planning and design, it can accommodate more than two hundred people to work in it.

This is a purely industrial town, and all the daily necessities needed have to be transported from Jianye City.

Since the completion of this simple road, the aborigines of the Black Valley tribe no longer carried coal to Jianye City.Instead, they began to pick coal and iron ore in coal mines and iron mines, and then sent them to Jianye City and Heishanbao by horse-drawn cart or mule cart respectively.The work seemed to be much easier, but Qi Tian knew that the aborigines would work in coal mines and iron mines all year round, and after a long time, they would inevitably suffer from some respiratory diseases.

But he deliberately and selectively forgets, or even ignores the occurrence of this kind of thing.The rise of every country, every nation, and even every power will definitely sacrifice some people.If you want to blame, you can only blame the world for being too cruel.Who made it too difficult for our Han people to come here, everyone is so precious! ...Moreover, who made you natives too backward and too ignorant.

For this reason, Qi Tian mobilized more than 100 people to build Heishan Fort and a small blast furnace for iron and steel making.

The construction of small blast furnaces is mainly based on "shi", which has advantages that modern iron and steel factories do not have, such as: less investment, simple equipment, easy to master technology, short construction time and so on.

Qitian initially planned to build a blast furnace of 5 cubic meters, with a designed production capacity of 40-50 tons of pig iron per year.When the technical level and steelmaking process are stabilized, consider building more blast furnaces.

The structure of a general blast furnace is the same as that of a human body, which can be divided into several parts: 1-cylinder; 2-bosh; 3-waist; 4-body (chest); 5-throat.In order to protect the bottom of the furnace from being scoured and eroded by gas and slag, a layer of water is often reserved at the lower part of the mouth, which is called a dead layer, and the general height is 30 to 40 cm.The hearth part has a taphole, a slag outlet and an air inlet.Therefore, to make this shape, it is necessary to create good conditions for various smelting processes in the furnace: the top-down descent of the charge, the bottom-up flow of gas, and a series of physical and chemical changes. .

The charge of blast furnace is put into the furnace throat first, there is a bell and a hopper on it, and there is a detection hole next to the hopper, which can adjust the height of charge.In order to make the charge go down smoothly, and it is easy to install the furnace throat protection plate (to prevent the material from damaging the furnace wall), the furnace throat is made into a cylindrical shape.There is a gas pipe on the side of the furnace throat (usually a small blast furnace), which guides the gas, passes through a dust collector, etc. to remove dust, and then sends it to the hot blast stove for combustion.The excess gas can be released or burned through the release valve, and the temperature of the furnace throat is about 500~700°C
The main function of the furnace body is to preheat the reduced ore.The temperature in the furnace body area is about 800-1000°C in the upper part and 1000-1200°C in the lower part.As the charge is lowered and heated, the volume expands, and at the same time, the carbon black produced by the decomposition of carbon monoxide is deposited in the charge, which deteriorates the gas permeability of the charge.In order to let the gas pass through quickly, the material blocks must be loosened, so the shape of the furnace body is a flat cone with a small top and a large bottom, and the belly angle at the bottom is generally around 90°.

The main function of the furnace waist is reduction, liquid slag and iron begin to form, and the temperature is 1200-1300°C.Because the reaction does not change much, it is made into a cylindrical shape and its diameter is about 1.5 times larger than the diameter of the hearth.

The main function of the bosh is the area where the ore is directly reduced, where the ore has all become liquid, the coke gradually descends, and the tuyere part is completely melted, so the volume is reduced, so this part is made into an inverted flat cone with a large upper part and a smaller lower part.The temperature of the lower part of the bosh is 1300-1400°C.

The function of the hearth is mainly to store molten iron and slag, but it also has some functions such as direct reduction, carburizing and desulfurization of molten iron.Its shape is a straight cylinder, with a taphole on the bottom, a slag outlet on the top, and an air inlet on the top.The cold air blown out from the bellows is heated by the hot blast stove, and blows into the stove from the tuyere.A peep hole needs to be left at the outer end of the tuyere so that the temperature and conditions in the furnace can be observed.The temperature here is 1400-1500 (the temperature of the burning focus of the tuyere can reach 1800-2000 ℃ or higher), so the furnace wall here requires high refractoriness and strength, and must have the ability to resist high temperature and slag invasion. When using refractory bricks, it is required that there are almost no gaps in the brick joints of the hearth and the bottom of the furnace.

The blast furnace charge is loaded into the blast furnace from the hopper on the top of the furnace according to the batch (referring to the weight of one charge into the furnace, including ore, limestone and fuel).After ignition, air is blown in from the air inlet at the lower part of the blast furnace.Most of the air contains one-fifth of combustion-supporting oxygen and four-fifths of non-combustion-supporting nitrogen, so when the air meets red coke in the chamber, high temperature and strong flame will occur.Coke quickly combines with oxygen in the air to form carbon dioxide gas (carbon dioxide), which is called coke combustion.

After reduction of iron oxides, spongy iron is formed, and the temperature drops gradually, absorbing some impurities, the main ones are silicon, manganese, phosphorus, sulfur, etc. At the same time, the melting point of iron is greatly reduced after carburizing, and the lower part of the blast furnace is burned to form The high heat turns it into liquid, which is molten iron.

Both molten iron and slag sink to the bottom of the furnace.Every once in a while, it can be released at the tap hole.

The molten iron has a large specificity and sinks below, while the slag is relatively light and floats on the molten iron. The slag released from the slag hole before tapping is called upper slag, and the slag that flows out from the iron hole together with water during tapping is called lower slag. The more slag the better, generally the slag accounts for 2/3 of the amount of slag.The final main product of blast furnace smelting is pig iron, and the rest is slag, gas and dust removed from the gas.

As for the small steelmaking blast furnace next to it, molten iron can be introduced into the furnace using a refractory crucible, and the excess carbon in the molten iron can be removed to reduce the carbon content and become steel.

The slag after ironmaking and steelmaking is a good raw material for cement production, which lays a certain foundation for the expansion of cement production in the later period.At the same time, a large amount of slag is also a good material for paving.

Of course, steelmaking is not something that ordinary coal can use.For this reason, Qi Tian also set up another coke workshop near the planned coal storage yard.A large amount of coal is dry-distilled to make coke, which can provide a steady stream of fuel for small steelmaking blast furnaces.

Watching more than 100 people build walls and build wooden houses under the guidance of a few teenagers, they are already familiar with all the procedures.Qi Tian felt very relieved that in the future, they would be the leaders in the construction of the Hanzhou Continent.

Qi Tian took Chen Dalang to a nearby small river, the stream was still very shallow, it could be seen that it should be a seasonal river.In the wet season from December to March and April next year, it may surge into a big river again.

"A reservoir must be built there!" Qi Tian pointed to the many depressions on the south side of the small river, forming a water sill, with patches of reeds growing in it, which was caused by the overflow of the river after its surge.

"In addition to providing water for production and living here, it can also adjust the water potential of the seasonal river. Don't expect a flood to flood our steel base. How wrong it is!"

"...We don't have the manpower to do this right now." Chen Dalang said with a wry smile.

"Then wait for three months and see how many people my uncle can bring back from Daming! ... However, if this river really floods in December, we must first build a dam or something to stop it."

"It's getting late, shall we go back to Jianye City?" Chen Dalang suggested.Although the natives of the Black Valley were overwhelmed and overwhelmed by Cao Xiong's "big soldiers" last time, who knows if their brains are not enough and they suddenly want to attack them again.This Black Mountain Fortress has not yet been built and has no defense conditions. It is safer to return to Jianye City.

"Okay, let's go!" Qi Tian was not hypocritical, let alone pretending to be a hero, and followed Chen Dalang back to Jianye City in a coal-drawing carriage.

More than 200 kilometers away from Jianye City, the five ships dropped half of their sails and slowly slowed down, only relying on the breeze and ocean currents to slowly sail towards the south.

(End of this chapter)