The blast furnace was the most difficult part of the whole project. In order to build the blast furnace, a special team was set up to collect everything about the blast furnace structure. Jishu materials of materials and construction methods. A 125-cubic-meter blast furnace, with a height of more than 10 meters and a weight of several thousand tons, is the largest type of industrial equipment that the veterans have ever touched, and its difficulty surpasses that of all previous industrial construction projects.

Structurally, the blast furnace must meet two prerequisites: the charge can be evenly reduced; The furnace gas rises evenly at all height sections.

The top part of a modern blast furnace is the throat, and the charge is loaded into the furnace by a special feeding machine above. In order to protect the furnace throat from being damaged by the collision of the charge, a layer of steel bricks is inlaid on it. The charge is added to the throat and then heated by the scorching furnace gas rising from below. From here, the furnace gas is discharged through the pipes at the top of the furnace - this part is very tightly sealed to prevent the gas, which accounts for most of the furnace gas, from leaking out or returning to poison the workers.

Part of the exhaust gas is re-entered into the blast furnace as fuel, and the other part is transported to the hot blast furnace to heat the blast air.

The furnace body is a small cone. After the charge has been in contact with the furnace gas, the volume is heated and expanded. In order to accommodate this expansion, the furnace body gradually grows larger from top to bottom. This design is designed to prevent sagging. The blast furnace is the most taboo in combustion, which not only wastes the charge, but also has to stop the fire and clean up. Blast furnaces are produced without stopping fire in principle, and once they are fired, it takes a long time to resume production.

The finer the ore particles are smelted, the greater the gas flow at the edges, so that the blast furnace will not hang the material. The flow of the edge gas stream is related to the furnace body angle. In the process of the charge dropping, the heavier ore tends to fall vertically, and when the furnace angle is small, the ore will be far away from the furnace wall, and the coke will move to the furnace wall in large quantities. At this time, a loose ring belt is formed near the furnace wall, which encourages a large amount of gas to pass through to form a large gas stream. When the furnace body is too steep, the opposite situation occurs - there is hanging. Therefore, the angle of the furnace body angle is generally 86 degrees.

Underneath the furnace body is the furnace waist, which is a cylindrical part designed to eliminate dead spots created by the furnace body. Underneath the waist of the furnace is the belly of the furnace, where the volume of the charge is built up due to the continuous melting of the coke and the continuous melting of the charge. Therefore, its shape is large at the top and small at the bottom. The angle of the furnace belly is generally 76~82 degrees. The use of a larger angle can reduce the friction of the furnace wall, and at the same time, due to the increase of the angle, the diameter of the furnace cylinder is expanded, and the coke is fully combusted, which improves the production efficiency of the furnace.

At the bottom is the furnace cylinder, where the molten iron and slag are stored. The temperature of the furnace is very high, and it is not enough to use only ordinary refractory materials, and the temperature in the furnace is enough to melt the refractory bricks in the furnace cylinder. The general practice is to install a cast steel or cast iron shell on the outer layer of the furnace wall, and then install a serpentine cooling water pipe in the shell to cool and protect the refractory bricks inside. Because steel is very difficult to cast - steel has very poor fluidity. After many studies by the people of the industrial department, they felt that they were not sure to make such a large steel casting. Zuihou decided to settle for a large cast iron cooling jacket. Just this casting took Xiao Bailang several months.

The air inlet is located at the upper end of the furnace cylinder, and there are 8 in total, and the air nozzle should be protruding into the furnace wall. Due to its high temperature resistance, the nozzle is made of bronze, and there is a water pipe for cooling inside the nozzle, which circulates the cooling with an uninterrupted water supply during operation. The tap hole is located near the bottom of the furnace cylinder, and the slag outlet is above the tap hole. The same is made of bronze and cooled using circulating water.

The blast furnace not only has a large capacity but also is a continuous production, and the temperature of the throat of the large blast furnace is extremely high, so it cannot be manually fed, but mechanically and automatically fed. There are several ways to feed the blast furnace, and Jiang Ye and Ji Wusheng discussed and decided to use the simplest charging barrel feeding method in the mechanical structure. The charging drum is bell-shaped, the hopper is transported to the top of the furnace, the charging barrel is then raised to the top of the furnace, the top is jammed, and the charge leaks from the bottom of the openable barrel into the throat. The hopper is driven by the crank linkage mechanism that slides on the track to drive the barrel. Although uncomplicated, the system requires reliable equipment in the industrial system in terms of chains, mechanical transmissions and power machinery.

Jiang Ye said: "At the beginning, Zhan Wuya could not say that the blast furnace was only engaged in converters, and imported pig iron from Guangdong to make steel. I also think he was a bit right-leaning conservative -- and it seems that even if he wanted to build a blast furnace at that time, he might not have been able to do it. ”

"At that time, if you wanted to build it, you could go to a three- to five-meter-high earthen blast furnace. Two or three tons of pig iron are produced in a day and night, and the top of the sky is five tons. Most of the feeding materials are still wrenched with a winch, and then the workers add a shovel to the throat of the furnace - the workers are roasted half to death, not to mention, the feeding is slow, and the blanking is uneven. The efficiency is as poor as today's small chemical plants. Ji Wusheng is very sympathetic to the family of the chemical system. The industrial scale of his family is not even up to the county-level chemical plants in the 70s according to the standards of the old time and space, and many products are still manufactured at the laboratory level, and if it were not for the coal coking joint production plant transported from the old time and space, the pitiful output of the 800 tons of synthetic ammonia and electrolytic salt workshop alone made him roar at every meeting of the planning institute.

"As soon as our steel complex is put into operation, there will be a large-scale explosion of chemical equipment, and the burden of your machinery department is not light."

"That's nothing." Jiang Ye didn't care, "Can you make some special steel or something?" Especially stainless steel and the like. There are too many places to use, and there is silicon steel, which is needed to build generators, motors and transformers. Don't you know that Chang Gong came to us twice in three days to cry and complain that he is useless in power construction. ”

The power of the group is a fatal shortcoming, whether it is power generation, power supply or power use, it is probably the level of the small county town in the late 70s of the 20th century in the old time and space - even worse - the formation of the county power grid is not yet possible. And the direct result of the lack of electricity is the boilers of steam engines everywhere.

"Your requirements are more difficult, the former requires non-ferrous metals that we can't get, and the latter is difficult to smelt. However, manganese steel can come out quickly - Tiandu's iron ore itself contains high manganese, and there is also a manganese ore that can be mined locally. Ji Wusheng said, "Besides, hasn't Chang Gong been planning the development of the East Asian Power Grid's ultra-high voltage transmission and transformation system, the Himalayan super power station, and the Yangtze River cascade power station in his notebook -- can he work as an electrician and do it first?" ”

"Although it is not as exciting as stainless steel and silicon steel, it is also very good news." Jiang Ye said. Manganese steel has the characteristics of high strength and high wear resistance, and plays an important role in many large machinery. With manganese steel, the performance of current low-quality bearings, gears, structural parts and connectors can be greatly improved. Manganese steel can also be used to make knives for industrial use, providing high-quality weapons steel for the military industry.

Next to the blast furnace stands a large hot blast furnace that has been completed – a 125 cubic metre blast furnace that requires far more blast air than the small converters and iron melting furnaces of the past. Big often means more efficiency. The hot blast stove has been built when the converter steelmaking workshop was built, and it has considerable experience in construction and use. This time, with enough refractory materials, not only the volume has been increased, but the internal structure has also been optimized, and the new hot blast stove is a decent Kaopa hot blast stove with a height of 10 meters. The hot blast furnace uses the high-temperature exhaust gas of the blast furnace to preheat the air entering the blast furnace from the blower, and the design goal is to achieve an air outlet temperature of up to 620°C. At such high temperatures, the reducibility of iron ore is at its highest, and coke consumption can be reduced by a fifth.

"Jiang Gong", a naturalized intern, hurriedly ran over, "The gas plant site just called, please take a look." There's something wrong over there. ”

"Okay, I'll go over here." Jiang Ye said hello to Ji Wusheng and went down from the small mound, where a farm vehicle had already been prepared.

The gas plant is an important project of the Ma Yuan Consortium. Gas can also be supplied at the coal-coking plant in Bopu, but it has chemical equipment for the subsequent processing of the gas and tar produced in the coking industry. Therefore, the gas is generally consumed directly as a chemical raw material, and a small amount of the surplus is given to the Bopu Industrial Zone as fuel.

Instead of coking lignite specially brought from the Jiazi Coal Mine - the blast furnace coke is supplied by the coal and coke complex in Bopu - the gas plant uses a special gas generator to dry distill all kinds of inferior coal, which is produced not for coke, but for gas.

After the completion of the gas workshop, it will provide gas fuel for the whole plant, and the main purpose is to provide fuel for open-hearth steelmaking - the calorific value of the gas produced in blast furnace smelting is too low to be used as fuel for open-hearth.

Unlike the specialized large-scale coke ovens of coking plants, gas generators have a simple structure and are easy to operate. In addition, the mechanical port also has a lot of experience in manufacturing and using gas generators. There is no difficulty in manufacturing and use.

After the coal is added to the furnace, it is ignited for dry distillation, and the air added from the bottom of the furnace reacts soundingly, that is, coal gas is generated. However, at this time, the calorific value of coal gas is low, and the calorific value of open-hearth fuel is low, so at the same time of coking, the water vapor produced by the boiler evaporator is mixed with air in proportion and then blown into the generator furnace to produce semi-water gas, which has a much higher calorific value than air gas, and can be used as fuel for open-hearth.

The tar produced during the dry distillation is stored in a special tar tank and then transported to the coal and coke complex in Bopu for further refining. Ji Huisi plans to set up a tar treatment plant at the Mayuan Gas Plant in the future to process coal tar and produce chemical products on site.