Lin Gao Qiming

Chapter 806 Blast Furnace (Technical Text!)
The blast furnace is 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.Technical information on materials and methods of construction.A 125-cubic-meter blast furnace is more than ten meters high and weighs several thousand tons. It is the largest industrial equipment the elders have ever come into contact with, and its difficulty surpasses all previous industrial construction projects.

In terms of structure, the blast furnace must meet two prerequisites: the burden can be uniformly lowered; the furnace gas can be evenly raised at all heights.

The uppermost part of the modern blast furnace is the furnace throat, and the charge is loaded into the furnace by the special charging machine above.In order to protect the furnace throat from being damaged by the impact of the charge, a layer of steel bricks should be inlaid on it.Furnace material is fed into the furnace throat, and then it is dried and preheated by the scorching furnace gas rising from below.From here, the furnace gas is exhausted through the pipes on the top of the furnace-this part must be very tightly sealed to prevent the gas that accounts for most of the furnace gas from leaking or returning to poison the workers.

Part of the exhausted furnace gas will re-enter the blast furnace as fuel, and the other part will be sent to the hot blast stove to heat the blast.

The furnace body is a cone with a small top and a big bottom.The volume of the furnace material expands due to heat after contact with the furnace gas.In order to adapt to this expansion, the charge can be lowered smoothly, so the furnace body gradually becomes larger from top to bottom.This design is adopted to prevent hang-up.Blast furnaces are most forbidden to hang material during combustion, which not only wastes the furnace material, but also has to stop fire and clean up if it is serious.In principle, blast furnaces are produced without stopping the fire. Once the fire is stopped, it will take a long time to resume production.

The finer the smelted ore particles, the greater the gas flow at the edge, so that the blast furnace will not hang up.The flow of the edge gas flow is related to the angle of the furnace shaft.During the process of falling the furnace charge, the heavier ore tends to fall vertically. When the furnace body angle is small, the ore will be far away from the furnace wall, and a large amount of coke will move to the furnace wall.At this time, a loose ring zone is formed near the furnace wall, which promotes a large amount of gas to pass through to form a large gas flow.When the furnace body is too steep, the opposite situation occurs - the occurrence of material hanging.Therefore, the angle of the shaft angle is generally 86 degrees.

Below the furnace body is the furnace waist, which is a cylindrical part designed to eliminate the dead angle generated by the furnace body.Below the furnace waist is the bosh. Due to the burning of coke, the charge is continuously melted, and the volume of the charge is increased.So its shape is big at the top and small at the bottom.The bosh angle is generally 76-82 degrees.The use of a larger angle can reduce the friction of the furnace wall. At the same time, due to the increase of the angle, the diameter of the furnace hearth is enlarged, the coke is fully burned, and the production efficiency of the furnace is improved.

The bottom is the hearth, where the molten iron and slag are stored.The temperature of the hearth is very high, and it is not enough to use only general refractory materials. The temperature in the hearth is enough to melt the refractory bricks in the hearth.The general practice is to install a cast steel or cast iron shell on the outer layer of the furnace wall, and install a serpentine cooling water pipe in the shell to cool and protect the internal refractory bricks.Because steel is difficult to cast - steel has poor fluidity.After many times of research, the people at the industrial gate felt that they were not sure about making such a large steel casting.In the end it was decided to settle for the next best thing and make a large cast iron cooling jacket.It took Xiao Bailang several months for this casting.

There are 8 air inlets located on the upper end of the hearth, and the air nozzles should protrude into the furnace wall.Due to the high temperature resistance, the furnace nozzle is made of bronze, and there is a cooling water pipe inside the furnace nozzle, which also continuously supplies water for circulating cooling during operation.The taphole is located near the bottom of the hearth, and above the taphole is the slag outlet.Also made of bronze and cooled with circulating water.

The blast furnace not only has a large capacity but also operates continuously. The temperature of the throat of a large blast furnace is extremely high, so manual feeding cannot be used, but mechanical automatic feeding.There are several ways to charge the blast furnace. After discussing with Ji Wusheng, Jiang Ye and Ji Wusheng decided to use the simplest method of charging the barrel in the mechanical structure.The charging bucket is bell-shaped, and the hopper is transported to the top of the furnace, and then the charging bucket is lifted to the top of the furnace, and the top is stuck, and then the charge leaks from the bottom of the openable bucket into the furnace throat.The hopper drives the barrel by sliding on the track through the crank linkage mechanism.Although this system is not complicated, it requires industrial systems to provide reliable equipment in terms of chains, mechanical transmission and power machinery.

Jiang Ye said: "At the beginning, Zhan Wuya could not say that he only engaged in blast furnaces, and imported pig iron from Guangdong to make steel. I still think he is a bit right-leaning and conservative-now it seems that even if he wanted to build blast furnaces at that time, he might not be able to succeed."

"At that time, a blast furnace with a height of three to five meters could be installed. Two or three tons of pig iron could be produced in a day and night, and the top day was five tons. Most of the feed was twisted up with a winch, and then the workers shoveled the furnace throat with a shovel. Riga—workers were roasted half to death, the feeding was slow, and the feeding was uneven. The efficiency was as poor as the current small chemical factory." Ji Wusheng felt sympathetic to the family of the chemical system.According to the standards of the old time and space, the industrial scale of his family is not even up to the county-level chemical plants in the 70s. Many products are still manufactured at the laboratory level. The poor output of the 800-ton synthetic ammonia and electrolytic salt workshop alone made him roar at every Planning Academy meeting.

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

"It's nothing." Jiang Ye didn't care, "Can you produce some special steel or something? Especially stainless steel. There are too many places to use, and silicon steel is needed to make generators, motors and transformers. You I don’t know that Mr. Chang came to us every three days and cried and complained that he was useless in power construction.”

The power of the Crossing Group is a fatal shortcoming. Whether it is power generation, power supply or power usage, it is probably at the level of a small county in the late 20s in the old time and space—even worse—the establishment of a county-wide power grid is still impossible .The direct result of the lack of electricity is the boilers of steam engines everywhere.

"Your request is more difficult. We can't get the non-ferrous metals needed by the former, and the latter is difficult to smelt. However, manganese steel can be produced quickly-the iron ore in Tiandu itself contains relatively high manganese, and the local There is a manganese mine that can be mined.” Ji Wusheng said, “Besides, Mr. Chang has not been planning the ultra-high voltage power transmission and transformation system of the East Asia Power Grid, the Himalaya super power station, and the development plan of the Yangtze River Cascade Power Station in his notebook—he can work as an electrician while making plans. Do you have a plan?"

"Although it is not as exciting as stainless steel and silicon steel, it is still 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 the current low-quality bearings, gears, structural parts, and connectors can be greatly improved.Manganese steel can also manufacture knives for industrial use and provide high-quality weapon steel for military industry.

Next to the blast furnace stands a large hot blast furnace that has been completed - the blast furnace of 125 cubic meters requires far more blast than the small converters and iron furnaces in the past.Larger often means higher efficiency.The hot blast stove has already been built in the converter steelmaking workshop, and has considerable experience in construction and use.This time, with enough refractory materials, not only the volume has become larger, but the internal structure has also been optimized. The new hot blast stove is a standard Kaupa hot blast stove, with a height of 10 meters.The hot blast stove uses the high-temperature exhaust gas from the blast furnace to preheat the air entering the blast furnace from the blower. The design target is that the temperature at the air outlet can reach 620°C.At such a high temperature, the reducibility of iron ore will reach the highest level, and the consumption of coke can be reduced by one-fifth.

"Jiang Gong!" A naturalized intern hurried over, "The gas plant site just called, please go and have a look. There are some problems over there."

"Okay, I'll go right away." Jiang Ye and Ji Wusheng greeted each other and went down the small mound. A farm vehicle had already been prepared here.

The gas plant is an important project of the Marie Consortium.The coal coking joint chemical plant put into use in Bopu can also provide gas, but because it has chemical equipment for subsequent processing and refining of the gas and tar produced in the coking process.Therefore, gas is generally consumed directly as a chemical raw material, and a small amount of the remaining gas is used as fuel in Bopu Industrial Zone.

The gas plant does not use the lignite for coking that is specially transported from the Jiazi Coal Mine—the blast furnace coke is provided by the Coal and Coke Combined Plant in Bopu—but uses a special gas generator to dry distill various low-quality coals. Its production purpose is not to obtain coke, but gas.

After the gas workshop is completed, it will provide gas fuel for the entire factory area, and the main purpose is to provide fuel for open-hearth steelmaking - the gas produced in blast furnace smelting has a low calorific value and cannot be used as fuel for the open-hearth furnace.

Different from the special large coke oven in the coking plant, the gasifier has a simple structure and is easy to operate.Moreover, the mechanical port also has a lot of experience in manufacturing and using gas generators.There is no difficulty in making and using it.

After the coal is put into the furnace, it is ignited for dry distillation, and it reacts with the air added from the bottom of the furnace to produce gas.But at this time, the calorific value of the gas is low, and the calorific value of the open hearth furnace fuel is low. Therefore, 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 half-water gas and half-water gas. The calorific value of gas is much higher than that of air gas, and it can be used as fuel for open hearth furnaces.

The tar produced during dry distillation is stored in a special tar tank, and then transported to Bopu Coal and Coke Combined Plant for further refining.Ji Tuisi planned to build a tar treatment plant at the Mariao Gas Plant to process coal tar locally to produce chemical products.

(End of this chapter)