What are the differences and characteristics of flat furnace, converter and electric furnace?

The steelmaking method can be divided into converter steelmaking, flat steelmaking and electric furnace steelmaking. The following are the details:
1. Oxygen is the oxidant used in converter steelmaking. Compress the air into the molten Piron to enable oxidation of impurities such as silicon and manganese. In the process of oxidation, a large amount of heat (containing 1% silicon can increase the temperature of Piron by 200 degrees Celsius) can be released, so that the furnace can reach a high enough temperature. Therefore, converter steelmaking does not require additional fuel.
Converter steelmaking is carried out in the converter. The converter is like a pear, with refractory bricks on the inner wall and many holes (tuyere) on the furnace side. compressed air is blown from these holes into the furnace, which is also called the side blow converter. At the beginning, the converter is at the level, injecting 1300 degrees Celsius of liquid pig, adding a certain amount of quicklime, Then drum into the air and rotating the converter to erect it. At this time, the surface of the liquid Piron produces slag by oxidation of iron, silicon and manganese (FeO, SiO2, MnO,) and convection of the melted steel and slag, make the reaction spread throughout the furnace. A few minutes later, when only a small amount of silicon and manganese are left in the molten steel, carbon starts to be oxidized, and carbon monoxide (Exothermic) is generated to make the molten steel boil violently. A great flame exists in the furnace due to the overflow of charcoal. Finally, phosphorus is oxidized and further ferrous phosphate is formed. Ferrous phosphate reacts with quicklime to generate stable calcium phosphate and calcium sulfide, which together form slag.
When the phosphorus in Sulfur gradually decreases, the flame drops, and the furnace mouth appears brown steam of titanium oxide, it indicates that the steel has been made. At this time, the blast should be stopped immediately, and the converter should be switched to the horizontal position, the molten steel should be dumped into the steel water package, and the deoxidize agent should be added to conduct the oxygen. The entire process takes about 15 minutes. If the air is blow from the furnace, It is the low blow converter.
With the development of oxygen production technology, the oxygen top blow converter is now widely used (there are also side blow converters ). Such converters blow high-pressure industrial pure oxygen, the reaction is more intense, can further improve production efficiency and steel quality.
2. Flat Furnace Steelmaking method (flat Furnace Steelmaking method is also called Martin method)
Iron, scrap, iron ore, iron ore, and iron oxides in the air and charge used by iron-making in a flat furnace ). The heat required for the reaction is provided by the combustion gas fuel (Blast Furnace Gas, furnace gas) or liquid fuel (heavy oil.
The furnace of the flat furnace is a slot made of fire-proof bricks. It is covered by the top of the furnace made of fire-proof bricks. There is a loading port on the front wall of the furnace, and the loading machine will load the charge from here. Close the door caused by Refractory Bricks during smelting. Both ends of the furnace are built with a furnace head. The furnace head has two channels for importing fuel and hot air, or for guiding furnace gas from the furnace.
The raw materials used for steel-making in flat furnace are scrap steel, scrap iron, iron ore and solvent (limestone and quicklime ). At the beginning of smelting, the imported hot air is burned on the fuel surface, and the temperature is as high as 1800 degrees Celsius. Heat is directly transmitted from the flame to the charge, causing rapid melting of the charge (the melting point of the iron is 1535 degrees Celsius, and the steel is slightly lower ). At the same time, some melted piiron is used to generate ferrous oxide, And the impurity silicon and manganese in piiron are oxidized by ferrous oxide to generate slag. Because the furnace contains excessive limestone, phosphorus and sulfur impurities generate calcium phosphate and calcium sulfide into slag. Second, carbon dioxide is also oxidized to generate carbon monoxide from the melting metal, as if the metal is boiling.
When the reaction is about to complete, add the deoxidizing agent and regularly extract the slag. When smelting is completed, it is necessary to check whether the steel composition meets the requirements according to the pre-furnace analysis (quick analysis can be completed in a few minutes. Refining Steel from the steel mouth into the steel bag, and then from the steel bag into the mold cast into products or steel ingot.
To increase the furnace temperature, the gas fuel should be preheated in the regenerative chamber (I, II, III, IV.
In the flat furnace, liquid Piron can be added, solid piiron can be added, and scrap iron and iron ore can be added after the attack. In addition, if 30% of the oxygen-rich air is blown in the furnace and oxygen is blown into the molten metal, the productivity can be increased by 80%, and the smelting time can be shortened by 2 ~ 4 hours, fuel saving, and oxygen-rich air does not need to be preheated.
3. Electric Furnace Steelmaking steel can also be smelting in an electric furnace with electric energy as a heat source. High quality alloy steel can be produced by using electric furnace steelmaking. Electric furnaces have many types and are most widely used.