Working Principle of Steelmaking Furnace

The steelmaking furnace is one of the most critical equipment in steelmaking. Its main function is to heat, decarburize and alloy the pig iron or molten steel after pretreatment to produce steel that meets various production requirements. Let's take a closer look at the working principle of the steelmaking furnace.

1. Basic composition of the steelmaking furnace

The steelmaking furnace is mainly composed of the furnace body, electrodes (for electric arc steelmaking furnaces), fuel injection systems (for some steelmaking furnaces using gas or oil), steel outlets, slag outlets and other parts. The inside of the furnace body is covered with refractory materials to protect the furnace wall from being melted by high temperature.

2. The main steps of the steelmaking process

Step 1: Melting zone

The melting zone of the steelmaking furnace is the area where the molten steel is heated to a liquid state. In this area, heating is usually carried out through gas or oil nozzles, and the temperature in the furnace is usually as high as 1650 degrees Celsius or more. Due to the balance between the heat generated by combustion and the heat lost in the furnace, the temperature in the furnace will fluctuate within a certain range.

Step 2: Reduction zone

Below the melting zone is the reduction zone, whose function is to gradually remove carbon from pig iron or molten steel. This process is mainly to accelerate the melting of scrap steel and scrap iron with low carbon content and release some steam. After the scrap steel and scrap iron are dissolved, they will be suspended in the furnace in the form of granular materials, providing surface area and reaction rate for the reduction zone.

Step 3: Oxidation zone

Below the reduction zone is the oxidation zone, which is used to alloy the molten steel. In this area, violent eddies and bumps mix the molten steel with the reduction zone materials, and various oxidants and alloying elements are added to the molten steel. In this process, even a small change in elements may have a great impact on the quality of the molten steel, so the furnace operator must strictly control every link.

3. Supporting equipment and technology of steelmaking furnace

Fire grate: used to support the raw materials and molten steel in the furnace to prevent them from directly contacting the bottom of the furnace.

Automatic feeding system: automatically feeds raw materials into the furnace to improve production efficiency.

Waste gas treatment equipment: treats waste gas generated during steelmaking to reduce pollution to the environment.

Water cooling system: used to cool the furnace body and other high-temperature components to prevent them from overheating and damage.

Dust removal system: collects and processes dust generated during steelmaking to keep the production environment clean.

4. Summary

The steelmaking furnace heats the raw materials to melt them, then removes impurities and adjusts the composition through oxidation and reduction reactions, and finally obtains molten steel that meets the requirements. In this process, the temperature, atmosphere, and time and intensity of each reaction step in the furnace need to be strictly controlled to ensure the quality and performance of the molten steel.

The working principle of the steelmaking furnace is a complex and delicate process that requires superb technology and strict control to ensure the production of high-quality steel.