Electric arc furnace water cooled furnace roof
The electric arc furnace (EAF) water-cooled cover is a critical thermal protection and process control component for electric arc furnaces—equipment widely used in steelmaking, ferroalloy refining, and non-ferrous metal smelting. It replaces traditional refractory brick covers with a closed water circulation structure to seal the furnace top, isolate high-temperature arc radiation, and manage furnace gas. This component directly impacts the EAF’s energy efficiency, safety, and environmental performance, making it indispensable for modern high-efficiency EAF operations.
Unlike general industrial furnace covers, the EAF water-cooled cover is designed to withstand extreme conditions (high arc temperature, molten splashes, and corrosive furnace gas), with four key functions:
- High-Temperature Shielding: Resists direct scouring from 1600-2200°C arc radiation and molten steel/slag splashes, preventing deformation or burnout of the EAF’s steel shell and extending the furnace body’s service life.
- Furnace Gas Sealing & Recovery: For modern closed EAFs (e.g., ultra-high-power EAFs for steelmaking), it forms an airtight space with the furnace body to collect CO-rich furnace gas. This gas is either reused as fuel (reducing energy consumption) or treated to meet emission standards, avoiding toxic gas leakage.
- Heat Loss Reduction: The water-cooled structure minimizes top heat dissipation—compared to traditional refractory covers, it cuts heat loss by 35%-55%, improving the EAF’s thermal efficiency and reducing electricity consumption (typically by 30-60 kWh/ton of steel).
- Operational Flexibility: Supports frequent opening/closing (for scrap charging, electrode adjustment, and tapping) while maintaining structural stability, reducing downtime for maintenance or process transitions.
It operates on the principle of continuous heat transfer via cooling water circulation, ensuring the cover remains within a safe temperature range (outer wall ≤80°C) even under extreme furnace conditions:
- The cover’s internal structure (hollow panels or embedded coils) is connected to an external closed cooling system (including water pumps, heat exchangers, and expansion tanks).
- Low-temperature cooling water (30-40°C, usually softened or demineralized to avoid scaling) is pumped into the cover’s internal channels.
- High-temperature heat from the furnace (arc radiation, hot furnace gas) is absorbed by the cover’s inner wall and transferred to the flowing cooling water.
- Heated water (50-60°C) flows out of the cover, is cooled by heat exchangers (or cooling towers), and is recycled back to the cover—forming a continuous, energy-efficient heat dissipation cycle.
The EAF water-cooled cover features a modular, high-strength design, with materials selected to balance heat resistance, corrosion resistance, and mechanical stability.
Parameters are customized based on the EAF’s capacity (e.g., 50t, 100t, 200t steelmaking EAFs) and process requirements (e.g., ultra-high power, low-carbon steel production). Core parameters include:
It is widely used in various EAF types, with tailored designs for different smelting goals:
Compared to traditional refractory brick covers, its advantages are significant:
To ensure safe and stable operation, strict daily maintenance and timely fault resolution are required:
- Cooling System Check: Monitor water inlet/outlet temperature, pressure, and flow rate. If the outlet temperature exceeds 60°C or pressure drops by ≥0.1 MPa, stop the furnace to inspect for pipe blockage or leakage.
- Sealing Inspection: Use a gas detector to check for furnace gas leakage at electrode holes and cover edges. Replace aging graphite packing or gaskets if leakage is detected.
- Structural Inspection: Use an infrared thermometer to scan the cover body—local temperatures exceeding 100°C indicate potential pipe blockage or water shortage.
- Lifting Mechanism Check: Inspect hydraulic cylinders and hinges for lubrication; ensure position sensors work normally to avoid misalignment.
There are many types of furnace cover structures of electric arc furnaces, Can be selected according to the different power of electric arc furnaces.
1.Brick type furnace cover
2. Box type water cooling furnace cover
3. Tube type water cooling furnace cover
4. Atomizing furnace cover
Among them, the brick type furnace cover is suitable for ordinary power arc furnace.
Box type water cooled furnace covers are suitable for high power arc furnaces
The tube type water cooled furnace cover is mainly used in ultra-high power electric arc furnace, and the atomizing furnace cover has a wide application range and is basically not limited by power.
In the design of ultra-high power DC electric arc furnace, the tube type water-cooled furnace cover with good cooling effect and the most widely used is selected.
Water cooling furnace cover structure diagram:
