ToolFusion
📋 Case Study

Electric Arc Furnace Retrofit at Midwestern Steel Mill

Inconsistent scrap temperature leading to 12% longer melt times and electrode wear variability

🏗️ Project Overview

Conversion of natural gas-fired ladle preheater and scrap preheat system to induction + resistive hybrid

🎯 Challenge

Inconsistent scrap temperature leading to 12% longer melt times and electrode wear variability

🔧 Design Approach

Dual-zone induction (bottom) + top-mounted resistive radiant panels with closed-loop IR feedback control

📐 Design Diagram

Electric Arc Furnace RetrofitMidwestern Steel MillEAF ShellDual-Zone Induction (Bottom)2.8 GJ/ton preheatTop Radiant PanelsIR Feedback SensorHarmonic FilterQₕ = 1.2 Mvar(5th/7th)Challenge: +12% melt time, electrode wear variability

AI-generated project design illustration

📐 Key Calculations

Scrap Preheat Energy Requirement

m × cp × ΔT
Result: 2.8 GJ/ton
Defines minimum electrical capacity needed

Harmonic Filter Sizing (5th/7th)

Qh = V² × (h²−1)/Xh
Result: 1.2 Mvar
Prevents voltage distortion >3% THD

📊 Results

Melt time reduced by 18%, electrode consumption down 22%, annual CO₂ reduction: 14,200 tCO₂e

💡 Lessons Learned

  • •IR feedback loop essential for real-time power modulation
  • •Harmonic filters must be sized for worst-case duty cycle, not nominal

✅ Key Takeaways

  • 1IR feedback loop essential for real-time power modulation
  • 2Harmonic filters must be sized for worst-case duty cycle, not nominal