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Green Furnace

The Green Furnace: Our popular low-frequency model has been further improved upon leading to furnace orders of 19MTPA capacity out of which 6 MTPA are orders of plants using furnaces of other makes. Some of the largest secondary steel manufacturers globally are joining the Green revolution. Below are the reasons why…

  • Green furnace incorporates the best aspects of parallel as well as series circuits to give the lowest energy consumption and higher productivity
  • Latest SMD-based inverter with a digital interface
  • Fibre optics used in inverters & signal boosting in rectifiers
  • Guaranteed energy consumption of 465 kWh/t using mill heavy/end cutting scrap
  • Guaranteed 30 kWh/t – 40 kWh/t lower than all other latest furnaces and 60 kWh/t – 75 kWh/t lower than previous generation furnaces
  • 9% – 11% higher productivity compared to other brands
  • Power factor of 98%
  • No capacitor switching. Sustained power throughout the heat cycle
  • High power pickup achieved via voltage boosting
  • Eight energy consumption and productivity improvement features
  • Harmonic distortion is restricted strictly within IEEE 519 norms
  • State-of-the-art digital system with alarms, remote access, digital parameter displays, data logging, trend analysis, etc.

Topology Comparison

Series Circuit Parallel Circuit Green Furnace
Name Voltage Source Inverter Current Source Inverter Voltage-Boosted Current Source Inverter
Power Pickup & melt rate Good power pickup and high melt rate Poor power pickup. Low melt rate High power pickup and best melt rate due to voltage boosting and low-power consumption
Power Factor 96% – 97% (from start) Max 93% – 94% (from 80% of rated power) 97% – 98% (from 40% of rated power using CPF system)
Capacitor Switching & frequency Switching is not required. Low frequency maintained throughout the heat cycle Switching Required. Done via PLC-controlled pneumatics. Medium freq due to the large frequency range Switching is not required. Low frequency maintained throughout
Energy Consumption  Higher than Green Higher than Green Lowest due to 8 Green furnace features
After-sales parts cost Expensive due to high current carrying devices Cheaper than a series circuit Cheaper than a series circuit
Reliability (Shock load and short circuit resilience) Poor due to the presence of a DC link discharge capacitor Better due to the presence of heavy current sourcing DC reactor Better due to the presence of heavy current sourcing DC reactor

Features of Green Furnace & Impact on Performance:

Feature No. Feature kWh/t Saving Productivity Improvement
1 Compact Layout & improved copper sections lead to minimal current density and line losses 3 – 5 1%
2 Nano Cable Design: Lowest cable loss & voltage drop 8 – 12 1%
3 Power factor of 98% as seen in a series circuit 2 – 3 2%
4 Strict Harmonics Control 2 0% – 1%
5 Low Loss Higher Rated Capacitors 2 – 3 0% – 1%
6 Automatic Voltage Boosting, High Power Pickup, Higher Voltage (4150V up to 8MW/5250V 10MW onwards) 8 – 10 2%
7 Higher power pickup. Highest Load Factor. Stretching Increased. 10 1%
8 Tight Frequency Range (up to 280 Hz unlike others which go up to 400+ Hz) because of no capacitor switching 25 – 30 2%
Total 60 – 75 10%

End Result

  1. 60 – 75 kWh/t savings compared to previous generation furnace
  2. 25– 30kWh/t lower than the latest model of all other makes
  3. 9% to 11% higher production than any furnace in the market

Feature 6 and 7 explained:

Load Graph 18th Heat 14.5 MW with Voltage Stretching




Load Graph without Voltage Boosting



Feature No. 2: Nano Cable Design


Typical Layout