INDUCTION MELTING FURNACE
Category:
Steel Melt Shop Equipment
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
- 60 – 75 kWh/t savings compared to previous generation furnace
- 25– 30kWh/t lower than the latest model of all other makes
- 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 FACTOR-95%
Load Graph without Voltage Boosting
LOAD FACTOR– <90%
Feature No. 2: Nano Cable Design
Typical Layout
