Indian experiences on Energye Efficiency in Steel Rolling Mills
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The document outlines various energy efficiency initiatives and technologies adopted in Indian steel rolling mills to reduce energy consumption and improve productivity. It details low-end and high-end technologies, their investment costs, and corresponding energy savings, along with recommendations for equipment and operational improvements. Additionally, it presents an energy balance sheet comparing baseline and projected operational parameters to highlight potential gains in efficiency.
Indian experiences on Energye Efficiency in Steel Rolling Mills
- 1. D. Pawan Kumar Team Leader D. Pawan Kumar Team Leader ENERGY EFFICIENCY SHARING INDIAN EXPERIENCES ENERGY EFFICIENCY SHARING INDIAN EXPERIENCES 08/02/13
- 2. Current Major EE initiatives/Drivers 08/02/13 Accelerated depreciation for EETs Energy Conservation Act implementation, NMEEE MNRE initiatives APDRP & RAPDRP programmes MSME schemes for SME sector CDM and other international Programmes SDA capacity building DC & PAT Scheme S&L Programmes SME Clutter programme DSM (Agriculture, Municipal DSM) NECA, initiatives, BLY, ECBC Scheme ISO 50001 ESCO capacity building Financial instruments /Bank Schemes
- 3. ENERGY CONSERVATION TECHNOLOGIES ADOPTED IN INDIAN STEEL ROLLING MILLS: • Low - end Technologies Requires investment Rs. 1.5 to 2 Crores and energy saving 20-25% • High-end Technologies • Requires investment Rs. 5 to 6 Crores and energy saving 30-40% 08/02/13
- 4. Low - end Technologies • High efficiency recuperator with improved furnace design • Change of lump coal to producer gas as fuel • Technology for use of pulverized coal as fuel • Use of Bio-mass gas as fuel 08/02/13
- 5. High-end Technologies • Regenerative burner system • Hot charging of continuous cast billet • Top and bottom firing system in reheating furnace • Oxy - fuel combustion system in reheating furnace • Walking hearth/beam furnace 08/02/13
- 6. ECO TECH OPTIONS IN FURNACES • Total replacement of the existing pusher type with the energy efficient furnace. • Walking beam reheating furnace • Producer gas based reheating furnace • Modifying of grate coal fired system to pulverized 08/02/13
- 7. ECO TECH OPTIONS IN FURNACES Contd… • Revamping /modernization of existing pusher furnace • Efficient oil burners • Regenerative burners • Complete change of furnace line • Ceramic fibre veneering 08/02/13
- 8. ECO TECH OPTIONS IN FURNACES Contd… • Microprocessor based furnace zone temperature/pressure control • Metallic Recuperator • Hot Charging in composite mills • Variable voltage variable frequency drive (VVVF) 08/02/13
- 9. ECO Tech options in Rolling Mills • Crop length optimization • Rollers guide • Spindle and coupling • Antifriction bearing • Installation of Y-roller table • Installation of drop tilter • Installation of tilting table 08/02/13
- 10. ECO Tech options in Rolling Mills Contd… • Quenching and self-tempering of re-bars • Oval repeaters • No - Twist Block • Slit rolling • Computerized roll pass design • Lubrication technology 08/02/13
- 11. ECO Tech options in Rolling Mills Contd… • Cast in carbide rolls in conventional stands • Endless welding roll • Reactive power compensation • Energy efficient drives for rolling mills • Pre-stressed housing less stands • High voltage (HT) AC motor for rolling mills etc 08/02/13
- 12. Recommendatio n Key Technical elements of proposed design Major Specificatio n Standard Equipmen t Suppliers Productivity/Yiel d Improvements, Power consumption reduction, Fuel Consumption Reduction etc. Investmen t in Rs. Lakh Reheating Furnace Proper Coal storage House keeping measure which reduces carpet loss Furnace Instrumentation 1.Pressure gauge, 2.Thermocoupl e for flue gas, 3.O2 Analyser for flue gas 4. Automation of air and fuel ratio +0.1mm W.G 800 (max)degC Electronic gas analyser Amsat EDC Pune Maharastra Better operation control and efficiency improvement 2 lakhs TECHNOLOGY PACKAGES /ECO-TECH OPTIONS & SPECIFICATION OF MAJOR FACILITIES 08/02/13
- 13. Recommendatio n Key Technical elements of proposed design Major Specificatio n Standard Equipment Suppliers Productivity/Yiel d Improvements, Power consumption reduction, Fuel Consumption Reduction etc. Investmen t in Rs. Lakh Variable Frequency drive for combustion air blower Variable Frequency Drive (VFD) ABB Power savings 0. 8 lakhs Waste heat recovery by installing metallic recuperator Metallic recuperator Indaid Engineers (P) Ltd., Chennai Waste heat recovery,fuel saving and efficiency improvement 7 lakhs Energy efficient burner Energy efficient burner Webster Engineers & manufactur ing Company Better turbulence and excess air reduction 1.5 lakh Contd… 08/02/13
- 14. Recommendatio n Key Technical elements of proposed design Major Specificatio n Standard Equipmen t Suppliers Productivity/Yiel d Improvements, Power consumption reduction, Fuel Consumption Reduction etc. Investmen t in Rs. Lakh Rerolling Mill Universal spindle and coupling Spindle & coupling Armech Engineers (P) Ltd., Noida Power savings 6 lakh Antifriction bearing for rollers Antifriction bearings Power savings 2 lakh Installation of roller table at furnace discharge Mill Mechanization Delay in rolling 1.5 lakhs Installation of tilting table and drop tilter at roughing stand, Skew table& roller table at all mill stand Mill Mechanization Power saving 3 lakhs Contd… 08/02/13
- 15. Practice Parameters on which performance is measured Producti vity (tph) Utilization (%) Fuel (kg/t) (lt/t) (Nm3/t) Power (kWh/t) Burning loss % Mill Scale (%) Rolling and cuts (%) Yield (%) Current Practices 8TPH 70% 100 kg/t 97 1.57 0.50 1.4 96.53 % Projected Case 8TPH 70% 75 kg/t 85 1.5 0.50 1.4 96.60 % Benchmark 80% 65 kg/t 80 1.3 0.5 0.5 97.7% 08/02/13
- 16. The energy balance sheet of unit for baseline and ecotech for Reheating furnace Operating Parameter Base line Projected Case Fuel Consumption( per MT of throughput), kg 100 75 Scale loss,( per MT of throughput), kg 20.6 20 Through put rate ( tonnes per hour), tph 7.25 8 Furnace Parameter Rolling Temperature, Hs(0C) 1280 1200 Avg Skin Temperature, ts 67 67 O2 in flue Gas (%) 12 7 CO2 in Flue Gas(%) 9 12.5 CO in Flue Gas ( PPM) 60 60 Excess air ( %) 133 50 Exhaust gas temp at furnace backend, Th in (0C) 518 600 Exhaust gas temp at Stack, Th out (0C) 518 250 Air Preheat Tf (0C) NA 300 Fuel Preheat ( 0C) NA NA 08/02/13
- 17. Operating Parameter Base line Projected Case Thickness of Refractory lining , X (cm) 50 50 Calorific value of fuel 6000 6000 Energy Input ( Thermal) Fuel ( Mcal/t) 600 450 Sensible heat of fuel (Mcal/t) NA NA Sensible heat of air ( Mcal/t) NA 67.5 Heat of formation of scale ( Mcal/t) 20.9595 20 Total 620.9595 537.5 Energy Output (Thermal) Steel (Mcal/t) 149.52 149.52 Scale (Mcal/t) ………….. Dry exhaust gas , (Mcal/t) 191.5262237 124.0262237 Water vapur ( Mcal/t) 37.580366 37.580366 Heat Loss due to radiation and convection(Mcal/t) 41.56015617 41.56015617 Heat Loss due to opening (Mcal/t) 42.63917863 30 Heat Loss due to non continous operation (Mcal/t) 48 40 Total 510.8259245 422.6867459 Other difference , (Mcal/t) 110.1335755 114.8132541 Contd… 08/02/13
- 18. Summary of Rolling Mill Parameter Operating Parameter Baseline Projected Case Specific power consumption ( KWh/t) 97 85 power Factor 0.98 0.99 Mill utilization (%) 70 70 Mill yield (%) 96.5 96.6 Miss roll (% of furnace throuput) 1.04 1 Mill scale (%) 0.49 0.49 08/02/13
- 19. Summary of Rolling Mill Parameter Operating Parameter Baseline Projected Case Rolling Mill Parameter Rolling Temperature at furnace discharge (⁰C) 1200 1150 Rolling Temperature at roughing mill inlet (⁰C) 1125 1125 Rolling time (Seconds) Roughing Intermediate Finishing 40 40 08/02/13
- 20. Summary of Rolling Mill Parameter Operating Parameter Baseline Projected Case Rolling Temperature at finishing mill outlet (⁰C) 850 850 Rolling Temperature at cooling bed (⁰C) 850 850 Mill efficiency (%) 70 70 Mill delays ( Min)/day 75 50 Total roll cooling water consumption (m3/s/t) Total roll consumption (kg/tonne of finished product) 08/02/13
- 21. Thank you