BEST PRACTICES TOWARDS ENERGY EFFICIENCY UltraTech Cement Limited. (Unit Narmada Cement, Jafarabad Works)
Overview of NCJW Narmada Cement-Jafarabad Works was established in 1982 with an installed capacity of 1 MMTPA clinker and has been gradually increased to 1.50 MMTPA (4,300 4,500 TPD). Cement capacity is 0.50 MMTPA (1,150 TPD). The Unit is ISO 9001:2008, ISO 14001:2004, OHSAS 18001:2007, ISMS 27001:2005 & SA 8000:2008, ISO-50001:2011certified It is India's first split location dry process cement plant with Fuller technology having four-stage suspension pre-heater, in-line flash calciner, reverse air bag house dust collector, vertical roller mills besides to be the first to unload imported South African coal at plant jetty. It transports 100% clinker to grinding units is in bulk by sea route. The special feature of this plant is 'Just in Time design for raw mill circuit. As against conventional norms of 20,000 MT silo for raw meal storage it has 2,000 MT silo.
Overview of NCJW The grinding units associated with Jafrabad Cement Works are Magdalla Cement Works having capacity of 0.80 MMTPA and Ratnagiri Cement Works having capacity of 0.50 MMTPA. All three coast-based split location units have Jetties for marine transportation. Narmada Cement was the prime supplier of fly ash based Portland Pozzolana Cement (PPC) to Sardar Sarovar Dam on river Narmada, which is the World's second largest concrete gravity dam (by volume). We created a benchmark in Indian cement industry with installation of SF 3 X 6 cross bar cooler supplied by FLS, in record 41 days. With the hand holding of DuPont Sustainable Solutions, we are marching towards "Zero Accident" goal and articulating "Safety" as fundamental core belief with the theme "Life is precious, We care for it"as advocated by Shri O P Puranmalka, Business Director. Moving ahead in the safety journey, we achieved lost time injury frequency rate (LTIFR) 0.00 in the year 2014-15.
ENERGY SAVING PROJECTS 4
1.0 Case Study-Elimination of material settling at separator inlet duct by providing hump to increase air velocity. 1. Problem Statement: Dust settling in separator inlet duct. 2. Impact of Problem : Higher power consumption of separator fan to maintain the velocity in duct and maintain the DP in separator. 3. Action taken : Separator all duct pressure readings were taken. Dust settle point identified Velocity measured in the separator inlet duct & found velocity was lower than desired. It was decided to provide the hump in the inlet duct to increase the velocity. Hump size & location decided in the duct & provided.
Dust accumulation in duct
Calculation for Hump size Before Area Measurement UOM Sep I/L Duct Radius(Rb) 1.5 Mtr Duct Area 1.7671 M2 Flow 26.578 M3/Sec Flow 95680 M3/Hr After Area Measurement UOM Radius (Ra) 1.25 Mtr Duct Area 1.23 M2 Flow 26.578 M3/Sec Flow 95680 M3/Hr Velocity 15.04 M/Sec Velocity 21.66 M/Sec Ø Cos = (Height Of hump)/(a/2) Ø 250mm a 532mm Height of hump = Rb-Ra Cement angle of repose( Ø)= 20 deg Base of hump (a) = 532mm
Profile of dust settling inside duct Before After Separator Inlet Duct 8
Hump view in separator Hump in separator inlet duct 9
Power Saving Calculation BEFORE AFTER Previous fan power in KW 96 Existing Fan running KW 84 Run Hrs 24 Run Hrs 24 Power/Day 2304 Power/Day 2016 Power per month 69120 Power per month 60480 Saving Saving in energy KWh per year 103680 Saving in Lacs/ Year (considering unit rate @ 4.85) 5.03
2.0 Reduction in heat losses across Preheater 1. Problem Statement : High Pressure drop across the Preheater, High velocity at orifice because of high velocity difference in short span, Puffing occur at orifice. 2. Impact of Problem : High heat consumption across Preheater. 3. Action taken : Brought down the velocity at orifice to reduce pressure drop across calciner
Velocity at orifice at different location Existing Velocity 30m/Sec after orifice modification 21.23 m/sec 21.23 m/sec 41.35 m/sec 21.23 m/sec 30m/sec 21.23 m/sec 12.09 12.09 m/sec m/sec
Result 1000 900 800 700 600 500 400 300 200 100 0 Kiln Feed PH Fan Speed PH O/L Temp PH O/L Draft Calciner Exit Temp Calciner Exit Draft Kiln feed Hood draft Kiln Riser DP Calciner Inlet Draft 875 902 850 880 688 382 386 300 304 Before 650 113 84 69 28 51 27 42 49 After
Result Kiln Riser DP 90 84 Before After 80 70 60 50 40 42 30 20 10 0 Before After
Result 2350 2300 2250 2200 2150 2100 2050 2000 1950 1900 906 2310 899 2157 2159 KWH 894 893 SG Fan RPM 895 893 2143 2143 2152 886 2094 877 2062 Nov-14 Dec-14 Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Month 910 905 900 895 890 885 880 875 870 865 860
Result Saving in Orifice Modification Saving Average 280KWH of PH Fan Kiln Running hours =345*24 =8280 Total Saving in KWh =8280*248 =2053440 Saving of Rs = 2053440 *4.67Rs/Unit =95.89Lacs/Annum
3.0 Reduction in heat by increasing insulation in TA duct Increased insulation thickness in TAD from 65 to 100mm in 20m lining area BEFORE AFTER Backup Insulation of 35mm provided in Stage IV feed pipe. BEFORE AFTER
Result Before radiation losses with castable : 2.91 kcal/kg of clinker After radiation losses with Brick lining : 2.22 kcal/kg of clinker Benefit in kcal/hour : 129312.65 Total Benefit in kcal kg/clinker : 0.69 18
4. Various energy saving projects SNo. Title 1 Grindingaidmotor running with constant speed without considering variation in Cement mill Feed. Pre grinder dust collector material conveying air slide 2 blowers were running continuously even if pre grinder is kept stop condition. 3 Separator fan was running on RPM basisso power is not monitored, also due to material settling in duct it was difficult maintain the draft in circuit. Action Taken Foroptimizing Grinding Aid system VFD installed. Now Motor speed is varied with TPH. Saving KW/Month 136.80 Interlock provided such that if pre grinder stopped two blowers stopped 1367.81 after 10 min. 1) Sep. Fan control changed from RPM baseto KW base. 2) Trommelscreen was taken in operation to reducethe nibs settling in duct 3) One hump is provided to increase the velocity in duct. 17561.84
4. Various energy saving projects SNo. Title 4 Reduction in Mill fan RPM 5 Mill taking more power with considering TPH. Pregrinder running hrs was 6 more because fresh feed was monitoring manually. Action Taken To maintain the mill discharge Blaine mill fan rpm maintainingfrom 400 to 460. Mill power optimized with maintaining the media size & qty. Close loop system was developed and feed was controlled w.r.t. reject.through put set point to be kept manually by monitoring the crusher load. Saving KW/Month 688.03 7495.20 13200 7 Separatormotor was of old version i.e. DC motor and taking more power to operate. Converted sep motor from DC to AC. 8208.00
Our Goal is to achieve Excellence in Energy Conservation Thank You 21
Saving calculation of G-Aid motor after VFD. Earlier motor KW----------A 0.37 After VFD motor running KW------B 0.18 Difference(A-B)---------C 0.19 Normal Day Run Hrs---------D 24 Saving in KW/Day (C X D)-------E 4.56 Saving in KW/Month (E X 30)-------F 136.8
Saving calculation of Pre grinder blower running hours Calculation-Earlier Condition Motor rated KW 3.7 Operating KW 2.74 No. of blowers 2 Pre grinder running Hrs 15 Idle running 9 Power/Day of both blowers 131.52 Calculation-Existing Condition Motor Rated KW 3.7 Operating KW 2.74 No. of blowers 2 Pre grinder running Hrs 15 Idle running for each stoppage of pre grinder 0.17 Total start stop of Pre grinder 4 Total idle running Hrs 0.68 Power/day of both blowers 85.93 Saving in energy KWh per day 45.59 Saving in energy KWh per Month 1367.81
Saving calculation Cement Mill Separator fan Power calculation on Last year performance Operating current in Amps 198.42 Operating KW 108.39 Running hours 24 Power/day in KWh 2601.395 Power per month in KWh 78041.84 Power calculation on current year performance Fan running KW 84 Running Hrs 24 Power/Day in KWh 2016 Power per month in KWh 60480 Saving of KWh per month 17561.84
Saving calculation Cement mill fan Power calculation on Last year performance Operating current in Amps 8.8 Operating KW 4.81 Running hours 24 Power/day in KWh 115.37 Power per month in KWh 3461.18 Power calculation on current year performance Operating current in Amp 7.05 Operating KW 3.85 Running hours 24.00 Power/day in KWh 92.43 Power per month in KWh 2772.88 Saving of KWh per month 688.30
Saving calculation Mill main Motor KW Power calculation on Last year performance Operating KW 1363.63 Running hours 24 Power/day in KWh 32727.12 Power per month in KWh 981813.6 Power calculation on current year performance Operating KW 1353.22 Running hours 24 Power/day in KWh 32477.28 Power per month in KWh 974318.4 Saving of KWh per month 7495.20
Saving calculation of Pre grinder circuit Power calculation on Last year performance Operating KW 140.00 Running hours 14 Power/day in KWh 1960 Power calculation on current year performance Operating KW 95.00 Running hours 16 Power/day in KWh 1520 Power per month in KWh 58800 Power per month in KWh 45600 Saving of KWh per month 13200.00
Saving calculation of Cement mill separator Motor from DC to AC Power calculation on Earlier performance Power calculation on current year performance 2Nos DC Motor Cooling fan operating KW 5.4 No Cooling fan for AC Motor. 0 DC Motor operating KW 13.00 Total Power drawnby the separator drive system. 18.40 Running hours per day 24 Daily Power Consumption in KWh 441.6 Monthly Power Consumption in KWh 13248 Sep AC motor Operating KW 7.00 Total Power drawn by the Separator drive system. 7.00 Running hours per day 24 Daily Power Consumption in KWh 168 Monthly Power Consumption in KWh 5040 Saving of KWh per month 8208.00