Cement, Energy and Environment

ACC fans play a major role in maintaining the vacuum condi on of the TG system, thus affec ng the power genera on. It becomes all the more important in case of Waste Heat Recovery system, as it is en rely dependent on the available heat and its complete u liza on. We, at JKLC, have WHR system of 15Mw. The system is designed for vaccum of 0.80 at ambient temperature 42°C. It was observed that with the onset of summer season, the vacuum fell to a level of 0.66. Thus leading to drop in genera on. With the objec ve of maintaining the genera on levels, it was decided to take various rec fica on ac ons as cleaning of fins, water spray on the fins which marginally improved the situa on. Then next step was to ascertain the flow of the exis ng M/s Aerotech fans at full angle of a ack i.e 14°. The readings of the average fan air flow were 15.59 lac m3/hr observed at 54.8 KW against the design air flow of 23.94 m3/hr at full load (15MW). Exis ng fans were not able to deliver design air flow to achieve 15 MW Genera on in summer season ( > 44°C) so It was then decided to replace the fans. A er thorough technical discussions, M/s Encon fans were selected. While doing so two design aspects were taken care of: 1. At exis ng design Flow (15.59 lac m3/hr) M/s Encon will deliver 30 KW savings. 2. Fans should be capable of delivering the design air flow 23.94 m3/hr at full load (15MW) without any power saving (Motor Power at design Flow is 89.00 KW). A er replacement following observa ons were taken: 1. Flow of 15.59 lac m3/hr, could be achieved with the blade angle of 8 deg. 2. Achieved Power saving of 30 kwh per fan (Total fans -06 nos). 3. In summers, the blade angle was again increased to 18 deg and the rated flow of 23.94 m3/hr could be achieved with the power consump on of 54.8 Kw. 4. The vacuum could be maintained at 0.76 as compared to earlier 0.66 without water spraying (100 m3/Day) on fins. 5. Increase in the vacuum resulted in increase in WHR Genera on by 0.7 MW/hr in summer season. The total savings achieved, considering running of 25 days in each month, is a. For 9 months running the fan at low speed 30kw/hr x 6 x 24 x 225 days x Rs.5= Rs. 48.60 lacs b. For 3 months of summer 0.7Mw/hr x 24 x 75 days x Rs.5 = Rs. 63.00 lacs Total savings achieved = Rs. 111.60 lacs only CASE STUDY ON REPLACEMENT OF AEROTECH FRP FANS WITH ENCON FRP FANS Rajesh Keswani, Sr.General Manager ( Engineering), B K Vivekanand Dy General Manager ( Power House) JK Lakshmi Cement Ltd. Sirohi The detailed comparison of major parameters is as given below 64