Cement Energy and Environment

- Energy Conservation Through Innovation in Kiln Reverse Air Baghouse (RABH) K. K Vasavada Sr. Vice President - Operations Sanghi Industries Limited P.O: Sanghipuram, Kutch, Gujarat, Pin. : 370511 1.0 Introduction Sanghi Industries Limited is operating a 3.5 MTPA Cement Plant, 60 MW Captive Thermal Power Plant, 5500 M 3 /day MED Plant and Captive Port facilities in Kutch District of Gujarat. The Brand is well recognized as premium in National as well as International Markets. The original installed capacity of 7500 TPD is enhanced to 9000 TPD in year 2006 through commissioning of 3rdPreheater String. Sanghi management is extremely conscious of continual improvement of energy management as well as environmental improvement and new technologies are being assimilated regularly to improve efficiencies related to energy & environment. One major factor requiring DE-bottlenecking at higher capacity was to counter higher pressure drop at Bag House and consequently lower volume capacity. This required modification in existing Gas Flow profile and velocities to reduce pressure drop at higher volume handling. Four key factors which effects RASH performance are gas flow (M 3 /hrs), gas velocities (M/sec), Differential pressure (DP, mmWG) and air to cloth ratio (ACR). Changes to any of these key system parameters will result in system-wide performance issues. 2.0 RABH general norms: a) CAN velocity : below 0.75 m/s b) ACR : 0.7 (Max) c) Inlet and Outlet gas velocity: 10 (Min) to 18 (Max). d) Inlet damper velocity: 10 to 12 m/sec. e) Outlet damper velocity : 8 to 9 m/sec. General formula to calculate RA gas volume: Gross ACR x Filtration area x 60 (M3/hrs) 3.0 Effect of capacity enhancement on RABH With the increase in RASH inlet gas volume after capacity enhancement, following problems were observed in RASH. a) High differential pressure (DP) b) Increase in RASH inlet temperature in direct mode of operation. c) Reduction in filter bag life. d) Maintenance cost increased. e) RASH & RA fan power consumption increased. Table No. 01 RASH Operating Parameter Particular UOM Before After Capacity Capacity Enhancement Enhancement Gas Flow M 3 /hr 12,80,000 15,80,000 during Direct Mode operation Gross fiHration M 3 / 0.42 0.52 ratio min/ m2 Actual duct M/sec 18.42 24 velocity