Cement Energy and Environment

.. iv) v) vi) vii) Higher HP motors were replaced with lower HP ones and the connection of under-loaded motors was converted from Delta to Star which helped reduce power consumption further. Raw mix design was changed and speed of kiln increased from 1.0 to 1.6 rpm , which increased production. Raw mill and cement mill internals were changed, which resulted in higher output and lower power consumption . Awareness was created amongst the staff and workmen for reducing power consumption by holding regular training classes, meetings, etc. Implementation of all these measures has helped the plant to achieve a figure of 103/104 units per tonne of cement which could be amongst the lowest for an old plant of its type with ball mills for raw meal, coal and cement grinding. Measures in the Pipeline Following are the further energy conservation measures proposed: • Installation of multi-channel burner • Change of C&I system. Existing one is the old Simatic Cl system • Installation of solid flow feeder in kiln feed • Installation of low-pressure cyclones in preheater section With these, the plant aims to bring down the power consumption to less than 100 units per tonne of cement in the near future. COOLER ENERGY SAVINGS * Biman Datta & Tanmay Maitra, Sat11a Cement Works M ajor innovations in the cement manufacturing process are not confined merely to clinker burning and cement grinding processes but extend also to areas, such as crushing, raw grinding, blowers, fans. Indian cement industry is currently faci ng problems of poor coal quality, power shortages and, above all , very tough competition in the market. Therefore it becomes necessary to modify existing system of operation to overcome problems. With regard to energy consumption, both thennal and electrical, continuous efforts are being made to minimise the amount used. This paper describes attempts to reduce the power consumption of cooler fans using a rather novel method. Cooler Fans Power consumption of cooler fans accounts for about 70 per cent of the overall power requirement in the cooler section. It was therefore felt that possibilities to reduce the power consumption in cooler fan operation should be explored. At the Satna Cement Works, cooler fans with * Reproduced from International Cement Review, December 1998 a fixed-speed AC motor with butterfl y damper for volume control had been installed. However, modern DC drive motors are also being installed for cooler fans. The following two options are readily available for reducing the power consumed by cooler fans, operating with the earlier system of AC motor with butter fly damper control. Variable speed drive By installing a DC drive or AC converter, the required flow can be achieved through reduction of the fan RPM and thereby power saved. Inlet vane control damper By installing an inlet vane control damper, the required flow can be achieved by controlling its open ing. A vane control device at the fan inlet deflects the inflowing air at the direction of the impeller and this will be more advantageous as the power saving witlr a vane damper will be considerably higher than with a butterfly control. 3