Use Of Smart Drives and PLC for Energy Saving

This research work deals with the aspect of efficient energy utilization in steel rolling mills for cooling arrangements for main-stand-motor. It deals with innovative schemes to device methods for speed management dynamically, based on the rolling load on the motor and temperature of the motor, automatically. Acceptability of this proposal will depend on detailed economic aspects. The details of the same have to be worked out for the concerned processes. The analysis presented here leads to confident acceptance of the hypothesis. The load variation is assumed to have step-changes, for simpler analysis. This paves way for methods of handling dynamic speed variation of blower motor. Implementation of this scheme will save around 40 to 60% blower-motor power as compared to the conventional system. This scheme can be implemented to all the rolling mills not only in India, but may also be recognized internationally. After studying the start-up sequence, loading and unloading of the main-stand-motors, the expected energy savings due to the proposed scheme is 50,000 to 60,000 Units per month for the continuous steel Industry where the number of operating stand are 18 - 20, with 11 kW blower Motor. This may vary with rating of the blower motor and number rolling stand used for continuous steel rolling mill. In M/s Sunflag Iron and Steel Company, Bhandara numbers of stands in the rolling are 20. Average rolling stand in the operation are 15 for the month. Average saving per stand for blower-motor is 115 kWh per day. For the month in terms of money, it is around Rs. 20125 /-. For the industry in terms of money, it is around Rs.3.1 Lakhs per month (i. e. Rs. 37.2 Lakhs per annum).