Reduction in energy consumption at Chanderia Cement Works

This is second part of the article energy saving exercises carried out at Chanderia Cement Works (Rajasthan) of MP Birla Group.

Limestone grinding technology has been continuously improving with numerous innovations in view of improving productivity and to reduce specific power consumption. In order to reduce the manufacturing costs for cement, it is very important to optimise the existing mill installations as far as the grinding process is concerned and also to use high quality spare parts and consumables.

Many types of grinding systems presently being used for raw meal grinding in cement plants are:

• Open and close circuit ball mills
• Roller press in combi circuit/finished mode
• Vertical roller mill (VRM)
• Tube mill with pre-grinder/crusher

We at MP Birla Group at Chanderia plant, for line-1 in the raw grinding circuit having one vertical roller mill (VRM) supplied by Shenyang Heavy Machinery Company, China having design capacity of 155 tph (at 16 per cent +R on 90?, < 2 per cent R on 212?,).

Mill was running at 170 tph at 18.0 kWh/tonne raw meal but as observed, frequent stoppages observed due to vibration high (up to 98.0 numbers per month) causing high power consumption and loss of production. We have done many small in house modifications, logic changes and process optimisation in steps to reduce breakdowns and to improve its performance.

After all the steps/trials, stoppages (due to vibration high) has been reduced to only 8 to 10 numbers per month and mill throughput also improved which is > 175 tph at 16.0 kWh/tonne of raw meal.

Issues observed:

• Every month 70 to 100 numbers of stoppages observed in RVRM due to vibration high
• High Power consumption (approximately 20.0 kWh/tonne raw meal)
• Huge variation in main drive load causing frequent tripping and low feed
• Huge false air across mill

One dedicated team has been formed to analyse all the issues and for corrective action accordingly. Details as below:

ABOUT THE AUTHORS:
Dinesh Kumar, D Banerjee, D C Jagetiya, Narpat Anjana of MP Birla Group (Chanderia Cement Works, Chanderia), Rajasthan. This paper was originally presented at NCCBM International seminar held in December 2019. The first part of article was published in our April 2020 issue.